This driver add support to the new Atmel QSPI controller embedded into
sama5d2x SoCs. It expects a NOR memory to be connected to the QSPI
controller.

Signed-off-by: Cyrille Pitchen <cyrille.pitc...@atmel.com>
---
 drivers/mtd/spi-nor/Kconfig         |   7 +
 drivers/mtd/spi-nor/Makefile        |   1 +
 drivers/mtd/spi-nor/atmel-quadspi.c | 901 ++++++++++++++++++++++++++++++++++++
 3 files changed, 909 insertions(+)
 create mode 100644 drivers/mtd/spi-nor/atmel-quadspi.c

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 64a4f0edabc7..bcdda302f5ab 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -28,4 +28,11 @@ config SPI_FSL_QUADSPI
          This enables support for the Quad SPI controller in master mode.
          We only connect the NOR to this controller now.
 
+config SPI_ATMEL_QUADSPI
+       tristate "Atmel Quad SPI Controller"
+       depends on (ARCH_AT91 || COMPILE_TEST)
+       help
+         This enables support for the Quad SPI controller in master mode.
+         We only connect the NOR to this controller now.
+
 endif # MTD_SPI_NOR
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index 6a7ce1462247..243ea8a479ef 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_MTD_SPI_NOR)      += spi-nor.o
 obj-$(CONFIG_SPI_FSL_QUADSPI)  += fsl-quadspi.o
+obj-$(CONFIG_SPI_ATMEL_QUADSPI)        += atmel-quadspi.o
diff --git a/drivers/mtd/spi-nor/atmel-quadspi.c 
b/drivers/mtd/spi-nor/atmel-quadspi.c
new file mode 100644
index 000000000000..b39d799f8fe4
--- /dev/null
+++ b/drivers/mtd/spi-nor/atmel-quadspi.c
@@ -0,0 +1,901 @@
+/*
+ * Driver for Atmel QSPI Controller
+ *
+ * Copyright (C) 2015 Atmel Corporation
+ *
+ * Author: Cyrille Pitchen <cyrille.pitc...@atmel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * This driver is based on drivers/mtd/spi-nor/fsl-quadspi.c from Freescale.
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/platform_data/atmel.h>
+#include <linux/platform_data/dma-atmel.h>
+#include <linux/of.h>
+
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/pinctrl/consumer.h>
+
+/* QSPI register offsets */
+#define QSPI_CR                0x0000  /* Control Register */
+#define QSPI_MR                0x0004  /* Mode Register */
+#define QSPI_RD                0x0008  /* Receive Data Register */
+#define QSPI_TD                0x000c  /* Transmit Data Register */
+#define QSPI_SR                0x0010  /* Status Register */
+#define QSPI_IER       0x0014  /* Interrupt Enable Register */
+#define QSPI_IDR       0x0018  /* Interrupt Disable Register */
+#define QSPI_IMR       0x001c  /* Interrupt Mask Register */
+#define QSPI_SCR       0x0020  /* Serial Clock Register */
+
+#define QSPI_IAR       0x0030  /* Instruction Address Register */
+#define QSPI_ICR       0x0034  /* Instruction Code Register */
+#define QSPI_IFR       0x0038  /* Instruction Frame Register */
+
+#define QSPI_SMR       0x0040  /* Scrambling Mode Register */
+#define QSPI_SKR       0x0044  /* Scrambling Key Register */
+
+#define QSPI_WPMR      0x00E4  /* Write Protection Mode Register */
+#define QSPI_WPSR      0x00E8  /* Write Protection Status Register */
+
+#define QSPI_VERSION   0x00FC  /* Version Register */
+
+/* Bitfields in QSPI_CR (Control Register) */
+#define QSPI_CR_QSPIEN_OFFSET          0
+#define QSPI_CR_QSPIEN_SIZE            1
+#define QSPI_CR_QSPIDIS_OFFSET         1
+#define QSPI_CR_QSPIDIS_SIZE           1
+#define QSPI_CR_SWRST_OFFSET           7
+#define QSPI_CR_SWRST_SIZE             1
+#define QSPI_CR_LASTXFER_OFFSET                24
+#define QSPI_CR_LASTXFER_SIZE          1
+
+/* Bitfields in QSPI_MR (Mode Register) */
+#define QSPI_MR_SSM_OFFSET             0
+#define QSPI_MR_SSM_SIZE               1
+#define QSPI_MR_LLB_OFFSET             1
+#define QSPI_MR_LLB_SIZE               1
+#define QSPI_MR_WDRBT_OFFSET           2
+#define QSPI_MR_WDRBT_SIZE             1
+#define QPSI_MR_SMRM_OFFSET            3
+#define QSPI_MR_SMRM_SIZE              1
+#define QSPI_MR_CSMODE_OFFSET          4
+#define QSPI_MR_CSMODE_SIZE            2
+#define QSPI_MR_NBBITS_OFFSET          8
+#define QSPI_MR_NBBITS_SIZE            4
+#define                QSPI_MR_NBBITS_8_BIT            0
+#define                QSPI_MR_NBBITS_9_BIT            1
+#define                QSPI_MR_NBBITS_10_BIT           2
+#define                QSPI_MR_NBBITS_11_BIT           3
+#define                QSPI_MR_NBBITS_12_BIT           4
+#define                QSPI_MR_NBBITS_13_BIT           5
+#define                QSPI_MR_NBBITS_14_BIT           6
+#define                QSPI_MR_NBBITS_15_BIT           7
+#define                QSPI_MR_NBBITS_16_BIT           8
+#define QSPI_MR_DLYBCT_OFFSET          16
+#define QSPI_MR_DLYBCT_SIZE            8
+#define QSPI_MR_DLYCS_OFFSET           24
+#define QSPI_MR_DLYCS_SIZE             8
+
+/* Bitfields in QSPI_SR/QSPI_IER/QSPI_IDR/QSPI_IMR  */
+#define QSPI_SR_RDRF_OFFSET            0
+#define QSPI_SR_RDRF_SIZE              1
+#define QSPI_SR_TDRE_OFFSET            1
+#define QSPI_SR_TDRE_SIZE              1
+#define QSPI_SR_TXEMPTY_OFFSET         2
+#define QSPI_SR_TXEMPTY_SIZE           1
+#define QSPI_SR_OVRES_OFFSET           3
+#define QSPI_SR_OVRES_SIZE             1
+#define QSPI_SR_CSR_OFFSET             8
+#define QSPI_SR_CSR_SIZE               1
+#define QPSI_SR_CSS_OFFSET             9
+#define QPSI_SR_CSS_SIZE               1
+#define QSPI_SR_INSTRE_OFFSET          10
+#define QSPI_SR_INSTRE_SIZE            1
+#define QSPI_SR_QSPIENS_OFFSET         24
+#define QSPI_SR_QSPIENS_SIZE           1
+
+/* Bitfields in QSPI_SCR (Serial Clock Register) */
+#define QSPI_SCR_CPOL_OFFSET           0
+#define QSPI_SCR_CPOL_SIZE             1
+#define QSPI_SCR_CPHA_OFFSET           1
+#define QSPI_SCR_CPHA_SIZE             1
+#define QSPI_SCR_SCBR_OFFSET           8
+#define QSPI_SCR_SCBR_SIZE             8
+#define QSPI_SCR_DLYBS_OFFSET          16
+#define QSPI_SCR_DLYBS_SIZE            8
+
+/* Bitfields in QSPI_ICR (Instruction Code Register) */
+#define QSPI_ICR_INST_OFFSET           0
+#define QSPI_ICR_INST_SIZE             8
+#define QSPI_ICR_OPT_OFFSET            16
+#define QSPI_ICR_OPT_SIZE              8
+
+/* Bitfields in QSPI_IFR (Instruction Frame Register) */
+#define QSPI_IFR_WIDTH_OFFSET          0
+#define QSPI_IFR_WIDTH_SIZE            3
+#define                QSPI_IFR_WIDTH_SINGLE_BIT_SPI           0
+#define                QSPI_IFR_WIDTH_DUAL_OUTPUT              1
+#define                QSPI_IFR_WIDTH_QUAD_OUTPUT              2
+#define                QSPI_IFR_WIDTH_DUAL_IO                  3
+#define                QSPI_IFR_WIDTH_QUAD_IO                  4
+#define                QSPI_IFR_WIDTH_DUAL_CMD                 5
+#define                QSPI_IFR_WIDTH_QUAD_CMD                 6
+#define QSPI_IFR_INSTEN_OFFSET         4
+#define QSPI_IFR_INSTEN_SIZE           1
+#define QSPI_IFR_ADDREN_OFFSET         5
+#define QSPI_IFR_ADDREN_SIZE           1
+#define QSPI_IFR_OPTEN_OFFSET          6
+#define QSPI_IFR_OPTEN_SIZE            1
+#define QSPI_IFR_DATAEN_OFFSET         7
+#define QSPI_IFR_DATAEN_SIZE           1
+#define QSPI_IFR_OPTL_OFFSET           8
+#define QSPI_IFR_OPTL_SIZE             2
+#define                QSPI_IFR_OPTL_OPTION_1BIT               0
+#define                QSPI_IFR_OPTL_OPTION_2BIT               1
+#define                QSPI_IFR_OPTL_OPTION_4BIT               2
+#define                QSPI_IFR_OPTL_OPTION_8BIT               3
+#define QSPI_IFR_ADDRL_OFFSET          10
+#define QSPI_IFR_ADDRL_SIZE            1
+#define QSPI_IFR_TFRTYP_OFFSET         12
+#define QSPI_IFR_TFRTYP_SIZE           2
+#define                QSPI_IFR_TFRTYP_TRSFR_READ              0
+#define                QSPI_IFR_TFRTYP_TRSFR_READ_MEMORY       1
+#define                QSPI_IFR_TFRTYP_TRSFR_WRITE             2
+#define                QSPI_IFR_TFRTYP_TRSFR_WRITE_MEMORY      3
+#define QSPI_IFR_CRM_OFFSET            14
+#define QSPI_IFR_CRM_SIZE              1
+#define QSPI_IFR_NBDUM_OFFSET          16
+#define QSPI_IFR_NBDUM_SIZE            5
+
+/* Bitfields in QSPI_SMR (Scrambling Mode Register) */
+#define QSPI_SMR_SCREN_OFFSET          0
+#define QSPI_SMR_SCREN_SIZE            1
+#define QSPI_SMR_RVDIS_OFFSET          1
+#define QSPI_SMR_RVDIS_SIZE            1
+
+/* Bitfields in QSPI_WPMR (Write Protection Mode Register) */
+#define QSPI_WPMR_WPEN_OFFSET          0
+#define QSPI_WPMR_WPEN_SIZE            1
+#define QSPI_WPMR_WPKEY_OFFSET         8
+#define QSPI_WPMR_WPKEY_SIZE           24
+
+/* Bitfields in QSPI_WPSR (Write Protection Status Register) */
+#define QSPI_WPSR_WPVS_OFFSET          0
+#define QSPI_WPSR_WPVS_SIZE            1
+#define QSPI_WPSR_WPVSRC_OFFSET                8
+#define QSPI_WPSR_WPVSRC_SIZE          8
+
+/* Bit manipulation macros */
+#define QSPI_BIT(name) \
+       (1 << QSPI_##name##_OFFSET)
+#define QSPI_BF(name, value) \
+       (((value) & ((1 << QSPI_##name##_SIZE) - 1)) << QSPI_##name##_OFFSET)
+#define QSPI_BFEXT(name, value) \
+       (((value) >> QSPI_##name##_OFFSET) & ((1 << QSPI_##name##_SIZE) - 1))
+#define QSPI_BFINS(name, value, old) \
+       (((old) & ~(((1 << QSPI_##name##_SIZE) - 1) << QSPI_##name##_OFFSET)) \
+        | QSPI_BF(name, value))
+
+/* Register access macros */
+#define qspi_readl(port, reg) \
+       readl_relaxed((port)->regs + QSPI_##reg)
+#define qspi_writel(port, reg, value) \
+       writel_relaxed((value), (port)->regs + QSPI_##reg)
+
+#define qspi_readw(port, reg) \
+       readw_relaxed((port)->regs + QSPI_##reg)
+#define qspi_writew(port, reg, value) \
+       writew_relaxed((value), (port)->regs + QSPI_##reg)
+
+#define qspi_readb(port, reg) \
+       readb_relaxed((port)->regs + QSPI_##reg)
+#define qspi_writeb(port, reg, value) \
+       writeb_relaxed((value), (port)->regs + QSPI_##reg)
+
+
+struct atmel_qspi {
+       void __iomem            *regs;
+       void __iomem            *mem;
+       dma_addr_t              phys_addr;
+       struct dma_chan         *chan;
+       struct clk              *clk;
+       struct platform_device  *pdev;
+       u32                     ifr_width;
+       u32                     pending;
+
+       struct mtd_info         mtd;
+       struct spi_nor          nor;
+       u32                     clk_rate;
+       struct completion       completion;
+
+#ifdef DEBUG
+       u8                      last_instruction;
+#endif
+};
+
+struct atmel_qspi_command {
+       u32     ifr_tfrtyp;
+       union {
+               struct {
+                       u32     instruction:1;
+                       u32     address:3;
+                       u32     mode:1;
+                       u32     dummy:1;
+                       u32     data:1;
+                       u32     dma:1;
+                       u32     reserved:24;
+               }               bits;
+               u32     word;
+       }       enable;
+       u8      instruction;
+       u8      mode;
+       u8      num_mode_cycles;
+       u8      num_dummy_cycles;
+       u32     address;
+
+       size_t          buf_len;
+       const void      *tx_buf;
+       void            *rx_buf;
+};
+
+#define QSPI_DMA_THRESHOLD     32
+
+static void atmel_qspi_dma_callback(void *arg)
+{
+       struct completion *c = arg;
+
+       complete(c);
+}
+
+static int atmel_qspi_run_dma_transfer(struct atmel_qspi *aq,
+                                      const struct atmel_qspi_command *cmd)
+{
+       u32 offset = (cmd->enable.bits.address) ? cmd->address : 0;
+       struct dma_chan *chan = aq->chan;
+       struct device *dev = &aq->pdev->dev;
+       enum dma_data_direction direction;
+       dma_addr_t phys_addr, dst, src;
+       struct dma_async_tx_descriptor *desc;
+       struct completion completion;
+       dma_cookie_t cookie;
+       int err = 0;
+
+       if (cmd->tx_buf) {
+               direction = DMA_TO_DEVICE;
+               phys_addr = dma_map_single(dev, (void *)cmd->tx_buf,
+                                          cmd->buf_len, direction);
+               src = phys_addr;
+               dst = aq->phys_addr + offset;
+       } else {
+               direction = DMA_FROM_DEVICE;
+               phys_addr = dma_map_single(dev, (void *)cmd->rx_buf,
+                                          cmd->buf_len, direction);
+               src = aq->phys_addr + offset;
+               dst = phys_addr;
+       }
+       err = dma_mapping_error(dev, phys_addr);
+       if (err)
+               goto exit;
+
+       desc = chan->device->device_prep_dma_memcpy(chan, dst, src,
+                                                   cmd->buf_len,
+                                                   DMA_PREP_INTERRUPT);
+       if (!desc) {
+               err = -ENOMEM;
+               goto unmap_single;
+       }
+
+       init_completion(&completion);
+       desc->callback = atmel_qspi_dma_callback;
+       desc->callback_param = &completion;
+       cookie = dmaengine_submit(desc);
+       err = dma_submit_error(cookie);
+       if (err)
+               goto unmap_single;
+       dma_async_issue_pending(chan);
+
+       if (!wait_for_completion_timeout(&completion, msecs_to_jiffies(1000)))
+               err = -ETIMEDOUT;
+
+       if (dma_async_is_tx_complete(chan, cookie, NULL, NULL) != DMA_COMPLETE)
+               err = -ETIMEDOUT;
+
+       if (err)
+               dmaengine_terminate_all(chan);
+unmap_single:
+       dma_unmap_single(dev, phys_addr, cmd->buf_len, direction);
+exit:
+       return err;
+}
+
+static int atmel_qspi_run_transfer(struct atmel_qspi *aq,
+                                  const struct atmel_qspi_command *cmd)
+{
+       void __iomem *ahb_mem;
+
+       /* First try a DMA transfer */
+       if (aq->chan && cmd->enable.bits.dma &&
+           cmd->buf_len >= QSPI_DMA_THRESHOLD)
+               return atmel_qspi_run_dma_transfer(aq, cmd);
+
+       /* Then fallback to a PIO transfer */
+       ahb_mem = aq->mem;
+       if (cmd->enable.bits.address)
+               ahb_mem += cmd->address;
+       if (cmd->tx_buf)
+               memcpy_toio(ahb_mem, cmd->tx_buf, cmd->buf_len);
+       else
+               memcpy_fromio(cmd->rx_buf, ahb_mem, cmd->buf_len);
+
+       return 0;
+}
+
+#ifdef DEBUG
+static void atmel_qspi_debug_command(struct atmel_qspi *aq,
+                                    const struct atmel_qspi_command *cmd)
+{
+       u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];
+       size_t len = 0;
+       int i;
+
+       if (cmd->enable.bits.instruction) {
+               if (aq->last_instruction == cmd->instruction)
+                       return;
+               aq->last_instruction = cmd->instruction;
+       }
+
+       if (cmd->enable.bits.instruction)
+               cmd_buf[len++] = cmd->instruction;
+
+       for (i = cmd->enable.bits.address-1; i >= 0; --i)
+               cmd_buf[len++] = (cmd->address >> (i << 3)) & 0xff;
+
+       if (cmd->enable.bits.mode)
+               cmd_buf[len++] = cmd->mode;
+
+       if (cmd->enable.bits.dummy) {
+               int num = cmd->num_dummy_cycles;
+
+               switch (aq->ifr_width) {
+               case QSPI_IFR_WIDTH_SINGLE_BIT_SPI:
+               case QSPI_IFR_WIDTH_DUAL_OUTPUT:
+               case QSPI_IFR_WIDTH_QUAD_OUTPUT:
+                       num >>= 3;
+                       break;
+               case QSPI_IFR_WIDTH_DUAL_IO:
+               case QSPI_IFR_WIDTH_DUAL_CMD:
+                       num >>= 2;
+                       break;
+               case QSPI_IFR_WIDTH_QUAD_IO:
+               case QSPI_IFR_WIDTH_QUAD_CMD:
+                       num >>= 1;
+                       break;
+               default:
+                       return;
+               }
+
+               for (i = 0; i < num; ++i)
+                       cmd_buf[len++] = 0;
+       }
+
+       print_hex_dump(KERN_DEBUG, "qspi cmd: ", DUMP_PREFIX_NONE,
+                      32, 1, cmd_buf, len, false);
+
+#ifdef VERBOSE_DEBUG
+       if (cmd->enable.bits.data && cmd->tx_buf)
+               print_hex_dump(KERN_DEBUG, "qspi tx : ", DUMP_PREFIX_NONE,
+                              32, 1, cmd->tx_buf, cmd->buf_len, false);
+#endif
+}
+#else
+#define atmel_qspi_debug_command(aq, cmd)
+#endif
+
+static int atmel_qspi_run_command(struct atmel_qspi *aq,
+                                 const struct atmel_qspi_command *cmd)
+{
+       u32 iar, icr, ifr, sr;
+       int err = 0;
+
+       iar = 0;
+       icr = 0;
+       ifr = (QSPI_BF(IFR_WIDTH, aq->ifr_width) |
+              QSPI_BF(IFR_TFRTYP, cmd->ifr_tfrtyp));
+
+
+       /* Compute instruction parameters */
+       if (cmd->enable.bits.instruction) {
+               icr |= QSPI_BF(ICR_INST, cmd->instruction);
+               ifr |= QSPI_BIT(IFR_INSTEN);
+       }
+
+       /* Compute address parameters */
+       switch (cmd->enable.bits.address) {
+       case 4:
+               ifr |= QSPI_BIT(IFR_ADDRL);
+               /*break;*/ /* fallback to the 24bit address case */
+       case 3:
+               iar = (cmd->enable.bits.data) ? 0 : cmd->address;
+               ifr |= QSPI_BIT(IFR_ADDREN);
+               break;
+       case 0:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       /* Compute option parameters */
+       if (cmd->enable.bits.mode && cmd->num_mode_cycles) {
+               u32 mode_cycle_bits, mode_bits;
+
+               icr |= QSPI_BF(ICR_OPT, cmd->mode);
+               ifr |= QSPI_BIT(IFR_OPTEN);
+
+               switch (QSPI_BFEXT(IFR_WIDTH, ifr)) {
+               case QSPI_IFR_WIDTH_SINGLE_BIT_SPI:
+               case QSPI_IFR_WIDTH_DUAL_OUTPUT:
+               case QSPI_IFR_WIDTH_QUAD_OUTPUT:
+                       mode_cycle_bits = 1;
+                       break;
+               case QSPI_IFR_WIDTH_DUAL_IO:
+               case QSPI_IFR_WIDTH_DUAL_CMD:
+                       mode_cycle_bits = 2;
+                       break;
+               case QSPI_IFR_WIDTH_QUAD_IO:
+               case QSPI_IFR_WIDTH_QUAD_CMD:
+                       mode_cycle_bits = 4;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+
+               mode_bits = cmd->num_mode_cycles * mode_cycle_bits;
+               switch (mode_bits) {
+               case 1:
+                       ifr |= QSPI_BF(IFR_OPTL, QSPI_IFR_OPTL_OPTION_1BIT);
+                       break;
+
+               case 2:
+                       ifr |= QSPI_BF(IFR_OPTL, QSPI_IFR_OPTL_OPTION_2BIT);
+                       break;
+
+               case 4:
+                       ifr |= QSPI_BF(IFR_OPTL, QSPI_IFR_OPTL_OPTION_4BIT);
+                       break;
+
+               case 8:
+                       ifr |= QSPI_BF(IFR_OPTL, QSPI_IFR_OPTL_OPTION_8BIT);
+                       break;
+
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       /* Set number of dummy cycles */
+       if (cmd->enable.bits.dummy)
+               ifr |= QSPI_BF(IFR_NBDUM, cmd->num_dummy_cycles);
+       else
+               ifr |= QSPI_BF(IFR_NBDUM, 0);
+
+       /* Set data enable */
+       if (cmd->enable.bits.data) {
+               ifr |= QSPI_BIT(IFR_DATAEN);
+
+               /* Special case for Continuous Read Mode */
+               if (!cmd->tx_buf && !cmd->rx_buf)
+                       ifr |= QSPI_BIT(IFR_CRM);
+       }
+
+       /* Set QSPI Instruction Frame registers */
+       atmel_qspi_debug_command(aq, cmd);
+       qspi_writel(aq, IAR, iar);
+       qspi_writel(aq, ICR, icr);
+       qspi_writel(aq, IFR, ifr);
+
+       /* Skip to the final steps if there is no data */
+       if (!cmd->enable.bits.data)
+               goto no_data;
+
+       /* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
+       (void)qspi_readl(aq, IFR);
+
+       /* Stop here for continuous read */
+       if (!cmd->tx_buf && !cmd->rx_buf)
+               return 0;
+       /* Send/Receive data */
+       err = atmel_qspi_run_transfer(aq, cmd);
+
+       /* Release the chip-select */
+       qspi_writel(aq, CR, QSPI_BIT(CR_LASTXFER));
+
+       if (err)
+               return err;
+#ifdef VERBOSE_DEBUG
+       if (cmd->rx_buf)
+               print_hex_dump(KERN_DEBUG, "qspi rx : ", DUMP_PREFIX_NONE,
+                              32, 1, cmd->rx_buf, cmd->buf_len, false);
+#endif
+no_data:
+       /* Poll INSTRuction End status */
+       sr = qspi_readl(aq, SR);
+       if (sr & QSPI_BIT(SR_INSTRE))
+               return err;
+
+       /* Wait for INSTRuction End interrupt */
+       init_completion(&aq->completion);
+       aq->pending = 0;
+       qspi_writel(aq, IER, QSPI_BIT(SR_INSTRE));
+       if (!wait_for_completion_timeout(&aq->completion,
+                                        msecs_to_jiffies(1000)))
+               err = -ETIMEDOUT;
+       qspi_writel(aq, IDR, QSPI_BIT(SR_INSTRE));
+
+       return err;
+}
+
+static int atmel_qspi_read_reg(struct spi_nor *nor, u8 opcode,
+                              u8 *buf, int len)
+{
+       struct atmel_qspi *aq = nor->priv;
+       struct atmel_qspi_command cmd;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.ifr_tfrtyp = QSPI_IFR_TFRTYP_TRSFR_READ;
+       cmd.enable.bits.instruction = 1;
+       cmd.enable.bits.data = 1;
+       cmd.instruction = opcode;
+       cmd.rx_buf = buf;
+       cmd.buf_len = len;
+       return atmel_qspi_run_command(aq, &cmd);
+}
+
+static int atmel_qspi_write_reg(struct spi_nor *nor, u8 opcode,
+                               u8 *buf, int len,
+                               int write_enable)
+{
+       struct atmel_qspi *aq = nor->priv;
+       struct atmel_qspi_command cmd;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.ifr_tfrtyp = QSPI_IFR_TFRTYP_TRSFR_WRITE;
+       cmd.enable.bits.instruction = 1;
+       cmd.enable.bits.data = (buf != NULL && len > 0);
+       cmd.instruction = opcode;
+       cmd.tx_buf = buf;
+       cmd.buf_len = len;
+       return atmel_qspi_run_command(aq, &cmd);
+}
+
+static void atmel_qspi_write(struct spi_nor *nor, loff_t to, size_t len,
+                            size_t *retlen, const u_char *write_buf)
+{
+       struct atmel_qspi *aq = nor->priv;
+       struct atmel_qspi_command cmd;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.ifr_tfrtyp = QSPI_IFR_TFRTYP_TRSFR_WRITE_MEMORY;
+       cmd.enable.bits.instruction = 1;
+       cmd.enable.bits.address = nor->addr_width;
+       cmd.enable.bits.data = 1;
+       cmd.enable.bits.dma = 1;
+       cmd.instruction = nor->program_opcode;
+       cmd.address = (u32)to;
+       cmd.tx_buf = write_buf;
+       cmd.buf_len = len;
+       if (!atmel_qspi_run_command(aq, &cmd))
+               *retlen += len;
+}
+
+static int atmel_qspi_erase(struct spi_nor *nor, loff_t offs)
+{
+       struct atmel_qspi *aq = nor->priv;
+       struct atmel_qspi_command cmd;
+
+       dev_dbg(nor->dev, "%dKiB at 0x%08x\n",
+               aq->mtd.erasesize / 1024, (u32)offs);
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.ifr_tfrtyp = QSPI_IFR_TFRTYP_TRSFR_WRITE;
+       cmd.enable.bits.instruction = 1;
+       cmd.enable.bits.address = nor->addr_width;
+       cmd.instruction = nor->erase_opcode;
+       cmd.address = (u32)offs;
+       return atmel_qspi_run_command(aq, &cmd);
+}
+
+static int atmel_qspi_read(struct spi_nor *nor, loff_t from, size_t len,
+                          size_t *retlen, u_char *read_buf)
+{
+       struct atmel_qspi *aq = nor->priv;
+       struct atmel_qspi_command cmd;
+       int err;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.ifr_tfrtyp = QSPI_IFR_TFRTYP_TRSFR_READ_MEMORY;
+       cmd.enable.bits.instruction = 1;
+       cmd.enable.bits.address = nor->addr_width;
+       cmd.enable.bits.dummy = (nor->read_dummy > 0);
+       cmd.enable.bits.data = 1;
+       cmd.enable.bits.dma = 1;
+       cmd.instruction = nor->read_opcode;
+       cmd.address = (u32)from;
+       cmd.num_dummy_cycles = nor->read_dummy;
+       cmd.rx_buf = read_buf;
+       cmd.buf_len = len;
+       err = atmel_qspi_run_command(aq, &cmd);
+       if (err)
+               return err;
+
+       *retlen += len;
+       return 0;
+}
+
+static int atmel_qspi_set_protocol(struct spi_nor *nor, enum spi_protocol 
proto)
+{
+       struct atmel_qspi *aq = nor->priv;
+
+       switch (proto) {
+       case SPI_PROTO_1_1_1:
+               aq->ifr_width = QSPI_IFR_WIDTH_SINGLE_BIT_SPI;
+               break;
+       case SPI_PROTO_1_1_2:
+               aq->ifr_width = QSPI_IFR_WIDTH_DUAL_OUTPUT;
+               break;
+       case SPI_PROTO_1_1_4:
+               aq->ifr_width = QSPI_IFR_WIDTH_QUAD_OUTPUT;
+               break;
+       case SPI_PROTO_1_2_2:
+               aq->ifr_width = QSPI_IFR_WIDTH_DUAL_IO;
+               break;
+       case SPI_PROTO_1_4_4:
+               aq->ifr_width = QSPI_IFR_WIDTH_QUAD_IO;
+               break;
+       case SPI_PROTO_2_2_2:
+               aq->ifr_width = QSPI_IFR_WIDTH_DUAL_CMD;
+               break;
+       case SPI_PROTO_4_4_4:
+               aq->ifr_width = QSPI_IFR_WIDTH_QUAD_CMD;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int atmel_qspi_init(struct atmel_qspi *aq)
+{
+       unsigned long src_rate;
+       u32 mr, scr, scbr;
+
+       /* Reset the QSPI controller */
+       qspi_writel(aq, CR, QSPI_BIT(CR_SWRST));
+
+       /* Set the QSPI controller in Serial Memory Mode */
+       mr = (QSPI_BIT(MR_SSM) |
+             QSPI_BF(MR_NBBITS, QSPI_MR_NBBITS_8_BIT));
+       qspi_writel(aq, MR, mr);
+
+       src_rate = clk_get_rate(aq->clk);
+       if (!src_rate)
+               return -EINVAL;
+
+       /* Compute the QSPI baudrate */
+       scbr = DIV_ROUND_UP(src_rate, aq->clk_rate);
+       if (scbr > 0)
+               scbr--;
+       scr = QSPI_BF(SCR_SCBR, scbr);
+       qspi_writel(aq, SCR, scr);
+
+       /* Enable the QSPI controller */
+       qspi_writel(aq, CR, QSPI_BIT(CR_QSPIEN));
+
+       return 0;
+}
+
+static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
+{
+       struct atmel_qspi *aq = (struct atmel_qspi *)dev_id;
+       u32 status, mask, pending;
+
+       status = qspi_readl(aq, SR);
+       mask = qspi_readl(aq, IMR);
+       pending = status & mask;
+
+       if (!pending)
+               return IRQ_NONE;
+
+       aq->pending |= pending;
+       if (pending & QSPI_BIT(SR_INSTRE))
+               complete(&aq->completion);
+
+       return IRQ_HANDLED;
+}
+
+static int atmel_qspi_probe(struct platform_device *pdev)
+{
+       struct device_node *child, *np = pdev->dev.of_node;
+       struct mtd_part_parser_data ppdata;
+       struct atmel_qspi *aq;
+       struct resource *res;
+       dma_cap_mask_t mask;
+       struct spi_nor *nor;
+       struct mtd_info *mtd;
+       char modalias[40];
+       int irq, err = 0;
+
+       if (of_get_child_count(np) != 1)
+               return -ENODEV;
+       child = of_get_next_child(np, NULL);
+
+       aq = devm_kzalloc(&pdev->dev, sizeof(*aq), GFP_KERNEL);
+       if (!aq)
+               return -ENOMEM;
+       platform_set_drvdata(pdev, aq);
+       aq->pdev = pdev;
+       /* Start in Extended SPI (1-1-1) */
+       aq->ifr_width = QSPI_IFR_WIDTH_SINGLE_BIT_SPI;
+
+       /* Map the registers */
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       aq->regs = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(aq->regs)) {
+               dev_err(&pdev->dev, "missing registers\n");
+               err = PTR_ERR(aq->regs);
+               goto exit;
+       }
+
+       /* Map the AHB memory */
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       aq->mem = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(aq->mem)) {
+               dev_err(&pdev->dev, "missing AHB memory\n");
+               err = PTR_ERR(aq->regs);
+               goto exit;
+       }
+       aq->phys_addr = (dma_addr_t)res->start;
+
+       /* Get the peripheral clock */
+       aq->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(aq->clk)) {
+               dev_err(&pdev->dev, "missing peripheral clock\n");
+               err = PTR_ERR(aq->clk);
+               goto exit;
+       }
+
+       /* Enable the peripheral clock */
+       err = clk_prepare_enable(aq->clk);
+       if (err) {
+               dev_err(&pdev->dev, "failed to enable the peripheral clock\n");
+               goto exit;
+       }
+
+       /* Request the IRQ */
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "missing IRQ\n");
+               err = irq;
+               goto disable_clk;
+       }
+       err = devm_request_irq(&pdev->dev, irq, atmel_qspi_interrupt,
+                              0, dev_name(&pdev->dev), aq);
+       if (err)
+               goto disable_clk;
+
+       /* Try to get a DMA channel for memcpy() operation */
+       dma_cap_zero(mask);
+       dma_cap_set(DMA_MEMCPY, mask);
+       aq->chan = dma_request_channel(mask, NULL, NULL);
+       if (!aq->chan)
+               dev_warn(&pdev->dev, "no available DMA channel\n");
+
+       /* Setup the spi-nor */
+       nor = &aq->nor;
+       mtd = &aq->mtd;
+
+       nor->mtd = mtd;
+       nor->dev = &pdev->dev;
+       nor->priv = aq;
+       mtd->priv = nor;
+
+       nor->read_reg = atmel_qspi_read_reg;
+       nor->write_reg = atmel_qspi_write_reg;
+       nor->read = atmel_qspi_read;
+       nor->write = atmel_qspi_write;
+       nor->erase = atmel_qspi_erase;
+       nor->set_protocol = atmel_qspi_set_protocol;
+
+       if (of_modalias_node(child, modalias, sizeof(modalias)) < 0) {
+               err = -ENODEV;
+               goto release_channel;
+       }
+
+       err = of_property_read_u32(child, "spi-max-frequency", &aq->clk_rate);
+       if (err < 0)
+               goto release_channel;
+
+       err = atmel_qspi_init(aq);
+       if (err)
+               goto release_channel;
+
+       nor->dev->of_node = child;
+       err = spi_nor_scan(nor, modalias, SPI_NOR_QUAD);
+       nor->dev->of_node = np;
+       if (err)
+               goto release_channel;
+
+       ppdata.of_node = child;
+       err = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
+       if (err)
+               goto release_channel;
+
+       return 0;
+
+release_channel:
+       if (aq->chan)
+               dma_release_channel(aq->chan);
+disable_clk:
+       clk_disable_unprepare(aq->clk);
+exit:
+       return err;
+}
+
+static int atmel_qspi_remove(struct platform_device *pdev)
+{
+       struct atmel_qspi *aq = platform_get_drvdata(pdev);
+
+       mtd_device_unregister(&aq->mtd);
+       qspi_writel(aq, CR, QSPI_BIT(CR_QSPIDIS));
+       if (aq->chan)
+               dma_release_channel(aq->chan);
+       clk_disable_unprepare(aq->clk);
+       return 0;
+}
+
+
+static const struct of_device_id atmel_qspi_dt_ids[] = {
+       { .compatible = "atmel,sama5d2-qspi" },
+       { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_qspi_dt_ids);
+
+static struct platform_driver atmel_qspi_driver = {
+       .driver         = {
+               .name   = "atmel_qspi",
+               .bus    = &platform_bus_type,
+               .of_match_table = of_match_ptr(atmel_qspi_dt_ids),
+       },
+       .probe          = atmel_qspi_probe,
+       .remove         = atmel_qspi_remove,
+};
+module_platform_driver(atmel_qspi_driver);
+
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitc...@atmel.com>");
+MODULE_DESCRIPTION("Atmel QSPI Controller driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.2.2

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