This controller provides DMAengine capabilities for a variety of peripheral
buses such as I2C, UART, and SPI. By using GPI dmaengine driver, bus
drivers can use a standardize interface that is protocol independent to
transfer data between memory and peripheral.

Signed-off-by: Vinod Koul <vk...@kernel.org>
---
 drivers/dma/qcom/Kconfig  |   12 +
 drivers/dma/qcom/Makefile |    1 +
 drivers/dma/qcom/gpi.c    | 2269 +++++++++++++++++++++++++++++++++++++
 3 files changed, 2282 insertions(+)
 create mode 100644 drivers/dma/qcom/gpi.c

diff --git a/drivers/dma/qcom/Kconfig b/drivers/dma/qcom/Kconfig
index 3bcb689162c6..f925296b0c85 100644
--- a/drivers/dma/qcom/Kconfig
+++ b/drivers/dma/qcom/Kconfig
@@ -8,6 +8,18 @@ config QCOM_BAM_DMA
          Enable support for the QCOM BAM DMA controller.  This controller
          provides DMA capabilities for a variety of on-chip devices.
 
+config QCOM_GPI_DMA
+        tristate "Qualcomm Technologies GPI DMA support"
+        depends on ARCH_QCOM
+        select DMA_ENGINE
+        select DMA_VIRTUAL_CHANNELS
+        help
+          Enable support for the QCOM GPI DMA controller. This controller
+          provides DMA capabilities for a variety of peripheral buses such
+          as I2C, UART, and SPI. By using GPI dmaengine driver, bus drivers
+          can use a standardize interface that is protocol independent to
+          transfer data between DDR and peripheral.
+
 config QCOM_HIDMA_MGMT
        tristate "Qualcomm Technologies HIDMA Management support"
        select DMA_ENGINE
diff --git a/drivers/dma/qcom/Makefile b/drivers/dma/qcom/Makefile
index 1ae92da88b0c..f33f027dd0fc 100644
--- a/drivers/dma/qcom/Makefile
+++ b/drivers/dma/qcom/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_QCOM_BAM_DMA) += bam_dma.o
+obj-$(CONFIG_QCOM_GPI_DMA) += gpi.o
 obj-$(CONFIG_QCOM_HIDMA_MGMT) += hdma_mgmt.o
 hdma_mgmt-objs  := hidma_mgmt.o hidma_mgmt_sys.o
 obj-$(CONFIG_QCOM_HIDMA) +=  hdma.o
diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
new file mode 100644
index 000000000000..592fd39a7740
--- /dev/null
+++ b/drivers/dma/qcom/gpi.c
@@ -0,0 +1,2269 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020, Linaro Limited
+ */
+
+#define DEBUG
+
+#include <linux/bitfield.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+#define TRE_TYPE_DMA           0x10
+#define TRE_TYPE_GO            0x20
+#define TRE_TYPE_CONFIG0       0x22
+
+/* TRE flags */
+#define TRE_FLAGS_CHAIN                BIT(0)
+#define TRE_FLAGS_IEOB         BIT(8)
+#define TRE_FLAGS_IEOT         BIT(9)
+#define TRE_FLAGS_BEI          BIT(10)
+#define TRE_FLAGS_LINK         BIT(11)
+#define TRE_FLAGS_TYPE         GENMASK(23, 16)
+
+/* SPI CONFIG0 WD0 */
+#define TRE_SPI_C0_WORD_SZ     GENMASK(4, 0)
+#define TRE_SPI_C0_LOOPBACK    BIT(8)
+#define TRE_SPI_C0_CS          BIT(11)
+#define TRE_SPI_C0_CPHA                BIT(12)
+#define TRE_SPI_C0_CPOL                BIT(13)
+#define TRE_SPI_C0_TX_PACK     BIT(24)
+#define TRE_SPI_C0_RX_PACK     BIT(25)
+
+/* SPI CONFIG0 WD2 */
+#define TRE_SPI_C0_CLK_DIV     GENMASK(11, 0)
+#define TRE_SPI_C0_CLK_SRC     GENMASK(19, 16)
+
+/* SPI GO WD0 */
+#define TRE_SPI_GO_CMD         GENMASK(4, 0)
+#define TRE_SPI_GO_CS          GENMASK(10, 8)
+#define TRE_SPI_GO_FRAG                BIT(26)
+#define TRE_SPI_RX_LEN         GENMASK(23, 0)
+
+/* DMA TRE */
+#define TRE_DMA_LEN            GENMASK(23, 0)
+
+/* Register offsets from gpi-top */
+#define GPII_n_CH_k_CNTXT_0_OFFS(n, k) (0x20000 + (0x4000 * (n)) + (0x80 * 
(k)))
+#define GPII_n_CH_k_CNTXT_0_EL_SIZE    GENMASK(31, 24)
+#define GPII_n_CH_k_CNTXT_0_CHSTATE    GENMASK(23, 20)
+#define GPII_n_CH_k_CNTXT_0_ERIDX      GENMASK(18, 14)
+#define GPII_n_CH_k_CNTXT_0_DIR                BIT(3)
+#define GPII_n_CH_k_CNTXT_0_PROTO      GENMASK(2, 0)
+
+#define GPII_n_CH_k_CNTXT_0(el_size, erindex, dir, chtype_proto)  \
+       (FIELD_PREP(GPII_n_CH_k_CNTXT_0_EL_SIZE, el_size)       | \
+        FIELD_PREP(GPII_n_CH_k_CNTXT_0_ERIDX, erindex)         | \
+        FIELD_PREP(GPII_n_CH_k_CNTXT_0_DIR, dir)               | \
+        FIELD_PREP(GPII_n_CH_k_CNTXT_0_PROTO, chtype_proto))
+
+#define GPI_CHTYPE_DIR_IN      (0)
+#define GPI_CHTYPE_DIR_OUT     (1)
+
+#define GPI_CHTYPE_PROTO_GPI   (0x2)
+
+#define GPII_n_CH_k_DOORBELL_0_OFFS(n, k)      (0x22000 + (0x4000 * (n)) + 
(0x8 * (k)))
+#define GPII_n_CH_CMD_OFFS(n)                  (0x23008 + (0x4000 * (n)))
+#define GPII_n_CH_CMD_OPCODE                   GENMASK(31, 24)
+#define GPII_n_CH_CMD_CHID                     GENMASK(7, 0)
+#define GPII_n_CH_CMD(opcode, chid)                             \
+                    (FIELD_PREP(GPII_n_CH_CMD_OPCODE, opcode) | \
+                     FIELD_PREP(GPII_n_CH_CMD_CHID, chid))
+
+#define GPII_n_CH_CMD_ALLOCATE         (0)
+#define GPII_n_CH_CMD_START            (1)
+#define GPII_n_CH_CMD_STOP             (2)
+#define GPII_n_CH_CMD_RESET            (9)
+#define GPII_n_CH_CMD_DE_ALLOC         (10)
+#define GPII_n_CH_CMD_UART_SW_STALE    (32)
+#define GPII_n_CH_CMD_UART_RFR_READY   (33)
+#define GPII_n_CH_CMD_UART_RFR_NOT_READY (34)
+
+/* EV Context Array */
+#define GPII_n_EV_CH_k_CNTXT_0_OFFS(n, k) (0x21000 + (0x4000 * (n)) + (0x80 * 
(k)))
+#define GPII_n_EV_k_CNTXT_0_EL_SIZE    GENMASK(31, 24)
+#define GPII_n_EV_k_CNTXT_0_CHSTATE    GENMASK(23, 20)
+#define GPII_n_EV_k_CNTXT_0_INTYPE     BIT(16)
+#define GPII_n_EV_k_CNTXT_0_CHTYPE     GENMASK(3, 0)
+
+#define GPII_n_EV_k_CNTXT_0(el_size, inttype, chtype)          \
+       (FIELD_PREP(GPII_n_EV_k_CNTXT_0_EL_SIZE, el_size) |     \
+        FIELD_PREP(GPII_n_EV_k_CNTXT_0_INTYPE, inttype)  |     \
+        FIELD_PREP(GPII_n_EV_k_CNTXT_0_CHTYPE, chtype))
+
+#define GPI_INTTYPE_IRQ                (1)
+#define GPI_CHTYPE_GPI_EV      (0x2)
+
+enum CNTXT_OFFS {
+       CNTXT_0_CONFIG = 0x0,
+       CNTXT_1_R_LENGTH = 0x4,
+       CNTXT_2_RING_BASE_LSB = 0x8,
+       CNTXT_3_RING_BASE_MSB = 0xC,
+       CNTXT_4_RING_RP_LSB = 0x10,
+       CNTXT_5_RING_RP_MSB = 0x14,
+       CNTXT_6_RING_WP_LSB = 0x18,
+       CNTXT_7_RING_WP_MSB = 0x1C,
+       CNTXT_8_RING_INT_MOD = 0x20,
+       CNTXT_9_RING_INTVEC = 0x24,
+       CNTXT_10_RING_MSI_LSB = 0x28,
+       CNTXT_11_RING_MSI_MSB = 0x2C,
+       CNTXT_12_RING_RP_UPDATE_LSB = 0x30,
+       CNTXT_13_RING_RP_UPDATE_MSB = 0x34,
+};
+
+#define GPII_n_EV_CH_k_DOORBELL_0_OFFS(n, k)   (0x22100 + (0x4000 * (n)) + 
(0x8 * (k)))
+#define GPII_n_EV_CH_CMD_OFFS(n)               (0x23010 + (0x4000 * (n)))
+#define GPII_n_EV_CMD_OPCODE                   GENMASK(31, 24)
+#define GPII_n_EV_CMD_CHID                     GENMASK(7, 0)
+#define GPII_n_EV_CMD(opcode, chid)                             \
+                    (FIELD_PREP(GPII_n_EV_CMD_OPCODE, opcode) | \
+                     FIELD_PREP(GPII_n_EV_CMD_CHID, chid))
+
+#define GPII_n_EV_CH_CMD_ALLOCATE              (0x00)
+#define GPII_n_EV_CH_CMD_RESET                 (0x09)
+#define GPII_n_EV_CH_CMD_DE_ALLOC              (0x0A)
+
+#define GPII_n_CNTXT_TYPE_IRQ_OFFS(n)          (0x23080 + (0x4000 * (n)))
+
+/* mask type register */
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_OFFS(n)      (0x23088 + (0x4000 * (n)))
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_BMSK         GENMASK(6, 0)
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_GENERAL      BIT(6)
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB         BIT(3)
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_GLOB         BIT(2)
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_EV_CTRL      BIT(1)
+#define GPII_n_CNTXT_TYPE_IRQ_MSK_CH_CTRL      BIT(0)
+
+#define GPII_n_CNTXT_SRC_GPII_CH_IRQ_OFFS(n)   (0x23090 + (0x4000 * (n)))
+#define GPII_n_CNTXT_SRC_EV_CH_IRQ_OFFS(n)     (0x23094 + (0x4000 * (n)))
+
+/* Mask channel control interrupt register */
+#define GPII_n_CNTXT_SRC_CH_IRQ_MSK_OFFS(n)    (0x23098 + (0x4000 * (n)))
+#define GPII_n_CNTXT_SRC_CH_IRQ_MSK_BMSK       GENMASK(1, 0)
+
+/* Mask event control interrupt register */
+#define GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_OFFS(n) (0x2309C + (0x4000 * (n)))
+#define GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_BMSK    BIT(0)
+
+#define GPII_n_CNTXT_SRC_CH_IRQ_CLR_OFFS(n)    (0x230A0 + (0x4000 * (n)))
+#define GPII_n_CNTXT_SRC_EV_CH_IRQ_CLR_OFFS(n) (0x230A4 + (0x4000 * (n)))
+
+/* Mask event interrupt register */
+#define GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_OFFS(n)  (0x230B8 + (0x4000 * (n)))
+#define GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_BMSK     BIT(0)
+
+#define GPII_n_CNTXT_SRC_IEOB_IRQ_CLR_OFFS(n)  (0x230C0 + (0x4000 * (n)))
+#define GPII_n_CNTXT_GLOB_IRQ_STTS_OFFS(n)     (0x23100 + (0x4000 * (n)))
+#define GPI_GLOB_IRQ_ERROR_INT_MSK             BIT(0)
+
+/* GPII specific Global - Enable bit register */
+#define GPII_n_CNTXT_GLOB_IRQ_EN_OFFS(n)       (0x23108 + (0x4000 * (n)))
+#define GPII_n_CNTXT_GLOB_IRQ_CLR_OFFS(n)      (0x23110 + (0x4000 * (n)))
+#define GPII_n_CNTXT_GPII_IRQ_STTS_OFFS(n)     (0x23118 + (0x4000 * (n)))
+
+/* GPII general interrupt - Enable bit register */
+#define GPII_n_CNTXT_GPII_IRQ_EN_OFFS(n)       (0x23120 + (0x4000 * (n)))
+#define GPII_n_CNTXT_GPII_IRQ_EN_BMSK          GENMASK(3, 0)
+
+#define GPII_n_CNTXT_GPII_IRQ_CLR_OFFS(n)      (0x23128 + (0x4000 * (n)))
+
+/* GPII Interrupt Type register */
+#define GPII_n_CNTXT_INTSET_OFFS(n)            (0x23180 + (0x4000 * (n)))
+#define GPII_n_CNTXT_INTSET_BMSK               BIT(0)
+
+#define GPII_n_CNTXT_MSI_BASE_LSB_OFFS(n)      (0x23188 + (0x4000 * (n)))
+#define GPII_n_CNTXT_MSI_BASE_MSB_OFFS(n)      (0x2318C + (0x4000 * (n)))
+#define GPII_n_CNTXT_SCRATCH_0_OFFS(n)         (0x23400 + (0x4000 * (n)))
+#define GPII_n_CNTXT_SCRATCH_1_OFFS(n)         (0x23404 + (0x4000 * (n)))
+
+#define GPII_n_ERROR_LOG_OFFS(n)               (0x23200 + (0x4000 * (n)))
+
+/* QOS Registers */
+#define GPII_n_CH_k_QOS_OFFS(n, k)             (0x2005C + (0x4000 * (n)) + 
(0x80 * (k)))
+
+/* Scratch registeres */
+#define GPII_n_CH_k_SCRATCH_0_OFFS(n, k)       (0x20060 + (0x4000 * (n)) + 
(0x80 * (k)))
+#define GPII_n_CH_k_SCRATCH_0_SEID             GENMASK(2, 0)
+#define GPII_n_CH_k_SCRATCH_0_PROTO            GENMASK(7, 4)
+#define GPII_n_CH_k_SCRATCH_0_PAIR             GENMASK(20, 16)
+#define GPII_n_CH_k_SCRATCH_0(pair, proto, seid)               \
+                            (FIELD_PREP(GPII_n_CH_k_SCRATCH_0_PAIR, pair)      
| \
+                             FIELD_PREP(GPII_n_CH_k_SCRATCH_0_PROTO, proto)    
| \
+                             FIELD_PREP(GPII_n_CH_k_SCRATCH_0_SEID, seid))
+#define GPII_n_CH_k_SCRATCH_1_OFFS(n, k)       (0x20064 + (0x4000 * (n)) + 
(0x80 * (k)))
+#define GPII_n_CH_k_SCRATCH_2_OFFS(n, k)       (0x20068 + (0x4000 * (n)) + 
(0x80 * (k)))
+#define GPII_n_CH_k_SCRATCH_3_OFFS(n, k)       (0x2006C + (0x4000 * (n)) + 
(0x80 * (k)))
+
+struct __packed gpi_tre {
+       u32 dword[4];
+};
+
+enum EV_PRIORITY {
+       EV_PRIORITY_ISR,
+       EV_PRIORITY_TASKLET,
+};
+
+enum msm_gpi_tce_code {
+       MSM_GPI_TCE_SUCCESS = 1,
+       MSM_GPI_TCE_EOT = 2,
+       MSM_GPI_TCE_EOB = 4,
+       MSM_GPI_TCE_UNEXP_ERR = 16,
+};
+
+#define CMD_TIMEOUT_MS         (250)
+
+#define MAX_CHANNELS_PER_GPII  (2)
+#define GPI_TX_CHAN            (0)
+#define GPI_RX_CHAN            (1)
+#define STATE_IGNORE           (U32_MAX)
+#define REQ_OF_DMA_ARGS                (5) /* # of arguments required from 
client */
+
+struct __packed gpi_error_log_entry {
+       u32 routine:4;
+       u32 type:4;
+       u32 reserved0:4;
+       u32 code:4;
+       u32 reserved1:3;
+       u32 chid:5;
+       u32 reserved2:1;
+       u32 chtype:1;
+       u32 ee:1;
+};
+
+struct __packed xfer_compl_event {
+       u64 ptr;
+       u32 length:24;
+       u8 code;
+       u16 status;
+       u8 type;
+       u8 chid;
+};
+
+struct __packed immediate_data_event {
+       u8 data_bytes[8];
+       u8 length:4;
+       u8 resvd:4;
+       u16 tre_index;
+       u8 code;
+       u16 status;
+       u8 type;
+       u8 chid;
+};
+
+struct __packed qup_notif_event {
+       u32 status;
+       u32 time;
+       u32 count:24;
+       u8 resvd;
+       u16 resvd1;
+       u8 type;
+       u8 chid;
+};
+
+struct __packed gpi_ere {
+       u32 dword[4];
+};
+
+enum GPI_EV_TYPE {
+       XFER_COMPLETE_EV_TYPE = 0x22,
+       IMMEDIATE_DATA_EV_TYPE = 0x30,
+       QUP_NOTIF_EV_TYPE = 0x31,
+       STALE_EV_TYPE = 0xFF,
+};
+
+union __packed gpi_event {
+       struct __packed xfer_compl_event xfer_compl_event;
+       struct __packed immediate_data_event immediate_data_event;
+       struct __packed qup_notif_event qup_notif_event;
+       struct __packed gpi_ere gpi_ere;
+};
+
+enum gpii_irq_settings {
+       DEFAULT_IRQ_SETTINGS,
+       MASK_IEOB_SETTINGS,
+};
+
+enum gpi_ev_state {
+       DEFAULT_EV_CH_STATE = 0,
+       EV_STATE_NOT_ALLOCATED = DEFAULT_EV_CH_STATE,
+       EV_STATE_ALLOCATED,
+       MAX_EV_STATES
+};
+
+static const char *const gpi_ev_state_str[MAX_EV_STATES] = {
+       [EV_STATE_NOT_ALLOCATED] = "NOT ALLOCATED",
+       [EV_STATE_ALLOCATED] = "ALLOCATED",
+};
+
+#define TO_GPI_EV_STATE_STR(_state) (((_state) >= MAX_EV_STATES) ? \
+                                   "INVALID" : gpi_ev_state_str[(_state)])
+
+enum gpi_ch_state {
+       DEFAULT_CH_STATE = 0x0,
+       CH_STATE_NOT_ALLOCATED = DEFAULT_CH_STATE,
+       CH_STATE_ALLOCATED = 0x1,
+       CH_STATE_STARTED = 0x2,
+       CH_STATE_STOPPED = 0x3,
+       CH_STATE_STOP_IN_PROC = 0x4,
+       CH_STATE_ERROR = 0xf,
+       MAX_CH_STATES
+};
+
+enum gpi_cmd {
+       GPI_CH_CMD_BEGIN,
+       GPI_CH_CMD_ALLOCATE = GPI_CH_CMD_BEGIN,
+       GPI_CH_CMD_START,
+       GPI_CH_CMD_STOP,
+       GPI_CH_CMD_RESET,
+       GPI_CH_CMD_DE_ALLOC,
+       GPI_CH_CMD_UART_SW_STALE,
+       GPI_CH_CMD_UART_RFR_READY,
+       GPI_CH_CMD_UART_RFR_NOT_READY,
+       GPI_CH_CMD_END = GPI_CH_CMD_UART_RFR_NOT_READY,
+       GPI_EV_CMD_BEGIN,
+       GPI_EV_CMD_ALLOCATE = GPI_EV_CMD_BEGIN,
+       GPI_EV_CMD_RESET,
+       GPI_EV_CMD_DEALLOC,
+       GPI_EV_CMD_END = GPI_EV_CMD_DEALLOC,
+       GPI_MAX_CMD,
+};
+
+#define IS_CHAN_CMD(_cmd) ((_cmd) <= GPI_CH_CMD_END)
+
+static const char *const gpi_cmd_str[GPI_MAX_CMD] = {
+       [GPI_CH_CMD_ALLOCATE] = "CH ALLOCATE",
+       [GPI_CH_CMD_START] = "CH START",
+       [GPI_CH_CMD_STOP] = "CH STOP",
+       [GPI_CH_CMD_RESET] = "CH_RESET",
+       [GPI_CH_CMD_DE_ALLOC] = "DE ALLOC",
+       [GPI_CH_CMD_UART_SW_STALE] = "UART SW STALE",
+       [GPI_CH_CMD_UART_RFR_READY] = "UART RFR READY",
+       [GPI_CH_CMD_UART_RFR_NOT_READY] = "UART RFR NOT READY",
+       [GPI_EV_CMD_ALLOCATE] = "EV ALLOCATE",
+       [GPI_EV_CMD_RESET] = "EV RESET",
+       [GPI_EV_CMD_DEALLOC] = "EV DEALLOC",
+};
+
+#define TO_GPI_CMD_STR(_cmd) (((_cmd) >= GPI_MAX_CMD) ? "INVALID" : \
+                                 gpi_cmd_str[(_cmd)])
+
+enum se_protocol {
+       SE_PROTOCOL_SPI = 1,
+       SE_PROTOCOL_UART = 2,
+       SE_PROTOCOL_I2C = 3,
+       SE_MAX_PROTOCOL
+};
+
+/*
+ * @DISABLE_STATE: no register access allowed
+ * @CONFIG_STATE:  client has configured the channel
+ * @PREP_HARDWARE: register access is allowed
+ *                however, no processing EVENTS
+ * @ACTIVE_STATE: channels are fully operational
+ * @PREPARE_TERIMNATE: graceful termination of channels
+ *                    register access is allowed
+ * @PAUSE_STATE: channels are active, but not processing any events
+ */
+enum gpi_pm_state {
+       DISABLE_STATE,
+       CONFIG_STATE,
+       PREPARE_HARDWARE,
+       ACTIVE_STATE,
+       PREPARE_TERMINATE,
+       PAUSE_STATE,
+       MAX_PM_STATE
+};
+
+#define REG_ACCESS_VALID(_pm_state) ((_pm_state) >= PREPARE_HARDWARE)
+
+static const char *const gpi_pm_state_str[MAX_PM_STATE] = {
+       [DISABLE_STATE] = "DISABLE",
+       [CONFIG_STATE] = "CONFIG",
+       [PREPARE_HARDWARE] = "PREPARE HARDWARE",
+       [ACTIVE_STATE] = "ACTIVE",
+       [PREPARE_TERMINATE] = "PREPARE TERMINATE",
+       [PAUSE_STATE] = "PAUSE",
+};
+
+#define TO_GPI_PM_STR(_state) (((_state) >= MAX_PM_STATE) ? \
+                             "INVALID" : gpi_pm_state_str[(_state)])
+
+static const struct {
+       enum gpi_cmd gpi_cmd;
+       u32 opcode;
+       u32 state;
+} gpi_cmd_info[GPI_MAX_CMD] = {
+       {
+               GPI_CH_CMD_ALLOCATE,
+               GPII_n_CH_CMD_ALLOCATE,
+               CH_STATE_ALLOCATED,
+       },
+       {
+               GPI_CH_CMD_START,
+               GPII_n_CH_CMD_START,
+               CH_STATE_STARTED,
+       },
+       {
+               GPI_CH_CMD_STOP,
+               GPII_n_CH_CMD_STOP,
+               CH_STATE_STOPPED,
+       },
+       {
+               GPI_CH_CMD_RESET,
+               GPII_n_CH_CMD_RESET,
+               CH_STATE_ALLOCATED,
+       },
+       {
+               GPI_CH_CMD_DE_ALLOC,
+               GPII_n_CH_CMD_DE_ALLOC,
+               CH_STATE_NOT_ALLOCATED,
+       },
+       {
+               GPI_CH_CMD_UART_SW_STALE,
+               GPII_n_CH_CMD_UART_SW_STALE,
+               STATE_IGNORE,
+       },
+       {
+               GPI_CH_CMD_UART_RFR_READY,
+               GPII_n_CH_CMD_UART_RFR_READY,
+               STATE_IGNORE,
+       },
+       {
+               GPI_CH_CMD_UART_RFR_NOT_READY,
+               GPII_n_CH_CMD_UART_RFR_NOT_READY,
+               STATE_IGNORE,
+       },
+       {
+               GPI_EV_CMD_ALLOCATE,
+               GPII_n_EV_CH_CMD_ALLOCATE,
+               EV_STATE_ALLOCATED,
+       },
+       {
+               GPI_EV_CMD_RESET,
+               GPII_n_EV_CH_CMD_RESET,
+               EV_STATE_ALLOCATED,
+       },
+       {
+               GPI_EV_CMD_DEALLOC,
+               GPII_n_EV_CH_CMD_DE_ALLOC,
+               EV_STATE_NOT_ALLOCATED,
+       },
+};
+
+struct gpi_ring {
+       void *pre_aligned;
+       size_t alloc_size;
+       phys_addr_t phys_addr;
+       dma_addr_t dma_handle;
+       void *base;
+       void *wp;
+       void *rp;
+       u32 len;
+       u32 el_size;
+       u32 elements;
+       bool configured;
+};
+
+struct gpi_dev {
+       struct dma_device dma_device;
+       struct device *dev;
+       struct resource *res;
+       void __iomem *regs;
+       void *ee_base; /*ee register base address*/
+       u32 max_gpii; /* maximum # of gpii instances available per gpi block */
+       u32 gpii_mask; /* gpii instances available for apps */
+       u32 ev_factor; /* ev ring length factor */
+       u32 smmu_cfg;
+       dma_addr_t iova_base;
+       size_t iova_size;
+       struct gpii *gpiis;
+};
+
+struct reg_info {
+       char *name;
+       u32 offset;
+       u32 val;
+};
+
+struct gpi_reg_table {
+       u64 timestamp;
+       struct reg_info *ev_cntxt_info;
+       struct reg_info *chan[MAX_CHANNELS_PER_GPII];
+       struct reg_info *gpi_debug_regs;
+       struct reg_info *gpii_cntxt;
+       struct reg_info *gpi_debug_qsb_regs;
+       u32 ev_scratch_0;
+       u32 ch_scratch_0[MAX_CHANNELS_PER_GPII];
+       void *ev_ring;
+       u32 ev_ring_len;
+       void *ch_ring[MAX_CHANNELS_PER_GPII];
+       u32 ch_ring_len[MAX_CHANNELS_PER_GPII];
+       u32 error_log;
+};
+
+struct gpii_chan {
+       struct virt_dma_chan vc;
+       u32 chid;
+       u32 seid;
+       enum se_protocol protocol;
+       enum EV_PRIORITY priority; /* comes from clients DT node */
+       struct gpii *gpii;
+       enum gpi_ch_state ch_state;
+       enum gpi_pm_state pm_state;
+       void __iomem *ch_cntxt_base_reg;
+       void __iomem *ch_cntxt_db_reg;
+       void __iomem *ch_cmd_reg;
+       u32 req_tres; /* # of tre's client requested */
+       u32 dir;
+       struct gpi_ring ch_ring;
+       struct dma_slave_config config;
+};
+
+struct gpii {
+       u32 gpii_id;
+       struct gpii_chan gpii_chan[MAX_CHANNELS_PER_GPII];
+       struct gpi_dev *gpi_dev;
+       enum EV_PRIORITY ev_priority;
+       enum se_protocol protocol;
+       int irq;
+       void __iomem *regs; /* points to gpi top */
+       void __iomem *ev_cntxt_base_reg;
+       void __iomem *ev_cntxt_db_reg;
+       void __iomem *ev_ring_rp_lsb_reg;
+       void __iomem *ev_cmd_reg;
+       void __iomem *ieob_clr_reg;
+       struct mutex ctrl_lock;
+       enum gpi_ev_state ev_state;
+       bool configured_irq;
+       enum gpi_pm_state pm_state;
+       rwlock_t pm_lock;
+       struct gpi_ring ev_ring;
+       struct tasklet_struct ev_task; /* event processing tasklet */
+       struct completion cmd_completion;
+       enum gpi_cmd gpi_cmd;
+       u32 cntxt_type_irq_msk;
+       bool ieob_set;
+};
+
+#define MAX_TRE 3
+
+struct gpi_desc {
+       struct virt_dma_desc vd;
+       size_t len;
+       void *wp; /* points to TRE last queued during issue_pending */
+       void *db; /* DB register to program */
+       struct gpii_chan *gpii_chan;
+       struct gpi_tre tre[MAX_TRE];
+};
+
+const u32 GPII_CHAN_DIR[MAX_CHANNELS_PER_GPII] = {
+       GPI_CHTYPE_DIR_OUT, GPI_CHTYPE_DIR_IN
+};
+
+static irqreturn_t gpi_handle_irq(int irq, void *data);
+static void gpi_ring_recycle_ev_element(struct gpi_ring *ring);
+static int gpi_ring_add_element(struct gpi_ring *ring, void **wp);
+static void gpi_process_events(struct gpii *gpii);
+
+static inline struct gpii_chan *to_gpii_chan(struct dma_chan *dma_chan)
+{
+       return container_of(dma_chan, struct gpii_chan, vc.chan);
+}
+
+static inline struct gpi_desc *to_gpi_desc(struct virt_dma_desc *vd)
+{
+       return container_of(vd, struct gpi_desc, vd);
+}
+
+static inline phys_addr_t to_physical(const struct gpi_ring *const ring,
+                                     void *addr)
+{
+       return ring->phys_addr + (addr - ring->base);
+}
+
+static inline void *to_virtual(const struct gpi_ring *const ring, phys_addr_t 
addr)
+{
+       return ring->base + (addr - ring->phys_addr);
+}
+
+static inline u32 gpi_read_reg(struct gpii *gpii, void __iomem *addr)
+{
+       return readl_relaxed(addr);
+}
+
+static inline void gpi_write_reg(struct gpii *gpii, void __iomem *addr, u32 
val)
+{
+       writel_relaxed(val, addr);
+}
+
+/* gpi_write_reg_field - write to specific bit field */
+static inline void gpi_write_reg_field(struct gpii *gpii, void __iomem *addr,
+                                      u32 mask, u32 shift, u32 val)
+{
+       u32 tmp = gpi_read_reg(gpii, addr);
+
+       tmp &= ~mask;
+       val = tmp | ((val << shift) & mask);
+       gpi_write_reg(gpii, addr, val);
+}
+
+static inline void
+gpi_update_reg(struct gpii *gpii, u32 offset, u32 mask, u32 val)
+{
+       void __iomem *addr = gpii->regs + offset;
+       u32 tmp = gpi_read_reg(gpii, addr);
+
+       tmp &= ~mask;
+       tmp |= u32_encode_bits(val, mask);
+
+       gpi_write_reg(gpii, addr, tmp);
+}
+
+static void gpi_disable_interrupts(struct gpii *gpii)
+{
+       gpi_update_reg(gpii, GPII_n_CNTXT_TYPE_IRQ_MSK_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_TYPE_IRQ_MSK_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_SRC_CH_IRQ_MSK_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_SRC_CH_IRQ_MSK_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_GLOB_IRQ_EN_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_GPII_IRQ_EN_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_GPII_IRQ_EN_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_GPII_IRQ_EN_BMSK, 0);
+       gpi_update_reg(gpii, GPII_n_CNTXT_INTSET_OFFS(gpii->gpii_id),
+                      GPII_n_CNTXT_INTSET_BMSK, 0);
+
+       gpii->cntxt_type_irq_msk = 0;
+       devm_free_irq(gpii->gpi_dev->dev, gpii->irq, gpii);
+       gpii->configured_irq = false;
+}
+
+/* configure and enable interrupts */
+static int gpi_config_interrupts(struct gpii *gpii, enum gpii_irq_settings 
settings, bool mask)
+{
+       const u32 enable = (GPII_n_CNTXT_TYPE_IRQ_MSK_GENERAL |
+                             GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB |
+                             GPII_n_CNTXT_TYPE_IRQ_MSK_GLOB |
+                             GPII_n_CNTXT_TYPE_IRQ_MSK_EV_CTRL |
+                             GPII_n_CNTXT_TYPE_IRQ_MSK_CH_CTRL);
+       int ret;
+
+       if (!gpii->configured_irq) {
+               ret = devm_request_irq(gpii->gpi_dev->dev, gpii->irq,
+                                      gpi_handle_irq, IRQF_TRIGGER_HIGH,
+                                      "gpi-dma", gpii);
+               if (ret < 0) {
+                       dev_err(gpii->gpi_dev->dev, "error request irq:%d 
ret:%d\n",
+                               gpii->irq, ret);
+                       return ret;
+               }
+       }
+
+       if (settings == MASK_IEOB_SETTINGS) {
+               /*
+                * GPII only uses one EV ring per gpii so we can globally
+                * enable/disable IEOB interrupt
+                */
+               if (mask)
+                       gpii->cntxt_type_irq_msk |= 
GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB;
+               else
+                       gpii->cntxt_type_irq_msk &= 
~(GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_TYPE_IRQ_MSK_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_TYPE_IRQ_MSK_BMSK, 
gpii->cntxt_type_irq_msk);
+       } else {
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_TYPE_IRQ_MSK_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_TYPE_IRQ_MSK_BMSK, enable);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_BMSK,
+                              GPII_n_CNTXT_SRC_IEOB_IRQ_MSK_BMSK);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_SRC_CH_IRQ_MSK_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_SRC_CH_IRQ_MSK_BMSK,
+                              GPII_n_CNTXT_SRC_CH_IRQ_MSK_BMSK);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_BMSK,
+                              GPII_n_CNTXT_SRC_EV_CH_IRQ_MSK_BMSK);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_GLOB_IRQ_EN_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_GPII_IRQ_EN_BMSK,
+                              GPII_n_CNTXT_GPII_IRQ_EN_BMSK);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_GPII_IRQ_EN_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_GPII_IRQ_EN_BMSK, 
GPII_n_CNTXT_GPII_IRQ_EN_BMSK);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_MSI_BASE_LSB_OFFS(gpii->gpii_id), U32_MAX, 0);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_MSI_BASE_MSB_OFFS(gpii->gpii_id), U32_MAX, 0);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_SCRATCH_0_OFFS(gpii->gpii_id), U32_MAX, 0);
+               gpi_update_reg(gpii, 
GPII_n_CNTXT_SCRATCH_1_OFFS(gpii->gpii_id), U32_MAX, 0);
+               gpi_update_reg(gpii, GPII_n_CNTXT_INTSET_OFFS(gpii->gpii_id),
+                              GPII_n_CNTXT_INTSET_BMSK, 1);
+               gpi_update_reg(gpii, GPII_n_ERROR_LOG_OFFS(gpii->gpii_id), 
U32_MAX, 0);
+
+               gpii->cntxt_type_irq_msk = enable;
+       }
+
+       gpii->configured_irq = true;
+       return 0;
+}
+
+/* Sends gpii event or channel command */
+static int gpi_send_cmd(struct gpii *gpii, struct gpii_chan *gpii_chan,
+                       enum gpi_cmd gpi_cmd)
+{
+       u32 chid = MAX_CHANNELS_PER_GPII;
+       unsigned long timeout;
+       void __iomem *cmd_reg;
+       u32 cmd;
+
+       if (gpi_cmd >= GPI_MAX_CMD)
+               return -EINVAL;
+       if (IS_CHAN_CMD(gpi_cmd))
+               chid = gpii_chan->chid;
+
+       dev_dbg(gpii->gpi_dev->dev,
+               "sending cmd: %s:%u\n", TO_GPI_CMD_STR(gpi_cmd), chid);
+
+       /* send opcode and wait for completion */
+       reinit_completion(&gpii->cmd_completion);
+       gpii->gpi_cmd = gpi_cmd;
+
+       cmd_reg = IS_CHAN_CMD(gpi_cmd) ? gpii_chan->ch_cmd_reg : 
gpii->ev_cmd_reg;
+       cmd = IS_CHAN_CMD(gpi_cmd) ? 
GPII_n_CH_CMD(gpi_cmd_info[gpi_cmd].opcode, chid) :
+                                    
GPII_n_EV_CMD(gpi_cmd_info[gpi_cmd].opcode, 0);
+       gpi_write_reg(gpii, cmd_reg, cmd);
+       timeout = wait_for_completion_timeout(&gpii->cmd_completion,
+                                             msecs_to_jiffies(CMD_TIMEOUT_MS));
+       if (!timeout) {
+               dev_err(gpii->gpi_dev->dev, "cmd: %s completion timeout:%u\n",
+                       TO_GPI_CMD_STR(gpi_cmd), chid);
+               return -EIO;
+       }
+
+       /* confirm new ch state is correct , if the cmd is a state change cmd */
+       if (gpi_cmd_info[gpi_cmd].state == STATE_IGNORE)
+               return 0;
+
+       if (IS_CHAN_CMD(gpi_cmd) && gpii_chan->ch_state == 
gpi_cmd_info[gpi_cmd].state)
+               return 0;
+
+       if (!IS_CHAN_CMD(gpi_cmd) && gpii->ev_state == 
gpi_cmd_info[gpi_cmd].state)
+               return 0;
+
+       return -EIO;
+}
+
+/* program transfer ring DB register */
+static inline void gpi_write_ch_db(struct gpii_chan *gpii_chan,
+                                  struct gpi_ring *ring, void *wp)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       phys_addr_t p_wp;
+
+       p_wp = to_physical(ring, wp);
+       gpi_write_reg(gpii, gpii_chan->ch_cntxt_db_reg, p_wp);
+}
+
+/* program event ring DB register */
+static inline void gpi_write_ev_db(struct gpii *gpii,
+                                  struct gpi_ring *ring, void *wp)
+{
+       phys_addr_t p_wp;
+
+       p_wp = ring->phys_addr + (wp - ring->base);
+       gpi_write_reg(gpii, gpii->ev_cntxt_db_reg, p_wp);
+}
+
+/* process transfer completion interrupt */
+static void gpi_process_ieob(struct gpii *gpii)
+{
+       gpi_write_reg(gpii, gpii->ieob_clr_reg, BIT(0));
+
+       /* process events based on priority */
+       if (likely(gpii->ev_priority >= EV_PRIORITY_TASKLET)) {
+               gpi_config_interrupts(gpii, MASK_IEOB_SETTINGS, 0);
+               tasklet_schedule(&gpii->ev_task);
+       } else {
+               gpi_process_events(gpii);
+       }
+}
+
+/* process channel control interrupt */
+static void gpi_process_ch_ctrl_irq(struct gpii *gpii)
+{
+       u32 gpii_id = gpii->gpii_id;
+       u32 offset = GPII_n_CNTXT_SRC_GPII_CH_IRQ_OFFS(gpii_id);
+       u32 ch_irq = gpi_read_reg(gpii, gpii->regs + offset);
+       struct gpii_chan *gpii_chan;
+       u32 chid, state;
+
+       /* clear the status */
+       offset = GPII_n_CNTXT_SRC_CH_IRQ_CLR_OFFS(gpii_id);
+       gpi_write_reg(gpii, gpii->regs + offset, (u32)ch_irq);
+
+       for (chid = 0; chid < MAX_CHANNELS_PER_GPII; chid++) {
+               if (!(BIT(chid) & ch_irq))
+                       continue;
+
+               gpii_chan = &gpii->gpii_chan[chid];
+               state = gpi_read_reg(gpii, gpii_chan->ch_cntxt_base_reg +
+                                    CNTXT_0_CONFIG);
+               state = FIELD_GET(GPII_n_CH_k_CNTXT_0_CHSTATE, state);
+
+               /*
+                * CH_CMD_DEALLOC cmd always successful. However cmd does
+                * not change hardware status. So overwriting software state
+                * to default state.
+                */
+               if (gpii->gpi_cmd == GPI_CH_CMD_DE_ALLOC)
+                       state = DEFAULT_CH_STATE;
+               gpii_chan->ch_state = state;
+
+               /*
+                * Triggering complete all if ch_state is not a stop in process.
+                * Stop in process is a transition state and we will wait for
+                * stop interrupt before notifying.
+                */
+               if (gpii_chan->ch_state != CH_STATE_STOP_IN_PROC)
+                       complete_all(&gpii->cmd_completion);
+       }
+}
+
+/* processing gpi general error interrupts */
+static void gpi_process_gen_err_irq(struct gpii *gpii)
+{
+       u32 gpii_id = gpii->gpii_id;
+       u32 offset = GPII_n_CNTXT_GPII_IRQ_STTS_OFFS(gpii_id);
+       u32 irq_stts = gpi_read_reg(gpii, gpii->regs + offset);
+
+       /* clear the status */
+       dev_dbg(gpii->gpi_dev->dev, "irq_stts:0x%x\n", irq_stts);
+
+       /* Clear the register */
+       offset = GPII_n_CNTXT_GPII_IRQ_CLR_OFFS(gpii_id);
+       gpi_write_reg(gpii, gpii->regs + offset, irq_stts);
+}
+
+/* processing gpi level error interrupts */
+static void gpi_process_glob_err_irq(struct gpii *gpii)
+{
+       u32 gpii_id = gpii->gpii_id;
+       u32 offset = GPII_n_CNTXT_GLOB_IRQ_STTS_OFFS(gpii_id);
+       u32 irq_stts = gpi_read_reg(gpii, gpii->regs + offset);
+       u32 error_log, chid;
+
+       offset = GPII_n_CNTXT_GLOB_IRQ_CLR_OFFS(gpii_id);
+       gpi_write_reg(gpii, gpii->regs + offset, irq_stts);
+
+       /* only error interrupt should be set */
+       if (irq_stts & ~GPI_GLOB_IRQ_ERROR_INT_MSK) {
+               dev_err(gpii->gpi_dev->dev, "invalid error status:0x%x\n", 
irq_stts);
+               return;
+       }
+
+       offset = GPII_n_ERROR_LOG_OFFS(gpii_id);
+       error_log = gpi_read_reg(gpii, gpii->regs + offset);
+       gpi_write_reg(gpii, gpii->regs + offset, 0);
+
+       /* get channel info */
+       chid = ((struct gpi_error_log_entry *)&error_log)->chid;
+       if (unlikely(chid >= MAX_CHANNELS_PER_GPII))
+               dev_err(gpii->gpi_dev->dev, "invalid chid reported:%u\n",  
chid);
+}
+
+/* gpii interrupt handler */
+static irqreturn_t gpi_handle_irq(int irq, void *data)
+{
+       struct gpii *gpii = data;
+       u32 gpii_id = gpii->gpii_id;
+       u32 type, offset;
+       unsigned long flags;
+
+       read_lock_irqsave(&gpii->pm_lock, flags);
+
+       /*
+        * States are out of sync to receive interrupt
+        * while software state is in DISABLE state, bailing out.
+        */
+       if (!REG_ACCESS_VALID(gpii->pm_state)) {
+               dev_err(gpii->gpi_dev->dev, "receive interrupt while in %s 
state\n",
+                       TO_GPI_PM_STR(gpii->pm_state));
+               goto exit_irq;
+       }
+
+       offset = GPII_n_CNTXT_TYPE_IRQ_OFFS(gpii->gpii_id);
+       type = gpi_read_reg(gpii, gpii->regs + offset);
+
+       do {
+               /* global gpii error */
+               if (type & GPII_n_CNTXT_TYPE_IRQ_MSK_GLOB) {
+                       gpi_process_glob_err_irq(gpii);
+                       type &= ~(GPII_n_CNTXT_TYPE_IRQ_MSK_GLOB);
+               }
+
+               /* transfer complete interrupt */
+               if (type & GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB) {
+                       gpi_process_ieob(gpii);
+                       type &= ~GPII_n_CNTXT_TYPE_IRQ_MSK_IEOB;
+               }
+
+               /* event control irq */
+               if (type & GPII_n_CNTXT_TYPE_IRQ_MSK_EV_CTRL) {
+                       u32 ev_state;
+                       u32 ev_ch_irq;
+
+                       dev_dbg(gpii->gpi_dev->dev,
+                               "processing EV CTRL interrupt\n");
+                       offset = GPII_n_CNTXT_SRC_EV_CH_IRQ_OFFS(gpii_id);
+                       ev_ch_irq = gpi_read_reg(gpii, gpii->regs + offset);
+
+                       offset = GPII_n_CNTXT_SRC_EV_CH_IRQ_CLR_OFFS
+                               (gpii_id);
+                       gpi_write_reg(gpii, gpii->regs + offset, ev_ch_irq);
+                       ev_state = gpi_read_reg(gpii, gpii->ev_cntxt_base_reg +
+                                               CNTXT_0_CONFIG);
+                       ev_state = FIELD_GET(GPII_n_EV_k_CNTXT_0_CHSTATE, 
ev_state);
+
+                       /*
+                        * CMD EV_CMD_DEALLOC is always successful. However
+                        * cmd does not change hardware status. So overwriting
+                        * software state to default state.
+                        */
+                       if (gpii->gpi_cmd == GPI_EV_CMD_DEALLOC)
+                               ev_state = DEFAULT_EV_CH_STATE;
+
+                       gpii->ev_state = ev_state;
+                       dev_dbg(gpii->gpi_dev->dev, "setting EV state to %s\n",
+                               TO_GPI_EV_STATE_STR(gpii->ev_state));
+                       complete_all(&gpii->cmd_completion);
+                       type &= ~(GPII_n_CNTXT_TYPE_IRQ_MSK_EV_CTRL);
+               }
+
+               /* channel control irq */
+               if (type & GPII_n_CNTXT_TYPE_IRQ_MSK_CH_CTRL) {
+                       dev_dbg(gpii->gpi_dev->dev, "process CH CTRL 
interrupts\n");
+                       gpi_process_ch_ctrl_irq(gpii);
+                       type &= ~(GPII_n_CNTXT_TYPE_IRQ_MSK_CH_CTRL);
+               }
+
+               if (type) {
+                       dev_err(gpii->gpi_dev->dev, "Unhandled interrupt 
status:0x%x\n", type);
+                       gpi_process_gen_err_irq(gpii);
+                       goto exit_irq;
+               }
+
+               offset = GPII_n_CNTXT_TYPE_IRQ_OFFS(gpii->gpii_id);
+               type = gpi_read_reg(gpii, gpii->regs + offset);
+       } while (type);
+
+exit_irq:
+       read_unlock_irqrestore(&gpii->pm_lock, flags);
+
+       return IRQ_HANDLED;
+}
+
+/* process DMA Immediate completion data events */
+static void gpi_process_imed_data_event(struct gpii_chan *gpii_chan,
+                                       struct immediate_data_event *imed_event)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       struct gpi_ring *ch_ring = &gpii_chan->ch_ring;
+       void *tre = ch_ring->base + (ch_ring->el_size * imed_event->tre_index);
+       struct dmaengine_result result;
+       struct gpi_desc *gpi_desc;
+       struct virt_dma_desc *vd;
+       unsigned long flags;
+       u32 chid;
+
+       /*
+        * If channel not active don't process event
+        */
+       if (gpii_chan->pm_state != ACTIVE_STATE) {
+               dev_err(gpii->gpi_dev->dev, "skipping processing event because 
ch @ %s state\n",
+                       TO_GPI_PM_STR(gpii_chan->pm_state));
+               return;
+       }
+
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       vd = vchan_next_desc(&gpii_chan->vc);
+       if (!vd) {
+               struct gpi_ere *gpi_ere;
+               struct gpi_tre *gpi_tre;
+
+               spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+               dev_dbg(gpii->gpi_dev->dev, "event without a pending 
descriptor!\n");
+               gpi_ere = (struct gpi_ere *)imed_event;
+               dev_dbg(gpii->gpi_dev->dev,
+                       "Event: %08x %08x %08x %08x\n",
+                       gpi_ere->dword[0], gpi_ere->dword[1],
+                       gpi_ere->dword[2], gpi_ere->dword[3]);
+               gpi_tre = tre;
+               dev_dbg(gpii->gpi_dev->dev,
+                       "Pending TRE: %08x %08x %08x %08x\n",
+                       gpi_tre->dword[0], gpi_tre->dword[1],
+                       gpi_tre->dword[2], gpi_tre->dword[3]);
+               return;
+       }
+       gpi_desc = to_gpi_desc(vd);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+
+       /*
+        * RP pointed by Event is to last TRE processed,
+        * we need to update ring rp to tre + 1
+        */
+       tre += ch_ring->el_size;
+       if (tre >= (ch_ring->base + ch_ring->len))
+               tre = ch_ring->base;
+       ch_ring->rp = tre;
+
+       /* make sure rp updates are immediately visible to all cores */
+       smp_wmb();
+
+       chid = imed_event->chid;
+       if (imed_event->code == MSM_GPI_TCE_EOT && gpii->ieob_set) {
+               if (chid == GPI_RX_CHAN)
+                       goto gpi_free_desc;
+               else
+                       return;
+       }
+
+       if (imed_event->code == MSM_GPI_TCE_UNEXP_ERR)
+               result.result = DMA_TRANS_ABORTED;
+       else
+               result.result = DMA_TRANS_NOERROR;
+       result.residue = gpi_desc->len - imed_event->length;
+
+       dma_cookie_complete(&vd->tx);
+       dmaengine_desc_get_callback_invoke(&vd->tx, &result);
+
+gpi_free_desc:
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       list_del(&vd->node);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+       kfree(gpi_desc);
+       gpi_desc = NULL;
+}
+
+/* processing transfer completion events */
+static void gpi_process_xfer_compl_event(struct gpii_chan *gpii_chan,
+                                        struct xfer_compl_event *compl_event)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       struct gpi_ring *ch_ring = &gpii_chan->ch_ring;
+       void *ev_rp = to_virtual(ch_ring, compl_event->ptr);
+       struct virt_dma_desc *vd;
+       struct gpi_desc *gpi_desc;
+       struct dmaengine_result result;
+       unsigned long flags;
+       u32 chid;
+
+       /* only process events on active channel */
+       if (unlikely(gpii_chan->pm_state != ACTIVE_STATE)) {
+               dev_err(gpii->gpi_dev->dev, "skipping processing event because 
ch @ %s state\n",
+                       TO_GPI_PM_STR(gpii_chan->pm_state));
+               return;
+       }
+
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       vd = vchan_next_desc(&gpii_chan->vc);
+       if (!vd) {
+               struct gpi_ere *gpi_ere;
+
+               spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+               dev_err(gpii->gpi_dev->dev, "Event without a pending 
descriptor!\n");
+               gpi_ere = (struct gpi_ere *)compl_event;
+               dev_err(gpii->gpi_dev->dev,
+                       "Event: %08x %08x %08x %08x\n",
+                       gpi_ere->dword[0], gpi_ere->dword[1],
+                       gpi_ere->dword[2], gpi_ere->dword[3]);
+               return;
+       }
+
+       gpi_desc = to_gpi_desc(vd);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+
+       /*
+        * RP pointed by Event is to last TRE processed,
+        * we need to update ring rp to ev_rp + 1
+        */
+       ev_rp += ch_ring->el_size;
+       if (ev_rp >= (ch_ring->base + ch_ring->len))
+               ev_rp = ch_ring->base;
+       ch_ring->rp = ev_rp;
+
+       /* update must be visible to other cores */
+       smp_wmb();
+
+       chid = compl_event->chid;
+       if (compl_event->code == MSM_GPI_TCE_EOT && gpii->ieob_set) {
+               if (chid == GPI_RX_CHAN)
+                       goto gpi_free_desc;
+               else
+                       return;
+       }
+
+       if (compl_event->code == MSM_GPI_TCE_UNEXP_ERR)
+               result.result = DMA_TRANS_ABORTED;
+       else
+               result.result = DMA_TRANS_NOERROR;
+       result.residue = gpi_desc->len - compl_event->length;
+
+       dma_cookie_complete(&vd->tx);
+       dmaengine_desc_get_callback_invoke(&vd->tx, &result);
+
+gpi_free_desc:
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       list_del(&vd->node);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+       kfree(gpi_desc);
+       gpi_desc = NULL;
+}
+
+/* process all events */
+static void gpi_process_events(struct gpii *gpii)
+{
+       struct gpi_ring *ev_ring = &gpii->ev_ring;
+       phys_addr_t cntxt_rp;
+       void *rp;
+       union gpi_event *gpi_event;
+       struct gpii_chan *gpii_chan;
+       u32 chid, type;
+
+       cntxt_rp = gpi_read_reg(gpii, gpii->ev_ring_rp_lsb_reg);
+       rp = to_virtual(ev_ring, cntxt_rp);
+
+       do {
+               while (rp != ev_ring->rp) {
+                       gpi_event = ev_ring->rp;
+                       chid = gpi_event->xfer_compl_event.chid;
+                       type = gpi_event->xfer_compl_event.type;
+
+                       switch (type) {
+                       case XFER_COMPLETE_EV_TYPE:
+                               gpii_chan = &gpii->gpii_chan[chid];
+                               gpi_process_xfer_compl_event(gpii_chan,
+                                                            
&gpi_event->xfer_compl_event);
+                               break;
+                       case STALE_EV_TYPE:
+                               dev_dbg(gpii->gpi_dev->dev, "stale event, not 
processing\n");
+                               break;
+                       case IMMEDIATE_DATA_EV_TYPE:
+                               gpii_chan = &gpii->gpii_chan[chid];
+                               gpi_process_imed_data_event(gpii_chan,
+                                                           
&gpi_event->immediate_data_event);
+                               break;
+                       case QUP_NOTIF_EV_TYPE:
+                               dev_dbg(gpii->gpi_dev->dev, 
"QUP_NOTIF_EV_TYPE\n");
+                               break;
+                       default:
+                               dev_dbg(gpii->gpi_dev->dev,
+                                       "not supported event type:0x%x\n", 
type);
+                       }
+                       gpi_ring_recycle_ev_element(ev_ring);
+               }
+               gpi_write_ev_db(gpii, ev_ring, ev_ring->wp);
+
+               /* clear pending IEOB events */
+               gpi_write_reg(gpii, gpii->ieob_clr_reg, BIT(0));
+
+               cntxt_rp = gpi_read_reg(gpii, gpii->ev_ring_rp_lsb_reg);
+               rp = to_virtual(ev_ring, cntxt_rp);
+
+       } while (rp != ev_ring->rp);
+}
+
+/* processing events using tasklet */
+static void gpi_ev_tasklet(unsigned long data)
+{
+       struct gpii *gpii = (struct gpii *)data;
+
+       read_lock_bh(&gpii->pm_lock);
+       if (!REG_ACCESS_VALID(gpii->pm_state)) {
+               read_unlock_bh(&gpii->pm_lock);
+               dev_err(gpii->gpi_dev->dev, "not processing any events, 
pm_state:%s\n",
+                       TO_GPI_PM_STR(gpii->pm_state));
+               return;
+       }
+
+       /* process the events */
+       gpi_process_events(gpii);
+
+       /* enable IEOB, switching back to interrupts */
+       gpi_config_interrupts(gpii, MASK_IEOB_SETTINGS, 1);
+       read_unlock_bh(&gpii->pm_lock);
+}
+
+/* marks all pending events for the channel as stale */
+static void gpi_mark_stale_events(struct gpii_chan *gpii_chan)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       struct gpi_ring *ev_ring = &gpii->ev_ring;
+       u32 cntxt_rp, local_rp;
+       void *ev_rp;
+
+       cntxt_rp = gpi_read_reg(gpii, gpii->ev_ring_rp_lsb_reg);
+
+       ev_rp = ev_ring->rp;
+       local_rp = (u32)to_physical(ev_ring, ev_rp);
+       while (local_rp != cntxt_rp) {
+               union gpi_event *gpi_event = ev_rp;
+               u32 chid = gpi_event->xfer_compl_event.chid;
+
+               if (chid == gpii_chan->chid)
+                       gpi_event->xfer_compl_event.type = STALE_EV_TYPE;
+               ev_rp += ev_ring->el_size;
+               if (ev_rp >= (ev_ring->base + ev_ring->len))
+                       ev_rp = ev_ring->base;
+               cntxt_rp = gpi_read_reg(gpii, gpii->ev_ring_rp_lsb_reg);
+               local_rp = (u32)to_physical(ev_ring, ev_rp);
+       }
+}
+
+/* reset sw state and issue channel reset or de-alloc */
+static int gpi_reset_chan(struct gpii_chan *gpii_chan, enum gpi_cmd gpi_cmd)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       struct gpi_ring *ch_ring = &gpii_chan->ch_ring;
+       unsigned long flags;
+       LIST_HEAD(list);
+       int ret;
+
+       ret = gpi_send_cmd(gpii, gpii_chan, gpi_cmd);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "Error with cmd:%s ret:%d\n",
+                       TO_GPI_CMD_STR(gpi_cmd), ret);
+               return ret;
+       }
+
+       /* initialize the local ring ptrs */
+       ch_ring->rp = ch_ring->base;
+       ch_ring->wp = ch_ring->base;
+
+       /* visible to other cores */
+       smp_wmb();
+
+       /* check event ring for any stale events */
+       write_lock_irq(&gpii->pm_lock);
+       gpi_mark_stale_events(gpii_chan);
+
+       /* remove all async descriptors */
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       vchan_get_all_descriptors(&gpii_chan->vc, &list);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+       write_unlock_irq(&gpii->pm_lock);
+       vchan_dma_desc_free_list(&gpii_chan->vc, &list);
+
+       return 0;
+}
+
+static int gpi_start_chan(struct gpii_chan *gpii_chan)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       int ret;
+
+       ret = gpi_send_cmd(gpii, gpii_chan, GPI_CH_CMD_START);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "Error with cmd:%s ret:%d\n",
+                       TO_GPI_CMD_STR(GPI_CH_CMD_START), ret);
+               return ret;
+       }
+
+       /* gpii CH is active now */
+       write_lock_irq(&gpii->pm_lock);
+       gpii_chan->pm_state = ACTIVE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+
+       return 0;
+}
+
+static int gpi_stop_chan(struct gpii_chan *gpii_chan)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       int ret;
+
+       ret = gpi_send_cmd(gpii, gpii_chan, GPI_CH_CMD_STOP);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "Error with cmd:%s ret:%d\n",
+                       TO_GPI_CMD_STR(GPI_CH_CMD_STOP), ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+/* allocate and configure the transfer channel */
+static int gpi_alloc_chan(struct gpii_chan *chan, bool send_alloc_cmd)
+{
+       struct gpii *gpii = chan->gpii;
+       struct gpi_ring *ring = &chan->ch_ring;
+       int ret;
+       u32 id = gpii->gpii_id;
+       u32 chid = chan->chid;
+
+       if (send_alloc_cmd) {
+               ret = gpi_send_cmd(gpii, chan, GPI_CH_CMD_ALLOCATE);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error with cmd:%s 
ret:%d\n",
+                               TO_GPI_CMD_STR(GPI_CH_CMD_ALLOCATE), ret);
+                       return ret;
+               }
+       }
+
+       gpi_write_reg(gpii, chan->ch_cntxt_base_reg + CNTXT_0_CONFIG,
+                     GPII_n_CH_k_CNTXT_0(ring->el_size, 0, chan->dir, 
GPI_CHTYPE_PROTO_GPI));
+       gpi_write_reg(gpii, chan->ch_cntxt_base_reg + CNTXT_1_R_LENGTH, 
ring->len);
+       gpi_write_reg(gpii, chan->ch_cntxt_base_reg + CNTXT_2_RING_BASE_LSB, 
ring->phys_addr);
+       gpi_write_reg(gpii, chan->ch_cntxt_base_reg + CNTXT_3_RING_BASE_MSB,
+                     upper_32_bits(ring->phys_addr));
+       gpi_write_reg(gpii, chan->ch_cntxt_db_reg + CNTXT_5_RING_RP_MSB - 
CNTXT_4_RING_RP_LSB,
+                     upper_32_bits(ring->phys_addr));
+       gpi_write_reg(gpii, gpii->regs + GPII_n_CH_k_SCRATCH_0_OFFS(id, chid),
+                     GPII_n_CH_k_SCRATCH_0(!chid, chan->protocol, chan->seid));
+       gpi_write_reg(gpii, gpii->regs + GPII_n_CH_k_SCRATCH_1_OFFS(id, chid), 
0);
+       gpi_write_reg(gpii, gpii->regs + GPII_n_CH_k_SCRATCH_2_OFFS(id, chid), 
0);
+       gpi_write_reg(gpii, gpii->regs + GPII_n_CH_k_SCRATCH_3_OFFS(id, chid), 
0);
+       gpi_write_reg(gpii, gpii->regs + GPII_n_CH_k_QOS_OFFS(id, chid), 1);
+
+       /* flush all the writes */
+       wmb();
+       return 0;
+}
+
+/* allocate and configure event ring */
+static int gpi_alloc_ev_chan(struct gpii *gpii)
+{
+       struct gpi_ring *ring = &gpii->ev_ring;
+       void *base = gpii->ev_cntxt_base_reg;
+       int ret;
+
+       ret = gpi_send_cmd(gpii, NULL, GPI_EV_CMD_ALLOCATE);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "error with cmd:%s ret:%d\n",
+                       TO_GPI_CMD_STR(GPI_EV_CMD_ALLOCATE), ret);
+               return ret;
+       }
+
+       /* program event context */
+       gpi_write_reg(gpii, base + CNTXT_0_CONFIG,
+                     GPII_n_EV_k_CNTXT_0(ring->el_size, GPI_INTTYPE_IRQ, 
GPI_CHTYPE_GPI_EV));
+       gpi_write_reg(gpii, base + CNTXT_1_R_LENGTH, ring->len);
+       gpi_write_reg(gpii, base + CNTXT_2_RING_BASE_LSB, 
lower_32_bits(ring->phys_addr));
+       gpi_write_reg(gpii, base + CNTXT_3_RING_BASE_MSB, 
upper_32_bits(ring->phys_addr));
+       gpi_write_reg(gpii, gpii->ev_cntxt_db_reg + CNTXT_5_RING_RP_MSB - 
CNTXT_4_RING_RP_LSB,
+                     upper_32_bits(ring->phys_addr));
+       gpi_write_reg(gpii, base + CNTXT_8_RING_INT_MOD, 0);
+       gpi_write_reg(gpii, base + CNTXT_10_RING_MSI_LSB, 0);
+       gpi_write_reg(gpii, base + CNTXT_11_RING_MSI_MSB, 0);
+       gpi_write_reg(gpii, base + CNTXT_8_RING_INT_MOD, 0);
+       gpi_write_reg(gpii, base + CNTXT_12_RING_RP_UPDATE_LSB, 0);
+       gpi_write_reg(gpii, base + CNTXT_13_RING_RP_UPDATE_MSB, 0);
+
+       /* add events to ring */
+       ring->wp = (ring->base + ring->len - ring->el_size);
+
+       /* flush all the writes */
+       wmb();
+
+       /* gpii is active now */
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = ACTIVE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+       gpi_write_ev_db(gpii, ring, ring->wp);
+
+       return 0;
+}
+
+/* calculate # of ERE/TRE available to queue */
+static int gpi_ring_num_elements_avail(const struct gpi_ring * const ring)
+{
+       int elements = 0;
+
+       if (ring->wp < ring->rp) {
+               elements = ((ring->rp - ring->wp) / ring->el_size) - 1;
+       } else {
+               elements = (ring->rp - ring->base) / ring->el_size;
+               elements += ((ring->base + ring->len - ring->wp) / 
ring->el_size) - 1;
+       }
+
+       return elements;
+}
+
+static int gpi_ring_add_element(struct gpi_ring *ring, void **wp)
+{
+       if (gpi_ring_num_elements_avail(ring) <= 0)
+               return -ENOMEM;
+
+       *wp = ring->wp;
+       ring->wp += ring->el_size;
+       if (ring->wp  >= (ring->base + ring->len))
+               ring->wp = ring->base;
+
+       /* visible to other cores */
+       smp_wmb();
+
+       return 0;
+}
+
+static void gpi_ring_recycle_ev_element(struct gpi_ring *ring)
+{
+       /* Update the WP */
+       ring->wp += ring->el_size;
+       if (ring->wp  >= (ring->base + ring->len))
+               ring->wp = ring->base;
+
+       /* Update the RP */
+       ring->rp += ring->el_size;
+       if (ring->rp  >= (ring->base + ring->len))
+               ring->rp = ring->base;
+
+       /* visible to other cores */
+       smp_wmb();
+}
+
+static void gpi_free_ring(struct gpi_ring *ring,
+                         struct gpii *gpii)
+{
+       dma_free_coherent(gpii->gpi_dev->dev, ring->alloc_size,
+                         ring->pre_aligned, ring->dma_handle);
+       memset(ring, 0, sizeof(*ring));
+}
+
+/* allocate memory for transfer and event rings */
+static int gpi_alloc_ring(struct gpi_ring *ring, u32 elements,
+                         u32 el_size, struct gpii *gpii)
+{
+       u64 len = elements * el_size;
+       int bit;
+
+       /* ring len must be power of 2 */
+       bit = find_last_bit((unsigned long *)&len, 32);
+       if (((1 << bit) - 1) & len)
+               bit++;
+       len = 1 << bit;
+       ring->alloc_size = (len + (len - 1));
+       dev_dbg(gpii->gpi_dev->dev,
+               "#el:%u el_size:%u len:%u actual_len:%llu alloc_size:%lu\n",
+                 elements, el_size, (elements * el_size), len,
+                 ring->alloc_size);
+
+       ring->pre_aligned = dma_alloc_coherent(gpii->gpi_dev->dev,
+                                              ring->alloc_size,
+                                              &ring->dma_handle, GFP_KERNEL);
+       if (!ring->pre_aligned) {
+               dev_err(gpii->gpi_dev->dev, "could not alloc size:%lu mem for 
ring\n",
+                       ring->alloc_size);
+               return -ENOMEM;
+       }
+
+       /* align the physical mem */
+       ring->phys_addr = (ring->dma_handle + (len - 1)) & ~(len - 1);
+       ring->base = ring->pre_aligned + (ring->phys_addr - ring->dma_handle);
+       ring->rp = ring->base;
+       ring->wp = ring->base;
+       ring->len = len;
+       ring->el_size = el_size;
+       ring->elements = ring->len / ring->el_size;
+       memset(ring->base, 0, ring->len);
+       ring->configured = true;
+
+       /* update to other cores */
+       smp_wmb();
+
+       dev_dbg(gpii->gpi_dev->dev,
+               "phy_pre:0x%0llx phy_alig:0x%0llx len:%u el_size:%u 
elements:%u\n",
+               ring->dma_handle, ring->phys_addr, ring->len,
+               ring->el_size, ring->elements);
+
+       return 0;
+}
+
+/* copy tre into transfer ring */
+static void gpi_queue_xfer(struct gpii *gpii, struct gpii_chan *gpii_chan,
+                          struct gpi_tre *gpi_tre, void **wp)
+{
+       struct gpi_tre *ch_tre;
+       int ret;
+
+       /* get next tre location we can copy */
+       ret = gpi_ring_add_element(&gpii_chan->ch_ring, (void **)&ch_tre);
+       if (unlikely(ret)) {
+               dev_err(gpii->gpi_dev->dev, "Error adding ring element to xfer 
ring\n");
+               return;
+       }
+
+       /* copy the tre info */
+       memcpy(ch_tre, gpi_tre, sizeof(*ch_tre));
+       *wp = ch_tre;
+}
+
+/* reset and restart transfer channel */
+static int gpi_terminate_all(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       int schid, echid, i;
+       int ret = 0;
+
+       mutex_lock(&gpii->ctrl_lock);
+
+       /*
+        * treat both channels as a group if its protocol is not UART
+        * STOP, RESET, or START needs to be in lockstep
+        */
+       schid = (gpii->protocol == SE_PROTOCOL_UART) ? gpii_chan->chid : 0;
+       echid = (gpii->protocol == SE_PROTOCOL_UART) ? schid + 1 : 
MAX_CHANNELS_PER_GPII;
+
+       /* stop the channel */
+       for (i = schid; i < echid; i++) {
+               gpii_chan = &gpii->gpii_chan[i];
+
+               /* disable ch state so no more TRE processing */
+               write_lock_irq(&gpii->pm_lock);
+               gpii_chan->pm_state = PREPARE_TERMINATE;
+               write_unlock_irq(&gpii->pm_lock);
+
+               /* send command to Stop the channel */
+               ret = gpi_stop_chan(gpii_chan);
+       }
+
+       /* reset the channels (clears any pending tre) */
+       for (i = schid; i < echid; i++) {
+               gpii_chan = &gpii->gpii_chan[i];
+
+               ret = gpi_reset_chan(gpii_chan, GPI_CH_CMD_RESET);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error resetting channel 
ret:%d\n", ret);
+                       goto terminate_exit;
+               }
+
+               /* reprogram channel CNTXT */
+               ret = gpi_alloc_chan(gpii_chan, false);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error alloc_channel 
ret:%d\n", ret);
+                       goto terminate_exit;
+               }
+       }
+
+       /* restart the channels */
+       for (i = schid; i < echid; i++) {
+               gpii_chan = &gpii->gpii_chan[i];
+
+               ret = gpi_start_chan(gpii_chan);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error Starting Channel 
ret:%d\n", ret);
+                       goto terminate_exit;
+               }
+       }
+
+terminate_exit:
+       mutex_unlock(&gpii->ctrl_lock);
+       return ret;
+}
+
+/* pause dma transfer for all channels */
+static int gpi_pause(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       int i, ret;
+
+       mutex_lock(&gpii->ctrl_lock);
+
+       /*
+        * pause/resume are per gpii not per channel, so
+        * client needs to call pause only once
+        */
+       if (gpii->pm_state == PAUSE_STATE) {
+               dev_dbg(gpii->gpi_dev->dev, "channel is already paused\n");
+               mutex_unlock(&gpii->ctrl_lock);
+               return 0;
+       }
+
+       /* send stop command to stop the channels */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++) {
+               ret = gpi_stop_chan(&gpii->gpii_chan[i]);
+               if (ret) {
+                       mutex_unlock(&gpii->ctrl_lock);
+                       return ret;
+               }
+       }
+
+       disable_irq(gpii->irq);
+
+       /* Wait for threads to complete out */
+       tasklet_kill(&gpii->ev_task);
+
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = PAUSE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+       mutex_unlock(&gpii->ctrl_lock);
+
+       return 0;
+}
+
+/* resume dma transfer */
+static int gpi_resume(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       int i, ret;
+
+       mutex_lock(&gpii->ctrl_lock);
+       if (gpii->pm_state == ACTIVE_STATE) {
+               dev_dbg(gpii->gpi_dev->dev, "channel is already active\n");
+               mutex_unlock(&gpii->ctrl_lock);
+               return 0;
+       }
+
+       enable_irq(gpii->irq);
+
+       /* send start command to start the channels */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++) {
+               ret = gpi_send_cmd(gpii, &gpii->gpii_chan[i], GPI_CH_CMD_START);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error starting chan, 
ret:%d\n", ret);
+                       mutex_unlock(&gpii->ctrl_lock);
+                       return ret;
+               }
+       }
+
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = ACTIVE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+       mutex_unlock(&gpii->ctrl_lock);
+
+       return 0;
+}
+
+static void gpi_desc_free(struct virt_dma_desc *vd)
+{
+       struct gpi_desc *gpi_desc = to_gpi_desc(vd);
+
+       kfree(gpi_desc);
+       gpi_desc = NULL;
+}
+
+static int
+gpi_peripheral_config(struct dma_chan *chan, struct dma_slave_config *config)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+
+       memcpy(&gpii_chan->config, config, sizeof(gpii_chan->config));
+
+       return 0;
+}
+
+static int gpi_create_tre(struct gpii_chan *chan, struct gpi_desc *desc,
+                         struct scatterlist *sgl, enum dma_transfer_direction 
direction)
+{
+       struct dmaengine_spi_config *spi = &chan->config.spi;
+       struct device *dev = chan->gpii->gpi_dev->dev;
+       unsigned int tre_idx = 0;
+       dma_addr_t address;
+       struct gpi_tre *tre;
+       unsigned int i;
+
+       /* first create config tre if applicable */
+       if (direction == DMA_MEM_TO_DEV && chan->config.set_config) {
+               tre = &desc->tre[tre_idx];
+               tre_idx++;
+
+               tre->dword[0] = u32_encode_bits(spi->word_len, 
TRE_SPI_C0_WORD_SZ);
+               tre->dword[0] |= u32_encode_bits(spi->loopback_en, 
TRE_SPI_C0_LOOPBACK);
+               tre->dword[0] |= u32_encode_bits(spi->clock_pol, 
TRE_SPI_C0_CPOL);
+               tre->dword[0] |= u32_encode_bits(spi->data_pol, 
TRE_SPI_C0_CPHA);
+               tre->dword[0] |= u32_encode_bits(spi->pack_en, 
TRE_SPI_C0_TX_PACK);
+               tre->dword[0] |= u32_encode_bits(spi->pack_en, 
TRE_SPI_C0_RX_PACK);
+
+               tre->dword[1] = 0;
+
+               tre->dword[2] = u32_encode_bits(spi->clk_div, 
TRE_SPI_C0_CLK_DIV);
+               tre->dword[2] |= u32_encode_bits(spi->clk_src, 
TRE_SPI_C0_CLK_SRC);
+
+               tre->dword[3] = u32_encode_bits(TRE_TYPE_CONFIG0, 
TRE_FLAGS_TYPE);
+               tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_CHAIN);
+       }
+
+       /* create the GO tre for Tx */
+       if (direction == DMA_MEM_TO_DEV) {
+               tre = &desc->tre[tre_idx];
+               tre_idx++;
+
+               tre->dword[0] = u32_encode_bits(spi->fragmentation, 
TRE_SPI_GO_FRAG);
+               tre->dword[0] |= u32_encode_bits(spi->cs, TRE_SPI_GO_CS);
+               tre->dword[0] |= u32_encode_bits(spi->cmd, TRE_SPI_GO_CMD);
+
+               tre->dword[1] = 0;
+
+               tre->dword[2] = u32_encode_bits(spi->rx_len, TRE_SPI_RX_LEN);
+
+               tre->dword[3] = u32_encode_bits(TRE_TYPE_GO, TRE_FLAGS_TYPE);
+               if (spi->cmd == SPI_RX)
+                       tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_IEOB);
+               else
+                       tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_CHAIN);
+       }
+
+       /* create the dma tre */
+       tre = &desc->tre[tre_idx];
+       tre_idx++;
+
+       address = sg_dma_address(sgl);
+       tre->dword[0] = lower_32_bits(address);
+       tre->dword[1] = upper_32_bits(address);
+
+       tre->dword[2] = u32_encode_bits(sg_dma_len(sgl), TRE_DMA_LEN);
+
+       tre->dword[3] = u32_encode_bits(TRE_TYPE_DMA, TRE_FLAGS_TYPE);
+       if (direction == DMA_MEM_TO_DEV)
+               tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_IEOT);
+
+       for (i = 0; i < tre_idx; i++)
+               dev_dbg(dev, "TRE:%d %x:%x:%x:%x\n", i, desc->tre[i].dword[0],
+                       desc->tre[i].dword[1], desc->tre[i].dword[2], 
desc->tre[i].dword[3]);
+
+       return tre_idx;
+}
+
+/* copy tre into transfer ring */
+static struct dma_async_tx_descriptor *
+gpi_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+                 unsigned int sg_len, enum dma_transfer_direction direction,
+                 unsigned long flags, void *context)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       struct device *dev = gpii->gpi_dev->dev;
+       struct gpi_ring *ch_ring = &gpii_chan->ch_ring;
+       void *tre, *wp = NULL;
+       struct gpi_desc *gpi_desc;
+       u32 nr, nr_tre = 0;
+       int i, j;
+
+       gpii->ieob_set = false;
+       if (!is_slave_direction(direction)) {
+               dev_err(gpii->gpi_dev->dev, "invalid dma direction: %d\n", 
direction);
+               return NULL;
+       }
+
+       if (sg_len > 1) {
+               dev_err(dev, "Multi sg sent, we support only one atm: %d\n", 
sg_len);
+               return NULL;
+       }
+
+       nr_tre = 3;
+       if (!gpii_chan->config.set_config)
+               nr_tre = 2;
+       if (direction == DMA_DEV_TO_MEM) /* rx */
+               nr_tre = 1;
+
+       /* calculate # of elements required & available */
+       nr = gpi_ring_num_elements_avail(ch_ring);
+       if (nr < nr_tre) {
+               dev_err(dev, "not enough space in ring, avail:%u 
required:%u\n", nr, nr_tre);
+               return NULL;
+       }
+
+       gpi_desc = kzalloc(sizeof(*gpi_desc), GFP_NOWAIT);
+       if (!gpi_desc)
+               return NULL;
+
+       /* create TREs for xfer */
+       i = gpi_create_tre(gpii_chan, gpi_desc, sgl, direction);
+       for (j = 0; j < i; j++) {
+               tre = &gpi_desc->tre[j];
+               gpi_queue_xfer(gpii, gpii_chan, tre, &wp);
+       }
+
+       /* set up the descriptor */
+       gpi_desc->db = ch_ring->wp;
+       gpi_desc->wp = wp;
+       gpi_desc->gpii_chan = gpii_chan;
+       gpi_desc->len = sg_dma_len(sgl);
+
+       return vchan_tx_prep(&gpii_chan->vc, &gpi_desc->vd, flags);
+}
+
+/* rings transfer ring db to being transfer */
+static void gpi_issue_pending(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       unsigned long flags, pm_lock_flags;
+       struct virt_dma_desc *vd = NULL;
+       struct gpi_desc *gpi_desc;
+
+       read_lock_irqsave(&gpii->pm_lock, pm_lock_flags);
+
+       /* move all submitted discriptors to issued list */
+       spin_lock_irqsave(&gpii_chan->vc.lock, flags);
+       if (vchan_issue_pending(&gpii_chan->vc))
+               vd = list_last_entry(&gpii_chan->vc.desc_issued,
+                                    struct virt_dma_desc, node);
+       spin_unlock_irqrestore(&gpii_chan->vc.lock, flags);
+
+       /* nothing to do list is empty */
+       if (!vd) {
+               read_unlock_irqrestore(&gpii->pm_lock, pm_lock_flags);
+               return;
+       }
+
+       gpi_desc = to_gpi_desc(vd);
+       gpi_write_ch_db(gpii_chan, &gpii_chan->ch_ring, gpi_desc->db);
+       read_unlock_irqrestore(&gpii->pm_lock, pm_lock_flags);
+}
+
+static int gpi_ch_init(struct gpii_chan *gpii_chan)
+{
+       struct gpii *gpii = gpii_chan->gpii;
+       const int ev_factor = gpii->gpi_dev->ev_factor;
+       u32 elements;
+       int i = 0, ret = 0;
+
+       gpii_chan->pm_state = CONFIG_STATE;
+
+       /* check if both channels are configured before continue */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++)
+               if (gpii->gpii_chan[i].pm_state != CONFIG_STATE)
+                       goto exit_gpi_init;
+
+       /* configure to highest priority from  two channels */
+       gpii->ev_priority = min(gpii->gpii_chan[0].priority,
+                               gpii->gpii_chan[1].priority);
+
+       /* protocol must be same for both channels */
+       if (gpii->gpii_chan[0].protocol !=
+                       gpii->gpii_chan[1].protocol) {
+               dev_err(gpii->gpi_dev->dev, "protocol did not match protocol %u 
!= %u\n",
+                       gpii->gpii_chan[0].protocol, 
gpii->gpii_chan[1].protocol);
+               ret = -EINVAL;
+               goto exit_gpi_init;
+       }
+       gpii->protocol = gpii_chan->protocol;
+
+       /* allocate memory for event ring */
+       elements = max(gpii->gpii_chan[0].req_tres,
+                      gpii->gpii_chan[1].req_tres);
+       ret = gpi_alloc_ring(&gpii->ev_ring, elements << ev_factor,
+                            sizeof(union gpi_event), gpii);
+       if (ret)
+               goto exit_gpi_init;
+
+       /* configure interrupts */
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = PREPARE_HARDWARE;
+       write_unlock_irq(&gpii->pm_lock);
+       ret = gpi_config_interrupts(gpii, DEFAULT_IRQ_SETTINGS, 0);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "error config. interrupts, 
ret:%d\n", ret);
+               goto error_config_int;
+       }
+
+       /* allocate event rings */
+       ret = gpi_alloc_ev_chan(gpii);
+       if (ret) {
+               dev_err(gpii->gpi_dev->dev, "error alloc_ev_chan:%d\n", ret);
+               goto error_alloc_ev_ring;
+       }
+
+       /* Allocate all channels */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++) {
+               ret = gpi_alloc_chan(&gpii->gpii_chan[i], true);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error allocating 
chan:%d\n", ret);
+                       goto error_alloc_chan;
+               }
+       }
+
+       /* start channels  */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++) {
+               ret = gpi_start_chan(&gpii->gpii_chan[i]);
+               if (ret) {
+                       dev_err(gpii->gpi_dev->dev, "Error start chan:%d\n", 
ret);
+                       goto error_start_chan;
+               }
+       }
+       return ret;
+
+error_start_chan:
+       for (i = i - 1; i >= 0; i++) {
+               gpi_stop_chan(&gpii->gpii_chan[i]);
+               gpi_send_cmd(gpii, gpii_chan, GPI_CH_CMD_RESET);
+       }
+       i = 2;
+error_alloc_chan:
+       for (i = i - 1; i >= 0; i--)
+               gpi_reset_chan(gpii_chan, GPI_CH_CMD_DE_ALLOC);
+error_alloc_ev_ring:
+       gpi_disable_interrupts(gpii);
+error_config_int:
+       gpi_free_ring(&gpii->ev_ring, gpii);
+exit_gpi_init:
+       mutex_unlock(&gpii->ctrl_lock);
+       return ret;
+}
+
+/* release all channel resources */
+static void gpi_free_chan_resources(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       enum gpi_pm_state cur_state;
+       int ret, i;
+
+       mutex_lock(&gpii->ctrl_lock);
+
+       cur_state = gpii_chan->pm_state;
+
+       /* disable ch state so no more TRE processing for this channel */
+       write_lock_irq(&gpii->pm_lock);
+       gpii_chan->pm_state = PREPARE_TERMINATE;
+       write_unlock_irq(&gpii->pm_lock);
+
+       /* attempt to do graceful hardware shutdown */
+       if (cur_state == ACTIVE_STATE) {
+               gpi_stop_chan(gpii_chan);
+
+               ret = gpi_send_cmd(gpii, gpii_chan, GPI_CH_CMD_RESET);
+               if (ret)
+                       dev_err(gpii->gpi_dev->dev, "error resetting 
channel:%d\n", ret);
+
+               gpi_reset_chan(gpii_chan, GPI_CH_CMD_DE_ALLOC);
+       }
+
+       /* free all allocated memory */
+       gpi_free_ring(&gpii_chan->ch_ring, gpii);
+       vchan_free_chan_resources(&gpii_chan->vc);
+
+       write_lock_irq(&gpii->pm_lock);
+       gpii_chan->pm_state = DISABLE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+
+       /* if other rings are still active exit */
+       for (i = 0; i < MAX_CHANNELS_PER_GPII; i++)
+               if (gpii->gpii_chan[i].ch_ring.configured)
+                       goto exit_free;
+
+       /* deallocate EV Ring */
+       cur_state = gpii->pm_state;
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = PREPARE_TERMINATE;
+       write_unlock_irq(&gpii->pm_lock);
+
+       /* wait for threads to complete out */
+       tasklet_kill(&gpii->ev_task);
+
+       /* send command to de allocate event ring */
+       if (cur_state == ACTIVE_STATE)
+               gpi_send_cmd(gpii, NULL, GPI_EV_CMD_DEALLOC);
+
+       gpi_free_ring(&gpii->ev_ring, gpii);
+
+       /* disable interrupts */
+       if (cur_state == ACTIVE_STATE)
+               gpi_disable_interrupts(gpii);
+
+       /* set final state to disable */
+       write_lock_irq(&gpii->pm_lock);
+       gpii->pm_state = DISABLE_STATE;
+       write_unlock_irq(&gpii->pm_lock);
+
+exit_free:
+       mutex_unlock(&gpii->ctrl_lock);
+}
+
+/* allocate channel resources */
+static int gpi_alloc_chan_resources(struct dma_chan *chan)
+{
+       struct gpii_chan *gpii_chan = to_gpii_chan(chan);
+       struct gpii *gpii = gpii_chan->gpii;
+       int ret;
+
+       mutex_lock(&gpii->ctrl_lock);
+
+       /* allocate memory for transfer ring */
+       ret = gpi_alloc_ring(&gpii_chan->ch_ring, gpii_chan->req_tres,
+                            sizeof(struct gpi_tre), gpii);
+       if (ret)
+               goto xfer_alloc_err;
+
+       ret = gpi_ch_init(gpii_chan);
+
+       mutex_unlock(&gpii->ctrl_lock);
+
+       return ret;
+xfer_alloc_err:
+       mutex_unlock(&gpii->ctrl_lock);
+
+       return ret;
+}
+
+static int gpi_find_avail_gpii(struct gpi_dev *gpi_dev, u32 seid)
+{
+       struct gpii_chan *tx_chan, *rx_chan;
+       unsigned int gpii;
+
+       /* check if same seid is already configured for another chid */
+       for (gpii = 0; gpii < gpi_dev->max_gpii; gpii++) {
+               if (!((1 << gpii) & gpi_dev->gpii_mask))
+                       continue;
+
+               tx_chan = &gpi_dev->gpiis[gpii].gpii_chan[GPI_TX_CHAN];
+               rx_chan = &gpi_dev->gpiis[gpii].gpii_chan[GPI_RX_CHAN];
+
+               if (rx_chan->vc.chan.client_count && rx_chan->seid == seid)
+                       return gpii;
+               if (tx_chan->vc.chan.client_count && tx_chan->seid == seid)
+                       return gpii;
+       }
+
+       /* no channels configured with same seid, return next avail gpii */
+       for (gpii = 0; gpii < gpi_dev->max_gpii; gpii++) {
+               if (!((1 << gpii) & gpi_dev->gpii_mask))
+                       continue;
+
+               tx_chan = &gpi_dev->gpiis[gpii].gpii_chan[GPI_TX_CHAN];
+               rx_chan = &gpi_dev->gpiis[gpii].gpii_chan[GPI_RX_CHAN];
+
+               /* check if gpii is configured */
+               if (tx_chan->vc.chan.client_count ||
+                   rx_chan->vc.chan.client_count)
+                       continue;
+
+               /* found a free gpii */
+               return gpii;
+       }
+
+       /* no gpii instance available to use */
+       return -EIO;
+}
+
+/* gpi_of_dma_xlate: open client requested channel */
+static struct dma_chan *gpi_of_dma_xlate(struct of_phandle_args *args,
+                                        struct of_dma *of_dma)
+{
+       struct gpi_dev *gpi_dev = (struct gpi_dev *)of_dma->of_dma_data;
+       u32 seid, chid;
+       int gpii;
+       struct gpii_chan *gpii_chan;
+
+       if (args->args_count < REQ_OF_DMA_ARGS) {
+               dev_err(gpi_dev->dev, "gpii require minimum 6 args, client 
passed:%d args\n",
+                       args->args_count);
+               return NULL;
+       }
+
+       chid = args->args[0];
+       if (chid >= MAX_CHANNELS_PER_GPII) {
+               dev_err(gpi_dev->dev, "gpii channel:%d not valid\n", chid);
+               return NULL;
+       }
+
+       seid = args->args[1];
+
+       /* find next available gpii to use */
+       gpii = gpi_find_avail_gpii(gpi_dev, seid);
+       if (gpii < 0) {
+               dev_err(gpi_dev->dev, "no available gpii instances\n");
+               return NULL;
+       }
+
+       gpii_chan = &gpi_dev->gpiis[gpii].gpii_chan[chid];
+       if (gpii_chan->vc.chan.client_count) {
+               dev_err(gpi_dev->dev, "gpii:%d chid:%d seid:%d already 
configured\n",
+                       gpii, chid, gpii_chan->seid);
+               return NULL;
+       }
+
+       /* get ring size, protocol, se_id, and priority */
+       gpii_chan->seid = seid;
+       gpii_chan->protocol = args->args[2];
+       gpii_chan->req_tres = args->args[3];
+       gpii_chan->priority = args->args[4];
+
+       dev_dbg(gpi_dev->dev,
+               "client req. gpii:%u chid:%u #_tre:%u priority:%u 
protocol:%u\n",
+               gpii, chid, gpii_chan->req_tres, gpii_chan->priority,
+               gpii_chan->protocol);
+
+       return dma_get_slave_channel(&gpii_chan->vc.chan);
+}
+
+static int gpi_probe(struct platform_device *pdev)
+{
+       struct gpi_dev *gpi_dev;
+       const char *mode = NULL;
+       u32 gpi_ee_offset;
+       unsigned int i;
+       int ret;
+
+       gpi_dev = devm_kzalloc(&pdev->dev, sizeof(*gpi_dev), GFP_KERNEL);
+       if (!gpi_dev)
+               return -ENOMEM;
+
+       gpi_dev->dev = &pdev->dev;
+       gpi_dev->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       gpi_dev->regs = devm_ioremap_resource(gpi_dev->dev, gpi_dev->res);
+       if (IS_ERR(gpi_dev->regs))
+               return PTR_ERR(gpi_dev->regs);
+       gpi_dev->ee_base = gpi_dev->regs;
+
+       ret = of_property_read_u32(gpi_dev->dev->of_node, "qcom,max-num-gpii",
+                                  &gpi_dev->max_gpii);
+       if (ret) {
+               dev_err(gpi_dev->dev, "missing 'max-no-gpii' DT node\n");
+               return ret;
+       }
+
+       ret = of_property_read_u32(gpi_dev->dev->of_node, "qcom,gpii-mask",
+                                  &gpi_dev->gpii_mask);
+       if (ret) {
+               dev_err(gpi_dev->dev, "missing 'gpii-mask' DT node\n");
+               return ret;
+       }
+
+       ret = of_property_read_u32(gpi_dev->dev->of_node,
+                                  "qcom,gpi-ee-offset", &gpi_ee_offset);
+       if (ret)
+               dev_dbg(gpi_dev->dev, "No variable ee offset present\n");
+       else
+               gpi_dev->ee_base = gpi_dev->ee_base - gpi_ee_offset;
+
+       ret = of_property_read_u32(gpi_dev->dev->of_node,
+                                  "qcom,ev-factor", &gpi_dev->ev_factor);
+       if (ret) {
+               dev_err(gpi_dev->dev, "missing 'qcom,ev-factor' DT node\n");
+               return ret;
+       }
+
+       of_property_read_string(gpi_dev->dev->of_node, "qcom,iommu-dma", &mode);
+       ret = dma_set_mask(gpi_dev->dev, DMA_BIT_MASK(64));
+       if (ret) {
+               dev_err(gpi_dev->dev, "Error setting dma_mask to 64, ret:%d\n", 
ret);
+               return ret;
+       }
+
+       gpi_dev->gpiis = devm_kzalloc(gpi_dev->dev, sizeof(*gpi_dev->gpiis) *
+                                     gpi_dev->max_gpii, GFP_KERNEL);
+       if (!gpi_dev->gpiis)
+               return -ENOMEM;
+
+       /* setup all the supported gpii */
+       INIT_LIST_HEAD(&gpi_dev->dma_device.channels);
+       for (i = 0; i < gpi_dev->max_gpii; i++) {
+               struct gpii *gpii = &gpi_dev->gpiis[i];
+               int chan;
+
+               if (!((1 << i) & gpi_dev->gpii_mask))
+                       continue;
+
+               /* set up ev cntxt register map */
+               gpii->ev_cntxt_base_reg = gpi_dev->ee_base + 
GPII_n_EV_CH_k_CNTXT_0_OFFS(i, 0);
+               gpii->ev_cntxt_db_reg = gpi_dev->ee_base + 
GPII_n_EV_CH_k_DOORBELL_0_OFFS(i, 0);
+               gpii->ev_ring_rp_lsb_reg = gpii->ev_cntxt_base_reg + 
CNTXT_4_RING_RP_LSB;
+               gpii->ev_cmd_reg = gpi_dev->ee_base + GPII_n_EV_CH_CMD_OFFS(i);
+               gpii->ieob_clr_reg = gpi_dev->ee_base + 
GPII_n_CNTXT_SRC_IEOB_IRQ_CLR_OFFS(i);
+
+               /* set up irq */
+               ret = platform_get_irq(pdev, i);
+               if (ret < 0) {
+                       dev_err(gpi_dev->dev, "platform_get_irq failed for 
%d:%d\n", i, ret);
+                       return ret;
+               }
+               gpii->irq = ret;
+
+               /* set up channel specific register info */
+               for (chan = 0; chan < MAX_CHANNELS_PER_GPII; chan++) {
+                       struct gpii_chan *gpii_chan = &gpii->gpii_chan[chan];
+
+                       /* set up ch cntxt register map */
+                       gpii_chan->ch_cntxt_base_reg = gpi_dev->ee_base +
+                               GPII_n_CH_k_CNTXT_0_OFFS(i, chan);
+                       gpii_chan->ch_cntxt_db_reg = gpi_dev->ee_base +
+                               GPII_n_CH_k_DOORBELL_0_OFFS(i, chan);
+                       gpii_chan->ch_cmd_reg = gpi_dev->ee_base + 
GPII_n_CH_CMD_OFFS(i);
+
+                       /* vchan setup */
+                       vchan_init(&gpii_chan->vc, &gpi_dev->dma_device);
+                       gpii_chan->vc.desc_free = gpi_desc_free;
+                       gpii_chan->chid = chan;
+                       gpii_chan->gpii = gpii;
+                       gpii_chan->dir = GPII_CHAN_DIR[chan];
+               }
+               mutex_init(&gpii->ctrl_lock);
+               rwlock_init(&gpii->pm_lock);
+               tasklet_init(&gpii->ev_task, gpi_ev_tasklet,
+                            (unsigned long)gpii);
+               init_completion(&gpii->cmd_completion);
+               gpii->gpii_id = i;
+               gpii->regs = gpi_dev->ee_base;
+               gpii->gpi_dev = gpi_dev;
+       }
+
+       platform_set_drvdata(pdev, gpi_dev);
+
+       /* clear and Set capabilities */
+       dma_cap_zero(gpi_dev->dma_device.cap_mask);
+       dma_cap_set(DMA_SLAVE, gpi_dev->dma_device.cap_mask);
+
+       /* configure dmaengine apis */
+       gpi_dev->dma_device.directions =
+               BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+       gpi_dev->dma_device.residue_granularity = 
DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
+       gpi_dev->dma_device.src_addr_widths = DMA_SLAVE_BUSWIDTH_8_BYTES;
+       gpi_dev->dma_device.dst_addr_widths = DMA_SLAVE_BUSWIDTH_8_BYTES;
+       gpi_dev->dma_device.device_alloc_chan_resources = 
gpi_alloc_chan_resources;
+       gpi_dev->dma_device.device_free_chan_resources = 
gpi_free_chan_resources;
+       gpi_dev->dma_device.device_tx_status = dma_cookie_status;
+       gpi_dev->dma_device.device_issue_pending = gpi_issue_pending;
+       gpi_dev->dma_device.device_prep_slave_sg = gpi_prep_slave_sg;
+       gpi_dev->dma_device.device_config = gpi_peripheral_config;
+       gpi_dev->dma_device.device_terminate_all = gpi_terminate_all;
+       gpi_dev->dma_device.dev = gpi_dev->dev;
+       gpi_dev->dma_device.device_pause = gpi_pause;
+       gpi_dev->dma_device.device_resume = gpi_resume;
+
+       /* register with dmaengine framework */
+       ret = dma_async_device_register(&gpi_dev->dma_device);
+       if (ret) {
+               dev_err(gpi_dev->dev, "async_device_register failed ret:%d", 
ret);
+               return ret;
+       }
+
+       ret = of_dma_controller_register(gpi_dev->dev->of_node,
+                                        gpi_of_dma_xlate, gpi_dev);
+       if (ret) {
+               dev_err(gpi_dev->dev, "of_dma_controller_reg failed ret:%d", 
ret);
+               return ret;
+       }
+
+       return ret;
+}
+
+static const struct of_device_id gpi_of_match[] = {
+       { .compatible = "qcom,gpi-dma" },
+       { },
+};
+MODULE_DEVICE_TABLE(of, gpi_of_match);
+
+static struct platform_driver gpi_driver = {
+       .probe = gpi_probe,
+       .driver = {
+               .name = KBUILD_MODNAME,
+               .of_match_table = gpi_of_match,
+       },
+};
+
+static int __init gpi_init(void)
+{
+       return platform_driver_register(&gpi_driver);
+}
+subsys_initcall(gpi_init)
+
+MODULE_DESCRIPTION("QCOM GPI DMA engine driver");
+MODULE_LICENSE("GPL v2");
-- 
2.26.2

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