Applied "spi: sprd: Add SPI driver for Spreadtrum SC9860" to the spi tree

[Mark Brown <broonie@xxxxxxxxxx>]

The patch

   spi: sprd: Add SPI driver for Spreadtrum SC9860

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From e7d973a31c24b3e82d54b6619f4b633038fce228 Mon Sep 17 00:00:00 2001
From: Lanqing Liu <lanqing.liu@xxxxxxxxxxxxxx>
Date: Thu, 16 Aug 2018 20:54:51 +0800
Subject: [PATCH] spi: sprd: Add SPI driver for Spreadtrum SC9860

This patch adds the SPI controller driver for Spreadtrum SC9860 platform.

Signed-off-by: Lanqing Liu <lanqing.liu@xxxxxxxxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/Kconfig    |   6 +
 drivers/spi/Makefile   |   1 +
 drivers/spi/spi-sprd.c | 745 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 752 insertions(+)
 create mode 100644 drivers/spi/spi-sprd.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 671d078349cc..7580eb76ab18 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -596,6 +596,12 @@ config SPI_SIRF
 	help
 	  SPI driver for CSR SiRFprimaII SoCs
 
+config SPI_SPRD
+	tristate "Spreadtrum SPI controller"
+	depends on ARCH_SPRD || COMPILE_TEST
+	help
+	  SPI driver for Spreadtrum SoCs.
+
 config SPI_SPRD_ADI
 	tristate "Spreadtrum ADI controller"
 	depends on ARCH_SPRD || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index a90d55970036..1920b6cc2b7e 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_SPI_SH_HSPI)		+= spi-sh-hspi.o
 obj-$(CONFIG_SPI_SH_MSIOF)		+= spi-sh-msiof.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi-sh-sci.o
 obj-$(CONFIG_SPI_SIRF)		+= spi-sirf.o
+obj-$(CONFIG_SPI_SPRD)			+= spi-sprd.o
 obj-$(CONFIG_SPI_SPRD_ADI)		+= spi-sprd-adi.o
 obj-$(CONFIG_SPI_STM32) 		+= spi-stm32.o
 obj-$(CONFIG_SPI_ST_SSC4)		+= spi-st-ssc4.o
diff --git a/drivers/spi/spi-sprd.c b/drivers/spi/spi-sprd.c
new file mode 100644
index 000000000000..a9a6c5ed443f
--- /dev/null
+++ b/drivers/spi/spi-sprd.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Spreadtrum Communications Inc.
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/spi/spi.h>
+
+#define SPRD_SPI_TXD			0x0
+#define SPRD_SPI_CLKD			0x4
+#define SPRD_SPI_CTL0			0x8
+#define SPRD_SPI_CTL1			0xc
+#define SPRD_SPI_CTL2			0x10
+#define SPRD_SPI_CTL3			0x14
+#define SPRD_SPI_CTL4			0x18
+#define SPRD_SPI_CTL5			0x1c
+#define SPRD_SPI_INT_EN			0x20
+#define SPRD_SPI_INT_CLR		0x24
+#define SPRD_SPI_INT_RAW_STS		0x28
+#define SPRD_SPI_INT_MASK_STS		0x2c
+#define SPRD_SPI_STS1			0x30
+#define SPRD_SPI_STS2			0x34
+#define SPRD_SPI_DSP_WAIT		0x38
+#define SPRD_SPI_STS3			0x3c
+#define SPRD_SPI_CTL6			0x40
+#define SPRD_SPI_STS4			0x44
+#define SPRD_SPI_FIFO_RST		0x48
+#define SPRD_SPI_CTL7			0x4c
+#define SPRD_SPI_STS5			0x50
+#define SPRD_SPI_CTL8			0x54
+#define SPRD_SPI_CTL9			0x58
+#define SPRD_SPI_CTL10			0x5c
+#define SPRD_SPI_CTL11			0x60
+#define SPRD_SPI_CTL12			0x64
+#define SPRD_SPI_STS6			0x68
+#define SPRD_SPI_STS7			0x6c
+#define SPRD_SPI_STS8			0x70
+#define SPRD_SPI_STS9			0x74
+
+/* Bits & mask definition for register CTL0 */
+#define SPRD_SPI_SCK_REV		BIT(13)
+#define SPRD_SPI_NG_TX			BIT(1)
+#define SPRD_SPI_NG_RX			BIT(0)
+#define SPRD_SPI_CHNL_LEN_MASK		GENMASK(4, 0)
+#define SPRD_SPI_CSN_MASK		GENMASK(11, 8)
+#define SPRD_SPI_CS0_VALID		BIT(8)
+
+/* Bits & mask definition for register SPI_INT_EN */
+#define SPRD_SPI_TX_END_INT_EN		BIT(8)
+#define SPRD_SPI_RX_END_INT_EN		BIT(9)
+
+/* Bits & mask definition for register SPI_INT_RAW_STS */
+#define SPRD_SPI_TX_END_RAW		BIT(8)
+#define SPRD_SPI_RX_END_RAW		BIT(9)
+
+/* Bits & mask definition for register SPI_INT_CLR */
+#define SPRD_SPI_TX_END_CLR		BIT(8)
+#define SPRD_SPI_RX_END_CLR		BIT(9)
+
+/* Bits & mask definition for register INT_MASK_STS */
+#define SPRD_SPI_MASK_RX_END		BIT(9)
+#define SPRD_SPI_MASK_TX_END		BIT(8)
+
+/* Bits & mask definition for register STS2 */
+#define SPRD_SPI_TX_BUSY		BIT(8)
+
+/* Bits & mask definition for register CTL1 */
+#define SPRD_SPI_RX_MODE		BIT(12)
+#define SPRD_SPI_TX_MODE		BIT(13)
+#define SPRD_SPI_RTX_MD_MASK		GENMASK(13, 12)
+
+/* Bits & mask definition for register CTL2 */
+#define SPRD_SPI_DMA_EN			BIT(6)
+
+/* Bits & mask definition for register CTL4 */
+#define SPRD_SPI_START_RX		BIT(9)
+#define SPRD_SPI_ONLY_RECV_MASK		GENMASK(8, 0)
+
+/* Bits & mask definition for register SPI_INT_CLR */
+#define SPRD_SPI_RX_END_INT_CLR		BIT(9)
+#define SPRD_SPI_TX_END_INT_CLR		BIT(8)
+
+/* Bits & mask definition for register SPI_INT_RAW */
+#define SPRD_SPI_RX_END_IRQ		BIT(9)
+#define SPRD_SPI_TX_END_IRQ		BIT(8)
+
+/* Bits & mask definition for register CTL12 */
+#define SPRD_SPI_SW_RX_REQ		BIT(0)
+#define SPRD_SPI_SW_TX_REQ		BIT(1)
+
+/* Bits & mask definition for register CTL7 */
+#define SPRD_SPI_DATA_LINE2_EN		BIT(15)
+#define SPRD_SPI_MODE_MASK		GENMASK(5, 3)
+#define SPRD_SPI_MODE_OFFSET		3
+#define SPRD_SPI_3WIRE_MODE		4
+#define SPRD_SPI_4WIRE_MODE		0
+
+/* Bits & mask definition for register CTL8 */
+#define SPRD_SPI_TX_MAX_LEN_MASK	GENMASK(19, 0)
+#define SPRD_SPI_TX_LEN_H_MASK		GENMASK(3, 0)
+#define SPRD_SPI_TX_LEN_H_OFFSET	16
+
+/* Bits & mask definition for register CTL9 */
+#define SPRD_SPI_TX_LEN_L_MASK		GENMASK(15, 0)
+
+/* Bits & mask definition for register CTL10 */
+#define SPRD_SPI_RX_MAX_LEN_MASK	GENMASK(19, 0)
+#define SPRD_SPI_RX_LEN_H_MASK		GENMASK(3, 0)
+#define SPRD_SPI_RX_LEN_H_OFFSET	16
+
+/* Bits & mask definition for register CTL11 */
+#define SPRD_SPI_RX_LEN_L_MASK		GENMASK(15, 0)
+
+/* Default & maximum word delay cycles */
+#define SPRD_SPI_MIN_DELAY_CYCLE	14
+#define SPRD_SPI_MAX_DELAY_CYCLE	130
+
+#define SPRD_SPI_FIFO_SIZE		32
+#define SPRD_SPI_CHIP_CS_NUM		0x4
+#define SPRD_SPI_CHNL_LEN		2
+#define SPRD_SPI_DEFAULT_SOURCE		26000000
+#define SPRD_SPI_MAX_SPEED_HZ		48000000
+#define SPRD_SPI_AUTOSUSPEND_DELAY	100
+
+struct sprd_spi {
+	void __iomem *base;
+	struct device *dev;
+	struct clk *clk;
+	u32 src_clk;
+	u32 hw_mode;
+	u32 trans_len;
+	u32 trans_mode;
+	u32 word_delay;
+	u32 hw_speed_hz;
+	u32 len;
+	int status;
+	const void *tx_buf;
+	void *rx_buf;
+	int (*read_bufs)(struct sprd_spi *ss, u32 len);
+	int (*write_bufs)(struct sprd_spi *ss, u32 len);
+};
+
+static u32 sprd_spi_transfer_max_timeout(struct sprd_spi *ss,
+					 struct spi_transfer *t)
+{
+	/*
+	 * The time spent on transmission of the full FIFO data is the maximum
+	 * SPI transmission time.
+	 */
+	u32 size = t->bits_per_word * SPRD_SPI_FIFO_SIZE;
+	u32 bit_time_us = DIV_ROUND_UP(USEC_PER_SEC, ss->hw_speed_hz);
+	u32 total_time_us = size * bit_time_us;
+	/*
+	 * There is an interval between data and the data in our SPI hardware,
+	 * so the total transmission time need add the interval time.
+	 */
+	u32 interval_cycle = SPRD_SPI_FIFO_SIZE * ss->word_delay;
+	u32 interval_time_us = DIV_ROUND_UP(interval_cycle * USEC_PER_SEC,
+					    ss->src_clk);
+
+	return total_time_us + interval_time_us;
+}
+
+static int sprd_spi_wait_for_tx_end(struct sprd_spi *ss, struct spi_transfer *t)
+{
+	u32 val, us;
+	int ret;
+
+	us = sprd_spi_transfer_max_timeout(ss, t);
+	ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_INT_RAW_STS, val,
+					 val & SPRD_SPI_TX_END_IRQ, 0, us);
+	if (ret) {
+		dev_err(ss->dev, "SPI error, spi send timeout!\n");
+		return ret;
+	}
+
+	ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_STS2, val,
+					 !(val & SPRD_SPI_TX_BUSY), 0, us);
+	if (ret) {
+		dev_err(ss->dev, "SPI error, spi busy timeout!\n");
+		return ret;
+	}
+
+	writel_relaxed(SPRD_SPI_TX_END_INT_CLR, ss->base + SPRD_SPI_INT_CLR);
+
+	return 0;
+}
+
+static int sprd_spi_wait_for_rx_end(struct sprd_spi *ss, struct spi_transfer *t)
+{
+	u32 val, us;
+	int ret;
+
+	us = sprd_spi_transfer_max_timeout(ss, t);
+	ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_INT_RAW_STS, val,
+					 val & SPRD_SPI_RX_END_IRQ, 0, us);
+	if (ret) {
+		dev_err(ss->dev, "SPI error, spi rx timeout!\n");
+		return ret;
+	}
+
+	writel_relaxed(SPRD_SPI_RX_END_INT_CLR, ss->base + SPRD_SPI_INT_CLR);
+
+	return 0;
+}
+
+static void sprd_spi_tx_req(struct sprd_spi *ss)
+{
+	writel_relaxed(SPRD_SPI_SW_TX_REQ, ss->base + SPRD_SPI_CTL12);
+}
+
+static void sprd_spi_rx_req(struct sprd_spi *ss)
+{
+	writel_relaxed(SPRD_SPI_SW_RX_REQ, ss->base + SPRD_SPI_CTL12);
+}
+
+static void sprd_spi_enter_idle(struct sprd_spi *ss)
+{
+	u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL1);
+
+	val &= ~SPRD_SPI_RTX_MD_MASK;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL1);
+}
+
+static void sprd_spi_set_transfer_bits(struct sprd_spi *ss, u32 bits)
+{
+	u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
+
+	/* Set the valid bits for every transaction */
+	val &= ~(SPRD_SPI_CHNL_LEN_MASK << SPRD_SPI_CHNL_LEN);
+	val |= bits << SPRD_SPI_CHNL_LEN;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
+}
+
+static void sprd_spi_set_tx_length(struct sprd_spi *ss, u32 length)
+{
+	u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL8);
+
+	length &= SPRD_SPI_TX_MAX_LEN_MASK;
+	val &= ~SPRD_SPI_TX_LEN_H_MASK;
+	val |= length >> SPRD_SPI_TX_LEN_H_OFFSET;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL8);
+
+	val = length & SPRD_SPI_TX_LEN_L_MASK;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL9);
+}
+
+static void sprd_spi_set_rx_length(struct sprd_spi *ss, u32 length)
+{
+	u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL10);
+
+	length &= SPRD_SPI_RX_MAX_LEN_MASK;
+	val &= ~SPRD_SPI_RX_LEN_H_MASK;
+	val |= length >> SPRD_SPI_RX_LEN_H_OFFSET;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL10);
+
+	val = length & SPRD_SPI_RX_LEN_L_MASK;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL11);
+}
+
+static void sprd_spi_chipselect(struct spi_device *sdev, bool cs)
+{
+	struct spi_controller *sctlr = sdev->controller;
+	struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
+	u32 val;
+
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
+	/*  The SPI controller will pull down CS pin if cs is 0 */
+	if (!cs) {
+		val &= ~SPRD_SPI_CS0_VALID;
+		writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
+	} else {
+		val |= SPRD_SPI_CSN_MASK;
+		writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
+	}
+}
+
+static int sprd_spi_write_only_receive(struct sprd_spi *ss, u32 len)
+{
+	u32 val;
+
+	/* Clear the start receive bit and reset receive data number */
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
+	val &= ~(SPRD_SPI_START_RX | SPRD_SPI_ONLY_RECV_MASK);
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
+
+	/* Set the receive data length */
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
+	val |= len & SPRD_SPI_ONLY_RECV_MASK;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
+
+	/* Trigger to receive data */
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
+	val |= SPRD_SPI_START_RX;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
+
+	return len;
+}
+
+static int sprd_spi_write_bufs_u8(struct sprd_spi *ss, u32 len)
+{
+	u8 *tx_p = (u8 *)ss->tx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		writeb_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
+
+	ss->tx_buf += i;
+	return i;
+}
+
+static int sprd_spi_write_bufs_u16(struct sprd_spi *ss, u32 len)
+{
+	u16 *tx_p = (u16 *)ss->tx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		writew_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
+
+	ss->tx_buf += i << 1;
+	return i << 1;
+}
+
+static int sprd_spi_write_bufs_u32(struct sprd_spi *ss, u32 len)
+{
+	u32 *tx_p = (u32 *)ss->tx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		writel_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
+
+	ss->tx_buf += i << 2;
+	return i << 2;
+}
+
+static int sprd_spi_read_bufs_u8(struct sprd_spi *ss, u32 len)
+{
+	u8 *rx_p = (u8 *)ss->rx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		rx_p[i] = readb_relaxed(ss->base + SPRD_SPI_TXD);
+
+	ss->rx_buf += i;
+	return i;
+}
+
+static int sprd_spi_read_bufs_u16(struct sprd_spi *ss, u32 len)
+{
+	u16 *rx_p = (u16 *)ss->rx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		rx_p[i] = readw_relaxed(ss->base + SPRD_SPI_TXD);
+
+	ss->rx_buf += i << 1;
+	return i << 1;
+}
+
+static int sprd_spi_read_bufs_u32(struct sprd_spi *ss, u32 len)
+{
+	u32 *rx_p = (u32 *)ss->rx_buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		rx_p[i] = readl_relaxed(ss->base + SPRD_SPI_TXD);
+
+	ss->rx_buf += i << 2;
+	return i << 2;
+}
+
+static int sprd_spi_txrx_bufs(struct spi_device *sdev, struct spi_transfer *t)
+{
+	struct sprd_spi *ss = spi_controller_get_devdata(sdev->controller);
+	u32 trans_len = ss->trans_len, len;
+	int ret, write_size = 0;
+
+	while (trans_len) {
+		len = trans_len > SPRD_SPI_FIFO_SIZE ? SPRD_SPI_FIFO_SIZE :
+			trans_len;
+		if (ss->trans_mode & SPRD_SPI_TX_MODE) {
+			sprd_spi_set_tx_length(ss, len);
+			write_size += ss->write_bufs(ss, len);
+
+			/*
+			 * For our 3 wires mode or dual TX line mode, we need
+			 * to request the controller to transfer.
+			 */
+			if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
+				sprd_spi_tx_req(ss);
+
+			ret = sprd_spi_wait_for_tx_end(ss, t);
+		} else {
+			sprd_spi_set_rx_length(ss, len);
+
+			/*
+			 * For our 3 wires mode or dual TX line mode, we need
+			 * to request the controller to read.
+			 */
+			if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
+				sprd_spi_rx_req(ss);
+			else
+				write_size += ss->write_bufs(ss, len);
+
+			ret = sprd_spi_wait_for_rx_end(ss, t);
+		}
+
+		if (ret)
+			goto complete;
+
+		if (ss->trans_mode & SPRD_SPI_RX_MODE)
+			ss->read_bufs(ss, len);
+
+		trans_len -= len;
+	}
+
+	ret = write_size;
+
+complete:
+	sprd_spi_enter_idle(ss);
+
+	return ret;
+}
+
+static void sprd_spi_set_speed(struct sprd_spi *ss, u32 speed_hz)
+{
+	/*
+	 * From SPI datasheet, the prescale calculation formula:
+	 * prescale = SPI source clock / (2 * SPI_freq) - 1;
+	 */
+	u32 clk_div = DIV_ROUND_UP(ss->src_clk, speed_hz << 1) - 1;
+
+	/* Save the real hardware speed */
+	ss->hw_speed_hz = (ss->src_clk >> 1) / (clk_div + 1);
+	writel_relaxed(clk_div, ss->base + SPRD_SPI_CLKD);
+}
+
+static void sprd_spi_init_hw(struct sprd_spi *ss, struct spi_transfer *t)
+{
+	u16 word_delay, interval;
+	u32 val;
+
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL7);
+	val &= ~(SPRD_SPI_SCK_REV | SPRD_SPI_NG_TX | SPRD_SPI_NG_RX);
+	/* Set default chip selection, clock phase and clock polarity */
+	val |= ss->hw_mode & SPI_CPHA ? SPRD_SPI_NG_RX : SPRD_SPI_NG_TX;
+	val |= ss->hw_mode & SPI_CPOL ? SPRD_SPI_SCK_REV : 0;
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
+
+	/*
+	 * Set the intervals of two SPI frames, and the inteval calculation
+	 * formula as below per datasheet:
+	 * interval time (source clock cycles) = interval * 4 + 10.
+	 */
+	word_delay = clamp_t(u16, t->word_delay, SPRD_SPI_MIN_DELAY_CYCLE,
+			     SPRD_SPI_MAX_DELAY_CYCLE);
+	interval = DIV_ROUND_UP(word_delay - 10, 4);
+	ss->word_delay = interval * 4 + 10;
+	writel_relaxed(interval, ss->base + SPRD_SPI_CTL5);
+
+	/* Reset SPI fifo */
+	writel_relaxed(1, ss->base + SPRD_SPI_FIFO_RST);
+	writel_relaxed(0, ss->base + SPRD_SPI_FIFO_RST);
+
+	/* Set SPI work mode */
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL7);
+	val &= ~SPRD_SPI_MODE_MASK;
+
+	if (ss->hw_mode & SPI_3WIRE)
+		val |= SPRD_SPI_3WIRE_MODE << SPRD_SPI_MODE_OFFSET;
+	else
+		val |= SPRD_SPI_4WIRE_MODE << SPRD_SPI_MODE_OFFSET;
+
+	if (ss->hw_mode & SPI_TX_DUAL)
+		val |= SPRD_SPI_DATA_LINE2_EN;
+	else
+		val &= ~SPRD_SPI_DATA_LINE2_EN;
+
+	writel_relaxed(val, ss->base + SPRD_SPI_CTL7);
+}
+
+static int sprd_spi_setup_transfer(struct spi_device *sdev,
+				   struct spi_transfer *t)
+{
+	struct sprd_spi *ss = spi_controller_get_devdata(sdev->controller);
+	u8 bits_per_word = t->bits_per_word;
+	u32 val, mode = 0;
+
+	ss->len = t->len;
+	ss->tx_buf = t->tx_buf;
+	ss->rx_buf = t->rx_buf;
+
+	ss->hw_mode = sdev->mode;
+	sprd_spi_init_hw(ss, t);
+
+	/* Set tansfer speed and valid bits */
+	sprd_spi_set_speed(ss, t->speed_hz);
+	sprd_spi_set_transfer_bits(ss, bits_per_word);
+
+	if (bits_per_word > 16)
+		bits_per_word = round_up(bits_per_word, 16);
+	else
+		bits_per_word = round_up(bits_per_word, 8);
+
+	switch (bits_per_word) {
+	case 8:
+		ss->trans_len = t->len;
+		ss->read_bufs = sprd_spi_read_bufs_u8;
+		ss->write_bufs = sprd_spi_write_bufs_u8;
+		break;
+	case 16:
+		ss->trans_len = t->len >> 1;
+		ss->read_bufs = sprd_spi_read_bufs_u16;
+		ss->write_bufs = sprd_spi_write_bufs_u16;
+		break;
+	case 32:
+		ss->trans_len = t->len >> 2;
+		ss->read_bufs = sprd_spi_read_bufs_u32;
+		ss->write_bufs = sprd_spi_write_bufs_u32;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Set transfer read or write mode */
+	val = readl_relaxed(ss->base + SPRD_SPI_CTL1);
+	val &= ~SPRD_SPI_RTX_MD_MASK;
+	if (t->tx_buf)
+		mode |= SPRD_SPI_TX_MODE;
+	if (t->rx_buf)
+		mode |= SPRD_SPI_RX_MODE;
+
+	writel_relaxed(val | mode, ss->base + SPRD_SPI_CTL1);
+
+	ss->trans_mode = mode;
+
+	/*
+	 * If in only receive mode, we need to trigger the SPI controller to
+	 * receive data automatically.
+	 */
+	if (ss->trans_mode == SPRD_SPI_RX_MODE)
+		ss->write_bufs = sprd_spi_write_only_receive;
+
+	return 0;
+}
+
+static int sprd_spi_transfer_one(struct spi_controller *sctlr,
+				 struct spi_device *sdev,
+				 struct spi_transfer *t)
+{
+	int ret;
+
+	ret = sprd_spi_setup_transfer(sdev, t);
+	if (ret)
+		goto setup_err;
+
+	ret = sprd_spi_txrx_bufs(sdev, t);
+	if (ret == t->len)
+		ret = 0;
+	else if (ret >= 0)
+		ret = -EREMOTEIO;
+
+setup_err:
+	spi_finalize_current_transfer(sctlr);
+
+	return ret;
+}
+
+static int sprd_spi_clk_init(struct platform_device *pdev, struct sprd_spi *ss)
+{
+	struct clk *clk_spi, *clk_parent;
+
+	clk_spi = devm_clk_get(&pdev->dev, "spi");
+	if (IS_ERR(clk_spi)) {
+		dev_warn(&pdev->dev, "can't get the spi clock\n");
+		clk_spi = NULL;
+	}
+
+	clk_parent = devm_clk_get(&pdev->dev, "source");
+	if (IS_ERR(clk_parent)) {
+		dev_warn(&pdev->dev, "can't get the source clock\n");
+		clk_parent = NULL;
+	}
+
+	ss->clk = devm_clk_get(&pdev->dev, "enable");
+	if (IS_ERR(ss->clk)) {
+		dev_err(&pdev->dev, "can't get the enable clock\n");
+		return PTR_ERR(ss->clk);
+	}
+
+	if (!clk_set_parent(clk_spi, clk_parent))
+		ss->src_clk = clk_get_rate(clk_spi);
+	else
+		ss->src_clk = SPRD_SPI_DEFAULT_SOURCE;
+
+	return 0;
+}
+
+static int sprd_spi_probe(struct platform_device *pdev)
+{
+	struct spi_controller *sctlr;
+	struct resource *res;
+	struct sprd_spi *ss;
+	int ret;
+
+	pdev->id = of_alias_get_id(pdev->dev.of_node, "spi");
+	sctlr = spi_alloc_master(&pdev->dev, sizeof(*ss));
+	if (!sctlr)
+		return -ENOMEM;
+
+	ss = spi_controller_get_devdata(sctlr);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ss->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ss->base)) {
+		ret = PTR_ERR(ss->base);
+		goto free_controller;
+	}
+
+	ss->dev = &pdev->dev;
+	sctlr->dev.of_node = pdev->dev.of_node;
+	sctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE | SPI_TX_DUAL;
+	sctlr->bus_num = pdev->id;
+	sctlr->set_cs = sprd_spi_chipselect;
+	sctlr->transfer_one = sprd_spi_transfer_one;
+	sctlr->auto_runtime_pm = true;
+	sctlr->max_speed_hz = min_t(u32, ss->src_clk >> 1,
+				    SPRD_SPI_MAX_SPEED_HZ);
+
+	platform_set_drvdata(pdev, sctlr);
+	ret = sprd_spi_clk_init(pdev, ss);
+	if (ret)
+		goto free_controller;
+
+	ret = clk_prepare_enable(ss->clk);
+	if (ret)
+		goto free_controller;
+
+	ret = pm_runtime_set_active(&pdev->dev);
+	if (ret < 0)
+		goto disable_clk;
+
+	pm_runtime_set_autosuspend_delay(&pdev->dev,
+					 SPRD_SPI_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to resume SPI controller\n");
+		goto err_rpm_put;
+	}
+
+	ret = devm_spi_register_controller(&pdev->dev, sctlr);
+	if (ret)
+		goto err_rpm_put;
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
+	return 0;
+
+err_rpm_put:
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+disable_clk:
+	clk_disable_unprepare(ss->clk);
+free_controller:
+	spi_controller_put(sctlr);
+
+	return ret;
+}
+
+static int __exit sprd_spi_remove(struct platform_device *pdev)
+{
+	struct spi_controller *sctlr = platform_get_drvdata(pdev);
+	struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
+	int ret;
+
+	ret = pm_runtime_get_sync(ss->dev);
+	if (ret < 0) {
+		dev_err(ss->dev, "failed to resume SPI controller\n");
+		return ret;
+	}
+
+	clk_disable_unprepare(ss->clk);
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused sprd_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_controller *sctlr = dev_get_drvdata(dev);
+	struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
+
+	clk_disable_unprepare(ss->clk);
+
+	return 0;
+}
+
+static int __maybe_unused sprd_spi_runtime_resume(struct device *dev)
+{
+	struct spi_controller *sctlr = dev_get_drvdata(dev);
+	struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
+	int ret;
+
+	ret = clk_prepare_enable(ss->clk);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct dev_pm_ops sprd_spi_pm_ops = {
+	SET_RUNTIME_PM_OPS(sprd_spi_runtime_suspend,
+			   sprd_spi_runtime_resume, NULL)
+};
+
+static const struct of_device_id sprd_spi_of_match[] = {
+	{ .compatible = "sprd,sc9860-spi", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver sprd_spi_driver = {
+	.driver = {
+		.name = "sprd-spi",
+		.of_match_table = sprd_spi_of_match,
+		.pm = &sprd_spi_pm_ops,
+	},
+	.probe = sprd_spi_probe,
+	.remove  = sprd_spi_remove,
+};
+
+module_platform_driver(sprd_spi_driver);
+
+MODULE_DESCRIPTION("Spreadtrum SPI Controller driver");
+MODULE_AUTHOR("Lanqing Liu <lanqing.liu@xxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
2.18.0