OSDN Git Service

spi: Add spi driver for Socionext SynQuacer platform
authorMasahisa Kojima <masahisa.kojima@linaro.org>
Tue, 4 Jun 2019 05:12:57 +0000 (14:12 +0900)
committerMark Brown <broonie@kernel.org>
Tue, 4 Jun 2019 14:50:33 +0000 (15:50 +0100)
This patch adds support for controller found on synquacer platforms.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/spi-synquacer.c [new file with mode: 0644]

index 3ee152f..5c903e5 100644 (file)
@@ -732,6 +732,16 @@ config SPI_SUN6I
        help
          This enables using the SPI controller on the Allwinner A31 SoCs.
 
+config SPI_SYNQUACER
+       tristate "Socionext's SynQuacer HighSpeed SPI controller"
+       depends on ARCH_SYNQUACER || COMPILE_TEST
+       help
+         SPI driver for Socionext's High speed SPI controller which provides
+         various operating modes for interfacing to serial peripheral devices
+         that use the de-facto standard SPI protocol.
+
+         It also supports the new dual-bit and quad-bit SPI protocol.
+
 config SPI_MXIC
         tristate "Macronix MX25F0A SPI controller"
         depends on SPI_MASTER
index f2f78d0..63dcab5 100644 (file)
@@ -106,6 +106,7 @@ obj-$(CONFIG_SPI_STM32_QSPI)                += spi-stm32-qspi.o
 obj-$(CONFIG_SPI_ST_SSC4)              += spi-st-ssc4.o
 obj-$(CONFIG_SPI_SUN4I)                        += spi-sun4i.o
 obj-$(CONFIG_SPI_SUN6I)                        += spi-sun6i.o
+obj-$(CONFIG_SPI_SYNQUACER)            += spi-synquacer.o
 obj-$(CONFIG_SPI_TEGRA114)             += spi-tegra114.o
 obj-$(CONFIG_SPI_TEGRA20_SFLASH)       += spi-tegra20-sflash.o
 obj-$(CONFIG_SPI_TEGRA20_SLINK)                += spi-tegra20-slink.o
diff --git a/drivers/spi/spi-synquacer.c b/drivers/spi/spi-synquacer.c
new file mode 100644 (file)
index 0000000..c8c8d9c
--- /dev/null
@@ -0,0 +1,822 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Synquacer HSSPI controller driver
+//
+// Copyright (c) 2015-2018 Socionext Inc.
+// Copyright (c) 2018-2019 Linaro Ltd.
+//
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+
+/* HSSPI register address definitions */
+#define SYNQUACER_HSSPI_REG_MCTRL      0x00
+#define SYNQUACER_HSSPI_REG_PCC0       0x04
+#define SYNQUACER_HSSPI_REG_PCC(n)     (SYNQUACER_HSSPI_REG_PCC0 + (n) * 4)
+#define SYNQUACER_HSSPI_REG_TXF                0x14
+#define SYNQUACER_HSSPI_REG_TXE                0x18
+#define SYNQUACER_HSSPI_REG_TXC                0x1C
+#define SYNQUACER_HSSPI_REG_RXF                0x20
+#define SYNQUACER_HSSPI_REG_RXE                0x24
+#define SYNQUACER_HSSPI_REG_RXC                0x28
+#define SYNQUACER_HSSPI_REG_FAULTF     0x2C
+#define SYNQUACER_HSSPI_REG_FAULTC     0x30
+#define SYNQUACER_HSSPI_REG_DMCFG      0x34
+#define SYNQUACER_HSSPI_REG_DMSTART    0x38
+#define SYNQUACER_HSSPI_REG_DMBCC      0x3C
+#define SYNQUACER_HSSPI_REG_DMSTATUS   0x40
+#define SYNQUACER_HSSPI_REG_FIFOCFG    0x4C
+#define SYNQUACER_HSSPI_REG_TX_FIFO    0x50
+#define SYNQUACER_HSSPI_REG_RX_FIFO    0x90
+#define SYNQUACER_HSSPI_REG_MID                0xFC
+
+/* HSSPI register bit definitions */
+#define SYNQUACER_HSSPI_MCTRL_MEN                      BIT(0)
+#define SYNQUACER_HSSPI_MCTRL_COMMAND_SEQUENCE_EN      BIT(1)
+#define SYNQUACER_HSSPI_MCTRL_CDSS                     BIT(3)
+#define SYNQUACER_HSSPI_MCTRL_MES                      BIT(4)
+#define SYNQUACER_HSSPI_MCTRL_SYNCON                   BIT(5)
+
+#define SYNQUACER_HSSPI_PCC_CPHA               BIT(0)
+#define SYNQUACER_HSSPI_PCC_CPOL               BIT(1)
+#define SYNQUACER_HSSPI_PCC_ACES               BIT(2)
+#define SYNQUACER_HSSPI_PCC_RTM                        BIT(3)
+#define SYNQUACER_HSSPI_PCC_SSPOL              BIT(4)
+#define SYNQUACER_HSSPI_PCC_SDIR               BIT(7)
+#define SYNQUACER_HSSPI_PCC_SENDIAN            BIT(8)
+#define SYNQUACER_HSSPI_PCC_SAFESYNC           BIT(16)
+#define SYNQUACER_HSSPI_PCC_SS2CD_SHIFT                5U
+#define SYNQUACER_HSSPI_PCC_CDRS_MASK          0x7f
+#define SYNQUACER_HSSPI_PCC_CDRS_SHIFT         9U
+
+#define SYNQUACER_HSSPI_TXF_FIFO_FULL          BIT(0)
+#define SYNQUACER_HSSPI_TXF_FIFO_EMPTY         BIT(1)
+#define SYNQUACER_HSSPI_TXF_SLAVE_RELEASED     BIT(6)
+
+#define SYNQUACER_HSSPI_TXE_FIFO_FULL          BIT(0)
+#define SYNQUACER_HSSPI_TXE_FIFO_EMPTY         BIT(1)
+#define SYNQUACER_HSSPI_TXE_SLAVE_RELEASED     BIT(6)
+
+#define SYNQUACER_HSSPI_RXF_FIFO_MORE_THAN_THRESHOLD           BIT(5)
+#define SYNQUACER_HSSPI_RXF_SLAVE_RELEASED                     BIT(6)
+
+#define SYNQUACER_HSSPI_RXE_FIFO_MORE_THAN_THRESHOLD           BIT(5)
+#define SYNQUACER_HSSPI_RXE_SLAVE_RELEASED                     BIT(6)
+
+#define SYNQUACER_HSSPI_DMCFG_SSDC             BIT(1)
+#define SYNQUACER_HSSPI_DMCFG_MSTARTEN         BIT(2)
+
+#define SYNQUACER_HSSPI_DMSTART_START          BIT(0)
+#define SYNQUACER_HSSPI_DMSTOP_STOP            BIT(8)
+#define SYNQUACER_HSSPI_DMPSEL_CS_MASK         0x3
+#define SYNQUACER_HSSPI_DMPSEL_CS_SHIFT                16U
+#define SYNQUACER_HSSPI_DMTRP_BUS_WIDTH_SHIFT  24U
+#define SYNQUACER_HSSPI_DMTRP_DATA_MASK                0x3
+#define SYNQUACER_HSSPI_DMTRP_DATA_SHIFT       26U
+#define SYNQUACER_HSSPI_DMTRP_DATA_TXRX                0
+#define SYNQUACER_HSSPI_DMTRP_DATA_RX          1
+#define SYNQUACER_HSSPI_DMTRP_DATA_TX          2
+
+#define SYNQUACER_HSSPI_DMSTATUS_RX_DATA_MASK  0x1f
+#define SYNQUACER_HSSPI_DMSTATUS_RX_DATA_SHIFT 8U
+#define SYNQUACER_HSSPI_DMSTATUS_TX_DATA_MASK  0x1f
+#define SYNQUACER_HSSPI_DMSTATUS_TX_DATA_SHIFT 16U
+
+#define SYNQUACER_HSSPI_FIFOCFG_RX_THRESHOLD_MASK      0xf
+#define SYNQUACER_HSSPI_FIFOCFG_RX_THRESHOLD_SHIFT     0U
+#define SYNQUACER_HSSPI_FIFOCFG_TX_THRESHOLD_MASK      0xf
+#define SYNQUACER_HSSPI_FIFOCFG_TX_THRESHOLD_SHIFT     4U
+#define SYNQUACER_HSSPI_FIFOCFG_FIFO_WIDTH_MASK                0x3
+#define SYNQUACER_HSSPI_FIFOCFG_FIFO_WIDTH_SHIFT       8U
+#define SYNQUACER_HSSPI_FIFOCFG_RX_FLUSH               BIT(11)
+#define SYNQUACER_HSSPI_FIFOCFG_TX_FLUSH               BIT(12)
+
+#define SYNQUACER_HSSPI_FIFO_DEPTH             16U
+#define SYNQUACER_HSSPI_FIFO_TX_THRESHOLD      4U
+#define SYNQUACER_HSSPI_FIFO_RX_THRESHOLD \
+       (SYNQUACER_HSSPI_FIFO_DEPTH - SYNQUACER_HSSPI_FIFO_TX_THRESHOLD)
+
+#define SYNQUACER_HSSPI_TRANSFER_MODE_TX       BIT(1)
+#define SYNQUACER_HSSPI_TRANSFER_MODE_RX       BIT(2)
+#define SYNQUACER_HSSPI_TRANSFER_TMOUT_MSEC    2000U
+#define SYNQUACER_HSSPI_ENABLE_TMOUT_MSEC      1000U
+
+#define SYNQUACER_HSSPI_CLOCK_SRC_IHCLK                0
+#define SYNQUACER_HSSPI_CLOCK_SRC_IPCLK                1
+
+#define SYNQUACER_HSSPI_NUM_CHIP_SELECT                4U
+#define SYNQUACER_HSSPI_IRQ_NAME_MAX           32U
+
+struct synquacer_spi {
+       struct device *dev;
+       struct completion transfer_done;
+       unsigned int cs;
+       unsigned int bpw;
+       unsigned int mode;
+       unsigned int speed;
+       bool aces, rtm;
+       void *rx_buf;
+       const void *tx_buf;
+       struct clk *clk;
+       int clk_src_type;
+       void __iomem *regs;
+       u32 tx_words, rx_words;
+       unsigned int bus_width;
+       unsigned int transfer_mode;
+       char rx_irq_name[SYNQUACER_HSSPI_IRQ_NAME_MAX];
+       char tx_irq_name[SYNQUACER_HSSPI_IRQ_NAME_MAX];
+};
+
+static int read_fifo(struct synquacer_spi *sspi)
+{
+       u32 len = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTATUS);
+
+       len = (len >> SYNQUACER_HSSPI_DMSTATUS_RX_DATA_SHIFT) &
+              SYNQUACER_HSSPI_DMSTATUS_RX_DATA_MASK;
+       len = min(len, sspi->rx_words);
+
+       switch (sspi->bpw) {
+       case 8: {
+               u8 *buf = sspi->rx_buf;
+
+               readsb(sspi->regs + SYNQUACER_HSSPI_REG_RX_FIFO, buf, len);
+               sspi->rx_buf = buf + len;
+               break;
+       }
+       case 16: {
+               u16 *buf = sspi->rx_buf;
+
+               readsw(sspi->regs + SYNQUACER_HSSPI_REG_RX_FIFO, buf, len);
+               sspi->rx_buf = buf + len;
+               break;
+       }
+       case 24:
+               /* fallthrough, should use 32-bits access */
+       case 32: {
+               u32 *buf = sspi->rx_buf;
+
+               readsl(sspi->regs + SYNQUACER_HSSPI_REG_RX_FIFO, buf, len);
+               sspi->rx_buf = buf + len;
+               break;
+       }
+       default:
+               return -EINVAL;
+       }
+
+       sspi->rx_words -= len;
+       return 0;
+}
+
+static int write_fifo(struct synquacer_spi *sspi)
+{
+       u32 len = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTATUS);
+
+       len = (len >> SYNQUACER_HSSPI_DMSTATUS_TX_DATA_SHIFT) &
+              SYNQUACER_HSSPI_DMSTATUS_TX_DATA_MASK;
+       len = min(SYNQUACER_HSSPI_FIFO_DEPTH - len,
+                   sspi->tx_words);
+
+       switch (sspi->bpw) {
+       case 8: {
+               const u8 *buf = sspi->tx_buf;
+
+               writesb(sspi->regs + SYNQUACER_HSSPI_REG_TX_FIFO, buf, len);
+               sspi->tx_buf = buf + len;
+               break;
+       }
+       case 16: {
+               const u16 *buf = sspi->tx_buf;
+
+               writesw(sspi->regs + SYNQUACER_HSSPI_REG_TX_FIFO, buf, len);
+               sspi->tx_buf = buf + len;
+               break;
+       }
+       case 24:
+               /* fallthrough, should use 32-bits access */
+       case 32: {
+               const u32 *buf = sspi->tx_buf;
+
+               writesl(sspi->regs + SYNQUACER_HSSPI_REG_TX_FIFO, buf, len);
+               sspi->tx_buf = buf + len;
+               break;
+       }
+       default:
+               return -EINVAL;
+       }
+
+       sspi->tx_words -= len;
+       return 0;
+}
+
+static int synquacer_spi_config(struct spi_master *master,
+                               struct spi_device *spi,
+                               struct spi_transfer *xfer)
+{
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+       unsigned int speed, mode, bpw, cs, bus_width, transfer_mode;
+       u32 rate, val, div;
+
+       /* Full Duplex only on 1-bit wide bus */
+       if (xfer->rx_buf && xfer->tx_buf &&
+           (xfer->rx_nbits != 1 || xfer->tx_nbits != 1)) {
+               dev_err(sspi->dev,
+                       "RX and TX bus widths must be 1-bit for Full-Duplex!\n");
+               return -EINVAL;
+       }
+
+       if (xfer->tx_buf) {
+               bus_width = xfer->tx_nbits;
+               transfer_mode = SYNQUACER_HSSPI_TRANSFER_MODE_TX;
+       } else {
+               bus_width = xfer->rx_nbits;
+               transfer_mode = SYNQUACER_HSSPI_TRANSFER_MODE_RX;
+       }
+
+       mode = spi->mode;
+       cs = spi->chip_select;
+       speed = xfer->speed_hz;
+       bpw = xfer->bits_per_word;
+
+       /* return if nothing to change */
+       if (speed == sspi->speed &&
+               bus_width == sspi->bus_width && bpw == sspi->bpw &&
+               mode == sspi->mode && cs == sspi->cs &&
+               transfer_mode == sspi->transfer_mode) {
+               return 0;
+       }
+
+       sspi->transfer_mode = transfer_mode;
+       rate = master->max_speed_hz;
+
+       div = DIV_ROUND_UP(rate, speed);
+       if (div > 254) {
+               dev_err(sspi->dev, "Requested rate too low (%u)\n",
+                       sspi->speed);
+               return -EINVAL;
+       }
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_PCC(cs));
+       val &= ~SYNQUACER_HSSPI_PCC_SAFESYNC;
+       if (bpw == 8 && (mode & (SPI_TX_DUAL | SPI_RX_DUAL)) && div < 3)
+               val |= SYNQUACER_HSSPI_PCC_SAFESYNC;
+       if (bpw == 8 && (mode & (SPI_TX_QUAD | SPI_RX_QUAD)) && div < 6)
+               val |= SYNQUACER_HSSPI_PCC_SAFESYNC;
+       if (bpw == 16 && (mode & (SPI_TX_QUAD | SPI_RX_QUAD)) && div < 3)
+               val |= SYNQUACER_HSSPI_PCC_SAFESYNC;
+
+       if (mode & SPI_CPHA)
+               val |= SYNQUACER_HSSPI_PCC_CPHA;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_CPHA;
+
+       if (mode & SPI_CPOL)
+               val |= SYNQUACER_HSSPI_PCC_CPOL;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_CPOL;
+
+       if (mode & SPI_CS_HIGH)
+               val |= SYNQUACER_HSSPI_PCC_SSPOL;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_SSPOL;
+
+       if (mode & SPI_LSB_FIRST)
+               val |= SYNQUACER_HSSPI_PCC_SDIR;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_SDIR;
+
+       if (sspi->aces)
+               val |= SYNQUACER_HSSPI_PCC_ACES;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_ACES;
+
+       if (sspi->rtm)
+               val |= SYNQUACER_HSSPI_PCC_RTM;
+       else
+               val &= ~SYNQUACER_HSSPI_PCC_RTM;
+
+       val |= (3 << SYNQUACER_HSSPI_PCC_SS2CD_SHIFT);
+       val |= SYNQUACER_HSSPI_PCC_SENDIAN;
+
+       val &= ~(SYNQUACER_HSSPI_PCC_CDRS_MASK <<
+                SYNQUACER_HSSPI_PCC_CDRS_SHIFT);
+       val |= ((div >> 1) << SYNQUACER_HSSPI_PCC_CDRS_SHIFT);
+
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_PCC(cs));
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+       val &= ~(SYNQUACER_HSSPI_FIFOCFG_FIFO_WIDTH_MASK <<
+                SYNQUACER_HSSPI_FIFOCFG_FIFO_WIDTH_SHIFT);
+       val |= ((bpw / 8 - 1) << SYNQUACER_HSSPI_FIFOCFG_FIFO_WIDTH_SHIFT);
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+       val &= ~(SYNQUACER_HSSPI_DMTRP_DATA_MASK <<
+                SYNQUACER_HSSPI_DMTRP_DATA_SHIFT);
+
+       if (xfer->rx_buf)
+               val |= (SYNQUACER_HSSPI_DMTRP_DATA_RX <<
+                       SYNQUACER_HSSPI_DMTRP_DATA_SHIFT);
+       else
+               val |= (SYNQUACER_HSSPI_DMTRP_DATA_TX <<
+                       SYNQUACER_HSSPI_DMTRP_DATA_SHIFT);
+
+       val &= ~(3 << SYNQUACER_HSSPI_DMTRP_BUS_WIDTH_SHIFT);
+       val |= ((bus_width >> 1) << SYNQUACER_HSSPI_DMTRP_BUS_WIDTH_SHIFT);
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+
+       sspi->bpw = bpw;
+       sspi->mode = mode;
+       sspi->speed = speed;
+       sspi->cs = spi->chip_select;
+       sspi->bus_width = bus_width;
+
+       return 0;
+}
+
+static int synquacer_spi_transfer_one(struct spi_master *master,
+                                     struct spi_device *spi,
+                                     struct spi_transfer *xfer)
+{
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+       int ret;
+       int status = 0;
+       u32 words;
+       u8 bpw;
+       u32 val;
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+       val &= ~SYNQUACER_HSSPI_DMSTOP_STOP;
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+       val |= SYNQUACER_HSSPI_FIFOCFG_RX_FLUSH;
+       val |= SYNQUACER_HSSPI_FIFOCFG_TX_FLUSH;
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+
+       /*
+        * See if we can transfer 4-bytes as 1 word
+        * to maximize the FIFO buffer efficiency.
+        */
+       bpw = xfer->bits_per_word;
+       if (bpw == 8 && !(xfer->len % 4) && !(spi->mode & SPI_LSB_FIRST))
+               xfer->bits_per_word = 32;
+
+       ret = synquacer_spi_config(master, spi, xfer);
+
+       /* restore */
+       xfer->bits_per_word = bpw;
+
+       if (ret)
+               return ret;
+
+       reinit_completion(&sspi->transfer_done);
+
+       sspi->tx_buf = xfer->tx_buf;
+       sspi->rx_buf = xfer->rx_buf;
+
+       switch (sspi->bpw) {
+       case 8:
+               words = xfer->len;
+               break;
+       case 16:
+               words = xfer->len / 2;
+               break;
+       case 24:
+               /* fallthrough, should use 32-bits access */
+       case 32:
+               words = xfer->len / 4;
+               break;
+       default:
+               dev_err(sspi->dev, "unsupported bpw: %d\n", sspi->bpw);
+               return -EINVAL;
+       }
+
+       if (xfer->tx_buf)
+               sspi->tx_words = words;
+       else
+               sspi->tx_words = 0;
+
+       if (xfer->rx_buf)
+               sspi->rx_words = words;
+       else
+               sspi->rx_words = 0;
+
+       if (xfer->tx_buf) {
+               status = write_fifo(sspi);
+               if (status < 0) {
+                       dev_err(sspi->dev, "failed write_fifo. status: 0x%x\n",
+                               status);
+                       return status;
+               }
+       }
+
+       if (xfer->rx_buf) {
+               val = readl(sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+               val &= ~(SYNQUACER_HSSPI_FIFOCFG_RX_THRESHOLD_MASK <<
+                        SYNQUACER_HSSPI_FIFOCFG_RX_THRESHOLD_SHIFT);
+               val |= ((sspi->rx_words > SYNQUACER_HSSPI_FIFO_DEPTH ?
+                       SYNQUACER_HSSPI_FIFO_RX_THRESHOLD : sspi->rx_words) <<
+                       SYNQUACER_HSSPI_FIFOCFG_RX_THRESHOLD_SHIFT);
+               writel(val, sspi->regs + SYNQUACER_HSSPI_REG_FIFOCFG);
+       }
+
+       writel(~0, sspi->regs + SYNQUACER_HSSPI_REG_TXC);
+       writel(~0, sspi->regs + SYNQUACER_HSSPI_REG_RXC);
+
+       /* Trigger */
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+       val |= SYNQUACER_HSSPI_DMSTART_START;
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+
+       if (xfer->tx_buf) {
+               val = SYNQUACER_HSSPI_TXE_FIFO_EMPTY;
+               writel(val, sspi->regs + SYNQUACER_HSSPI_REG_TXE);
+               status = wait_for_completion_timeout(&sspi->transfer_done,
+                       msecs_to_jiffies(SYNQUACER_HSSPI_TRANSFER_TMOUT_MSEC));
+               writel(0, sspi->regs + SYNQUACER_HSSPI_REG_TXE);
+       }
+
+       if (xfer->rx_buf) {
+               u32 buf[SYNQUACER_HSSPI_FIFO_DEPTH];
+
+               val = SYNQUACER_HSSPI_RXE_FIFO_MORE_THAN_THRESHOLD |
+                     SYNQUACER_HSSPI_RXE_SLAVE_RELEASED;
+               writel(val, sspi->regs + SYNQUACER_HSSPI_REG_RXE);
+               status = wait_for_completion_timeout(&sspi->transfer_done,
+                       msecs_to_jiffies(SYNQUACER_HSSPI_TRANSFER_TMOUT_MSEC));
+               writel(0, sspi->regs + SYNQUACER_HSSPI_REG_RXE);
+
+               /* stop RX and clean RXFIFO */
+               val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+               val |= SYNQUACER_HSSPI_DMSTOP_STOP;
+               writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+               sspi->rx_buf = buf;
+               sspi->rx_words = SYNQUACER_HSSPI_FIFO_DEPTH;
+               read_fifo(sspi);
+       }
+
+       if (status < 0) {
+               dev_err(sspi->dev, "failed to transfer. status: 0x%x\n",
+                       status);
+               return status;
+       }
+
+       return 0;
+}
+
+static void synquacer_spi_set_cs(struct spi_device *spi, bool enable)
+{
+       struct synquacer_spi *sspi = spi_master_get_devdata(spi->master);
+       u32 val;
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+       val &= ~(SYNQUACER_HSSPI_DMPSEL_CS_MASK <<
+                SYNQUACER_HSSPI_DMPSEL_CS_SHIFT);
+       val |= spi->chip_select << SYNQUACER_HSSPI_DMPSEL_CS_SHIFT;
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMSTART);
+}
+
+static int synquacer_spi_wait_status_update(struct synquacer_spi *sspi,
+                                           bool enable)
+{
+       u32 val;
+       unsigned long timeout = jiffies +
+               msecs_to_jiffies(SYNQUACER_HSSPI_ENABLE_TMOUT_MSEC);
+
+       /* wait MES(Module Enable Status) is updated */
+       do {
+               val = readl(sspi->regs + SYNQUACER_HSSPI_REG_MCTRL) &
+                     SYNQUACER_HSSPI_MCTRL_MES;
+               if (enable && val)
+                       return 0;
+               if (!enable && !val)
+                       return 0;
+       } while (time_before(jiffies, timeout));
+
+       dev_err(sspi->dev, "timeout occurs in updating Module Enable Status\n");
+       return -EBUSY;
+}
+
+static int synquacer_spi_enable(struct spi_master *master)
+{
+       u32 val;
+       int status;
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+
+       /* Disable module */
+       writel(0, sspi->regs + SYNQUACER_HSSPI_REG_MCTRL);
+       status = synquacer_spi_wait_status_update(sspi, false);
+       if (status < 0)
+               return status;
+
+       writel(0, sspi->regs + SYNQUACER_HSSPI_REG_TXE);
+       writel(0, sspi->regs + SYNQUACER_HSSPI_REG_RXE);
+       writel(~0, sspi->regs + SYNQUACER_HSSPI_REG_TXC);
+       writel(~0, sspi->regs + SYNQUACER_HSSPI_REG_RXC);
+       writel(~0, sspi->regs + SYNQUACER_HSSPI_REG_FAULTC);
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_DMCFG);
+       val &= ~SYNQUACER_HSSPI_DMCFG_SSDC;
+       val &= ~SYNQUACER_HSSPI_DMCFG_MSTARTEN;
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_DMCFG);
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_MCTRL);
+       if (sspi->clk_src_type == SYNQUACER_HSSPI_CLOCK_SRC_IPCLK)
+               val |= SYNQUACER_HSSPI_MCTRL_CDSS;
+       else
+               val &= ~SYNQUACER_HSSPI_MCTRL_CDSS;
+
+       val &= ~SYNQUACER_HSSPI_MCTRL_COMMAND_SEQUENCE_EN;
+       val |= SYNQUACER_HSSPI_MCTRL_MEN;
+       val |= SYNQUACER_HSSPI_MCTRL_SYNCON;
+
+       /* Enable module */
+       writel(val, sspi->regs + SYNQUACER_HSSPI_REG_MCTRL);
+       status = synquacer_spi_wait_status_update(sspi, true);
+       if (status < 0)
+               return status;
+
+       return 0;
+}
+
+static irqreturn_t sq_spi_rx_handler(int irq, void *priv)
+{
+       uint32_t val;
+       struct synquacer_spi *sspi = priv;
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_RXF);
+       if ((val & SYNQUACER_HSSPI_RXF_SLAVE_RELEASED) ||
+           (val & SYNQUACER_HSSPI_RXF_FIFO_MORE_THAN_THRESHOLD)) {
+               read_fifo(sspi);
+
+               if (sspi->rx_words == 0) {
+                       writel(0, sspi->regs + SYNQUACER_HSSPI_REG_RXE);
+                       complete(&sspi->transfer_done);
+               }
+               return IRQ_HANDLED;
+       }
+
+       return IRQ_NONE;
+}
+
+static irqreturn_t sq_spi_tx_handler(int irq, void *priv)
+{
+       uint32_t val;
+       struct synquacer_spi *sspi = priv;
+
+       val = readl(sspi->regs + SYNQUACER_HSSPI_REG_TXF);
+       if (val & SYNQUACER_HSSPI_TXF_FIFO_EMPTY) {
+               if (sspi->tx_words == 0) {
+                       writel(0, sspi->regs + SYNQUACER_HSSPI_REG_TXE);
+                       complete(&sspi->transfer_done);
+               } else {
+                       write_fifo(sspi);
+               }
+               return IRQ_HANDLED;
+       }
+
+       return IRQ_NONE;
+}
+
+static int synquacer_spi_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct spi_master *master;
+       struct synquacer_spi *sspi;
+       int ret;
+       int rx_irq, tx_irq;
+
+       master = spi_alloc_master(&pdev->dev, sizeof(*sspi));
+       if (!master)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, master);
+
+       sspi = spi_master_get_devdata(master);
+       sspi->dev = &pdev->dev;
+
+       init_completion(&sspi->transfer_done);
+
+       sspi->regs = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(sspi->regs)) {
+               ret = PTR_ERR(sspi->regs);
+               goto put_spi;
+       }
+
+       sspi->clk_src_type = SYNQUACER_HSSPI_CLOCK_SRC_IHCLK; /* Default */
+       device_property_read_u32(&pdev->dev, "socionext,ihclk-rate",
+                                &master->max_speed_hz); /* for ACPI */
+
+       if (dev_of_node(&pdev->dev)) {
+               if (device_property_match_string(&pdev->dev,
+                                        "clock-names", "iHCLK") >= 0) {
+                       sspi->clk_src_type = SYNQUACER_HSSPI_CLOCK_SRC_IHCLK;
+                       sspi->clk = devm_clk_get(sspi->dev, "iHCLK");
+               } else if (device_property_match_string(&pdev->dev,
+                                               "clock-names", "iPCLK") >= 0) {
+                       sspi->clk_src_type = SYNQUACER_HSSPI_CLOCK_SRC_IPCLK;
+                       sspi->clk = devm_clk_get(sspi->dev, "iPCLK");
+               } else {
+                       dev_err(&pdev->dev, "specified wrong clock source\n");
+                       ret = -EINVAL;
+                       goto put_spi;
+               }
+
+               if (IS_ERR(sspi->clk)) {
+                       if (!(PTR_ERR(sspi->clk) == -EPROBE_DEFER))
+                               dev_err(&pdev->dev, "clock not found\n");
+                       ret = PTR_ERR(sspi->clk);
+                       goto put_spi;
+               }
+
+               ret = clk_prepare_enable(sspi->clk);
+               if (ret) {
+                       dev_err(&pdev->dev, "failed to enable clock (%d)\n",
+                               ret);
+                       goto put_spi;
+               }
+
+               master->max_speed_hz = clk_get_rate(sspi->clk);
+       }
+
+       if (!master->max_speed_hz) {
+               dev_err(&pdev->dev, "missing clock source\n");
+               return -EINVAL;
+       }
+       master->min_speed_hz = master->max_speed_hz / 254;
+
+       sspi->aces = device_property_read_bool(&pdev->dev,
+                                              "socionext,set-aces");
+       sspi->rtm = device_property_read_bool(&pdev->dev, "socionext,use-rtm");
+
+       master->num_chipselect = SYNQUACER_HSSPI_NUM_CHIP_SELECT;
+
+       rx_irq = platform_get_irq(pdev, 0);
+       if (rx_irq <= 0) {
+               dev_err(&pdev->dev, "get rx_irq failed (%d)\n", rx_irq);
+               ret = rx_irq;
+               goto put_spi;
+       }
+       snprintf(sspi->rx_irq_name, SYNQUACER_HSSPI_IRQ_NAME_MAX, "%s-rx",
+                dev_name(&pdev->dev));
+       ret = devm_request_irq(&pdev->dev, rx_irq, sq_spi_rx_handler,
+                               0, sspi->rx_irq_name, sspi);
+       if (ret) {
+               dev_err(&pdev->dev, "request rx_irq failed (%d)\n", ret);
+               goto put_spi;
+       }
+
+       tx_irq = platform_get_irq(pdev, 1);
+       if (tx_irq <= 0) {
+               dev_err(&pdev->dev, "get tx_irq failed (%d)\n", tx_irq);
+               ret = tx_irq;
+               goto put_spi;
+       }
+       snprintf(sspi->tx_irq_name, SYNQUACER_HSSPI_IRQ_NAME_MAX, "%s-tx",
+                dev_name(&pdev->dev));
+       ret = devm_request_irq(&pdev->dev, tx_irq, sq_spi_tx_handler,
+                               0, sspi->tx_irq_name, sspi);
+       if (ret) {
+               dev_err(&pdev->dev, "request tx_irq failed (%d)\n", ret);
+               goto put_spi;
+       }
+
+       master->dev.of_node = np;
+       master->dev.fwnode = pdev->dev.fwnode;
+       master->auto_runtime_pm = true;
+       master->bus_num = pdev->id;
+
+       master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL |
+                           SPI_TX_QUAD | SPI_RX_QUAD;
+       master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(24) |
+                                    SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
+
+       master->set_cs = synquacer_spi_set_cs;
+       master->transfer_one = synquacer_spi_transfer_one;
+
+       ret = synquacer_spi_enable(master);
+       if (ret)
+               goto fail_enable;
+
+       pm_runtime_set_active(sspi->dev);
+       pm_runtime_enable(sspi->dev);
+
+       ret = devm_spi_register_master(sspi->dev, master);
+       if (ret)
+               goto disable_pm;
+
+       return 0;
+
+disable_pm:
+       pm_runtime_disable(sspi->dev);
+fail_enable:
+       clk_disable_unprepare(sspi->clk);
+put_spi:
+       spi_master_put(master);
+
+       return ret;
+}
+
+static int synquacer_spi_remove(struct platform_device *pdev)
+{
+       struct spi_master *master = platform_get_drvdata(pdev);
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+
+       pm_runtime_disable(sspi->dev);
+
+       clk_disable_unprepare(sspi->clk);
+
+       return 0;
+}
+
+static int __maybe_unused synquacer_spi_suspend(struct device *dev)
+{
+       struct spi_master *master = dev_get_drvdata(dev);
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+       int ret;
+
+       ret = spi_master_suspend(master);
+       if (ret)
+               return ret;
+
+       if (!pm_runtime_suspended(dev))
+               clk_disable_unprepare(sspi->clk);
+
+       return ret;
+}
+
+static int __maybe_unused synquacer_spi_resume(struct device *dev)
+{
+       struct spi_master *master = dev_get_drvdata(dev);
+       struct synquacer_spi *sspi = spi_master_get_devdata(master);
+       int ret;
+
+       if (!pm_runtime_suspended(dev)) {
+               /* Ensure reconfigure during next xfer */
+               sspi->speed = 0;
+
+               ret = clk_prepare_enable(sspi->clk);
+               if (ret < 0) {
+                       dev_err(dev, "failed to enable clk (%d)\n",
+                               ret);
+                       return ret;
+               }
+
+               ret = synquacer_spi_enable(master);
+               if (ret) {
+                       dev_err(dev, "failed to enable spi (%d)\n", ret);
+                       return ret;
+               }
+       }
+
+       ret = spi_master_resume(master);
+       if (ret < 0)
+               clk_disable_unprepare(sspi->clk);
+
+       return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(synquacer_spi_pm_ops, synquacer_spi_suspend,
+                        synquacer_spi_resume);
+
+static const struct of_device_id synquacer_spi_of_match[] = {
+       {.compatible = "socionext,synquacer-spi"},
+       {}
+};
+MODULE_DEVICE_TABLE(of, synquacer_spi_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id synquacer_hsspi_acpi_ids[] = {
+       { "SCX0004" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, synquacer_hsspi_acpi_ids);
+#endif
+
+static struct platform_driver synquacer_spi_driver = {
+       .driver = {
+               .name = "synquacer-spi",
+               .pm = &synquacer_spi_pm_ops,
+               .of_match_table = synquacer_spi_of_match,
+               .acpi_match_table = ACPI_PTR(synquacer_hsspi_acpi_ids),
+       },
+       .probe = synquacer_spi_probe,
+       .remove = synquacer_spi_remove,
+};
+module_platform_driver(synquacer_spi_driver);
+
+MODULE_DESCRIPTION("Socionext Synquacer HS-SPI controller driver");
+MODULE_AUTHOR("Masahisa Kojima <masahisa.kojima@linaro.org>");
+MODULE_AUTHOR("Jassi Brar <jaswinder.singh@linaro.org>");
+MODULE_LICENSE("GPL v2");