Re: [PATCH v6 1/2] spi: Add MXIC controller driver

[Boris Brezillon]

On Wed, 17 Oct 2018 10:08:11 +0800
masonccyang@xxxxxxxxxxx wrote:

> From: Mason Yang <masonccyang@xxxxxxxxxxx>
> 
> Add a driver for Macronix SPI controller IP.
> 
> Signed-off-by: Mason Yang <masonccyang@xxxxxxxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>

> ---
>  drivers/spi/Kconfig    |   6 +
>  drivers/spi/Makefile   |   1 +
>  drivers/spi/spi-mxic.c | 619 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 626 insertions(+)
>  create mode 100644 drivers/spi/spi-mxic.c
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index ad5d68e..7e900b5 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -633,6 +633,12 @@ config SPI_SUN6I
>  	help
>  	  This enables using the SPI controller on the Allwinner A31 SoCs.
>  
> +config SPI_MXIC
> +        tristate "Macronix MX25F0A SPI controller"
> +        depends on SPI_MASTER
> +        help
> +          This selects the Macronix MX25F0A SPI controller driver.
> +
>  config SPI_MXS
>  	tristate "Freescale MXS SPI controller"
>  	depends on ARCH_MXS
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index cb1f437..d7a1ceb 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -57,6 +57,7 @@ obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
>  obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
>  obj-$(CONFIG_SPI_MPC52xx)		+= spi-mpc52xx.o
>  obj-$(CONFIG_SPI_MT65XX)                += spi-mt65xx.o
> +obj-$(CONFIG_SPI_MXIC)			+= spi-mxic.o
>  obj-$(CONFIG_SPI_MXS)			+= spi-mxs.o
>  obj-$(CONFIG_SPI_NUC900)		+= spi-nuc900.o
>  obj-$(CONFIG_SPI_OC_TINY)		+= spi-oc-tiny.o
> diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
> new file mode 100644
> index 0000000..e41ae6e
> --- /dev/null
> +++ b/drivers/spi/spi-mxic.c
> @@ -0,0 +1,619 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2018 Macronix International Co., Ltd.
> +//
> +// Authors:
> +//	Mason Yang <masonccyang@xxxxxxxxxxx>
> +//	zhengxunli <zhengxunli@xxxxxxxxxxx>
> +//	Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> +//
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi-mem.h>
> +
> +#define HC_CFG			0x0
> +#define HC_CFG_IF_CFG(x)	((x) << 27)
> +#define HC_CFG_DUAL_SLAVE	BIT(31)
> +#define HC_CFG_INDIVIDUAL	BIT(30)
> +#define HC_CFG_NIO(x)		(((x) / 4) << 27)
> +#define HC_CFG_TYPE(s, t)	((t) << (23 + ((s) * 2)))
> +#define HC_CFG_TYPE_SPI_NOR	0
> +#define HC_CFG_TYPE_SPI_NAND	1
> +#define HC_CFG_TYPE_SPI_RAM	2
> +#define HC_CFG_TYPE_RAW_NAND	3
> +#define HC_CFG_SLV_ACT(x)	((x) << 21)
> +#define HC_CFG_CLK_PH_EN	BIT(20)
> +#define HC_CFG_CLK_POL_INV	BIT(19)
> +#define HC_CFG_BIG_ENDIAN	BIT(18)
> +#define HC_CFG_DATA_PASS	BIT(17)
> +#define HC_CFG_IDLE_SIO_LVL(x)	((x) << 16)
> +#define HC_CFG_MAN_START_EN	BIT(3)
> +#define HC_CFG_MAN_START	BIT(2)
> +#define HC_CFG_MAN_CS_EN	BIT(1)
> +#define HC_CFG_MAN_CS_ASSERT	BIT(0)
> +
> +#define INT_STS			0x4
> +#define INT_STS_EN		0x8
> +#define INT_SIG_EN		0xc
> +#define INT_STS_ALL		GENMASK(31, 0)
> +#define INT_RDY_PIN		BIT(26)
> +#define INT_RDY_SR		BIT(25)
> +#define INT_LNR_SUSP		BIT(24)
> +#define INT_ECC_ERR		BIT(17)
> +#define INT_CRC_ERR		BIT(16)
> +#define INT_LWR_DIS		BIT(12)
> +#define INT_LRD_DIS		BIT(11)
> +#define INT_SDMA_INT		BIT(10)
> +#define INT_DMA_FINISH		BIT(9)
> +#define INT_RX_NOT_FULL		BIT(3)
> +#define INT_RX_NOT_EMPTY	BIT(2)
> +#define INT_TX_NOT_FULL		BIT(1)
> +#define INT_TX_EMPTY		BIT(0)
> +
> +#define HC_EN			0x10
> +#define HC_EN_BIT		BIT(0)
> +
> +#define TXD(x)			(0x14 + ((x) * 4))
> +#define RXD			0x24
> +
> +#define SS_CTRL(s)		(0x30 + ((s) * 4))
> +#define LRD_CFG			0x44
> +#define LWR_CFG			0x80
> +#define RWW_CFG			0x70
> +#define OP_READ			BIT(23)
> +#define OP_DUMMY_CYC(x)		((x) << 17)
> +#define OP_ADDR_BYTES(x)	((x) << 14)
> +#define OP_CMD_BYTES(x)		(((x) - 1) << 13)
> +#define OP_OCTA_CRC_EN		BIT(12)
> +#define OP_DQS_EN		BIT(11)
> +#define OP_ENHC_EN		BIT(10)
> +#define OP_PREAMBLE_EN		BIT(9)
> +#define OP_DATA_DDR		BIT(8)
> +#define OP_DATA_BUSW(x)		((x) << 6)
> +#define OP_ADDR_DDR		BIT(5)
> +#define OP_ADDR_BUSW(x)		((x) << 3)
> +#define OP_CMD_DDR		BIT(2)
> +#define OP_CMD_BUSW(x)		(x)
> +#define OP_BUSW_1		0
> +#define OP_BUSW_2		1
> +#define OP_BUSW_4		2
> +#define OP_BUSW_8		3
> +
> +#define OCTA_CRC		0x38
> +#define OCTA_CRC_IN_EN(s)	BIT(3 + ((s) * 16))
> +#define OCTA_CRC_CHUNK(s, x)	((fls((x) / 32)) << (1 + ((s) * 16)))
> +#define OCTA_CRC_OUT_EN(s)	BIT(0 + ((s) * 16))
> +
> +#define ONFI_DIN_CNT(s)		(0x3c + (s))
> +
> +#define LRD_CTRL		0x48
> +#define RWW_CTRL		0x74
> +#define LWR_CTRL		0x84
> +#define LMODE_EN		BIT(31)
> +#define LMODE_SLV_ACT(x)	((x) << 21)
> +#define LMODE_CMD1(x)		((x) << 8)
> +#define LMODE_CMD0(x)		(x)
> +
> +#define LRD_ADDR		0x4c
> +#define LWR_ADDR		0x88
> +#define LRD_RANGE		0x50
> +#define LWR_RANGE		0x8c
> +
> +#define AXI_SLV_ADDR		0x54
> +
> +#define DMAC_RD_CFG		0x58
> +#define DMAC_WR_CFG		0x94
> +#define DMAC_CFG_PERIPH_EN	BIT(31)
> +#define DMAC_CFG_ALLFLUSH_EN	BIT(30)
> +#define DMAC_CFG_LASTFLUSH_EN	BIT(29)
> +#define DMAC_CFG_QE(x)		(((x) + 1) << 16)
> +#define DMAC_CFG_BURST_LEN(x)	(((x) + 1) << 12)
> +#define DMAC_CFG_BURST_SZ(x)	((x) << 8)
> +#define DMAC_CFG_DIR_READ	BIT(1)
> +#define DMAC_CFG_START		BIT(0)
> +
> +#define DMAC_RD_CNT		0x5c
> +#define DMAC_WR_CNT		0x98
> +
> +#define SDMA_ADDR		0x60
> +
> +#define DMAM_CFG		0x64
> +#define DMAM_CFG_START		BIT(31)
> +#define DMAM_CFG_CONT		BIT(30)
> +#define DMAM_CFG_SDMA_GAP(x)	(fls((x) / 8192) << 2)
> +#define DMAM_CFG_DIR_READ	BIT(1)
> +#define DMAM_CFG_EN		BIT(0)
> +
> +#define DMAM_CNT		0x68
> +
> +#define LNR_TIMER_TH		0x6c
> +
> +#define RDM_CFG0		0x78
> +#define RDM_CFG0_POLY(x)	(x)
> +
> +#define RDM_CFG1		0x7c
> +#define RDM_CFG1_RDM_EN		BIT(31)
> +#define RDM_CFG1_SEED(x)	(x)
> +
> +#define LWR_SUSP_CTRL		0x90
> +#define LWR_SUSP_CTRL_EN	BIT(31)
> +
> +#define DMAS_CTRL		0x9c
> +#define DMAS_CTRL_DIR_READ	BIT(31)
> +#define DMAS_CTRL_EN		BIT(30)
> +
> +#define DATA_STROB		0xa0
> +#define DATA_STROB_EDO_EN	BIT(2)
> +#define DATA_STROB_INV_POL	BIT(1)
> +#define DATA_STROB_DELAY_2CYC	BIT(0)
> +
> +#define IDLY_CODE(x)		(0xa4 + ((x) * 4))
> +#define IDLY_CODE_VAL(x, v)	((v) << (((x) % 4) * 8))
> +
> +#define GPIO			0xc4
> +#define GPIO_PT(x)		BIT(3 + ((x) * 16))
> +#define GPIO_RESET(x)		BIT(2 + ((x) * 16))
> +#define GPIO_HOLDB(x)		BIT(1 + ((x) * 16))
> +#define GPIO_WPB(x)		BIT((x) * 16)
> +
> +#define HC_VER			0xd0
> +
> +#define HW_TEST(x)		(0xe0 + ((x) * 4))
> +
> +struct mxic_spi {
> +	struct clk *ps_clk;
> +	struct clk *send_clk;
> +	struct clk *send_dly_clk;
> +	void __iomem *regs;
> +	u32 cur_speed_hz;
> +};
> +
> +static int mxic_spi_clk_enable(struct mxic_spi *mxic)
> +{
> +	int ret;
> +
> +	ret = clk_prepare_enable(mxic->send_clk);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_prepare_enable(mxic->send_dly_clk);
> +	if (ret)
> +		goto err_send_dly_clk;
> +
> +	return ret;
> +
> +err_send_dly_clk:
> +	clk_disable_unprepare(mxic->send_clk);
> +
> +	return ret;
> +}
> +
> +static void mxic_spi_clk_disable(struct mxic_spi *mxic)
> +{
> +	clk_disable_unprepare(mxic->send_clk);
> +	clk_disable_unprepare(mxic->send_dly_clk);
> +}
> +
> +static void mxic_spi_set_input_delay_dqs(struct mxic_spi *mxic, u8 idly_code)
> +{
> +	writel(IDLY_CODE_VAL(0, idly_code) |
> +	       IDLY_CODE_VAL(1, idly_code) |
> +	       IDLY_CODE_VAL(2, idly_code) |
> +	       IDLY_CODE_VAL(3, idly_code),
> +	       mxic->regs + IDLY_CODE(0));
> +	writel(IDLY_CODE_VAL(4, idly_code) |
> +	       IDLY_CODE_VAL(5, idly_code) |
> +	       IDLY_CODE_VAL(6, idly_code) |
> +	       IDLY_CODE_VAL(7, idly_code),
> +	       mxic->regs + IDLY_CODE(1));
> +}
> +
> +static int mxic_spi_clk_setup(struct mxic_spi *mxic, unsigned long freq)
> +{
> +	int ret;
> +
> +	ret = clk_set_rate(mxic->send_clk, freq);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_set_rate(mxic->send_dly_clk, freq);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * A constant delay range from 0x0 ~ 0x1F for input delay,
> +	 * the unit is 78 ps, the max input delay is 2.418 ns.
> +	 */
> +	mxic_spi_set_input_delay_dqs(mxic, 0xf);
> +
> +	/*
> +	 * Phase degree = 360 * freq * output-delay
> +	 * where output-delay is a constant value 1 ns in FPGA.
> +	 *
> +	 * Get Phase degree = 360 * freq * 1 ns
> +	 *                  = 360 * freq * 1 sec / 1000000000
> +	 *                  = 9 * freq / 25000000
> +	 */
> +	ret = clk_set_phase(mxic->send_dly_clk, 9 * freq / 25000000);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int mxic_spi_set_freq(struct mxic_spi *mxic, unsigned long freq)
> +{
> +	int ret;
> +
> +	if (mxic->cur_speed_hz == freq)
> +		return 0;
> +
> +	mxic_spi_clk_disable(mxic);
> +	ret = mxic_spi_clk_setup(mxic, freq);
> +	if (ret)
> +		return ret;
> +
> +	ret = mxic_spi_clk_enable(mxic);
> +	if (ret)
> +		return ret;
> +
> +	mxic->cur_speed_hz = freq;
> +
> +	return 0;
> +}
> +
> +static void mxic_spi_hw_init(struct mxic_spi *mxic)
> +{
> +	writel(0, mxic->regs + DATA_STROB);
> +	writel(INT_STS_ALL, mxic->regs + INT_STS_EN);
> +	writel(0, mxic->regs + HC_EN);
> +	writel(0, mxic->regs + LRD_CFG);
> +	writel(0, mxic->regs + LRD_CTRL);
> +	writel(HC_CFG_NIO(1) | HC_CFG_TYPE(0, HC_CFG_TYPE_SPI_NAND) |
> +	       HC_CFG_SLV_ACT(0) | HC_CFG_MAN_CS_EN | HC_CFG_IDLE_SIO_LVL(1),
> +	       mxic->regs + HC_CFG);
> +}
> +
> +static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
> +			      void *rxbuf, unsigned int len)
> +{
> +	unsigned int pos = 0;
> +
> +	while (pos < len) {
> +		unsigned int nbytes = len - pos;
> +		u32 data = 0xffffffff;
> +		u32 sts;
> +		int ret;
> +
> +		if (nbytes > 4)
> +			nbytes = 4;
> +
> +		if (txbuf)
> +			memcpy(&data, txbuf + pos, nbytes);
> +
> +		ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
> +					 sts & INT_TX_EMPTY, 0, USEC_PER_SEC);
> +		if (ret)
> +			return ret;
> +
> +		writel(data, mxic->regs + TXD(nbytes % 4));
> +
> +		if (rxbuf) {
> +			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
> +						 sts & INT_TX_EMPTY, 0,
> +						 USEC_PER_SEC);
> +			if (ret)
> +				return ret;
> +
> +			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
> +						 sts & INT_RX_NOT_EMPTY, 0,
> +						 USEC_PER_SEC);
> +			if (ret)
> +				return ret;
> +
> +			data = readl(mxic->regs + RXD);
> +			data >>= (8 * (4 - nbytes));
> +			memcpy(rxbuf + pos, &data, nbytes);
> +			WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
> +		} else {
> +			readl(mxic->regs + RXD);
> +		}
> +		WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
> +
> +		pos += nbytes;
> +	}
> +
> +	return 0;
> +}
> +
> +static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
> +				     const struct spi_mem_op *op)
> +{
> +	if (op->data.buswidth > 4 || op->addr.buswidth > 4 ||
> +	    op->dummy.buswidth > 4 || op->cmd.buswidth > 4)
> +		return false;
> +
> +	if (op->data.nbytes && op->dummy.nbytes &&
> +	    op->data.buswidth != op->dummy.buswidth)
> +		return false;
> +
> +	if (op->addr.nbytes > 7)
> +		return false;
> +
> +	return true;
> +}
> +
> +static int mxic_spi_mem_exec_op(struct spi_mem *mem,
> +				const struct spi_mem_op *op)
> +{
> +	struct mxic_spi *mxic = spi_master_get_devdata(mem->spi->master);
> +	int nio = 1, i, ret;
> +	u32 ss_ctrl;
> +	u8 addr[8];
> +
> +	ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
> +	if (ret)
> +		return ret;
> +
> +	if (mem->spi->mode & (SPI_TX_QUAD | SPI_RX_QUAD))
> +		nio = 4;
> +	else if (mem->spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
> +		nio = 2;
> +
> +	writel(HC_CFG_NIO(nio) |
> +	       HC_CFG_TYPE(mem->spi->chip_select, HC_CFG_TYPE_SPI_NOR) |
> +	       HC_CFG_SLV_ACT(mem->spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1) |
> +	       HC_CFG_MAN_CS_EN,
> +	       mxic->regs + HC_CFG);
> +	writel(HC_EN_BIT, mxic->regs + HC_EN);
> +
> +	ss_ctrl = OP_CMD_BYTES(1) | OP_CMD_BUSW(fls(op->cmd.buswidth) - 1);
> +
> +	if (op->addr.nbytes)
> +		ss_ctrl |= OP_ADDR_BYTES(op->addr.nbytes) |
> +			   OP_ADDR_BUSW(fls(op->addr.buswidth) - 1);
> +
> +	if (op->dummy.nbytes)
> +		ss_ctrl |= OP_DUMMY_CYC(op->dummy.nbytes);
> +
> +	if (op->data.nbytes) {
> +		ss_ctrl |= OP_DATA_BUSW(fls(op->data.buswidth) - 1);
> +		if (op->data.dir == SPI_MEM_DATA_IN)
> +			ss_ctrl |= OP_READ;
> +	}
> +
> +	writel(ss_ctrl, mxic->regs + SS_CTRL(mem->spi->chip_select));
> +
> +	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
> +	       mxic->regs + HC_CFG);
> +
> +	ret = mxic_spi_data_xfer(mxic, &op->cmd.opcode, NULL, 1);
> +	if (ret)
> +		goto out;
> +
> +	for (i = 0; i < op->addr.nbytes; i++)
> +		addr[i] = op->addr.val >> (8 * (op->addr.nbytes - i - 1));
> +
> +	ret = mxic_spi_data_xfer(mxic, addr, NULL, op->addr.nbytes);
> +	if (ret)
> +		goto out;
> +
> +	ret = mxic_spi_data_xfer(mxic, NULL, NULL, op->dummy.nbytes);
> +	if (ret)
> +		goto out;
> +
> +	ret = mxic_spi_data_xfer(mxic,
> +				 op->data.dir == SPI_MEM_DATA_OUT ?
> +				 op->data.buf.out : NULL,
> +				 op->data.dir == SPI_MEM_DATA_IN ?
> +				 op->data.buf.in : NULL,
> +				 op->data.nbytes);
> +
> +out:
> +	writel(readl(mxic->regs + HC_CFG) & ~HC_CFG_MAN_CS_ASSERT,
> +	       mxic->regs + HC_CFG);
> +	writel(0, mxic->regs + HC_EN);
> +
> +	return ret;
> +}
> +
> +static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
> +	.supports_op = mxic_spi_mem_supports_op,
> +	.exec_op = mxic_spi_mem_exec_op,
> +};
> +
> +static void mxic_spi_set_cs(struct spi_device *spi, bool lvl)
> +{
> +	struct mxic_spi *mxic = spi_master_get_devdata(spi->master);
> +
> +	if (!lvl) {
> +		writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_EN,
> +		       mxic->regs + HC_CFG);
> +		writel(HC_EN_BIT, mxic->regs + HC_EN);
> +		writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
> +		       mxic->regs + HC_CFG);
> +	} else {
> +		writel(readl(mxic->regs + HC_CFG) & ~HC_CFG_MAN_CS_ASSERT,
> +		       mxic->regs + HC_CFG);
> +		writel(0, mxic->regs + HC_EN);
> +	}
> +}
> +
> +static int mxic_spi_transfer_one(struct spi_master *master,
> +				 struct spi_device *spi,
> +				 struct spi_transfer *t)
> +{
> +	struct mxic_spi *mxic = spi_master_get_devdata(master);
> +	unsigned int busw = OP_BUSW_1;
> +	int ret;
> +
> +	if (t->rx_buf && t->tx_buf) {
> +		if (((spi->mode & SPI_TX_QUAD) &&
> +		     !(spi->mode & SPI_RX_QUAD)) ||
> +		    ((spi->mode & SPI_TX_DUAL) &&
> +		     !(spi->mode & SPI_RX_DUAL)))
> +			return -ENOTSUPP;
> +	}
> +
> +	ret = mxic_spi_set_freq(mxic, t->speed_hz);
> +	if (ret)
> +		return ret;
> +
> +	if (t->tx_buf) {
> +		if (spi->mode & SPI_TX_QUAD)
> +			busw = OP_BUSW_4;
> +		else if (spi->mode & SPI_TX_DUAL)
> +			busw = OP_BUSW_2;
> +	} else if (t->rx_buf) {
> +		if (spi->mode & SPI_RX_QUAD)
> +			busw = OP_BUSW_4;
> +		else if (spi->mode & SPI_RX_DUAL)
> +			busw = OP_BUSW_2;
> +	}
> +
> +	writel(OP_CMD_BYTES(1) | OP_CMD_BUSW(busw) |
> +	       OP_DATA_BUSW(busw) | (t->rx_buf ? OP_READ : 0),
> +	       mxic->regs + SS_CTRL(0));
> +
> +	ret = mxic_spi_data_xfer(mxic, t->tx_buf, t->rx_buf, t->len);
> +	if (ret)
> +		return ret;
> +
> +	spi_finalize_current_transfer(master);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused mxic_spi_runtime_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct spi_master *master = platform_get_drvdata(pdev);
> +	struct mxic_spi *mxic = spi_master_get_devdata(master);
> +
> +	mxic_spi_clk_disable(mxic);
> +	clk_disable_unprepare(mxic->ps_clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused mxic_spi_runtime_resume(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct spi_master *master = platform_get_drvdata(pdev);
> +	struct mxic_spi *mxic = spi_master_get_devdata(master);
> +	int ret;
> +
> +	ret = clk_prepare_enable(mxic->ps_clk);
> +	if (ret) {
> +		dev_err(dev, "Cannot enable ps_clock.\n");
> +		return ret;
> +	}
> +
> +	return mxic_spi_clk_enable(mxic);
> +}
> +
> +static const struct dev_pm_ops mxic_spi_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(mxic_spi_runtime_suspend,
> +			   mxic_spi_runtime_resume, NULL)
> +};
> +
> +static int mxic_spi_probe(struct platform_device *pdev)
> +{
> +	struct spi_master *master;
> +	struct resource *res;
> +	struct mxic_spi *mxic;
> +	int ret;
> +
> +	master = spi_alloc_master(&pdev->dev, sizeof(struct mxic_spi));
> +	if (!master)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, master);
> +
> +	mxic = spi_master_get_devdata(master);
> +
> +	master->dev.of_node = pdev->dev.of_node;
> +
> +	mxic->ps_clk = devm_clk_get(&pdev->dev, "ps_clk");
> +	if (IS_ERR(mxic->ps_clk))
> +		return PTR_ERR(mxic->ps_clk);
> +
> +	mxic->send_clk = devm_clk_get(&pdev->dev, "send_clk");
> +	if (IS_ERR(mxic->send_clk))
> +		return PTR_ERR(mxic->send_clk);
> +
> +	mxic->send_dly_clk = devm_clk_get(&pdev->dev, "send_dly_clk");
> +	if (IS_ERR(mxic->send_dly_clk))
> +		return PTR_ERR(mxic->send_dly_clk);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
> +	mxic->regs = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(mxic->regs))
> +		return PTR_ERR(mxic->regs);
> +
> +	pm_runtime_enable(&pdev->dev);
> +	master->auto_runtime_pm = true;
> +
> +	master->num_chipselect = 1;
> +	master->mem_ops = &mxic_spi_mem_ops;
> +
> +	master->set_cs = mxic_spi_set_cs;
> +	master->transfer_one = mxic_spi_transfer_one;
> +	master->bits_per_word_mask = SPI_BPW_MASK(8);
> +	master->mode_bits = SPI_CPOL | SPI_CPHA |
> +			SPI_RX_DUAL | SPI_TX_DUAL |
> +			SPI_RX_QUAD | SPI_TX_QUAD;
> +
> +	mxic_spi_hw_init(mxic);
> +
> +	ret = spi_register_master(master);
> +	if (ret) {
> +		dev_err(&pdev->dev, "spi_register_master failed\n");
> +		goto err_put_master;
> +	}
> +
> +	return 0;
> +
> +err_put_master:
> +	spi_master_put(master);
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return ret;
> +}
> +
> +static int mxic_spi_remove(struct platform_device *pdev)
> +{
> +	struct spi_master *master = platform_get_drvdata(pdev);
> +
> +	pm_runtime_disable(&pdev->dev);
> +	spi_unregister_master(master);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id mxic_spi_of_ids[] = {
> +	{ .compatible = "mxicy,mx25f0a-spi", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mxic_spi_of_ids);
> +
> +static struct platform_driver mxic_spi_driver = {
> +	.probe = mxic_spi_probe,
> +	.remove = mxic_spi_remove,
> +	.driver = {
> +		.name = "mxic-spi",
> +		.of_match_table = mxic_spi_of_ids,
> +		.pm = &mxic_spi_dev_pm_ops,
> +	},
> +};
> +module_platform_driver(mxic_spi_driver);
> +
> +MODULE_AUTHOR("Mason Yang <masonccyang@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("MX25F0A SPI controller driver");
> +MODULE_LICENSE("GPL v2");