Add a driver for Cadence I3C master IP.

Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
---
 drivers/i3c/master/Kconfig           |    4 +
 drivers/i3c/master/Makefile          |    1 +
 drivers/i3c/master/i3c-master-cdns.c | 1382 ++++++++++++++++++++++++++++++++++
 3 files changed, 1387 insertions(+)
 create mode 100644 drivers/i3c/master/i3c-master-cdns.c

diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
index e69de29bb2d1..23ed1642828c 100644
--- a/drivers/i3c/master/Kconfig
+++ b/drivers/i3c/master/Kconfig
@@ -0,0 +1,4 @@
+config CDNS_I3C_MASTER
+       tristate "Cadence I3C master driver"
+       help
+         Enable this driver if you want to support Cadence I3C master block.
diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile
index e69de29bb2d1..4c4304aa9534 100644
--- a/drivers/i3c/master/Makefile
+++ b/drivers/i3c/master/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_CDNS_I3C_MASTER)          += i3c-master-cdns.o
diff --git a/drivers/i3c/master/i3c-master-cdns.c 
b/drivers/i3c/master/i3c-master-cdns.c
new file mode 100644
index 000000000000..74564fe55247
--- /dev/null
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -0,0 +1,1382 @@
+/*
+ * Copyright (C) 2017 Cadence Design Systems Inc.
+ *
+ * Author: Boris Brezillon <boris.brezil...@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/i3c/master.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define DEV_ID                         0x0
+#define DEV_ID_VID(id)                 (((id) & GENMASK(31, 20)) >> 20)
+#define DEV_ID_PID(id)                 (((id) & GENMASK(19, 8)) >> 8)
+#define DEV_ID_REV_MAJOR(id)           (((id) & GENMASK(7, 4)) >> 4)
+#define DEV_ID_REV_MINOR(id)           ((id) & GENMASK(3, 0))
+
+#define CONF_STATUS                    0x4
+#define CONF_STATUS_HAS_FIFOS          BIT(26)
+#define CONF_STATUS_GPO_NUM(s)         (((s) & GENMASK(25, 18)) >> 18)
+#define CONF_STATUS_GPI_NUM(s)         (((s) & GENMASK(17, 10)) >> 10)
+#define CONF_STATUS_DEVS_NUM(s)                (((s) & GENMASK(6, 3)) >> 3)
+#define DEV_TYPE_MAIN_MASTER           0
+#define DEV_TYPE_SECONDARY_MASTER      1
+#define DEV_TYPE_SLAVE                 2
+#define CONF_STATUS_DEV_TYPE(s)                ((s) & GENMASK(2, 0))
+
+#define DEVS_CTRL                      0x8
+#define DEVS_CTRL_DEV_CLR_ALL          GENMASK(31, 16)
+#define DEVS_CTRL_DEV_CLR(dev)         BIT(16 + (dev))
+#define DEVS_CTRL_DEV_ACTIVE(dev)      BIT(dev)
+
+#define CTRL                           0x10
+#define CTRL_DEV_EN                    BIT(31)
+#define CTRL_HALT_EN                   BIT(30)
+#define CTRL_HJ_DISEC                  BIT(8)
+#define CTRL_MST_ACK                   BIT(7)
+#define CTRL_HJ_ACK                    BIT(6)
+#define CTRL_HJ_INIT                   BIT(5)
+#define CTRL_MST_INIT                  BIT(4)
+#define CTRL_AHDR_OPT                  BIT(3)
+#define CTRL_PURE_BUS_MODE             0
+#define CTRL_MIXED_FAST_BUS_MODE       2
+#define CTRL_MIXED_SLOW_BUS_MODE       3
+#define CTRL_BUS_MODE_MASK             GENMASK(1, 0)
+
+#define PRESCL_CTRL0                   0x14
+#define PRESCL_CTRL0_I2C(x)            ((x) << 16)
+#define PRESCL_CTRL0_I3C(x)            (x)
+#define PRESCL_CTRL0_MAX               GENMASK(15, 0)
+
+#define PRESCL_CTRL1                   0x18
+#define PRESCL_CTRL1_PP_LOW(x)         ((x) << 8)
+#define PRESCL_CTRL1_OD_LOW(x)         (x)
+
+#define MST_IER                                0x20
+#define MST_IDR                                0x24
+#define MST_IMR                                0x28
+#define MST_ICR                                0x2c
+#define MST_ISR                                0x30
+#define MST_INT_RX_THR                 BIT(24)
+#define MST_INT_TX_THR                 BIT(23)
+#define MST_INT_IBI_THR                        BIT(22)
+#define MST_INT_CMD_THR                        BIT(21)
+#define MST_INT_RX_UNF                 BIT(20)
+#define MST_INT_TX_OVF                 BIT(19)
+#define MST_INT_IBI_UNF                        BIT(18)
+#define MST_INT_CMD_OVF                        BIT(17)
+#define MST_INT_CMD_EMPTY              BIT(16)
+#define MST_INT_MR_DONE                        BIT(11)
+#define MST_INT_IBI_FAIL               BIT(10)
+#define MST_INT_SDR_FAIL               BIT(9)
+#define MST_INT_DDR_FAIL               BIT(8)
+#define MST_INT_HJ_REQ                 BIT(7)
+#define MST_INT_MR_REQ                 BIT(6)
+#define MST_INT_IBI_REQ                        BIT(5)
+#define MST_INT_BUS_DISCR              BIT(4)
+#define MST_INT_INVALID_DA             BIT(3)
+#define MST_INT_RD_ABORT               BIT(2)
+#define MST_INT_NACK                   BIT(1)
+#define MST_INT_COMP                   BIT(0)
+
+#define MST_STATUS0                    0x34
+#define MST_STATUS0_IDLE               BIT(31)
+#define MST_STATUS0_HALTED             BIT(30)
+#define MST_STATUS0_MASTER_MODE                BIT(29)
+#define MST_STATUS0_IMM_COMP           BIT(28)
+#define MST_STATUS0_DDR_ERR_ID(s)      ((s) & GENMASK(27, 25) >> 25)
+#define MST_STATUS0_DAA_COMP           BIT(24)
+#define MST_STATUS0_IBI_FIFO_FULL      BIT(23)
+#define MST_STATUS0_RX_FIFO_FULL       BIT(22)
+#define MST_STATUS0_XFER_BYTES(s)      ((s) & GENMASK(21, 10) >> 10)
+#define MST_STATUS0_DEV_ADDR(s)                ((s) & GENMASK(9, 0))
+
+#define SIR_STATUS                     0x3c
+#define SIR_STATUS_DEV(d)              BIT(d)
+
+#define SLV_IER                                0x40
+#define SLV_IDR                                0x44
+#define SLV_IMR                                0x48
+#define SLV_ICR                                0x4c
+#define SLV_ISR                                0x50
+#define SLV_INT_TM                     BIT(20)
+#define SLV_INT_ERROR                  BIT(19)
+#define SLV_INT_EVENT_UP               BIT(18)
+#define SLV_INT_HJ_DONE                        BIT(17)
+#define SLV_INT_MR_DONE                        BIT(16)
+#define SLV_INT_SDR_FAIL               BIT(14)
+#define SLV_INT_DDR_FAIL               BIT(13)
+#define SLV_INT_M_RD_ABORT             BIT(12)
+#define SLV_INT_DDR_RX_THR             BIT(11)
+#define SLV_INT_DDR_TX_THR             BIT(10)
+#define SLV_INT_SDR_RX_THR             BIT(9)
+#define SLV_INT_SDR_TX_THR             BIT(8)
+#define SLV_INT_DDR_RX_UNF             BIT(7)
+#define SLV_INT_DDR_TX_OVF             BIT(6)
+#define SLV_INT_SDR_RX_UNF             BIT(5)
+#define SLV_INT_SDR_TX_OVF             BIT(4)
+#define SLV_INT_DDR_RD_COMP            BIT(3)
+#define SLV_INT_DDR_WR_COMP            BIT(2)
+#define SLV_INT_SDR_RD_COMP            BIT(1)
+#define SLV_INT_SDR_WR_COMP            BIT(0)
+
+#define SLV_STATUS0                    0x54
+#define SLV_STATUS0_REG_ADDR(s)                (((s) & GENMASK(23, 16)) >> 16)
+#define SLV_STATUS0_XFRD_BYTES(s)      ((s) & GENMASK(15, 0))
+
+#define SLV_STATUS1                    0x58
+#define SLV_STATUS1_AS(s)              (((s) & GENMASK(21, 20)) >> 20)
+#define SLV_STATUS1_VEN_TM             BIT(19)
+#define SLV_STATUS1_HJ_DIS             BIT(18)
+#define SLV_STATUS1_MR_DIS             BIT(17)
+#define SLV_STATUS1_PROT_ERR           BIT(16)
+#define SLV_STATUS1_DDR_RX_FULL                BIT(7)
+#define SLV_STATUS1_DDR_TX_FULL                BIT(6)
+#define SLV_STATUS1_DDR_RX_EMPTY       BIT(5)
+#define SLV_STATUS1_DDR_TX_EMPTY       BIT(4)
+#define SLV_STATUS1_SDR_RX_FULL                BIT(3)
+#define SLV_STATUS1_SDR_TX_FULL                BIT(2)
+#define SLV_STATUS1_SDR_RX_EMPTY       BIT(1)
+#define SLV_STATUS1_SDR_TX_EMPTY       BIT(0)
+
+#define CMD0_FIFO                      0x60
+#define CMD0_FIFO_IS_DDR               BIT(31)
+#define CMD0_FIFO_IS_CCC               BIT(30)
+#define CMD0_FIFO_BCH                  BIT(29)
+#define XMIT_BURST_STATIC_SUBADDR      0
+#define XMIT_SINGLE_INC_SUBADDR                1
+#define XMIT_SINGLE_STATIC_SUBADDR     2
+#define XMIT_BURST_WITHOUT_SUBADDR     3
+#define CMD0_FIFO_PRIV_XMIT_MODE(m)    ((m) << 27)
+#define CMD0_FIFO_SBCA                 BIT(26)
+#define CMD0_FIFO_RSBC                 BIT(25)
+#define CMD0_FIFO_IS_10B               BIT(24)
+#define CMD0_FIFO_PL_LEN(l)            ((l) << 12)
+#define CMD0_FIFO_PL_LEN_MAX           4095
+#define CMD0_FIFO_DEV_ADDR(a)          ((a) << 1)
+#define CMD0_FIFO_RNW                  BIT(0)
+
+#define CMD1_FIFO                      0x64
+#define CMD1_FIFO_CSRADDR(a)           (a)
+#define CMD1_FIFO_CCC(id)              (id)
+
+#define TX_FIFO                                0x68
+
+#define IMD_CMD0                       0x70
+#define IMD_CMD0_PL_LEN(l)             ((l) << 12)
+#define IMD_CMD0_DEV_ADDR(a)           ((a) << 1)
+#define IMD_CMD0_RNW                   BIT(0)
+
+#define IMD_CMD1                       0x74
+#define IMD_CMD1_CCC(id)               (id)
+
+#define IMD_DATA                       0x78
+#define RX_FIFO                                0x80
+#define IBI_DATA_FIFO                  0x84
+#define SLV_DDR_TX_FIFO                        0x88
+#define SLV_DDR_RX_FIFO                        0x8c
+
+#define CMD_IBI_THR_CTRL               0x90
+#define IBI_THR(t)                     ((t) << 8)
+#define CMD_THR(t)                     (t)
+
+#define TX_RX_THR_CTRL                 0x94
+#define RX_THR(t)                      ((t) << 16)
+#define TX_THR(t)                      (t)
+
+#define SLV_DDR_TX_RX_THR_CTRL         0x98
+#define SLV_DDR_RX_THR(t)              ((t) << 16)
+#define SLV_DDR_TX_THR(t)              (t)
+
+#define FLUSH_CTRL                     0x9c
+#define FLUSH_SLV_DDR_RX_FIFO          BIT(22)
+#define FLUSH_SLV_DDR_TX_FIFO          BIT(21)
+#define FLUSH_IMM_FIFO                 BIT(20)
+#define FLUSH_IBI_FIFO                 BIT(19)
+#define FLUSH_RX_FIFO                  BIT(18)
+#define FLUSH_TX_FIFO                  BIT(17)
+#define FLUSH_CMD_FIFO                 BIT(16)
+
+#define DEV_ID_RR0(d)                  (0xa0 + ((d) * 0x10))
+#define DEV_ID_RR0_LVR_EXT_ADDR                BIT(11)
+#define DEV_ID_RR0_HDR_CAP             BIT(10)
+#define DEV_ID_RR0_IS_I3C              BIT(9)
+#define DEV_ID_RR0_SET_DEV_ADDR(a)     (((a) & GENMASK(6, 0)) |        \
+                                        (((a) & GENMASK(9, 7)) << 6))
+#define DEV_ID_RR0_GET_DEV_ADDR(x)     ((((x) >> 1) & GENMASK(6, 0)) | \
+                                        (((x) >> 6) & GENMASK(9, 7)))
+
+#define DEV_ID_RR1(d)                  (0xa4 + ((d) * 0x10))
+#define DEV_ID_RR1_PID_MSB(pid)                (pid)
+
+#define DEV_ID_RR2(d)                  (0xa8 + ((d) * 0x10))
+#define DEV_ID_RR2_PID_LSB(pid)                ((pid) << 16)
+#define DEV_ID_RR2_BCR(bcr)            ((bcr) << 8)
+#define DEV_ID_RR2_DCR(dcr)            (dcr)
+#define DEV_ID_RR2_LVR(lvr)            (lvr)
+
+#define SIR_MAP(x)                     (0x160 + ((x) * 4))
+#define SIR_MAP_DEV_REG(d)             SIR_MAP((d) / 2)
+#define SIR_MAP_DEV_SHIFT(d, fs)       ((fs) + (((d) % 2) ? 16 : 0))
+#define SIR_MAP_DEV_MASK(d)            (GENMASK(15, 0) << (((d) % 2) ? 16 : 0))
+#define DEV_ROLE_SLAVE                 0
+#define DEV_ROLE_MASTER                        1
+#define SIR_MAP_DEV_ROLE(d, role)      ((role) << SIR_MAP_DEV_SHIFT(d, 14))
+#define SIR_MAP_DEV_SLOW(d)            BIT(SIR_MAP_DEV_SHIFT(d, 13))
+#define SIR_MAP_DEV_PL(d, l)           ((l) << SIR_MAP_DEV_SHIFT(d, 8))
+#define SIR_MAP_PL_MAX                 GENMASK(4, 0)
+#define SIR_MAP_DEV_DA(d, a)           ((a) << SIR_MAP_DEV_SHIFT(d, 1))
+#define SIR_MAP_DEV_ACK_RESP(d)                BIT(SIR_MAP_DEV_SHIFT(d, 0))
+
+#define GPIR_WORD(x)                   (0x180 + ((x) * 4))
+#define GPI_REG(val, id)               \
+       (((val) >> (((id) % 4) * 8)) & GENMASK(7, 0))
+
+#define GPOR_WORD(x)                   (0x200 + ((x) * 4))
+#define GPO_REG(val, id)               \
+       (((val) >> (((id) % 4) * 8)) & GENMASK(7, 0))
+
+struct cdns_i3c_cmd {
+       struct list_head node;
+       u32 cmd0;
+       u32 cmd1;
+       struct {
+               void *in;
+               const void *out;
+       } data;
+       u32 dataptr;
+       u32 datalen;
+       struct completion *comp;
+};
+
+struct cdns_i3c_master_caps {
+       u32 cmdfifodepth;
+       u32 txfifodepth;
+       u32 rxfifodepth;
+};
+
+struct cdns_i3c_master {
+       struct i3c_master_controller base;
+       struct mutex lock;
+       unsigned long free_dev_slots;
+       void __iomem *regs;
+       struct clk *sysclk;
+       struct clk *pclk;
+       struct completion comp;
+       struct cdns_i3c_master_caps caps;
+};
+
+static inline struct cdns_i3c_master *
+to_cdns_i3c_master(struct i3c_master_controller *master)
+{
+       return container_of(master, struct cdns_i3c_master, base);
+}
+
+static void cdns_i3c_master_wr_to_tx_fifo(struct cdns_i3c_master *master,
+                                         const u8 *bytes, int nbytes)
+{
+       int i, j;
+
+       for (i = 0; i < nbytes; i += 4) {
+               u32 data = 0;
+
+               for (j = 0; j < 4 && (i + j) < nbytes; j++)
+                       data |= (u32)bytes[i + j] << (j * 8);
+
+               writel(data, master->regs + TX_FIFO);
+       }
+}
+
+static void cdns_i3c_master_drain_rx_fifo(struct cdns_i3c_master *master)
+{
+       int i;
+
+       for (i = 0; i < master->caps.rxfifodepth; i++) {
+               readl(master->regs + RX_FIFO);
+               if (readl(master->regs + MST_ISR) & MST_INT_RX_UNF) {
+                       writel(MST_INT_RX_UNF, master->regs + MST_ICR);
+                       break;
+               }
+       }
+}
+
+static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
+                                           u8 *bytes, int nbytes)
+{
+       u32 status0;
+       int i, j;
+
+       status0 = readl(master->regs + MST_STATUS0);
+
+       if (nbytes > MST_STATUS0_XFER_BYTES(status0))
+               nbytes = MST_STATUS0_XFER_BYTES(status0);
+
+       for (i = 0; i < nbytes; i += 4) {
+               u32 data;
+
+               data = readl(master->regs + RX_FIFO);
+
+               for (j = 0; j < 4 && (i + j) < nbytes; j++)
+                       bytes[i + j] = data >> (j * 8);
+       }
+}
+
+static bool cdns_i3c_master_supports_ccc_cmd(struct i3c_master_controller *m,
+                                            const struct i3c_ccc_cmd *cmd)
+{
+       if (cmd->ndests > 1)
+               return false;
+
+       switch (cmd->id) {
+       case I3C_CCC_ENEC(true):
+       case I3C_CCC_ENEC(false):
+       case I3C_CCC_DISEC(true):
+       case I3C_CCC_DISEC(false):
+       case I3C_CCC_ENTAS(0, true):
+       case I3C_CCC_ENTAS(0, false):
+       case I3C_CCC_RSTDAA(true):
+       case I3C_CCC_RSTDAA(false):
+       case I3C_CCC_ENTDAA:
+       case I3C_CCC_SETMWL(true):
+       case I3C_CCC_SETMWL(false):
+       case I3C_CCC_SETMRL(true):
+       case I3C_CCC_SETMRL(false):
+       case I3C_CCC_DEFSLVS:
+       case I3C_CCC_ENTHDR(0):
+       case I3C_CCC_SETDASA:
+       case I3C_CCC_SETNEWDA:
+       case I3C_CCC_GETMWL:
+       case I3C_CCC_GETMRL:
+       case I3C_CCC_GETPID:
+       case I3C_CCC_GETBCR:
+       case I3C_CCC_GETDCR:
+       case I3C_CCC_GETSTATUS:
+       case I3C_CCC_GETACCMST:
+       case I3C_CCC_GETMXDS:
+       case I3C_CCC_GETHDRCAP:
+               return true;
+       default:
+               break;
+       }
+
+       return false;
+}
+
+static void cdns_i3c_master_init_irqs(struct cdns_i3c_master *master,
+                                     u32 irqs)
+{
+       writel(irqs, master->regs + MST_ICR);
+       writel(0xffffffff, master->regs + MST_ICR);
+       reinit_completion(&master->comp);
+}
+
+static u32 cdns_i3c_master_wait_for_irqs(struct cdns_i3c_master *master,
+                                        u32 irqs)
+{
+       u32 ret;
+
+       writel(irqs, master->regs + MST_IER);
+       wait_for_completion_timeout(&master->comp, msecs_to_jiffies(1000));
+       writel(irqs, master->regs + MST_IDR);
+
+       ret = readl(master->regs + MST_ISR) & irqs;
+
+       return ret;
+}
+
+static int cdns_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
+                                       struct i3c_ccc_cmd *cmd)
+{
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       u32 cmd0, isr, irqs;
+
+       mutex_lock(&master->lock);
+       cmd0 = CMD0_FIFO_IS_CCC | CMD0_FIFO_PL_LEN(cmd->dests[0].payload.len);
+       if (cmd->id & I3C_CCC_DIRECT)
+               cmd0 |= CMD0_FIFO_DEV_ADDR(cmd->dests[0].addr);
+
+       if (cmd->rnw)
+               cmd0 |= CMD0_FIFO_RNW;
+
+       if (!cmd->rnw)
+               cdns_i3c_master_wr_to_tx_fifo(master,
+                                             cmd->dests[0].payload.data,
+                                             cmd->dests[0].payload.len);
+
+       irqs = MST_INT_COMP | (cmd->id != I3C_CCC_ENTDAA ? MST_INT_NACK : 0);
+       cdns_i3c_master_init_irqs(master, irqs);
+       writel(CMD1_FIFO_CCC(cmd->id), master->regs + CMD1_FIFO);
+       writel(cmd0, master->regs + CMD0_FIFO);
+       isr = cdns_i3c_master_wait_for_irqs(master, irqs);
+
+       if (cmd->rnw) {
+               int nbytes = cmd->dests[0].payload.len;
+               u32 status0 = readl(master->regs + MST_STATUS0);
+
+               if (nbytes > MST_STATUS0_XFER_BYTES(status0))
+                       nbytes = MST_STATUS0_XFER_BYTES(status0);
+
+               cdns_i3c_master_rd_from_rx_fifo(master,
+                                               cmd->dests[0].payload.data,
+                                               nbytes);
+               cmd->dests[0].payload.len = nbytes;
+       }
+       mutex_unlock(&master->lock);
+
+       /*
+        * MST_INT_NACK is not an error when doing DAA, it just means "no i3c
+        * devices on the bus".
+        */
+       if (isr & MST_INT_NACK)
+               return -EIO;
+       else if (!(isr & MST_INT_COMP))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int cdns_i3c_master_priv_xfers(struct i3c_master_controller *m,
+                                     const struct i3c_priv_xfer *xfers,
+                                     int nxfers)
+{
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       int tnxfers = 0, tntx = 0, tnrx = 0, j = 0, i, ret = 0;
+
+       for (i = 0; i < nxfers; i++) {
+               if (xfers[i].len > CMD0_FIFO_PL_LEN_MAX)
+                       return -ENOTSUPP;
+       }
+
+       if (!nxfers)
+               return 0;
+
+       /*
+        * First make sure that all transactions (block of transfers separated
+        * by a STOP marker) fit in the FIFOs.
+        */
+       for (i = 0; i < nxfers; i++) {
+               tnxfers++;
+
+               if (xfers[i].flags & I3C_PRIV_XFER_READ)
+                       tnrx += DIV_ROUND_UP(xfers[i].len, 4);
+               else
+                       tntx += DIV_ROUND_UP(xfers[i].len, 4);
+
+               if (!(xfers[i].flags & I3C_PRIV_XFER_STOP))
+                       continue;
+
+               if (tnxfers > master->caps.cmdfifodepth ||
+                   tnrx > master->caps.rxfifodepth ||
+                   tntx > master->caps.txfifodepth)
+                       return -ENOTSUPP;
+
+               tnxfers = 0;
+               tntx = 0;
+               tnrx = 0;
+       }
+
+       mutex_lock(&master->lock);
+
+       cdns_i3c_master_init_irqs(master, MST_INT_NACK | MST_INT_COMP);
+
+       /*
+        * FIXME: The IP does not support stalling the output message queue
+        * while we are queuing I3C commands, and we have no way to tell the
+        * I3C master whether we want a Repeated Start (Sr) or a Stop (S)
+        * between two transfers. Instead, the engine decides by itself when Sr
+        * should be used based on the next command in the queue.
+        * The problem is, we are not guaranteed to queue the second message
+        * before the master has finished transmitting the first one, and the
+        * engine might see an empty FIFO when it tries to figure what kind of
+        * transition should be used, thus generating a S when we expected a
+        * Sr.
+        *
+        * To guarantee atomicity on this transfer queuing operation, we
+        * disable the master, then queue things and finally re-enable it, but
+        * this means we have a short period of time during which we can miss
+        * IBI/HJ events.
+        *
+        * This should hopefully be fixed with the next version of this IP.
+        */
+       writel(readl(master->regs + CTRL) & ~CTRL_DEV_EN, master->regs + CTRL);
+
+       for (i = 0; i < nxfers; i++) {
+               u32 cmd0, isr;
+
+               cmd0 = CMD0_FIFO_DEV_ADDR(xfers[i].addr) |
+                      CMD0_FIFO_PL_LEN(xfers[i].len) |
+                      CMD0_FIFO_PRIV_XMIT_MODE(XMIT_BURST_WITHOUT_SUBADDR);
+
+               if (xfers[i].flags & I3C_PRIV_XFER_READ)
+                       cmd0 |= CMD0_FIFO_RNW;
+               else
+                       cdns_i3c_master_wr_to_tx_fifo(master,
+                                                     xfers[i].data.out,
+                                                     xfers[i].len);
+
+               if (!(xfers[i].flags & I3C_PRIV_XFER_STOP) || i == nxfers - 1)
+                       cmd0 |= CMD0_FIFO_RSBC;
+
+               if (!i || (xfers[i - 1].flags & I3C_PRIV_XFER_STOP))
+                       cmd0 |= CMD0_FIFO_BCH;
+
+               writel_relaxed(0, master->regs + CMD1_FIFO);
+               writel_relaxed(cmd0, master->regs + CMD0_FIFO);
+
+               if (!(xfers[i].flags & I3C_PRIV_XFER_STOP) && i < nxfers - 1)
+                       continue;
+
+               writel(readl(master->regs + CTRL) | CTRL_DEV_EN,
+                      master->regs + CTRL);
+
+               isr = cdns_i3c_master_wait_for_irqs(master,
+                                                   MST_INT_NACK |
+                                                   MST_INT_COMP);
+               if (isr != MST_INT_COMP) {
+                       cdns_i3c_master_drain_rx_fifo(master);
+                       if (isr & MST_INT_NACK)
+                               ret = -EIO;
+                       else
+                               ret = -ETIMEDOUT;
+
+                       break;
+               }
+
+               for (; j <= i; j++) {
+                       if (xfers[j].flags & I3C_PRIV_XFER_READ)
+                               cdns_i3c_master_rd_from_rx_fifo(master,
+                                                       xfers[j].data.in,
+                                                       xfers[j].len);
+               }
+
+               cdns_i3c_master_init_irqs(master, MST_INT_NACK | MST_INT_COMP);
+               writel(readl(master->regs + CTRL) & ~CTRL_DEV_EN,
+                      master->regs + CTRL);
+       }
+
+       writel(readl(master->regs + CTRL) | CTRL_DEV_EN, master->regs + CTRL);
+
+       mutex_unlock(&master->lock);
+
+       return ret;
+}
+
+#define I3C_DDR_FIRST_DATA_WORD_PREAMBLE       0x2
+#define I3C_DDR_DATA_WORD_PREAMBLE             0x3
+
+#define I3C_DDR_PREAMBLE(p)                    ((p) << 18)
+
+static u32 prepare_ddr_word(u16 payload)
+{
+       u32 ret;
+       u16 pb;
+
+       ret = (u32)payload << 2;
+
+       /* Calculate parity. */
+       pb = (payload >> 15) ^ (payload >> 13) ^ (payload >> 11) ^
+            (payload >> 9) ^ (payload >> 7) ^ (payload >> 5) ^
+            (payload >> 3) ^ (payload >> 1);
+       ret |= (pb & 1) << 1;
+       pb = (payload >> 14) ^ (payload >> 12) ^ (payload >> 10) ^
+            (payload >> 8) ^ (payload >> 6) ^ (payload >> 4) ^
+            (payload >> 2) ^ payload ^ 1;
+       ret |= (pb & 1);
+
+       return ret;
+}
+
+static u32 prepare_ddr_data_word(u16 data, bool first)
+{
+       return prepare_ddr_word(data) | I3C_DDR_PREAMBLE(first ? 2 : 3);
+}
+
+#define I3C_DDR_READ_CMD       BIT(15)
+
+static u32 prepare_ddr_cmd_word(u16 cmd)
+{
+       return prepare_ddr_word(cmd) | I3C_DDR_PREAMBLE(1);
+}
+
+static u32 prepare_ddr_crc_word(u8 crc5)
+{
+       return (((u32)crc5 & 0x1f) << 9) | (0xc << 14) |
+              I3C_DDR_PREAMBLE(1);
+}
+
+static u8 update_crc5(u8 crc5, u16 word)
+{
+       u8 crc0;
+       int i;
+
+       /*
+        * crc0 = next_data_bit ^ crc[4]
+        *                1         2            3       4
+        * crc[4:0] = { crc[3:2], crc[1]^crc0, crc[0], crc0 }
+        */
+       for (i = 0; i < 16; ++i) {
+               crc0 = ((word >> (15 - i)) ^ (crc5 >> 4)) & 0x1;
+               crc5 = ((crc5 << 1) & (0x18 | 0x2)) |
+                      (((crc5 >> 1) ^ crc0) << 2) | crc0;
+       }
+
+       return crc5 & 0x1F;
+}
+
+static int cdns_i3c_master_send_hdr_cmd(struct i3c_master_controller *m,
+                                       const struct i3c_hdr_cmd *cmds,
+                                       int ncmds)
+{
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       int ret, i, ntxwords = 1, nrxwords = 0, pl_len = 1, ncmdwords = 2;
+       u16 cmdword, datain;
+       u32 checkword, word;
+       u32 isr;
+       u8 crc5;
+
+       if (ncmds < 1)
+               return 0;
+
+       if (ncmds > 1 || cmds[0].ndatawords > CMD0_FIFO_PL_LEN_MAX)
+               return -ENOTSUPP;
+
+       if (cmds[0].mode != I3C_HDR_DDR)
+               return -ENOTSUPP;
+
+       cmdword = ((u16)cmds[0].code << 8) | (cmds[0].addr << 1);
+       if (cmdword & I3C_DDR_READ_CMD)
+               nrxwords += cmds[0].ndatawords + 1;
+       else
+               ntxwords += cmds[0].ndatawords + 1;
+
+       if (ntxwords > master->caps.txfifodepth ||
+           nrxwords > master->caps.rxfifodepth ||
+           ncmdwords > master->caps.cmdfifodepth)
+               return -ENOTSUPP;
+
+       if (cmdword & I3C_DDR_READ_CMD) {
+               u16 pb;
+
+               pb = (cmdword >> 14) ^ (cmdword >> 12) ^ (cmdword >> 10) ^
+                    (cmdword >> 8) ^ (cmdword >> 6) ^ (cmdword >> 4) ^
+                    (cmdword >> 2);
+
+               if (pb & 1)
+                       cmdword |= BIT(0);
+       }
+
+       mutex_lock(&master->lock);
+
+       writel(prepare_ddr_cmd_word(cmdword),
+              master->regs + TX_FIFO);
+
+       crc5 = update_crc5(0x1f, cmdword);
+
+       if (!(cmdword & I3C_DDR_READ_CMD)) {
+               for (i = 0; i < cmds[0].ndatawords; i++) {
+                       crc5 = update_crc5(crc5, cmds[0].data.out[i]);
+                       writel(prepare_ddr_data_word(cmds[0].data.out[i], !i),
+                              master->regs + TX_FIFO);
+               }
+
+               writel(prepare_ddr_crc_word(crc5), master->regs + TX_FIFO);
+               pl_len += 1 + cmds[0].ndatawords;
+       }
+
+       cdns_i3c_master_init_irqs(master,
+                                 MST_INT_NACK | MST_INT_COMP |
+                                 MST_INT_DDR_FAIL);
+
+       /*
+        * FIXME: The IP does not support stalling the output message queue
+        * while we are queuing I3C HDR commands, and we have no way to tell
+        * the I3C master whether we want an HDR Restart or an HDR Exit
+        * between two HDR commands. Instead, the engine decides by itself when
+        * HDR Restart should be used based on the next command in the queue.
+        * The problem is, we are not guaranteed to queue the second message
+        * before the master has finished transmitting the first one, and the
+        * engine might see an empty FIFO when it tries to figure what kind of
+        * transition should be used, thus generating an HDR Exit when we
+        * expected an HDR Restart.
+        *
+        * To guarantee atomicity on this command queuing operation, we disable
+        * the master, then queue things and finally re-enable it, but this
+        * means we have a short period of time during which we can miss IBI/HJ
+        * events.
+        *
+        * This should hopefully be fixed with the next version of this IP.
+        */
+       writel(readl(master->regs + CTRL) & ~CTRL_DEV_EN, master->regs + CTRL);
+
+       /* Queue ENTHDR command */
+       writel(CMD1_FIFO_CCC(I3C_CCC_ENTHDR(0)),
+              master->regs + CMD1_FIFO);
+       writel(CMD0_FIFO_IS_CCC, master->regs + CMD0_FIFO);
+
+       writel(0, master->regs + CMD1_FIFO);
+       writel(CMD0_FIFO_IS_DDR | CMD0_FIFO_PL_LEN(pl_len) |
+              (cmdword & I3C_DDR_READ_CMD ? CMD0_FIFO_RNW : 0) |
+              CMD0_FIFO_DEV_ADDR(cmds[0].addr),
+              master->regs + CMD0_FIFO);
+
+       writel(readl(master->regs + CTRL) | CTRL_DEV_EN, master->regs + CTRL);
+       isr = cdns_i3c_master_wait_for_irqs(master,
+                                           MST_INT_NACK |
+                                           MST_INT_COMP |
+                                           MST_INT_DDR_FAIL);
+       if (isr != MST_INT_COMP) {
+               if (!isr)
+                       ret = -ETIMEDOUT;
+               else
+                       ret = -EIO;
+
+               goto err_drain_fifo;
+       }
+
+       if (!(cmdword & I3C_DDR_READ_CMD))
+               return 0;
+
+       for (i = 0; i < cmds[0].ndatawords; i++) {
+               word = readl(master->regs + RX_FIFO);
+               datain = (word >> 2) & GENMASK(15, 0);
+               checkword = prepare_ddr_data_word(datain, !i);
+               word &= GENMASK(19, 0);
+               if (checkword != word) {
+                       ret = -EIO;
+                       goto err_drain_fifo;
+               }
+
+               crc5 = update_crc5(crc5, datain);
+               cmds[0].data.in[i] = datain;
+       }
+
+       word = readl(master->regs + RX_FIFO);
+       word &= GENMASK(19, 7);
+       datain = (word >> 2) & GENMASK(15, 0);
+       checkword = prepare_ddr_crc_word(crc5);
+       if (checkword != word) {
+               ret = -EIO;
+               goto err_drain_fifo;
+       }
+
+       mutex_unlock(&master->lock);
+
+       return 0;
+
+err_drain_fifo:
+       cdns_i3c_master_drain_rx_fifo(master);
+       mutex_unlock(&master->lock);
+
+       return ret;
+}
+
+static int cdns_i3c_master_i2c_xfers(struct i3c_master_controller *m,
+                                    const struct i2c_msg *xfers, int nxfers)
+{
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       int i, ret = 0;
+
+       for (i = 0; i < nxfers; i++) {
+               if (xfers[i].len > CMD0_FIFO_PL_LEN_MAX)
+                       return -ENOTSUPP;
+       }
+
+       mutex_lock(&master->lock);
+
+       for (i = 0; i < nxfers; i++) {
+               u32 cmd0, isr;
+
+               cmd0 = CMD0_FIFO_DEV_ADDR(xfers[i].addr) |
+                      CMD0_FIFO_PL_LEN(xfers[i].len) |
+                      CMD0_FIFO_PRIV_XMIT_MODE(XMIT_BURST_WITHOUT_SUBADDR);
+
+               if (xfers[i].flags & I2C_M_TEN)
+                       cmd0 |= CMD0_FIFO_IS_10B;
+
+               if (xfers[i].flags & I2C_M_RD)
+                       cmd0 |= CMD0_FIFO_RNW;
+               else
+                       cdns_i3c_master_wr_to_tx_fifo(master, xfers[i].buf,
+                                                     xfers[i].len);
+
+               cdns_i3c_master_init_irqs(master, MST_INT_NACK | MST_INT_COMP);
+               writel(0, master->regs + CMD1_FIFO);
+               writel(cmd0, master->regs + CMD0_FIFO);
+               isr = cdns_i3c_master_wait_for_irqs(master,
+                                                   MST_INT_NACK |
+                                                   MST_INT_COMP);
+
+               if (xfers[i].flags & I2C_M_RD) {
+                       if (isr == MST_INT_COMP)
+                               cdns_i3c_master_rd_from_rx_fifo(master,
+                                                               xfers[i].buf,
+                                                               xfers[i].len);
+                       else
+                               cdns_i3c_master_drain_rx_fifo(master);
+               }
+
+               if (isr & MST_INT_NACK) {
+                       ret = -EIO;
+                       break;
+               } else if (!(isr & MST_INT_COMP)) {
+                       ret = -ETIMEDOUT;
+                       break;
+               }
+       }
+
+       mutex_unlock(&master->lock);
+
+       return ret;
+}
+
+struct cdns_i3c_i2c_dev_data {
+       int id;
+};
+
+static u32 prepare_rr0_dev_address(u32 addr)
+{
+       u32 ret = (addr << 1) & 0xff;
+
+       /* RR0[7:1] = addr[6:0] */
+       ret |= (addr & GENMASK(6, 0)) << 1;
+
+       /* RR0[15:13] = addr[9:7] */
+       ret |= (addr & GENMASK(9, 7)) << 6;
+
+       /* RR0[0] = ~XOR(addr[6:0]) */
+       if (!(hweight8(addr & 0x7f) & 1))
+               ret |= 1;
+
+       return ret;
+}
+
+static int cdns_i3c_master_attach_i3c_dev(struct cdns_i3c_master *master,
+                                         struct i3c_device *dev)
+{
+       struct cdns_i3c_i2c_dev_data *data;
+       u32 val;
+
+       if (!master->free_dev_slots)
+               return -ENOMEM;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->id = ffs(master->free_dev_slots) - 1;
+       clear_bit(data->id, &master->free_dev_slots);
+       i3c_device_set_master_data(dev, data);
+
+       if (dev->info.dyn_addr)
+               val = prepare_rr0_dev_address(dev->info.dyn_addr) |
+                     DEV_ID_RR0_IS_I3C;
+       else
+               val = prepare_rr0_dev_address(dev->info.static_addr);
+
+       if (dev->info.dcr & I3C_BCR_HDR_CAP)
+               val |= DEV_ID_RR0_HDR_CAP;
+
+       writel(val, master->regs + DEV_ID_RR0(data->id));
+       writel(DEV_ID_RR1_PID_MSB(dev->info.pid),
+              master->regs + DEV_ID_RR1(data->id));
+       writel(DEV_ID_RR2_DCR(dev->info.dcr) | DEV_ID_RR2_BCR(dev->info.bcr) |
+              DEV_ID_RR2_PID_LSB(dev->info.pid),
+              master->regs + DEV_ID_RR2(data->id));
+       writel(readl(master->regs + DEVS_CTRL) |
+              DEVS_CTRL_DEV_ACTIVE(data->id), master->regs + DEVS_CTRL);
+
+       return 0;
+}
+
+static void cdns_i3c_master_detach_i3c_dev(struct cdns_i3c_master *master,
+                                          struct i3c_device *dev)
+{
+       struct cdns_i3c_i2c_dev_data *data = i3c_device_get_master_data(dev);
+
+       if (!data)
+               return;
+
+       set_bit(data->id, &master->free_dev_slots);
+       writel(readl(master->regs + DEVS_CTRL) |
+              DEVS_CTRL_DEV_CLR(data->id), master->regs + DEVS_CTRL);
+
+       i3c_device_set_master_data(dev, NULL);
+       kfree(data);
+}
+
+static int cdns_i3c_master_attach_i2c_dev(struct cdns_i3c_master *master,
+                                         struct i2c_device *dev)
+{
+       struct cdns_i3c_i2c_dev_data *data;
+
+       if (!master->free_dev_slots)
+               return -ENOMEM;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->id = ffs(master->free_dev_slots) - 1;
+       clear_bit(data->id, &master->free_dev_slots);
+       i2c_device_set_master_data(dev, data);
+
+       writel(prepare_rr0_dev_address(dev->info.addr) |
+              (dev->info.flags & I2C_CLIENT_TEN ? DEV_ID_RR0_LVR_EXT_ADDR : 0),
+              master->regs + DEV_ID_RR0(data->id));
+       writel(dev->lvr, master->regs + DEV_ID_RR2(data->id));
+       writel(readl(master->regs + DEVS_CTRL) |
+              DEVS_CTRL_DEV_ACTIVE(data->id), master->regs + DEVS_CTRL);
+
+       return 0;
+}
+
+static void cdns_i3c_master_detach_i2c_dev(struct cdns_i3c_master *master,
+                                          struct i2c_device *dev)
+{
+       struct cdns_i3c_i2c_dev_data *data = i2c_device_get_master_data(dev);
+
+       if (!data)
+               return;
+
+       set_bit(data->id, &master->free_dev_slots);
+       writel(readl(master->regs + DEVS_CTRL) |
+              DEVS_CTRL_DEV_CLR(data->id),
+              master->regs + DEVS_CTRL);
+
+       i2c_device_set_master_data(dev, NULL);
+       kfree(data);
+}
+
+static int cdns_i3c_master_disable(struct cdns_i3c_master *master)
+{
+       u32 status;
+
+       writel(0, master->regs + CTRL);
+
+       return readl_poll_timeout(master->regs + MST_STATUS0, status,
+                                 status & MST_STATUS0_IDLE, 10, 1000000);
+}
+
+static void cdns_i3c_master_bus_cleanup(struct i3c_master_controller *m)
+{
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       struct i2c_device *i2cdev;
+       struct i3c_device *i3cdev;
+
+       cdns_i3c_master_disable(master);
+
+       i3c_bus_for_each_i2cdev(m->bus, i2cdev)
+               cdns_i3c_master_detach_i2c_dev(master, i2cdev);
+
+       i3c_bus_for_each_i3cdev(m->bus, i3cdev)
+               cdns_i3c_master_detach_i3c_dev(master, i3cdev);
+}
+
+static void cdns_i3c_master_dev_rr_to_info(struct cdns_i3c_master *master,
+                                          unsigned int slot,
+                                          struct i3c_device_info *info)
+{
+       u32 rr;
+
+       memset(info, 0, sizeof(info));
+       rr = readl(master->regs + DEV_ID_RR0(slot));
+       info->dyn_addr = DEV_ID_RR0_GET_DEV_ADDR(rr);
+       rr = readl(master->regs + DEV_ID_RR2(slot));
+       info->dcr = rr;
+       info->bcr = rr >> 8;
+       info->pid = rr >> 16;
+       info->pid |= (u64)readl(master->regs + DEV_ID_RR1(slot)) << 16;
+}
+
+static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
+{
+       unsigned long pres_step, sysclk_rate, max_i2cfreq, i3c_scl_lim = 0;
+       struct cdns_i3c_master *master = to_cdns_i3c_master(m);
+       u32 ctrl, prescl0, prescl1, pres, low;
+       struct i3c_device_info info = { };
+       struct i3c_ccc_events events;
+       struct i2c_device *i2cdev;
+       struct i3c_device *i3cdev;
+       int ret, slot, ncycles;
+       u8 last_addr = 0;
+       u32 status, devs;
+
+       switch (m->bus->mode) {
+       case I3C_BUS_MODE_PURE:
+               ctrl = CTRL_PURE_BUS_MODE;
+               break;
+
+       case I3C_BUS_MODE_MIXED_FAST:
+               ctrl = CTRL_MIXED_FAST_BUS_MODE;
+               break;
+
+       case I3C_BUS_MODE_MIXED_SLOW:
+               ctrl = CTRL_MIXED_SLOW_BUS_MODE;
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       sysclk_rate = clk_get_rate(master->sysclk);
+       if (!sysclk_rate)
+               return -EINVAL;
+
+       pres = DIV_ROUND_UP(sysclk_rate, (m->bus->scl_rate.i3c * 4)) - 1;
+       if (pres > PRESCL_CTRL0_MAX)
+               return -ERANGE;
+
+       m->bus->scl_rate.i3c = sysclk_rate / ((pres + 1) * 4);
+
+       prescl0 = PRESCL_CTRL0_I3C(pres);
+
+       low = ((I3C_BUS_TLOW_OD_MIN_NS * sysclk_rate) / (pres + 1)) - 2;
+       prescl1 = PRESCL_CTRL1_OD_LOW(low);
+
+       max_i2cfreq = m->bus->scl_rate.i2c;
+
+       pres = (sysclk_rate / (max_i2cfreq * 5)) - 1;
+       if (pres > PRESCL_CTRL0_MAX)
+               return -ERANGE;
+
+       m->bus->scl_rate.i2c = sysclk_rate / ((pres + 1) * 5);
+
+       prescl0 |= PRESCL_CTRL0_I2C(pres);
+
+       writel(DEVS_CTRL_DEV_CLR_ALL, master->regs + DEVS_CTRL);
+
+       i3c_bus_for_each_i2cdev(m->bus, i2cdev) {
+               ret = cdns_i3c_master_attach_i2c_dev(master, i2cdev);
+               if (ret)
+                       goto err_detach_devs;
+       }
+
+       writel(prescl0, master->regs + PRESCL_CTRL0);
+
+       /* Calculate OD and PP low. */
+       pres_step = 1000000000 / (m->bus->scl_rate.i3c * 4);
+       ncycles = DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, pres_step) - 2;
+       if (ncycles < 0)
+               ncycles = 0;
+       prescl1 = PRESCL_CTRL1_OD_LOW(ncycles);
+       writel(prescl1, master->regs + PRESCL_CTRL1);
+
+       i3c_bus_for_each_i3cdev(m->bus, i3cdev) {
+               ret = cdns_i3c_master_attach_i3c_dev(master, i3cdev);
+               if (ret)
+                       goto err_detach_devs;
+       }
+
+       /* Get an address for the master. */
+       ret = i3c_master_get_free_addr(m, 0);
+       if (ret < 0)
+               goto err_detach_devs;
+
+       writel(prepare_rr0_dev_address(ret) | DEV_ID_RR0_IS_I3C,
+              master->regs + DEV_ID_RR0(0));
+
+       cdns_i3c_master_dev_rr_to_info(master, 0, &info);
+       if (info.bcr & I3C_BCR_HDR_CAP)
+               info.hdr_cap = I3C_CCC_HDR_MODE(I3C_HDR_DDR);
+
+       ret = i3c_master_set_info(&master->base, &info);
+       if (ret)
+               goto err_detach_devs;
+
+       /* Prepare RR slots before lauching DAA. */
+       for (slot = find_next_bit(&master->free_dev_slots, BITS_PER_LONG, 1);
+            slot < BITS_PER_LONG;
+            slot = find_next_bit(&master->free_dev_slots,
+                                 BITS_PER_LONG, slot + 1)) {
+               ret = i3c_master_get_free_addr(m, last_addr + 1);
+               if (ret < 0)
+                       goto err_disable_master;
+
+               last_addr = ret;
+               writel(prepare_rr0_dev_address(last_addr) | DEV_ID_RR0_IS_I3C,
+                      master->regs + DEV_ID_RR0(slot));
+               writel(0, master->regs + DEV_ID_RR1(slot));
+               writel(0, master->regs + DEV_ID_RR2(slot));
+       }
+
+       writel(ctrl | CTRL_DEV_EN, master->regs + CTRL);
+
+       /*
+        * Reset all dynamic addresses on the bus, because we don't know what
+        * happened before this point (the bootloader may have assigned dynamic
+        * addresses that we're not aware of).
+        */
+       ret = i3c_master_rstdaa_locked(m, I3C_BROADCAST_ADDR);
+       if (ret)
+               goto err_disable_master;
+
+       /* Disable all slave events (interrupts) before starting DAA. */
+       events.events = I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR |
+                       I3C_CCC_EVENT_HJ;
+       ret = i3c_master_disec_locked(m, I3C_BROADCAST_ADDR, &events);
+       if (ret)
+               goto err_disable_master;
+
+       ret = i3c_master_entdaa_locked(m);
+       if (ret)
+               goto err_disable_master;
+
+       status = readl(master->regs + MST_STATUS0);
+
+       /* No devices discovered, bail out. */
+       if (!(status & MST_STATUS0_DAA_COMP))
+               return 0;
+
+       /* Now add discovered devices to the bus. */
+       devs = readl(master->regs + DEVS_CTRL);
+       for (slot = find_next_bit(&master->free_dev_slots, BITS_PER_LONG, 1);
+            slot < BITS_PER_LONG;
+            slot = find_next_bit(&master->free_dev_slots,
+                                 BITS_PER_LONG, slot + 1)) {
+               struct cdns_i3c_i2c_dev_data *data;
+               u32 sircfg, rr, max_fscl = 0;
+               u8 addr;
+
+               if (!(devs & DEVS_CTRL_DEV_ACTIVE(slot)))
+                       continue;
+
+               data = kzalloc(sizeof(*data), GFP_KERNEL);
+               if (!data)
+                       goto err_disable_master;
+
+               data->id = slot;
+               rr = readl(master->regs + DEV_ID_RR0(slot));
+               addr = DEV_ID_RR0_GET_DEV_ADDR(rr);
+               i3cdev = i3c_master_add_i3c_dev_locked(m, addr);
+               if (IS_ERR(i3cdev)) {
+                       ret = PTR_ERR(i3cdev);
+                       goto err_disable_master;
+               }
+
+               i3c_device_get_info(i3cdev, &info);
+               clear_bit(data->id, &master->free_dev_slots);
+               i3c_device_set_master_data(i3cdev, data);
+
+               max_fscl = max(I3C_CCC_MAX_SDR_FSCL(info.max_read_ds),
+                              I3C_CCC_MAX_SDR_FSCL(info.max_write_ds));
+               switch (max_fscl) {
+               case I3C_SDR_DR_FSCL_8MHZ:
+                       max_fscl = 8000000;
+                       break;
+               case I3C_SDR_DR_FSCL_6MHZ:
+                       max_fscl = 6000000;
+                       break;
+               case I3C_SDR_DR_FSCL_4MHZ:
+                       max_fscl = 4000000;
+                       break;
+               case I3C_SDR_DR_FSCL_2MHZ:
+                       max_fscl = 2000000;
+                       break;
+               case I3C_SDR_DR_FSCL_MAX:
+               default:
+                       max_fscl = 0;
+                       break;
+               }
+
+               if (max_fscl && (max_fscl < i3c_scl_lim || !i3c_scl_lim))
+                       i3c_scl_lim = max_fscl;
+
+               if (!(info.bcr & I3C_BCR_IBI_REQ_CAP))
+                       continue;
+
+               if ((info.bcr & I3C_BCR_IBI_PAYLOAD) &&
+                   (!info.max_ibi_len ||
+                    info.max_ibi_len > SIR_MAP_PL_MAX)) {
+                       ret = -ENOTSUPP;
+                       goto err_disable_master;
+               }
+
+               sircfg = readl(master->regs + SIR_MAP_DEV_REG(slot));
+               sircfg &= ~SIR_MAP_DEV_MASK(slot);
+               sircfg |= SIR_MAP_DEV_ROLE(slot, info.bcr >> 6) |
+                         SIR_MAP_DEV_DA(slot, info.dyn_addr) |
+                         SIR_MAP_DEV_PL(slot, info.max_ibi_len);
+
+               if (info.bcr & I3C_BCR_MAX_DATA_SPEED_LIM)
+                       sircfg |= SIR_MAP_DEV_SLOW(slot);
+
+               /* Do not ack IBI requests until explicitly requested. */
+               writel(sircfg, master->regs + SIR_MAP_DEV_REG(slot));
+       }
+
+       ret = i3c_master_defslvs_locked(m);
+       if (ret)
+               goto err_disable_master;
+
+       /* Configure PP_LOW to meet I3C slave limitations. */
+       if (i3c_scl_lim && i3c_scl_lim < m->bus->scl_rate.i3c) {
+               unsigned long i3c_lim_period;
+
+               i3c_lim_period = DIV_ROUND_UP(1000000000, i3c_scl_lim);
+               ncycles = DIV_ROUND_UP(i3c_lim_period, pres_step) - 4;
+               if (ncycles < 0)
+                       ncycles = 0;
+               prescl1 |= PRESCL_CTRL1_PP_LOW(ncycles);
+
+               /* Disable I3C master before updating PRESCL_CTRL1. */
+               writel(ctrl, master->regs + CTRL);
+               ret = readl_poll_timeout(master->regs + MST_STATUS0, status,
+                                        status & MST_STATUS0_IDLE, 1,
+                                        1000000);
+               if (ret)
+                       goto err_disable_master;
+
+               writel(prescl1, master->regs + PRESCL_CTRL1);
+               writel(ctrl | CTRL_DEV_EN, master->regs + CTRL);
+       }
+
+       return 0;
+
+err_disable_master:
+       cdns_i3c_master_disable(master);
+
+err_detach_devs:
+       cdns_i3c_master_bus_cleanup(m);
+
+       return ret;
+}
+
+static const struct i3c_master_controller_ops cdns_i3c_master_ops = {
+       .bus_init = cdns_i3c_master_bus_init,
+       .bus_cleanup = cdns_i3c_master_bus_cleanup,
+       .supports_ccc_cmd = cdns_i3c_master_supports_ccc_cmd,
+       .send_ccc_cmd = cdns_i3c_master_send_ccc_cmd,
+       .send_hdr_cmds = cdns_i3c_master_send_hdr_cmd,
+       .priv_xfers = cdns_i3c_master_priv_xfers,
+       .i2c_xfers = cdns_i3c_master_i2c_xfers,
+};
+
+static irqreturn_t cdns_i3c_master_interrupt(int irq, void *data)
+{
+       struct cdns_i3c_master *master = data;
+       u32 status;
+
+       status = readl(master->regs + MST_ISR) & readl(master->regs + MST_IMR);
+       if (!status)
+               return IRQ_NONE;
+
+       writel(status, master->regs + MST_IDR);
+       complete(&master->comp);
+
+       return IRQ_HANDLED;
+}
+
+static int cdns_i3c_master_probe(struct platform_device *pdev)
+{
+       struct cdns_i3c_master *master;
+       struct resource *res;
+       int ret, irq;
+       u32 val;
+
+       master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL);
+       if (!master)
+               return -ENOMEM;
+
+       master->caps.cmdfifodepth = 8;
+       master->caps.rxfifodepth = 16;
+       master->caps.txfifodepth = 16;
+
+       init_completion(&master->comp);
+       mutex_init(&master->lock);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       master->regs = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(master->regs))
+               return PTR_ERR(master->regs);
+
+       master->pclk = devm_clk_get(&pdev->dev, "pclk");
+       if (IS_ERR(master->pclk))
+               return PTR_ERR(master->pclk);
+
+       master->sysclk = devm_clk_get(&pdev->dev, "sysclk");
+       if (IS_ERR(master->pclk))
+               return PTR_ERR(master->pclk);
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0)
+               return irq;
+
+       ret = clk_prepare_enable(master->pclk);
+       if (ret)
+               return ret;
+
+       ret = clk_prepare_enable(master->sysclk);
+       if (ret)
+               goto err_disable_pclk;
+
+       writel(0xffffffff, master->regs + MST_IDR);
+       writel(0xffffffff, master->regs + SLV_IDR);
+       ret = devm_request_irq(&pdev->dev, irq, cdns_i3c_master_interrupt, 0,
+                              dev_name(&pdev->dev), master);
+       if (ret)
+               goto err_disable_sysclk;
+
+       platform_set_drvdata(pdev, master);
+
+       val = readl(master->regs + CONF_STATUS);
+
+       /* Device ID0 is reserved to describe this master. */
+       master->free_dev_slots = GENMASK(CONF_STATUS_DEVS_NUM(val), 1);
+
+       ret = i3c_master_register(&master->base, &pdev->dev,
+                                 &cdns_i3c_master_ops, false);
+       if (ret)
+               goto err_disable_sysclk;
+
+err_disable_sysclk:
+       clk_disable_unprepare(master->sysclk);
+
+err_disable_pclk:
+       clk_disable_unprepare(master->pclk);
+
+       return ret;
+}
+
+static int cdns_i3c_master_remove(struct platform_device *pdev)
+{
+       struct cdns_i3c_master *master = platform_get_drvdata(pdev);
+       int ret;
+
+       ret = i3c_master_unregister(&master->base);
+       if (ret)
+               return ret;
+
+       clk_disable_unprepare(master->sysclk);
+       clk_disable_unprepare(master->pclk);
+
+       return 0;
+}
+
+static const struct of_device_id cdns_i3c_master_of_ids[] = {
+       { .compatible = "cdns,i3c-master" },
+};
+
+static struct platform_driver cdns_i3c_master = {
+       .probe = cdns_i3c_master_probe,
+       .remove = cdns_i3c_master_remove,
+       .driver = {
+               .name = "cdns-i3c-master",
+               .of_match_table = cdns_i3c_master_of_ids,
+       },
+};
+module_platform_driver(cdns_i3c_master);
-- 
2.7.4

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