Message-Id: <1415990912-31744-3-git-send-email-abrestic@chromium.org>
Date:	Fri, 14 Nov 2014 10:48:32 -0800
From:	Andrew Bresticker <abrestic@...omium.org>
To:	Mark Brown <broonie@...nel.org>
Cc:	Andrew Bresticker <abrestic@...omium.org>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Grant Likely <grant.likely@...aro.org>,
	James Hartley <James.Hartley@...tec.com>,
	Ezequiel Garcia <Ezequiel.Garcia@...tec.com>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-spi@...r.kernel.org
Subject: [PATCH V3 2/2] spi: Add driver for IMG SPFI controller

Add support for the Synchronous Peripheral Flash Interface (SPFI) master
controller found on IMG SoCs.  The SPFI controller supports 5 chip-select
lines and single/dual/quad mode SPI transfers.

Signed-off-by: Andrew Bresticker <abrestic@...omium.org>
---
Changes from v2:
 - fixed build errors due to missing #include
Changes from v1:
 - added timeout for tx fifo flush
 - added runtime PM callbacks
 - renamed spi-img -> spi-img-spfi
 - addressed Mark's review comments
---
 drivers/spi/Kconfig        |   7 +
 drivers/spi/Makefile       |   1 +
 drivers/spi/spi-img-spfi.c | 746 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 754 insertions(+)
 create mode 100644 drivers/spi/spi-img-spfi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 84e7c9e..98de207 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -225,6 +225,13 @@ config SPI_GPIO
 	  GPIO operations, you should be able to leverage that for better
 	  speed with a custom version of this driver; see the source code.
 
+config SPI_IMG_SPFI
+	tristate "IMG SPFI controller"
+	depends on MIPS || COMPILE_TEST
+	help
+	  This enables support for the SPFI master controller found on
+	  IMG SoCs.
+
 config SPI_IMX
 	tristate "Freescale i.MX SPI controllers"
 	depends on ARCH_MXC || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 78f24ca..37dc2e7 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_SPI_FSL_LIB)		+= spi-fsl-lib.o
 obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
 obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
 obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
+obj-$(CONFIG_SPI_IMG_SPFI)		+= spi-img-spfi.o
 obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
 obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c
new file mode 100644
index 0000000..43781c9
--- /dev/null
+++ b/drivers/spi/spi-img-spfi.c
@@ -0,0 +1,746 @@
+/*
+ * IMG SPFI controller driver
+ *
+ * Copyright (C) 2007,2008,2013 Imagination Technologies Ltd.
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.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>
+
+#define SPFI_DEVICE_PARAMETER(x)		(0x00 + 0x4 * (x))
+#define SPFI_DEVICE_PARAMETER_BITCLK_SHIFT	24
+#define SPFI_DEVICE_PARAMETER_BITCLK_MASK	0xff
+#define SPFI_DEVICE_PARAMETER_CSSETUP_SHIFT	16
+#define SPFI_DEVICE_PARAMETER_CSSETUP_MASK	0xff
+#define SPFI_DEVICE_PARAMETER_CSHOLD_SHIFT	8
+#define SPFI_DEVICE_PARAMETER_CSHOLD_MASK	0xff
+#define SPFI_DEVICE_PARAMETER_CSDELAY_SHIFT	0
+#define SPFI_DEVICE_PARAMETER_CSDELAY_MASK	0xff
+
+#define SPFI_CONTROL				0x14
+#define SPFI_CONTROL_CONTINUE			BIT(12)
+#define SPFI_CONTROL_SOFT_RESET			BIT(11)
+#define SPFI_CONTROL_SEND_DMA			BIT(10)
+#define SPFI_CONTROL_GET_DMA			BIT(9)
+#define SPFI_CONTROL_TMODE_SHIFT		5
+#define SPFI_CONTROL_TMODE_MASK			0x7
+#define SPFI_CONTROL_TMODE_SINGLE		0
+#define SPFI_CONTROL_TMODE_DUAL			1
+#define SPFI_CONTROL_TMODE_QUAD			2
+#define SPFI_CONTROL_SPFI_EN			BIT(0)
+
+#define SPFI_TRANSACTION			0x18
+#define SPFI_TRANSACTION_TSIZE_SHIFT		16
+#define SPFI_TRANSACTION_TSIZE_MASK		0xffff
+
+#define SPFI_PORT_STATE				0x1c
+#define SPFI_PORT_STATE_DEV_SEL_SHIFT		20
+#define SPFI_PORT_STATE_DEV_SEL_MASK		0x7
+#define SPFI_PORT_STATE_CK_POL(x)		BIT(19 - (x))
+#define SPFI_PORT_STATE_CK_PHASE(x)		BIT(14 - (x))
+
+#define SPFI_TX_32BIT_VALID_DATA		0x20
+#define SPFI_TX_8BIT_VALID_DATA			0x24
+#define SPFI_RX_32BIT_VALID_DATA		0x28
+#define SPFI_RX_8BIT_VALID_DATA			0x2c
+
+#define SPFI_INTERRUPT_STATUS			0x30
+#define SPFI_INTERRUPT_ENABLE			0x34
+#define SPFI_INTERRUPT_CLEAR			0x38
+#define SPFI_INTERRUPT_IACCESS			BIT(12)
+#define SPFI_INTERRUPT_GDEX8BIT			BIT(11)
+#define SPFI_INTERRUPT_ALLDONETRIG		BIT(9)
+#define SPFI_INTERRUPT_GDFUL			BIT(8)
+#define SPFI_INTERRUPT_GDHF			BIT(7)
+#define SPFI_INTERRUPT_GDEX32BIT		BIT(6)
+#define SPFI_INTERRUPT_GDTRIG			BIT(5)
+#define SPFI_INTERRUPT_SDFUL			BIT(3)
+#define SPFI_INTERRUPT_SDHF			BIT(2)
+#define SPFI_INTERRUPT_SDE			BIT(1)
+#define SPFI_INTERRUPT_SDTRIG			BIT(0)
+
+/*
+ * There are four parallel FIFOs of 16 bytes each.  The word buffer
+ * (*_32BIT_VALID_DATA) accesses all four FIFOs at once, resulting in an
+ * effective FIFO size of 64 bytes.  The byte buffer (*_8BIT_VALID_DATA)
+ * accesses only a single FIFO, resulting in an effective FIFO size of
+ * 16 bytes.
+ */
+#define SPFI_32BIT_FIFO_SIZE			64
+#define SPFI_8BIT_FIFO_SIZE			16
+
+struct img_spfi {
+	struct device *dev;
+	struct spi_master *master;
+	spinlock_t lock;
+
+	void __iomem *regs;
+	phys_addr_t phys;
+	int irq;
+	struct clk *spfi_clk;
+	struct clk *sys_clk;
+
+	struct dma_chan *rx_ch;
+	struct dma_chan *tx_ch;
+	bool tx_dma_busy;
+	bool rx_dma_busy;
+};
+
+static inline u32 spfi_readl(struct img_spfi *spfi, u32 reg)
+{
+	return readl(spfi->regs + reg);
+}
+
+static inline void spfi_writel(struct img_spfi *spfi, u32 val, u32 reg)
+{
+	writel(val, spfi->regs + reg);
+}
+
+static inline void spfi_start(struct img_spfi *spfi)
+{
+	u32 val;
+
+	val = spfi_readl(spfi, SPFI_CONTROL);
+	val |= SPFI_CONTROL_SPFI_EN;
+	spfi_writel(spfi, val, SPFI_CONTROL);
+}
+
+static inline void spfi_stop(struct img_spfi *spfi)
+{
+	u32 val;
+
+	val = spfi_readl(spfi, SPFI_CONTROL);
+	val &= ~SPFI_CONTROL_SPFI_EN;
+	spfi_writel(spfi, val, SPFI_CONTROL);
+}
+
+static inline void spfi_reset(struct img_spfi *spfi)
+{
+	spfi_writel(spfi, SPFI_CONTROL_SOFT_RESET, SPFI_CONTROL);
+	udelay(1);
+	spfi_writel(spfi, 0, SPFI_CONTROL);
+}
+
+static void spfi_flush_tx_fifo(struct img_spfi *spfi)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(10);
+
+	spfi_writel(spfi, SPFI_INTERRUPT_SDE, SPFI_INTERRUPT_CLEAR);
+	while (time_before(jiffies, timeout)) {
+		if (spfi_readl(spfi, SPFI_INTERRUPT_STATUS) &
+		    SPFI_INTERRUPT_SDE)
+			return;
+		cpu_relax();
+	}
+
+	dev_err(spfi->dev, "Timed out waiting for FIFO to drain\n");
+	spfi_reset(spfi);
+}
+
+static unsigned int spfi_pio_write32(struct img_spfi *spfi, const u32 *buf,
+				     unsigned int max)
+{
+	unsigned int count = 0;
+	u32 status;
+
+	while (count < max) {
+		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
+		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+		if (status & SPFI_INTERRUPT_SDFUL)
+			break;
+		spfi_writel(spfi, buf[count / 4], SPFI_TX_32BIT_VALID_DATA);
+		count += 4;
+	}
+
+	return count;
+}
+
+static unsigned int spfi_pio_write8(struct img_spfi *spfi, const u8 *buf,
+				    unsigned int max)
+{
+	unsigned int count = 0;
+	u32 status;
+
+	while (count < max) {
+		spfi_writel(spfi, SPFI_INTERRUPT_SDFUL, SPFI_INTERRUPT_CLEAR);
+		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+		if (status & SPFI_INTERRUPT_SDFUL)
+			break;
+		spfi_writel(spfi, buf[count], SPFI_TX_8BIT_VALID_DATA);
+		count++;
+	}
+
+	return count;
+}
+
+static unsigned int spfi_pio_read32(struct img_spfi *spfi, u32 *buf,
+				    unsigned int max)
+{
+	unsigned int count = 0;
+	u32 status;
+
+	while (count < max) {
+		spfi_writel(spfi, SPFI_INTERRUPT_GDEX32BIT,
+			    SPFI_INTERRUPT_CLEAR);
+		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+		if (!(status & SPFI_INTERRUPT_GDEX32BIT))
+			break;
+		buf[count / 4] = spfi_readl(spfi, SPFI_RX_32BIT_VALID_DATA);
+		count += 4;
+	}
+
+	return count;
+}
+
+static unsigned int spfi_pio_read8(struct img_spfi *spfi, u8 *buf,
+				   unsigned int max)
+{
+	unsigned int count = 0;
+	u32 status;
+
+	while (count < max) {
+		spfi_writel(spfi, SPFI_INTERRUPT_GDEX8BIT,
+			    SPFI_INTERRUPT_CLEAR);
+		status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+		if (!(status & SPFI_INTERRUPT_GDEX8BIT))
+			break;
+		buf[count] = spfi_readl(spfi, SPFI_RX_8BIT_VALID_DATA);
+		count++;
+	}
+
+	return count;
+}
+
+static int img_spfi_start_pio(struct spi_master *master,
+			       struct spi_device *spi,
+			       struct spi_transfer *xfer)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
+	unsigned int tx_bytes = 0, rx_bytes = 0;
+	const void *tx_buf = xfer->tx_buf;
+	void *rx_buf = xfer->rx_buf;
+	unsigned long timeout;
+
+	if (tx_buf)
+		tx_bytes = xfer->len;
+	if (rx_buf)
+		rx_bytes = xfer->len;
+
+	spfi_start(spfi);
+
+	timeout = jiffies +
+		msecs_to_jiffies(xfer->len * 8 * 1000 / xfer->speed_hz + 100);
+	while ((tx_bytes > 0 || rx_bytes > 0) &&
+	       time_before(jiffies, timeout)) {
+		unsigned int tx_count, rx_count;
+
+		switch (xfer->bits_per_word) {
+		case 32:
+			tx_count = spfi_pio_write32(spfi, tx_buf, tx_bytes);
+			rx_count = spfi_pio_read32(spfi, rx_buf, rx_bytes);
+			break;
+		case 8:
+		default:
+			tx_count = spfi_pio_write8(spfi, tx_buf, tx_bytes);
+			rx_count = spfi_pio_read8(spfi, rx_buf, rx_bytes);
+			break;
+		}
+
+		tx_buf += tx_count;
+		rx_buf += rx_count;
+		tx_bytes -= tx_count;
+		rx_bytes -= rx_count;
+
+		cpu_relax();
+	}
+
+	if (rx_bytes > 0 || tx_bytes > 0) {
+		dev_err(spfi->dev, "PIO transfer timed out\n");
+		spfi_reset(spfi);
+		return -ETIMEDOUT;
+	}
+
+	if (tx_buf)
+		spfi_flush_tx_fifo(spfi);
+	spfi_stop(spfi);
+
+	return 0;
+}
+
+static void img_spfi_dma_rx_cb(void *data)
+{
+	struct img_spfi *spfi = data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&spfi->lock, flags);
+
+	spfi->rx_dma_busy = false;
+	if (!spfi->tx_dma_busy) {
+		spfi_stop(spfi);
+		spi_finalize_current_transfer(spfi->master);
+	}
+
+	spin_unlock_irqrestore(&spfi->lock, flags);
+}
+
+static void img_spfi_dma_tx_cb(void *data)
+{
+	struct img_spfi *spfi = data;
+	unsigned long flags;
+
+	spfi_flush_tx_fifo(spfi);
+
+	spin_lock_irqsave(&spfi->lock, flags);
+
+	spfi->tx_dma_busy = false;
+	if (!spfi->rx_dma_busy) {
+		spfi_stop(spfi);
+		spi_finalize_current_transfer(spfi->master);
+	}
+
+	spin_unlock_irqrestore(&spfi->lock, flags);
+}
+
+static int img_spfi_start_dma(struct spi_master *master,
+			      struct spi_device *spi,
+			      struct spi_transfer *xfer)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
+	struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL;
+	struct dma_slave_config rxconf, txconf;
+
+	spfi->rx_dma_busy = false;
+	spfi->tx_dma_busy = false;
+
+	if (xfer->rx_buf) {
+		rxconf.direction = DMA_DEV_TO_MEM;
+		switch (xfer->bits_per_word) {
+		case 32:
+			rxconf.src_addr = spfi->phys + SPFI_RX_32BIT_VALID_DATA;
+			rxconf.src_addr_width = 4;
+			rxconf.src_maxburst = 4;
+			break;
+		case 8:
+		default:
+			rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA;
+			rxconf.src_addr_width = 1;
+			rxconf.src_maxburst = 1;
+		}
+		dmaengine_slave_config(spfi->rx_ch, &rxconf);
+
+		rxdesc = dmaengine_prep_slave_sg(spfi->rx_ch, xfer->rx_sg.sgl,
+						 xfer->rx_sg.nents,
+						 DMA_DEV_TO_MEM,
+						 DMA_PREP_INTERRUPT);
+		if (!rxdesc)
+			goto stop_dma;
+
+		rxdesc->callback = img_spfi_dma_rx_cb;
+		rxdesc->callback_param = spfi;
+	}
+
+	if (xfer->tx_buf) {
+		txconf.direction = DMA_MEM_TO_DEV;
+		switch (xfer->bits_per_word) {
+		case 32:
+			txconf.dst_addr = spfi->phys + SPFI_TX_32BIT_VALID_DATA;
+			txconf.dst_addr_width = 4;
+			txconf.dst_maxburst = 4;
+			break;
+		case 8:
+		default:
+			txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA;
+			txconf.dst_addr_width = 1;
+			txconf.dst_maxburst = 1;
+			break;
+		}
+		dmaengine_slave_config(spfi->tx_ch, &txconf);
+
+		txdesc = dmaengine_prep_slave_sg(spfi->tx_ch, xfer->tx_sg.sgl,
+						 xfer->tx_sg.nents,
+						 DMA_MEM_TO_DEV,
+						 DMA_PREP_INTERRUPT);
+		if (!txdesc)
+			goto stop_dma;
+
+		txdesc->callback = img_spfi_dma_tx_cb;
+		txdesc->callback_param = spfi;
+	}
+
+	if (xfer->rx_buf) {
+		spfi->rx_dma_busy = true;
+		dmaengine_submit(rxdesc);
+		dma_async_issue_pending(spfi->rx_ch);
+	}
+
+	if (xfer->tx_buf) {
+		spfi->tx_dma_busy = true;
+		dmaengine_submit(txdesc);
+		dma_async_issue_pending(spfi->tx_ch);
+	}
+
+	spfi_start(spfi);
+
+	return 1;
+
+stop_dma:
+	dmaengine_terminate_all(spfi->rx_ch);
+	dmaengine_terminate_all(spfi->tx_ch);
+	return -EIO;
+}
+
+static void img_spfi_config(struct spi_master *master, struct spi_device *spi,
+			    struct spi_transfer *xfer)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
+	u32 val, div;
+
+	/*
+	 * output = spfi_clk * (BITCLK / 512), where BITCLK must be a
+	 * power of 2 up to 256 (where 255 == 256 since BITCLK is 8 bits)
+	 */
+	div = DIV_ROUND_UP(master->max_speed_hz, xfer->speed_hz);
+	div = clamp(512 / (1 << get_count_order(div)), 1, 255);
+
+	val = spfi_readl(spfi, SPFI_DEVICE_PARAMETER(spi->chip_select));
+	val &= ~(SPFI_DEVICE_PARAMETER_BITCLK_MASK <<
+		 SPFI_DEVICE_PARAMETER_BITCLK_SHIFT);
+	val |= div << SPFI_DEVICE_PARAMETER_BITCLK_SHIFT;
+	spfi_writel(spfi, val, SPFI_DEVICE_PARAMETER(spi->chip_select));
+
+	val = spfi_readl(spfi, SPFI_CONTROL);
+	val &= ~(SPFI_CONTROL_SEND_DMA | SPFI_CONTROL_GET_DMA);
+	if (xfer->tx_buf)
+		val |= SPFI_CONTROL_SEND_DMA;
+	if (xfer->rx_buf)
+		val |= SPFI_CONTROL_GET_DMA;
+	val &= ~(SPFI_CONTROL_TMODE_MASK << SPFI_CONTROL_TMODE_SHIFT);
+	if (xfer->tx_nbits == SPI_NBITS_DUAL &&
+	    xfer->rx_nbits == SPI_NBITS_DUAL)
+		val |= SPFI_CONTROL_TMODE_DUAL << SPFI_CONTROL_TMODE_SHIFT;
+	else if (xfer->tx_nbits == SPI_NBITS_QUAD &&
+		 xfer->rx_nbits == SPI_NBITS_QUAD)
+		val |= SPFI_CONTROL_TMODE_QUAD << SPFI_CONTROL_TMODE_SHIFT;
+	val &= ~SPFI_CONTROL_CONTINUE;
+	if (!xfer->cs_change && !list_is_last(&xfer->transfer_list,
+					      &master->cur_msg->transfers))
+		val |= SPFI_CONTROL_CONTINUE;
+	spfi_writel(spfi, val, SPFI_CONTROL);
+
+	val = spfi_readl(spfi, SPFI_PORT_STATE);
+	if (spi->mode & SPI_CPHA)
+		val |= SPFI_PORT_STATE_CK_PHASE(spi->chip_select);
+	else
+		val &= ~SPFI_PORT_STATE_CK_PHASE(spi->chip_select);
+	if (spi->mode & SPI_CPOL)
+		val |= SPFI_PORT_STATE_CK_POL(spi->chip_select);
+	else
+		val &= ~SPFI_PORT_STATE_CK_POL(spi->chip_select);
+	spfi_writel(spfi, val, SPFI_PORT_STATE);
+
+	spfi_writel(spfi, xfer->len << SPFI_TRANSACTION_TSIZE_SHIFT,
+		    SPFI_TRANSACTION);
+}
+
+static int img_spfi_transfer_one(struct spi_master *master,
+				 struct spi_device *spi,
+				 struct spi_transfer *xfer)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
+	bool dma_reset = false;
+	unsigned long flags;
+	int ret;
+
+	/*
+	 * Stop all DMA and reset the controller if the previous transaction
+	 * timed-out and never completed it's DMA.
+	 */
+	spin_lock_irqsave(&spfi->lock, flags);
+	if (spfi->tx_dma_busy || spfi->rx_dma_busy) {
+		dev_err(spfi->dev, "SPI DMA still busy\n");
+		dma_reset = true;
+	}
+	spin_unlock_irqrestore(&spfi->lock, flags);
+
+	if (dma_reset) {
+		dmaengine_terminate_all(spfi->tx_ch);
+		dmaengine_terminate_all(spfi->rx_ch);
+		spfi_reset(spfi);
+	}
+
+	img_spfi_config(master, spi, xfer);
+	if (master->can_dma && master->can_dma(master, spi, xfer))
+		ret = img_spfi_start_dma(master, spi, xfer);
+	else
+		ret = img_spfi_start_pio(master, spi, xfer);
+
+	return ret;
+}
+
+static void img_spfi_set_cs(struct spi_device *spi, bool enable)
+{
+	struct img_spfi *spfi = spi_master_get_devdata(spi->master);
+	u32 val;
+
+	val = spfi_readl(spfi, SPFI_PORT_STATE);
+	val &= ~(SPFI_PORT_STATE_DEV_SEL_MASK << SPFI_PORT_STATE_DEV_SEL_SHIFT);
+	val |= spi->chip_select << SPFI_PORT_STATE_DEV_SEL_SHIFT;
+	spfi_writel(spfi, val, SPFI_PORT_STATE);
+}
+
+static bool img_spfi_can_dma(struct spi_master *master, struct spi_device *spi,
+			     struct spi_transfer *xfer)
+{
+	if (xfer->bits_per_word == 8 && xfer->len > SPFI_8BIT_FIFO_SIZE)
+		return true;
+	if (xfer->bits_per_word == 32 && xfer->len > SPFI_32BIT_FIFO_SIZE)
+		return true;
+	return false;
+}
+
+static irqreturn_t img_spfi_irq(int irq, void *dev_id)
+{
+	struct img_spfi *spfi = (struct img_spfi *)dev_id;
+	u32 status;
+
+	status = spfi_readl(spfi, SPFI_INTERRUPT_STATUS);
+	if (status & SPFI_INTERRUPT_IACCESS) {
+		spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_CLEAR);
+		dev_err(spfi->dev, "Illegal access interrupt");
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int img_spfi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct img_spfi *spfi;
+	struct resource *res;
+	int ret;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*spfi));
+	if (!master)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, master);
+
+	spfi = spi_master_get_devdata(master);
+	spfi->dev = &pdev->dev;
+	spfi->master = master;
+	spin_lock_init(&spfi->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	spfi->regs = devm_ioremap_resource(spfi->dev, res);
+	if (IS_ERR(spfi->regs)) {
+		ret = PTR_ERR(spfi->regs);
+		goto put_spi;
+	}
+	spfi->phys = res->start;
+
+	spfi->irq = platform_get_irq(pdev, 0);
+	if (spfi->irq < 0) {
+		ret = spfi->irq;
+		goto put_spi;
+	}
+	ret = devm_request_irq(spfi->dev, spfi->irq, img_spfi_irq,
+			       IRQ_TYPE_LEVEL_HIGH, dev_name(spfi->dev), spfi);
+	if (ret)
+		goto put_spi;
+
+	spfi->sys_clk = devm_clk_get(spfi->dev, "sys");
+	if (IS_ERR(spfi->sys_clk)) {
+		ret = PTR_ERR(spfi->sys_clk);
+		goto put_spi;
+	}
+	spfi->spfi_clk = devm_clk_get(spfi->dev, "spfi");
+	if (IS_ERR(spfi->spfi_clk)) {
+		ret = PTR_ERR(spfi->spfi_clk);
+		goto put_spi;
+	}
+
+	ret = clk_prepare_enable(spfi->sys_clk);
+	if (ret)
+		goto put_spi;
+	ret = clk_prepare_enable(spfi->spfi_clk);
+	if (ret)
+		goto disable_pclk;
+
+	spfi_reset(spfi);
+	/*
+	 * Only enable the error (IACCESS) interrupt.  In PIO mode we'll
+	 * poll the status of the FIFOs.
+	 */
+	spfi_writel(spfi, SPFI_INTERRUPT_IACCESS, SPFI_INTERRUPT_ENABLE);
+
+	master->auto_runtime_pm = true;
+	master->bus_num = pdev->id;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_DUAL | SPI_RX_DUAL;
+	if (of_property_read_bool(spfi->dev->of_node, "img,supports-quad-mode"))
+		master->mode_bits |= SPI_TX_QUAD | SPI_RX_QUAD;
+	master->num_chipselect = 5;
+	master->dev.of_node = pdev->dev.of_node;
+	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(8);
+	master->max_speed_hz = clk_get_rate(spfi->spfi_clk);
+	master->min_speed_hz = master->max_speed_hz / 512;
+
+	master->set_cs = img_spfi_set_cs;
+	master->transfer_one = img_spfi_transfer_one;
+
+	spfi->tx_ch = dma_request_slave_channel(spfi->dev, "tx");
+	spfi->rx_ch = dma_request_slave_channel(spfi->dev, "rx");
+	if (!spfi->tx_ch || !spfi->rx_ch) {
+		if (spfi->tx_ch)
+			dma_release_channel(spfi->tx_ch);
+		if (spfi->rx_ch)
+			dma_release_channel(spfi->rx_ch);
+		dev_warn(spfi->dev, "Failed to get DMA channels, falling back to PIO mode\n");
+	} else {
+		master->dma_tx = spfi->tx_ch;
+		master->dma_rx = spfi->rx_ch;
+		master->can_dma = img_spfi_can_dma;
+	}
+
+	pm_runtime_set_active(spfi->dev);
+	pm_runtime_enable(spfi->dev);
+
+	ret = devm_spi_register_master(spfi->dev, master);
+	if (ret)
+		goto disable_pm;
+
+	return 0;
+
+disable_pm:
+	pm_runtime_disable(spfi->dev);
+	if (spfi->rx_ch)
+		dma_release_channel(spfi->rx_ch);
+	if (spfi->tx_ch)
+		dma_release_channel(spfi->tx_ch);
+	clk_disable_unprepare(spfi->spfi_clk);
+disable_pclk:
+	clk_disable_unprepare(spfi->sys_clk);
+put_spi:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int img_spfi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+
+	if (spfi->tx_ch)
+		dma_release_channel(spfi->tx_ch);
+	if (spfi->rx_ch)
+		dma_release_channel(spfi->rx_ch);
+
+	pm_runtime_disable(spfi->dev);
+	if (!pm_runtime_status_suspended(spfi->dev)) {
+		clk_disable_unprepare(spfi->spfi_clk);
+		clk_disable_unprepare(spfi->sys_clk);
+	}
+
+	spi_master_put(master);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_RUNTIME
+static int img_spfi_runtime_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+
+	clk_disable_unprepare(spfi->spfi_clk);
+	clk_disable_unprepare(spfi->sys_clk);
+
+	return 0;
+}
+
+static int img_spfi_runtime_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+	int ret;
+
+	ret = clk_prepare_enable(spfi->sys_clk);
+	if (ret)
+		return ret;
+	ret = clk_prepare_enable(spfi->spfi_clk);
+	if (ret) {
+		clk_disable_unprepare(spfi->sys_clk);
+		return ret;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_RUNTIME */
+
+#ifdef CONFIG_PM_SLEEP
+static int img_spfi_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+
+	return spi_master_suspend(master);
+}
+
+static int img_spfi_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct img_spfi *spfi = spi_master_get_devdata(master);
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret)
+		return ret;
+	spfi_reset(spfi);
+	pm_runtime_put(dev);
+
+	return spi_master_resume(master);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops img_spfi_pm_ops = {
+	SET_RUNTIME_PM_OPS(img_spfi_runtime_suspend, img_spfi_runtime_resume,
+			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(img_spfi_suspend, img_spfi_resume)
+};
+
+static const struct of_device_id img_spfi_of_match[] = {
+	{ .compatible = "img,spfi", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, img_spfi_of_match);
+
+static struct platform_driver img_spfi_driver = {
+	.driver = {
+		.name = "img-spfi",
+		.pm = &img_spfi_pm_ops,
+		.of_match_table = of_match_ptr(img_spfi_of_match),
+	},
+	.probe = img_spfi_probe,
+	.remove = img_spfi_remove,
+};
+module_platform_driver(img_spfi_driver);
+
+MODULE_DESCRIPTION("IMG SPFI controller driver");
+MODULE_AUTHOR("Andrew Bresticker <abrestic@...omium.org>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0.rc2.206.gedb03e5

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