1 files changed, 952 insertions, 0 deletions

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
new file mode 100644
index 000000000..185bbdce6
--- /dev/null
+++ b/drivers/spi/spi-rockchip.c
@@ -0,0 +1,952 @@
+/*
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Addy Ke <addy.ke@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/pm_runtime.h>
+#include <linux/scatterlist.h>
+
+#define DRIVER_NAME "rockchip-spi"
+
+#define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
+		writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
+#define ROCKCHIP_SPI_SET_BITS(reg, bits) \
+		writel_relaxed(readl_relaxed(reg) | (bits), reg)
+
+/* SPI register offsets */
+#define ROCKCHIP_SPI_CTRLR0			0x0000
+#define ROCKCHIP_SPI_CTRLR1			0x0004
+#define ROCKCHIP_SPI_SSIENR			0x0008
+#define ROCKCHIP_SPI_SER			0x000c
+#define ROCKCHIP_SPI_BAUDR			0x0010
+#define ROCKCHIP_SPI_TXFTLR			0x0014
+#define ROCKCHIP_SPI_RXFTLR			0x0018
+#define ROCKCHIP_SPI_TXFLR			0x001c
+#define ROCKCHIP_SPI_RXFLR			0x0020
+#define ROCKCHIP_SPI_SR				0x0024
+#define ROCKCHIP_SPI_IPR			0x0028
+#define ROCKCHIP_SPI_IMR			0x002c
+#define ROCKCHIP_SPI_ISR			0x0030
+#define ROCKCHIP_SPI_RISR			0x0034
+#define ROCKCHIP_SPI_ICR			0x0038
+#define ROCKCHIP_SPI_DMACR			0x003c
+#define ROCKCHIP_SPI_DMATDLR		0x0040
+#define ROCKCHIP_SPI_DMARDLR		0x0044
+#define ROCKCHIP_SPI_TXDR			0x0400
+#define ROCKCHIP_SPI_RXDR			0x0800
+
+/* Bit fields in CTRLR0 */
+#define CR0_DFS_OFFSET				0
+
+#define CR0_CFS_OFFSET				2
+
+#define CR0_SCPH_OFFSET				6
+
+#define CR0_SCPOL_OFFSET			7
+
+#define CR0_CSM_OFFSET				8
+#define CR0_CSM_KEEP				0x0
+/* ss_n be high for half sclk_out cycles */
+#define CR0_CSM_HALF				0X1
+/* ss_n be high for one sclk_out cycle */
+#define CR0_CSM_ONE					0x2
+
+/* ss_n to sclk_out delay */
+#define CR0_SSD_OFFSET				10
+/*
+ * The period between ss_n active and
+ * sclk_out active is half sclk_out cycles
+ */
+#define CR0_SSD_HALF				0x0
+/*
+ * The period between ss_n active and
+ * sclk_out active is one sclk_out cycle
+ */
+#define CR0_SSD_ONE					0x1
+
+#define CR0_EM_OFFSET				11
+#define CR0_EM_LITTLE				0x0
+#define CR0_EM_BIG					0x1
+
+#define CR0_FBM_OFFSET				12
+#define CR0_FBM_MSB					0x0
+#define CR0_FBM_LSB					0x1
+
+#define CR0_BHT_OFFSET				13
+#define CR0_BHT_16BIT				0x0
+#define CR0_BHT_8BIT				0x1
+
+#define CR0_RSD_OFFSET				14
+
+#define CR0_FRF_OFFSET				16
+#define CR0_FRF_SPI					0x0
+#define CR0_FRF_SSP					0x1
+#define CR0_FRF_MICROWIRE			0x2
+
+#define CR0_XFM_OFFSET				18
+#define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
+#define CR0_XFM_TR					0x0
+#define CR0_XFM_TO					0x1
+#define CR0_XFM_RO					0x2
+
+#define CR0_OPM_OFFSET				20
+#define CR0_OPM_MASTER				0x0
+#define CR0_OPM_SLAVE				0x1
+
+#define CR0_MTM_OFFSET				0x21
+
+/* Bit fields in SER, 2bit */
+#define SER_MASK					0x3
+
+/* Bit fields in SR, 5bit */
+#define SR_MASK						0x1f
+#define SR_BUSY						(1 << 0)
+#define SR_TF_FULL					(1 << 1)
+#define SR_TF_EMPTY					(1 << 2)
+#define SR_RF_EMPTY					(1 << 3)
+#define SR_RF_FULL					(1 << 4)
+
+/* Bit fields in ISR, IMR, ISR, RISR, 5bit */
+#define INT_MASK					0x1f
+#define INT_TF_EMPTY				(1 << 0)
+#define INT_TF_OVERFLOW				(1 << 1)
+#define INT_RF_UNDERFLOW			(1 << 2)
+#define INT_RF_OVERFLOW				(1 << 3)
+#define INT_RF_FULL					(1 << 4)
+
+/* Bit fields in ICR, 4bit */
+#define ICR_MASK					0x0f
+#define ICR_ALL						(1 << 0)
+#define ICR_RF_UNDERFLOW			(1 << 1)
+#define ICR_RF_OVERFLOW				(1 << 2)
+#define ICR_TF_OVERFLOW				(1 << 3)
+
+/* Bit fields in DMACR */
+#define RF_DMA_EN					(1 << 0)
+#define TF_DMA_EN					(1 << 1)
+
+#define RXBUSY						(1 << 0)
+#define TXBUSY						(1 << 1)
+
+/* sclk_out: spi master internal logic in rk3x can support 50Mhz */
+#define MAX_SCLK_OUT		50000000
+
+/*
+ * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
+ * the controller seems to hang when given 0x10000, so stick with this for now.
+ */
+#define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
+
+#define ROCKCHIP_SPI_MAX_CS_NUM			2
+
+enum rockchip_ssi_type {
+	SSI_MOTO_SPI = 0,
+	SSI_TI_SSP,
+	SSI_NS_MICROWIRE,
+};
+
+struct rockchip_spi_dma_data {
+	struct dma_chan *ch;
+	enum dma_transfer_direction direction;
+	dma_addr_t addr;
+};
+
+struct rockchip_spi {
+	struct device *dev;
+	struct spi_master *master;
+
+	struct clk *spiclk;
+	struct clk *apb_pclk;
+
+	void __iomem *regs;
+	/*depth of the FIFO buffer */
+	u32 fifo_len;
+	/* max bus freq supported */
+	u32 max_freq;
+	/* supported slave numbers */
+	enum rockchip_ssi_type type;
+
+	u16 mode;
+	u8 tmode;
+	u8 bpw;
+	u8 n_bytes;
+	u32 rsd_nsecs;
+	unsigned len;
+	u32 speed;
+
+	const void *tx;
+	const void *tx_end;
+	void *rx;
+	void *rx_end;
+
+	u32 state;
+	/* protect state */
+	spinlock_t lock;
+
+	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
+
+	u32 use_dma;
+	struct sg_table tx_sg;
+	struct sg_table rx_sg;
+	struct rockchip_spi_dma_data dma_rx;
+	struct rockchip_spi_dma_data dma_tx;
+	struct dma_slave_caps dma_caps;
+};
+
+static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
+{
+	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
+}
+
+static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
+{
+	writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
+}
+
+static inline void flush_fifo(struct rockchip_spi *rs)
+{
+	while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
+		readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
+}
+
+static inline void wait_for_idle(struct rockchip_spi *rs)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(5);
+
+	do {
+		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
+			return;
+	} while (!time_after(jiffies, timeout));
+
+	dev_warn(rs->dev, "spi controller is in busy state!\n");
+}
+
+static u32 get_fifo_len(struct rockchip_spi *rs)
+{
+	u32 fifo;
+
+	for (fifo = 2; fifo < 32; fifo++) {
+		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
+		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
+			break;
+	}
+
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
+
+	return (fifo == 31) ? 0 : fifo;
+}
+
+static inline u32 tx_max(struct rockchip_spi *rs)
+{
+	u32 tx_left, tx_room;
+
+	tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
+	tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
+
+	return min(tx_left, tx_room);
+}
+
+static inline u32 rx_max(struct rockchip_spi *rs)
+{
+	u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
+	u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
+
+	return min(rx_left, rx_room);
+}
+
+static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
+{
+	struct spi_master *master = spi->master;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+	bool cs_asserted = !enable;
+
+	/* Return immediately for no-op */
+	if (cs_asserted == rs->cs_asserted[spi->chip_select])
+		return;
+
+	if (cs_asserted) {
+		/* Keep things powered as long as CS is asserted */
+		pm_runtime_get_sync(rs->dev);
+
+		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
+				      BIT(spi->chip_select));
+	} else {
+		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
+				      BIT(spi->chip_select));
+
+		/* Drop reference from when we first asserted CS */
+		pm_runtime_put(rs->dev);
+	}
+
+	rs->cs_asserted[spi->chip_select] = cs_asserted;
+}
+
+static int rockchip_spi_prepare_message(struct spi_master *master,
+					struct spi_message *msg)
+{
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+	struct spi_device *spi = msg->spi;
+
+	rs->mode = spi->mode;
+
+	return 0;
+}
+
+static void rockchip_spi_handle_err(struct spi_master *master,
+				    struct spi_message *msg)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	/*
+	 * For DMA mode, we need terminate DMA channel and flush
+	 * fifo for the next transfer if DMA thansfer timeout.
+	 * handle_err() was called by core if transfer failed.
+	 * Maybe it is reasonable for error handling here.
+	 */
+	if (rs->use_dma) {
+		if (rs->state & RXBUSY) {
+			dmaengine_terminate_async(rs->dma_rx.ch);
+			flush_fifo(rs);
+		}
+
+		if (rs->state & TXBUSY)
+			dmaengine_terminate_async(rs->dma_tx.ch);
+	}
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+}
+
+static int rockchip_spi_unprepare_message(struct spi_master *master,
+					  struct spi_message *msg)
+{
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	spi_enable_chip(rs, 0);
+
+	return 0;
+}
+
+static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
+{
+	u32 max = tx_max(rs);
+	u32 txw = 0;
+
+	while (max--) {
+		if (rs->n_bytes == 1)
+			txw = *(u8 *)(rs->tx);
+		else
+			txw = *(u16 *)(rs->tx);
+
+		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
+		rs->tx += rs->n_bytes;
+	}
+}
+
+static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
+{
+	u32 max = rx_max(rs);
+	u32 rxw;
+
+	while (max--) {
+		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
+		if (rs->n_bytes == 1)
+			*(u8 *)(rs->rx) = (u8)rxw;
+		else
+			*(u16 *)(rs->rx) = (u16)rxw;
+		rs->rx += rs->n_bytes;
+	}
+}
+
+static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
+{
+	int remain = 0;
+
+	do {
+		if (rs->tx) {
+			remain = rs->tx_end - rs->tx;
+			rockchip_spi_pio_writer(rs);
+		}
+
+		if (rs->rx) {
+			remain = rs->rx_end - rs->rx;
+			rockchip_spi_pio_reader(rs);
+		}
+
+		cpu_relax();
+	} while (remain);
+
+	/* If tx, wait until the FIFO data completely. */
+	if (rs->tx)
+		wait_for_idle(rs);
+
+	spi_enable_chip(rs, 0);
+
+	return 0;
+}
+
+static void rockchip_spi_dma_rxcb(void *data)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = data;
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	rs->state &= ~RXBUSY;
+	if (!(rs->state & TXBUSY)) {
+		spi_enable_chip(rs, 0);
+		spi_finalize_current_transfer(rs->master);
+	}
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+}
+
+static void rockchip_spi_dma_txcb(void *data)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = data;
+
+	/* Wait until the FIFO data completely. */
+	wait_for_idle(rs);
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	rs->state &= ~TXBUSY;
+	if (!(rs->state & RXBUSY)) {
+		spi_enable_chip(rs, 0);
+		spi_finalize_current_transfer(rs->master);
+	}
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+}
+
+static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
+{
+	unsigned long flags;
+	struct dma_slave_config rxconf, txconf;
+	struct dma_async_tx_descriptor *rxdesc, *txdesc;
+
+	memset(&rxconf, 0, sizeof(rxconf));
+	memset(&txconf, 0, sizeof(txconf));
+
+	spin_lock_irqsave(&rs->lock, flags);
+	rs->state &= ~RXBUSY;
+	rs->state &= ~TXBUSY;
+	spin_unlock_irqrestore(&rs->lock, flags);
+
+	rxdesc = NULL;
+	if (rs->rx) {
+		rxconf.direction = rs->dma_rx.direction;
+		rxconf.src_addr = rs->dma_rx.addr;
+		rxconf.src_addr_width = rs->n_bytes;
+		if (rs->dma_caps.max_burst > 4)
+			rxconf.src_maxburst = 4;
+		else
+			rxconf.src_maxburst = 1;
+		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
+
+		rxdesc = dmaengine_prep_slave_sg(
+				rs->dma_rx.ch,
+				rs->rx_sg.sgl, rs->rx_sg.nents,
+				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
+		if (!rxdesc)
+			return -EINVAL;
+
+		rxdesc->callback = rockchip_spi_dma_rxcb;
+		rxdesc->callback_param = rs;
+	}
+
+	txdesc = NULL;
+	if (rs->tx) {
+		txconf.direction = rs->dma_tx.direction;
+		txconf.dst_addr = rs->dma_tx.addr;
+		txconf.dst_addr_width = rs->n_bytes;
+		if (rs->dma_caps.max_burst > 4)
+			txconf.dst_maxburst = 4;
+		else
+			txconf.dst_maxburst = 1;
+		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
+
+		txdesc = dmaengine_prep_slave_sg(
+				rs->dma_tx.ch,
+				rs->tx_sg.sgl, rs->tx_sg.nents,
+				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
+		if (!txdesc) {
+			if (rxdesc)
+				dmaengine_terminate_sync(rs->dma_rx.ch);
+			return -EINVAL;
+		}
+
+		txdesc->callback = rockchip_spi_dma_txcb;
+		txdesc->callback_param = rs;
+	}
+
+	/* rx must be started before tx due to spi instinct */
+	if (rxdesc) {
+		spin_lock_irqsave(&rs->lock, flags);
+		rs->state |= RXBUSY;
+		spin_unlock_irqrestore(&rs->lock, flags);
+		dmaengine_submit(rxdesc);
+		dma_async_issue_pending(rs->dma_rx.ch);
+	}
+
+	if (txdesc) {
+		spin_lock_irqsave(&rs->lock, flags);
+		rs->state |= TXBUSY;
+		spin_unlock_irqrestore(&rs->lock, flags);
+		dmaengine_submit(txdesc);
+		dma_async_issue_pending(rs->dma_tx.ch);
+	}
+
+	return 0;
+}
+
+static void rockchip_spi_config(struct rockchip_spi *rs)
+{
+	u32 div = 0;
+	u32 dmacr = 0;
+	int rsd = 0;
+
+	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
+		| (CR0_SSD_ONE << CR0_SSD_OFFSET)
+		| (CR0_EM_BIG << CR0_EM_OFFSET);
+
+	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
+	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
+	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
+	cr0 |= (rs->type << CR0_FRF_OFFSET);
+
+	if (rs->use_dma) {
+		if (rs->tx)
+			dmacr |= TF_DMA_EN;
+		if (rs->rx)
+			dmacr |= RF_DMA_EN;
+	}
+
+	if (WARN_ON(rs->speed > MAX_SCLK_OUT))
+		rs->speed = MAX_SCLK_OUT;
+
+	/* the minimum divisor is 2 */
+	if (rs->max_freq < 2 * rs->speed) {
+		clk_set_rate(rs->spiclk, 2 * rs->speed);
+		rs->max_freq = clk_get_rate(rs->spiclk);
+	}
+
+	/* div doesn't support odd number */
+	div = DIV_ROUND_UP(rs->max_freq, rs->speed);
+	div = (div + 1) & 0xfffe;
+
+	/* Rx sample delay is expressed in parent clock cycles (max 3) */
+	rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
+				1000000000 >> 8);
+	if (!rsd && rs->rsd_nsecs) {
+		pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
+			     rs->max_freq, rs->rsd_nsecs);
+	} else if (rsd > 3) {
+		rsd = 3;
+		pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
+			     rs->max_freq, rs->rsd_nsecs,
+			     rsd * 1000000000U / rs->max_freq);
+	}
+	cr0 |= rsd << CR0_RSD_OFFSET;
+
+	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
+
+	if (rs->n_bytes == 1)
+		writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
+	else if (rs->n_bytes == 2)
+		writel_relaxed((rs->len / 2) - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
+	else
+		writel_relaxed((rs->len * 2) - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
+
+	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
+	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
+
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
+	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
+
+	spi_set_clk(rs, div);
+
+	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
+}
+
+static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
+{
+	return ROCKCHIP_SPI_MAX_TRANLEN;
+}
+
+static int rockchip_spi_transfer_one(
+		struct spi_master *master,
+		struct spi_device *spi,
+		struct spi_transfer *xfer)
+{
+	int ret = 0;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
+		(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
+
+	if (!xfer->tx_buf && !xfer->rx_buf) {
+		dev_err(rs->dev, "No buffer for transfer\n");
+		return -EINVAL;
+	}
+
+	if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
+		dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
+		return -EINVAL;
+	}
+
+	rs->speed = xfer->speed_hz;
+	rs->bpw = xfer->bits_per_word;
+	rs->n_bytes = rs->bpw >> 3;
+
+	rs->tx = xfer->tx_buf;
+	rs->tx_end = rs->tx + xfer->len;
+	rs->rx = xfer->rx_buf;
+	rs->rx_end = rs->rx + xfer->len;
+	rs->len = xfer->len;
+
+	rs->tx_sg = xfer->tx_sg;
+	rs->rx_sg = xfer->rx_sg;
+
+	if (rs->tx && rs->rx)
+		rs->tmode = CR0_XFM_TR;
+	else if (rs->tx)
+		rs->tmode = CR0_XFM_TO;
+	else if (rs->rx)
+		rs->tmode = CR0_XFM_RO;
+
+	/* we need prepare dma before spi was enabled */
+	if (master->can_dma && master->can_dma(master, spi, xfer))
+		rs->use_dma = 1;
+	else
+		rs->use_dma = 0;
+
+	rockchip_spi_config(rs);
+
+	if (rs->use_dma) {
+		if (rs->tmode == CR0_XFM_RO) {
+			/* rx: dma must be prepared first */
+			ret = rockchip_spi_prepare_dma(rs);
+			spi_enable_chip(rs, 1);
+		} else {
+			/* tx or tr: spi must be enabled first */
+			spi_enable_chip(rs, 1);
+			ret = rockchip_spi_prepare_dma(rs);
+		}
+		/* successful DMA prepare means the transfer is in progress */
+		ret = ret ? ret : 1;
+	} else {
+		spi_enable_chip(rs, 1);
+		ret = rockchip_spi_pio_transfer(rs);
+	}
+
+	return ret;
+}
+
+static bool rockchip_spi_can_dma(struct spi_master *master,
+				 struct spi_device *spi,
+				 struct spi_transfer *xfer)
+{
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	return (xfer->len > rs->fifo_len);
+}
+
+static int rockchip_spi_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct rockchip_spi *rs;
+	struct spi_master *master;
+	struct resource *mem;
+	u32 rsd_nsecs;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
+	if (!master)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, master);
+
+	rs = spi_master_get_devdata(master);
+
+	/* Get basic io resource and map it */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(rs->regs)) {
+		ret =  PTR_ERR(rs->regs);
+		goto err_put_master;
+	}
+
+	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
+	if (IS_ERR(rs->apb_pclk)) {
+		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
+		ret = PTR_ERR(rs->apb_pclk);
+		goto err_put_master;
+	}
+
+	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
+	if (IS_ERR(rs->spiclk)) {
+		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
+		ret = PTR_ERR(rs->spiclk);
+		goto err_put_master;
+	}
+
+	ret = clk_prepare_enable(rs->apb_pclk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
+		goto err_put_master;
+	}
+
+	ret = clk_prepare_enable(rs->spiclk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
+		goto err_disable_apbclk;
+	}
+
+	spi_enable_chip(rs, 0);
+
+	rs->type = SSI_MOTO_SPI;
+	rs->master = master;
+	rs->dev = &pdev->dev;
+	rs->max_freq = clk_get_rate(rs->spiclk);
+
+	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
+				  &rsd_nsecs))
+		rs->rsd_nsecs = rsd_nsecs;
+
+	rs->fifo_len = get_fifo_len(rs);
+	if (!rs->fifo_len) {
+		dev_err(&pdev->dev, "Failed to get fifo length\n");
+		ret = -EINVAL;
+		goto err_disable_spiclk;
+	}
+
+	spin_lock_init(&rs->lock);
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	master->auto_runtime_pm = true;
+	master->bus_num = pdev->id;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
+	master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
+	master->dev.of_node = pdev->dev.of_node;
+	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
+
+	master->set_cs = rockchip_spi_set_cs;
+	master->prepare_message = rockchip_spi_prepare_message;
+	master->unprepare_message = rockchip_spi_unprepare_message;
+	master->transfer_one = rockchip_spi_transfer_one;
+	master->max_transfer_size = rockchip_spi_max_transfer_size;
+	master->handle_err = rockchip_spi_handle_err;
+	master->flags = SPI_MASTER_GPIO_SS;
+
+	rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
+	if (IS_ERR(rs->dma_tx.ch)) {
+		/* Check tx to see if we need defer probing driver */
+		if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto err_disable_pm_runtime;
+		}
+		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
+		rs->dma_tx.ch = NULL;
+	}
+
+	rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
+	if (IS_ERR(rs->dma_rx.ch)) {
+		if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto err_free_dma_tx;
+		}
+		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
+		rs->dma_rx.ch = NULL;
+	}
+
+	if (rs->dma_tx.ch && rs->dma_rx.ch) {
+		dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
+		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
+		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
+		rs->dma_tx.direction = DMA_MEM_TO_DEV;
+		rs->dma_rx.direction = DMA_DEV_TO_MEM;
+
+		master->can_dma = rockchip_spi_can_dma;
+		master->dma_tx = rs->dma_tx.ch;
+		master->dma_rx = rs->dma_rx.ch;
+	}
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register master\n");
+		goto err_free_dma_rx;
+	}
+
+	return 0;
+
+err_free_dma_rx:
+	if (rs->dma_rx.ch)
+		dma_release_channel(rs->dma_rx.ch);
+err_free_dma_tx:
+	if (rs->dma_tx.ch)
+		dma_release_channel(rs->dma_tx.ch);
+err_disable_pm_runtime:
+	pm_runtime_disable(&pdev->dev);
+err_disable_spiclk:
+	clk_disable_unprepare(rs->spiclk);
+err_disable_apbclk:
+	clk_disable_unprepare(rs->apb_pclk);
+err_put_master:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int rockchip_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	clk_disable_unprepare(rs->spiclk);
+	clk_disable_unprepare(rs->apb_pclk);
+
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
+	if (rs->dma_tx.ch)
+		dma_release_channel(rs->dma_tx.ch);
+	if (rs->dma_rx.ch)
+		dma_release_channel(rs->dma_rx.ch);
+
+	spi_master_put(master);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int rockchip_spi_suspend(struct device *dev)
+{
+	int ret;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	ret = spi_master_suspend(rs->master);
+	if (ret < 0)
+		return ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret < 0)
+		return ret;
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int rockchip_spi_resume(struct device *dev)
+{
+	int ret;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	pinctrl_pm_select_default_state(dev);
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = spi_master_resume(rs->master);
+	if (ret < 0) {
+		clk_disable_unprepare(rs->spiclk);
+		clk_disable_unprepare(rs->apb_pclk);
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM
+static int rockchip_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	clk_disable_unprepare(rs->spiclk);
+	clk_disable_unprepare(rs->apb_pclk);
+
+	return 0;
+}
+
+static int rockchip_spi_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	ret = clk_prepare_enable(rs->apb_pclk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_prepare_enable(rs->spiclk);
+	if (ret < 0)
+		clk_disable_unprepare(rs->apb_pclk);
+
+	return 0;
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops rockchip_spi_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
+	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
+			   rockchip_spi_runtime_resume, NULL)
+};
+
+static const struct of_device_id rockchip_spi_dt_match[] = {
+	{ .compatible = "rockchip,rv1108-spi", },
+	{ .compatible = "rockchip,rk3036-spi", },
+	{ .compatible = "rockchip,rk3066-spi", },
+	{ .compatible = "rockchip,rk3188-spi", },
+	{ .compatible = "rockchip,rk3228-spi", },
+	{ .compatible = "rockchip,rk3288-spi", },
+	{ .compatible = "rockchip,rk3368-spi", },
+	{ .compatible = "rockchip,rk3399-spi", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
+
+static struct platform_driver rockchip_spi_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.pm = &rockchip_spi_pm,
+		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
+	},
+	.probe = rockchip_spi_probe,
+	.remove = rockchip_spi_remove,
+};
+
+module_platform_driver(rockchip_spi_driver);
+
+MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
+MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
+MODULE_LICENSE("GPL v2");