From:   Li-hao Kuo <lhjeff911@gmail.com>
To:     p.zabel@pengutronix.de, broonie@kernel.org,
        andyshevchenko@gmail.com, robh+dt@kernel.org,
        linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     wells.lu@sunplus.com, lh.kuo@sunplus.com,
        "Li-hao Kuo" <lhjeff911@gmail.com>
Subject: [PATCH v4 1/2] SPI: Add SPI driver for Sunplus SP7021
Date:   Fri, 10 Dec 2021 17:02:47 +0800
Message-Id: <65fb77debacc95ed3f54adac978ba24f2470f92e.1639123362.git.lhjeff911@gmail.com>
In-Reply-To: <cover.1639123362.git.lhjeff911@gmail.com>
References: <cover.1639123362.git.lhjeff911@gmail.com>
In-Reply-To: <cover.1639123362.git.lhjeff911@gmail.com>
References: <cover.1639123362.git.lhjeff911@gmail.com>
Precedence: bulk

From: "Li-hao Kuo" <lhjeff911@gmail.com>

Add SPI driver for Sunplus SP7021.

Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
---
Changes in v4:
 - Addressed all comments from Mr. Philipp Zabel
 - Addressed all comments from Mr. Rob Herring
 - Addressed all comments from Mr. Andy Shevchenko
 
 MAINTAINERS                      |   6 +
 drivers/spi/Kconfig              |  11 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/spi-sunplus-sp7021.c | 609 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 627 insertions(+)
 create mode 100644 drivers/spi/spi-sunplus-sp7021.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8691c53..91f5707 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18233,6 +18233,12 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/dlink/sundance.c
 
+SUNPLUS SPI CONTROLLER INTERFACE DRIVER
+M:	Li-hao Kuo <lhjeff911@gmail.com>
+L:	linux-spi@vger.kernel.org
+S:	Maintained
+F:	drivers/spi/spi-sunplus-sp7021.c
+
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
 M:	Rich Felker <dalias@libc.org>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 596705d..a3f45e9 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -866,6 +866,17 @@ config SPI_SUN6I
 	help
 	  This enables using the SPI controller on the Allwinner A31 SoCs.
 
+config SPI_SUNPLUS_SP7021
+	tristate "Sunplus SP7021 SPI controller"
+	depends on SOC_SP7021
+	help
+	  This enables Sunplus SP7021 SPI controller driver on the SP7021 SoCs.
+	  This driver can also be built as a module. If so, the module will be
+	  called as spi-sunplus-sp7021.
+
+	  If you have a Sunplus SP7021 platform say Y here.
+	  If unsure, say N.
+
 config SPI_SYNQUACER
 	tristate "Socionext's SynQuacer HighSpeed SPI controller"
 	depends on ARCH_SYNQUACER || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index dd7393a..b455eaf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -119,6 +119,7 @@ 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-$(CONFIG_SPI_SUNPLUS_SP7021)	+= spi-sunplus-sp7021.o
 obj-$(CONFIG_SPI_SYNQUACER)		+= spi-synquacer.o
 obj-$(CONFIG_SPI_TEGRA210_QUAD)		+= spi-tegra210-quad.o
 obj-$(CONFIG_SPI_TEGRA114)		+= spi-tegra114.o
diff --git a/drivers/spi/spi-sunplus-sp7021.c b/drivers/spi/spi-sunplus-sp7021.c
new file mode 100644
index 0000000..3269cad
--- /dev/null
+++ b/drivers/spi/spi-sunplus-sp7021.c
@@ -0,0 +1,609 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Sunplus Inc.
+// Author: Li-hao Kuo <lhjeff911@gmail.com>
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+
+#define SP7021_DATA_RDY_REG       0x0044
+#define SP7021_SLV_DMA_CTRL_REG   0x0048
+#define SP7021_SLV_DMA_LENGTH_REG 0x004c
+#define SP7021_SLV_DMA_ADDR_REG   0x004c
+
+#define SP7021_SLA_DATA_RDY       BIT(0)
+#define SP7021_SLA_SW_RST         BIT(1)
+#define SP7021_SLA_DMA_W_INT      BIT(8)
+#define SP7021_SLA_CLR_INT        BIT(8)
+#define SP7021_SLA_DMA_EN         BIT(0)
+#define SP7021_SLA_DMA_RW         BIT(6)
+#define SP7021_SLA_DMA_CMD        GENMASK(3, 2)
+
+#define SP7021_FIFO_REG           0x0034
+#define SP7021_SPI_STATUS_REG     0x0038
+#define SP7021_SPI_CONFIG_REG     0x003c
+#define SP7021_INT_BUSY_REG       0x004c
+#define SP7021_DMA_CTRL_REG       0x0050
+
+#define SP7021_SPI_START_FD       BIT(0)
+#define SP7021_FD_SW_RST          BIT(1)
+#define SP7021_TX_EMP_FLAG        BIT(2)
+#define SP7021_RX_EMP_FLAG        BIT(4)
+#define SP7021_RX_FULL_FLAG       BIT(5)
+#define SP7021_FINISH_FLAG        BIT(6)
+
+#define SP7021_TX_CNT_MASK        GENMASK(11, 8)
+#define SP7021_RX_CNT_MASK        GENMASK(15, 12)
+#define SP7021_TX_LEN_MASK        GENMASK(23, 16)
+#define SP7021_GET_LEN_MASK       GENMASK(31, 24)
+#define SP7021_SET_TX_LEN         GENMASK(23, 16)
+#define SP7021_SET_XFER_LEN       GENMASK(31, 24)
+
+#define SP7021_CPOL_FD            BIT(0)
+#define SP7021_CPHA_R             BIT(1)
+#define SP7021_CPHA_W             BIT(2)
+#define SP7021_LSB_SEL            BIT(4)
+#define SP7021_CS_POR             BIT(5)
+#define SP7021_FD_SEL             BIT(6)
+
+#define SP7021_RX_UNIT            GENMASK(8, 7)
+#define SP7021_TX_UNIT            GENMASK(10, 9)
+#define SP7021_TX_EMP_FLAG_MASK   BIT(11)
+#define SP7021_RX_FULL_FLAG_MASK  BIT(14)
+#define SP7021_FINISH_FLAG_MASK   BIT(15)
+#define SP7021_CLEAN_RW_BYTE      GENMASK(10, 7)
+#define SP7021_CLEAN_FLUG_MASK    GENMASK(15, 11)
+
+#define SP7021_INT_BYPASS         BIT(3)
+#define SP7021_CLR_MAS_INT        BIT(6)
+#define SP7021_CLR_MAS_W_INT      BIT(7)
+
+#define SP7021_SPI_DATA_SIZE      (255)
+#define SP7021_FIFO_DATA_BITS     (16 * 8)
+
+enum SP_SPI_MODE {
+	SP7021_SLA_READ = 0,
+	SP7021_SLA_WRITE = 1,
+	SP7021_SPI_IDLE = 2,
+};
+
+enum {
+	SP7021_MASTER_MODE = 0,
+	SP7021_SLAVE_MODE = 1,
+};
+
+struct sp7021_spi_ctlr {
+	struct device *dev;
+	struct spi_controller *ctlr;
+	void __iomem *mas_base;
+	void __iomem *sla_base;
+	u32 xfer_conf;
+	int mode;
+	int mas_irq;
+	int sla_irq;
+	struct clk *spi_clk;
+	struct reset_control *rstc;
+	// irq spin lock
+	spinlock_t lock;
+	// data xfer lock
+	struct mutex buf_lock;
+	struct completion isr_done;
+	struct completion sla_isr;
+	unsigned int  rx_cur_len;
+	unsigned int  tx_cur_len;
+	unsigned int  data_unit;
+	const u8 *tx_buf;
+	u8 *rx_buf;
+};
+
+static irqreturn_t sp7021_spi_sla_irq(int irq, void *dev)
+{
+	struct sp7021_spi_ctlr *pspim = dev;
+	unsigned int data_status;
+
+	data_status = readl(pspim->sla_base + SP7021_DATA_RDY_REG);
+	writel(data_status | SP7021_SLA_CLR_INT, pspim->sla_base + SP7021_DATA_RDY_REG);
+	complete(&pspim->sla_isr);
+	return IRQ_NONE;
+}
+
+static int sp7021_spi_sla_abort(struct spi_controller *ctlr)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	complete(&pspim->sla_isr);
+	complete(&pspim->isr_done);
+	return 0;
+}
+
+int sp7021_spi_sla_tx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);
+	u32 reg_temp = 0;
+
+	mutex_lock(&pspim->buf_lock);
+	reinit_completion(&pspim->sla_isr);
+	reg_temp = SP7021_SLA_DMA_EN | SP7021_SLA_DMA_RW | FIELD_PREP(SP7021_SLA_DMA_CMD, 3);
+	writel_relaxed(reg_temp, pspim->sla_base + SP7021_SLV_DMA_CTRL_REG);
+	writel_relaxed(xfer->len, pspim->sla_base + SP7021_SLV_DMA_LENGTH_REG);
+	writel_relaxed(xfer->tx_dma, pspim->sla_base + SP7021_SLV_DMA_ADDR_REG);
+	writel(readl(pspim->sla_base + SP7021_DATA_RDY_REG) | SP7021_SLA_DATA_RDY,
+	       pspim->sla_base + SP7021_DATA_RDY_REG);
+	if (wait_for_completion_interruptible(&pspim->isr_done)) {
+		dev_err(&spi->dev, "%s() wait_for_completion err\n", __func__);
+		return -EINTR;
+	}
+	mutex_unlock(&pspim->buf_lock);
+	return 0;
+}
+
+int sp7021_spi_sla_rx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);
+	u32 reg_temp = 0;
+	int ret = 0;
+
+	mutex_lock(&pspim->buf_lock);
+	reinit_completion(&pspim->isr_done);
+	reg_temp = SP7021_SLA_DMA_EN | FIELD_PREP(SP7021_SLA_DMA_CMD, 3);
+	writel_relaxed(reg_temp, pspim->sla_base + SP7021_SLV_DMA_CTRL_REG);
+	writel(xfer->len, pspim->sla_base + SP7021_SLV_DMA_LENGTH_REG);
+	writel(xfer->rx_dma, pspim->sla_base + SP7021_SLV_DMA_ADDR_REG);
+	if (wait_for_completion_interruptible(&pspim->isr_done)) {
+		dev_err(&spi->dev, "%s() wait_for_completion err\n", __func__);
+		return -EINTR;
+	}
+	writel(SP7021_SLA_SW_RST, pspim->sla_base + SP7021_SLV_DMA_CTRL_REG);
+	mutex_unlock(&pspim->buf_lock);
+	return ret;
+}
+
+void sp7021_spi_mas_rb(struct sp7021_spi_ctlr *pspim, unsigned int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		pspim->rx_buf[pspim->rx_cur_len] =
+			readl(pspim->mas_base + SP7021_FIFO_REG);
+		pspim->rx_cur_len++;
+	}
+}
+
+void sp7021_spi_mas_wb(struct sp7021_spi_ctlr *pspim, unsigned int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		writel(pspim->tx_buf[pspim->tx_cur_len],
+		       pspim->mas_base + SP7021_FIFO_REG);
+		pspim->tx_cur_len++;
+	}
+}
+
+static irqreturn_t sp7021_spi_mas_irq(int irq, void *dev)
+{
+	struct sp7021_spi_ctlr *pspim = dev;
+	unsigned int tx_cnt, total_len;
+	unsigned int tx_len, rx_cnt;
+	unsigned int fd_status;
+	unsigned long flags;
+	bool isrdone = false;
+
+	fd_status = readl(pspim->mas_base + SP7021_SPI_STATUS_REG);
+	tx_cnt = FIELD_GET(SP7021_TX_CNT_MASK, fd_status);
+	tx_len = FIELD_GET(SP7021_TX_LEN_MASK, fd_status);
+	total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+
+	if ((fd_status & SP7021_TX_EMP_FLAG) && (fd_status & SP7021_RX_EMP_FLAG) && total_len == 0)
+		return IRQ_NONE;
+
+	if (tx_len == 0 && total_len == 0)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&pspim->lock, flags);
+
+	rx_cnt = FIELD_GET(SP7021_RX_CNT_MASK, fd_status);
+	if (fd_status & SP7021_RX_FULL_FLAG)
+		rx_cnt = pspim->data_unit;
+
+	tx_cnt = min(tx_len - pspim->tx_cur_len, pspim->data_unit - tx_cnt);
+	dev_dbg(pspim->dev, "fd_st=0x%x rx_c:%d tx_c:%d tx_l:%d",
+		fd_status, rx_cnt, tx_cnt, tx_len);
+
+	if (rx_cnt > 0)
+		sp7021_spi_mas_rb(pspim, rx_cnt);
+	if (tx_cnt > 0)
+		sp7021_spi_mas_wb(pspim, tx_cnt);
+
+	fd_status = readl(pspim->mas_base + SP7021_SPI_STATUS_REG);
+	tx_len = FIELD_GET(SP7021_TX_LEN_MASK, fd_status);
+	total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+
+	if (fd_status & SP7021_FINISH_FLAG || tx_len == pspim->tx_cur_len) {
+		while (total_len != pspim->rx_cur_len) {
+			fd_status = readl(pspim->mas_base + SP7021_SPI_STATUS_REG);
+			total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+			if (fd_status & SP7021_RX_FULL_FLAG)
+				rx_cnt = pspim->data_unit;
+			else
+				rx_cnt = FIELD_GET(SP7021_RX_CNT_MASK, fd_status);
+
+			if (rx_cnt > 0)
+				sp7021_spi_mas_rb(pspim, rx_cnt);
+		}
+		writel(readl(pspim->mas_base + SP7021_INT_BUSY_REG)
+			| SP7021_CLR_MAS_INT, pspim->mas_base + SP7021_INT_BUSY_REG);
+		writel(SP7021_FINISH_FLAG, pspim->mas_base + SP7021_SPI_STATUS_REG);
+
+		isrdone = true;
+	}
+
+	if (isrdone)
+		complete(&pspim->isr_done);
+	spin_unlock_irqrestore(&pspim->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void sp7021_prep_transfer(struct spi_controller *ctlr, struct spi_device *spi)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	pspim->tx_cur_len = 0;
+	pspim->rx_cur_len = 0;
+	pspim->data_unit = SP7021_FIFO_DATA_BITS / spi->bits_per_word;
+}
+
+// preliminary set CS, CPOL, CPHA and LSB
+static int sp7021_spi_controller_prepare_message(struct spi_controller *ctlr,
+						 struct spi_message *msg)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	struct spi_device *s = msg->spi;
+	u32 rs = 0;
+
+	writel(readl(pspim->mas_base + SP7021_SPI_STATUS_REG) | SP7021_FD_SW_RST,
+	       pspim->mas_base + SP7021_SPI_STATUS_REG);
+	rs |= SP7021_FD_SEL;
+	if (s->mode & SPI_CPOL)
+		rs |= SP7021_CPOL_FD;
+
+	if (s->mode & SPI_LSB_FIRST)
+		rs |= SP7021_LSB_SEL;
+
+	if (s->mode & SPI_CS_HIGH)
+		rs |= SP7021_CS_POR;
+
+	if (s->mode & SPI_CPHA)
+		rs |=  SP7021_CPHA_R;
+	else
+		rs |=  SP7021_CPHA_W;
+
+	rs |=  FIELD_PREP(SP7021_TX_UNIT, 0) | FIELD_PREP(SP7021_RX_UNIT, 0);
+	pspim->xfer_conf = rs;
+	if (pspim->xfer_conf & SP7021_CPOL_FD)
+		writel(pspim->xfer_conf, pspim->mas_base + SP7021_SPI_CONFIG_REG);
+
+	return 0;
+}
+
+static void sp7021_spi_setup_clk(struct spi_controller *ctlr, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	unsigned int clk_rate, clk_sel, div;
+
+	clk_rate = clk_get_rate(pspim->spi_clk);
+	div = clk_rate / xfer->speed_hz;
+	if (div < 2)
+		div = 2;
+	clk_sel = (div / 2) - 1;
+	pspim->xfer_conf |= ((clk_sel & 0xffff) << 16);
+	writel(pspim->xfer_conf, pspim->mas_base + SP7021_SPI_CONFIG_REG);
+}
+
+static int sp7021_spi_mas_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
+				       struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	unsigned long timeout = msecs_to_jiffies(1000);
+	unsigned int xfer_cnt, xfer_len, last_len;
+	unsigned int i, len_temp;
+	u32 reg_temp;
+	int ret;
+
+	xfer_cnt = xfer->len / SP7021_SPI_DATA_SIZE;
+	last_len = xfer->len % SP7021_SPI_DATA_SIZE;
+
+	for (i = 0; i <= xfer_cnt; i++) {
+		mutex_lock(&pspim->buf_lock);
+		sp7021_prep_transfer(ctlr, spi);
+		sp7021_spi_setup_clk(ctlr, xfer);
+		reinit_completion(&pspim->isr_done);
+
+		if (i == xfer_cnt)
+			xfer_len = last_len;
+		else
+			xfer_len = SP7021_SPI_DATA_SIZE;
+
+		pspim->tx_buf = xfer->tx_buf + i * SP7021_SPI_DATA_SIZE;
+		pspim->rx_buf = xfer->rx_buf + i * SP7021_SPI_DATA_SIZE;
+
+		if (pspim->tx_cur_len < xfer_len) {
+			len_temp = min(pspim->data_unit, xfer_len);
+			sp7021_spi_mas_wb(pspim, len_temp);
+		}
+		reg_temp = readl(pspim->mas_base + SP7021_SPI_CONFIG_REG);
+		reg_temp &= ~SP7021_CLEAN_RW_BYTE;
+		reg_temp &= ~SP7021_CLEAN_FLUG_MASK;
+		reg_temp |= SP7021_FD_SEL | SP7021_FINISH_FLAG_MASK |
+			    SP7021_TX_EMP_FLAG_MASK | SP7021_RX_FULL_FLAG_MASK |
+			    FIELD_PREP(SP7021_TX_UNIT, 0) | FIELD_PREP(SP7021_RX_UNIT, 0);
+		writel(reg_temp, pspim->mas_base + SP7021_SPI_CONFIG_REG);
+
+		reg_temp = FIELD_PREP(SP7021_SET_TX_LEN, xfer_len) |
+				      FIELD_PREP(SP7021_SET_XFER_LEN, xfer_len) |
+				      SP7021_SPI_START_FD;
+		writel(reg_temp, pspim->mas_base + SP7021_SPI_STATUS_REG);
+
+		if (!wait_for_completion_interruptible_timeout(&pspim->isr_done, timeout)) {
+			dev_err(&spi->dev, "wait_for_completion err\n");
+			return -ETIMEDOUT;
+		}
+
+		reg_temp = readl(pspim->mas_base + SP7021_SPI_STATUS_REG);
+		if (reg_temp & SP7021_FINISH_FLAG) {
+			writel(SP7021_FINISH_FLAG, pspim->mas_base + SP7021_SPI_STATUS_REG);
+			writel(readl(pspim->mas_base + SP7021_SPI_CONFIG_REG) &
+				SP7021_CLEAN_FLUG_MASK, pspim->mas_base + SP7021_SPI_CONFIG_REG);
+		}
+
+		ret = 0;
+
+		if (pspim->xfer_conf & SP7021_CPOL_FD)
+			writel(pspim->xfer_conf, pspim->mas_base + SP7021_SPI_CONFIG_REG);
+
+		mutex_unlock(&pspim->buf_lock);
+	}
+	return ret;
+}
+
+static int sp7021_spi_sla_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
+				       struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	struct device *dev = pspim->dev;
+	int mode, ret = 0;
+
+	mode = SP7021_SPI_IDLE;
+	if (spi_controller_is_slave(ctlr)) {
+		if (xfer->tx_buf && xfer->rx_buf) {
+			dev_dbg(&ctlr->dev, "%s() wrong command\n", __func__);
+			ret = -EINVAL;
+		} else if (xfer->tx_buf) {
+			xfer->tx_dma = dma_map_single(dev, (void *)xfer->tx_buf,
+						      xfer->len, DMA_TO_DEVICE);
+			if (dma_mapping_error(dev, xfer->tx_dma))
+				return -ENOMEM;
+			mode = SP7021_SLA_WRITE;
+		} else if (xfer->rx_buf) {
+			xfer->rx_dma = dma_map_single(dev, xfer->rx_buf, xfer->len,
+						      DMA_FROM_DEVICE);
+			if (dma_mapping_error(dev, xfer->rx_dma))
+				return -ENOMEM;
+			mode = SP7021_SLA_READ;
+		}
+
+		switch (mode) {
+		case SP7021_SLA_WRITE:
+			sp7021_spi_sla_tx(spi, xfer);
+			break;
+		case SP7021_SLA_READ:
+			sp7021_spi_sla_rx(spi, xfer);
+			break;
+		default:
+			break;
+		}
+
+		if (xfer->tx_buf)
+			dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
+		if (xfer->rx_buf)
+			dma_unmap_single(dev, xfer->rx_dma, xfer->len, DMA_FROM_DEVICE);
+	}
+
+	spi_finalize_current_transfer(ctlr);
+	return ret;
+}
+
+static void sp7021_spi_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static void sp7021_spi_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int sp7021_spi_controller_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sp7021_spi_ctlr *pspim;
+	struct spi_controller *ctlr;
+	int mode, ret;
+
+	mode = SP7021_MASTER_MODE;
+	pdev->id = of_alias_get_id(pdev->dev.of_node, "sp_spi");
+
+	if (of_property_read_bool(pdev->dev.of_node, "spi-slave"))
+		mode = SP7021_SLAVE_MODE;
+
+	if (mode == SP7021_SLAVE_MODE)
+		ctlr = devm_spi_alloc_slave(dev, sizeof(*pspim));
+	else
+		ctlr = devm_spi_alloc_master(dev, sizeof(*pspim));
+	if (!ctlr)
+		return -ENOMEM;
+	device_set_node(&ctlr->dev, pdev->dev.fwnode);
+	ctlr->bus_num = pdev->id;
+	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+	ctlr->auto_runtime_pm = true;
+	ctlr->prepare_message = sp7021_spi_controller_prepare_message;
+	if (mode == SP7021_SLAVE_MODE) {
+		ctlr->transfer_one = sp7021_spi_sla_transfer_one;
+		ctlr->slave_abort = sp7021_spi_sla_abort;
+		ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
+	} else {
+		ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
+		ctlr->min_speed_hz = 40000;
+		ctlr->max_speed_hz = 25000000;
+		ctlr->use_gpio_descriptors = true;
+		ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
+		ctlr->transfer_one = sp7021_spi_mas_transfer_one;
+	}
+	platform_set_drvdata(pdev, ctlr);
+	pspim = spi_controller_get_devdata(ctlr);
+	pspim->ctlr = ctlr;
+	pspim->dev = dev;
+	spin_lock_init(&pspim->lock);
+	mutex_init(&pspim->buf_lock);
+	init_completion(&pspim->isr_done);
+	init_completion(&pspim->sla_isr);
+
+	pspim->mas_base = devm_platform_ioremap_resource_byname(pdev, "master");
+	if (IS_ERR(pspim->mas_base))
+		return dev_err_probe(dev, PTR_ERR(pspim->mas_base), "mas_base get fail\n");
+
+	pspim->sla_base = devm_platform_ioremap_resource_byname(pdev, "slave");
+	if (IS_ERR(pspim->sla_base))
+		return dev_err_probe(dev, PTR_ERR(pspim->sla_base), "sla_base get fail\n");
+
+	pspim->mas_irq = platform_get_irq_byname(pdev, "mas_risc");
+	if (pspim->mas_irq < 0)
+		return pspim->mas_irq;
+
+	pspim->sla_irq = platform_get_irq_byname(pdev, "slave_risc");
+	if (pspim->sla_irq < 0)
+		return pspim->sla_irq;
+
+	ret = devm_request_irq(dev, pspim->mas_irq, sp7021_spi_mas_irq,
+			       IRQF_TRIGGER_RISING, pdev->name, pspim);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(dev, pspim->sla_irq, sp7021_spi_sla_irq,
+			       IRQF_TRIGGER_RISING, pdev->name, pspim);
+	if (ret)
+		return ret;
+
+	pspim->spi_clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(pspim->spi_clk))
+		return dev_err_probe(dev, PTR_ERR(pspim->spi_clk), "clk get fail\n");
+
+	pspim->rstc = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(pspim->rstc))
+		return dev_err_probe(dev, PTR_ERR(pspim->rstc), "rst get fail\n");
+
+	ret = clk_prepare_enable(pspim->spi_clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable clk\n");
+
+	ret = devm_add_action_or_reset(dev, sp7021_spi_disable_unprepare, pspim->spi_clk);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(pspim->rstc);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to deassert reset\n");
+
+	ret = devm_add_action_or_reset(dev, sp7021_spi_reset_control_assert, pspim->rstc);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(dev);
+	ret = spi_register_controller(ctlr);
+	if (ret) {
+		pm_runtime_disable(dev);
+		return dev_err_probe(dev, ret, "spi_register_master fail\n");
+	}
+
+	return ret;
+}
+
+static int sp7021_spi_controller_remove(struct platform_device *pdev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
+
+	spi_unregister_controller(ctlr);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused sp7021_spi_controller_suspend(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_assert(pspim->rstc);
+}
+
+static int __maybe_unused sp7021_spi_controller_resume(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	reset_control_deassert(pspim->rstc);
+	return clk_prepare_enable(pspim->spi_clk);
+}
+
+static int sp7021_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_assert(pspim->rstc);
+}
+
+static int sp7021_spi_runtime_resume(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_deassert(pspim->rstc);
+}
+
+static const struct dev_pm_ops sp7021_spi_pm_ops = {
+	SET_RUNTIME_PM_OPS(sp7021_spi_runtime_suspend,
+			   sp7021_spi_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(sp7021_spi_controller_suspend,
+				sp7021_spi_controller_resume)
+};
+
+static const struct of_device_id sp7021_spi_controller_ids[] = {
+	{ .compatible = "sunplus,sp7021-spi" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sp7021_spi_controller_ids);
+
+static struct platform_driver sp7021_spi_controller_driver = {
+	.probe = sp7021_spi_controller_probe,
+	.remove = sp7021_spi_controller_remove,
+	.driver = {
+		.name = "sunplus,sp7021-spi-controller",
+		.of_match_table = sp7021_spi_controller_ids,
+		.pm     = &sp7021_spi_pm_ops,
+	},
+};
+module_platform_driver(sp7021_spi_controller_driver);
+
+MODULE_AUTHOR("Li-hao Kuo <lhjeff911@gmail.com>");
+MODULE_DESCRIPTION("Sunplus SPI controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4