Merge branch 'spi-5.3' into spi-next

17 files changed, 1603 insertions, 241 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 30a40280c157..3a1d8f1170de 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -120,7 +120,7 @@ config SPI_AXI_SPI_ENGINE
 config SPI_BCM2835
 	tristate "BCM2835 SPI controller"
 	depends on GPIOLIB
-	depends on ARCH_BCM2835 || COMPILE_TEST
+	depends on ARCH_BCM2835 || ARCH_BRCMSTB || COMPILE_TEST
 	help
 	  This selects a driver for the Broadcom BCM2835 SPI master.
 
@@ -131,7 +131,7 @@ config SPI_BCM2835
 
 config SPI_BCM2835AUX
 	tristate "BCM2835 SPI auxiliary controller"
-	depends on (ARCH_BCM2835 && GPIOLIB) || COMPILE_TEST
+	depends on ((ARCH_BCM2835 || ARCH_BRCMSTB) && GPIOLIB) || COMPILE_TEST
 	help
 	  This selects a driver for the Broadcom BCM2835 SPI aux master.
 
@@ -733,6 +733,16 @@ config SPI_SUN6I
 	help
 	  This enables using the SPI controller on the Allwinner A31 SoCs.
 
+config SPI_SYNQUACER
+	tristate "Socionext's SynQuacer HighSpeed SPI controller"
+	depends on ARCH_SYNQUACER || COMPILE_TEST
+	help
+	  SPI driver for Socionext's High speed SPI controller which provides
+	  various operating modes for interfacing to serial peripheral devices
+	  that use the de-facto standard SPI protocol.
+
+	  It also supports the new dual-bit and quad-bit SPI protocol.
+
 config SPI_MXIC
         tristate "Macronix MX25F0A SPI controller"
         depends on SPI_MASTER
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index f2f78d03dc28..63dcab552bcb 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -106,6 +106,7 @@ 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-$(CONFIG_SPI_SYNQUACER)		+= spi-synquacer.o
 obj-$(CONFIG_SPI_TEGRA114)		+= spi-tegra114.o
 obj-$(CONFIG_SPI_TEGRA20_SFLASH)	+= spi-tegra20-sflash.o
 obj-$(CONFIG_SPI_TEGRA20_SLINK)		+= spi-tegra20-slink.o
diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index 9f24d5f0b431..6a7d7b553d95 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -151,6 +151,7 @@ struct atmel_qspi {
 	const struct atmel_qspi_caps *caps;
 	u32			pending;
 	u32			mr;
+	u32			scr;
 	struct completion	cmd_completion;
 };
 
@@ -382,7 +383,7 @@ static int atmel_qspi_setup(struct spi_device *spi)
 	struct spi_controller *ctrl = spi->master;
 	struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
 	unsigned long src_rate;
-	u32 scr, scbr;
+	u32 scbr;
 
 	if (ctrl->busy)
 		return -EBUSY;
@@ -399,13 +400,13 @@ static int atmel_qspi_setup(struct spi_device *spi)
 	if (scbr > 0)
 		scbr--;
 
-	scr = QSPI_SCR_SCBR(scbr);
-	writel_relaxed(scr, aq->regs + QSPI_SCR);
+	aq->scr = QSPI_SCR_SCBR(scbr);
+	writel_relaxed(aq->scr, aq->regs + QSPI_SCR);
 
 	return 0;
 }
 
-static int atmel_qspi_init(struct atmel_qspi *aq)
+static void atmel_qspi_init(struct atmel_qspi *aq)
 {
 	/* Reset the QSPI controller */
 	writel_relaxed(QSPI_CR_SWRST, aq->regs + QSPI_CR);
@@ -416,8 +417,6 @@ static int atmel_qspi_init(struct atmel_qspi *aq)
 
 	/* Enable the QSPI controller */
 	writel_relaxed(QSPI_CR_QSPIEN, aq->regs + QSPI_CR);
-
-	return 0;
 }
 
 static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
@@ -536,9 +535,7 @@ static int atmel_qspi_probe(struct platform_device *pdev)
 	if (err)
 		goto disable_qspick;
 
-	err = atmel_qspi_init(aq);
-	if (err)
-		goto disable_qspick;
+	atmel_qspi_init(aq);
 
 	err = spi_register_controller(ctrl);
 	if (err)
@@ -587,7 +584,11 @@ static int __maybe_unused atmel_qspi_resume(struct device *dev)
 	clk_prepare_enable(aq->pclk);
 	clk_prepare_enable(aq->qspick);
 
-	return atmel_qspi_init(aq);
+	atmel_qspi_init(aq);
+
+	writel_relaxed(aq->scr, aq->regs + QSPI_SCR);
+
+	return 0;
 }
 
 static SIMPLE_DEV_PM_OPS(atmel_qspi_pm_ops, atmel_qspi_suspend,
diff --git a/drivers/spi/spi-at91-usart.c b/drivers/spi/spi-at91-usart.c
index f763e14bdf12..a40bb2ef89dc 100644
--- a/drivers/spi/spi-at91-usart.c
+++ b/drivers/spi/spi-at91-usart.c
@@ -8,9 +8,12 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-direction.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_platform.h>
 #include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
@@ -59,6 +62,8 @@
 
 #define US_INIT \
 	(US_MR_SPI_MASTER | US_MR_CHRL | US_MR_CLKO | US_MR_WRDBT)
+#define US_DMA_MIN_BYTES       16
+#define US_DMA_TIMEOUT         (msecs_to_jiffies(1000))
 
 /* Register access macros */
 #define at91_usart_spi_readl(port, reg) \
@@ -72,14 +77,19 @@
 	writeb_relaxed((value), (port)->regs + US_##reg)
 
 struct at91_usart_spi {
+	struct platform_device  *mpdev;
 	struct spi_transfer	*current_transfer;
 	void __iomem		*regs;
 	struct device		*dev;
 	struct clk		*clk;
 
+	struct completion	xfer_completion;
+
 	/*used in interrupt to protect data reading*/
 	spinlock_t		lock;
 
+	phys_addr_t		phybase;
+
 	int			irq;
 	unsigned int		current_tx_remaining_bytes;
 	unsigned int		current_rx_remaining_bytes;
@@ -88,8 +98,182 @@ struct at91_usart_spi {
 	u32			status;
 
 	bool			xfer_failed;
+	bool			use_dma;
 };
 
+static void dma_callback(void *data)
+{
+	struct spi_controller   *ctlr = data;
+	struct at91_usart_spi   *aus = spi_master_get_devdata(ctlr);
+
+	at91_usart_spi_writel(aus, IER, US_IR_RXRDY);
+	aus->current_rx_remaining_bytes = 0;
+	complete(&aus->xfer_completion);
+}
+
+static bool at91_usart_spi_can_dma(struct spi_controller *ctrl,
+				   struct spi_device *spi,
+				   struct spi_transfer *xfer)
+{
+	struct at91_usart_spi *aus = spi_master_get_devdata(ctrl);
+
+	return aus->use_dma && xfer->len >= US_DMA_MIN_BYTES;
+}
+
+static int at91_usart_spi_configure_dma(struct spi_controller *ctlr,
+					struct at91_usart_spi *aus)
+{
+	struct dma_slave_config slave_config;
+	struct device *dev = &aus->mpdev->dev;
+	phys_addr_t phybase = aus->phybase;
+	dma_cap_mask_t mask;
+	int err = 0;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	ctlr->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+	if (IS_ERR_OR_NULL(ctlr->dma_tx)) {
+		if (IS_ERR(ctlr->dma_tx)) {
+			err = PTR_ERR(ctlr->dma_tx);
+			goto at91_usart_spi_error_clear;
+		}
+
+		dev_dbg(dev,
+			"DMA TX channel not available, SPI unable to use DMA\n");
+		err = -EBUSY;
+		goto at91_usart_spi_error_clear;
+	}
+
+	ctlr->dma_rx = dma_request_slave_channel_reason(dev, "rx");
+	if (IS_ERR_OR_NULL(ctlr->dma_rx)) {
+		if (IS_ERR(ctlr->dma_rx)) {
+			err = PTR_ERR(ctlr->dma_rx);
+			goto at91_usart_spi_error;
+		}
+
+		dev_dbg(dev,
+			"DMA RX channel not available, SPI unable to use DMA\n");
+		err = -EBUSY;
+		goto at91_usart_spi_error;
+	}
+
+	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	slave_config.dst_addr = (dma_addr_t)phybase + US_THR;
+	slave_config.src_addr = (dma_addr_t)phybase + US_RHR;
+	slave_config.src_maxburst = 1;
+	slave_config.dst_maxburst = 1;
+	slave_config.device_fc = false;
+
+	slave_config.direction = DMA_DEV_TO_MEM;
+	if (dmaengine_slave_config(ctlr->dma_rx, &slave_config)) {
+		dev_err(&ctlr->dev,
+			"failed to configure rx dma channel\n");
+		err = -EINVAL;
+		goto at91_usart_spi_error;
+	}
+
+	slave_config.direction = DMA_MEM_TO_DEV;
+	if (dmaengine_slave_config(ctlr->dma_tx, &slave_config)) {
+		dev_err(&ctlr->dev,
+			"failed to configure tx dma channel\n");
+		err = -EINVAL;
+		goto at91_usart_spi_error;
+	}
+
+	aus->use_dma = true;
+	return 0;
+
+at91_usart_spi_error:
+	if (!IS_ERR_OR_NULL(ctlr->dma_tx))
+		dma_release_channel(ctlr->dma_tx);
+	if (!IS_ERR_OR_NULL(ctlr->dma_rx))
+		dma_release_channel(ctlr->dma_rx);
+	ctlr->dma_tx = NULL;
+	ctlr->dma_rx = NULL;
+
+at91_usart_spi_error_clear:
+	return err;
+}
+
+static void at91_usart_spi_release_dma(struct spi_controller *ctlr)
+{
+	if (ctlr->dma_rx)
+		dma_release_channel(ctlr->dma_rx);
+	if (ctlr->dma_tx)
+		dma_release_channel(ctlr->dma_tx);
+}
+
+static void at91_usart_spi_stop_dma(struct spi_controller *ctlr)
+{
+	if (ctlr->dma_rx)
+		dmaengine_terminate_all(ctlr->dma_rx);
+	if (ctlr->dma_tx)
+		dmaengine_terminate_all(ctlr->dma_tx);
+}
+
+static int at91_usart_spi_dma_transfer(struct spi_controller *ctlr,
+				       struct spi_transfer *xfer)
+{
+	struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+	struct dma_chan	 *rxchan = ctlr->dma_rx;
+	struct dma_chan *txchan = ctlr->dma_tx;
+	struct dma_async_tx_descriptor *rxdesc;
+	struct dma_async_tx_descriptor *txdesc;
+	dma_cookie_t cookie;
+
+	/* Disable RX interrupt */
+	at91_usart_spi_writel(aus, IDR, US_IR_RXRDY);
+
+	rxdesc = dmaengine_prep_slave_sg(rxchan,
+					 xfer->rx_sg.sgl,
+					 xfer->rx_sg.nents,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT |
+					 DMA_CTRL_ACK);
+	if (!rxdesc)
+		goto at91_usart_spi_err_dma;
+
+	txdesc = dmaengine_prep_slave_sg(txchan,
+					 xfer->tx_sg.sgl,
+					 xfer->tx_sg.nents,
+					 DMA_MEM_TO_DEV,
+					 DMA_PREP_INTERRUPT |
+					 DMA_CTRL_ACK);
+	if (!txdesc)
+		goto at91_usart_spi_err_dma;
+
+	rxdesc->callback = dma_callback;
+	rxdesc->callback_param = ctlr;
+
+	cookie = rxdesc->tx_submit(rxdesc);
+	if (dma_submit_error(cookie))
+		goto at91_usart_spi_err_dma;
+
+	cookie = txdesc->tx_submit(txdesc);
+	if (dma_submit_error(cookie))
+		goto at91_usart_spi_err_dma;
+
+	rxchan->device->device_issue_pending(rxchan);
+	txchan->device->device_issue_pending(txchan);
+
+	return 0;
+
+at91_usart_spi_err_dma:
+	/* Enable RX interrupt if something fails and fallback to PIO */
+	at91_usart_spi_writel(aus, IER, US_IR_RXRDY);
+	at91_usart_spi_stop_dma(ctlr);
+
+	return -ENOMEM;
+}
+
+static unsigned long at91_usart_spi_dma_timeout(struct at91_usart_spi *aus)
+{
+	return wait_for_completion_timeout(&aus->xfer_completion,
+					   US_DMA_TIMEOUT);
+}
+
 static inline u32 at91_usart_spi_tx_ready(struct at91_usart_spi *aus)
 {
 	return aus->status & US_IR_TXRDY;
@@ -216,6 +400,8 @@ static int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
 				       struct spi_transfer *xfer)
 {
 	struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+	unsigned long dma_timeout = 0;
+	int ret = 0;
 
 	at91_usart_spi_set_xfer_speed(aus, xfer);
 	aus->xfer_failed = false;
@@ -225,8 +411,25 @@ static int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
 
 	while ((aus->current_tx_remaining_bytes ||
 		aus->current_rx_remaining_bytes) && !aus->xfer_failed) {
-		at91_usart_spi_read_status(aus);
-		at91_usart_spi_tx(aus);
+		reinit_completion(&aus->xfer_completion);
+		if (at91_usart_spi_can_dma(ctlr, spi, xfer) &&
+		    !ret) {
+			ret = at91_usart_spi_dma_transfer(ctlr, xfer);
+			if (ret)
+				continue;
+
+			dma_timeout = at91_usart_spi_dma_timeout(aus);
+
+			if (WARN_ON(dma_timeout == 0)) {
+				dev_err(&spi->dev, "DMA transfer timeout\n");
+				return -EIO;
+			}
+			aus->current_tx_remaining_bytes = 0;
+		} else {
+			at91_usart_spi_read_status(aus);
+			at91_usart_spi_tx(aus);
+		}
+
 		cpu_relax();
 	}
 
@@ -345,6 +548,7 @@ static int at91_usart_spi_probe(struct platform_device *pdev)
 	controller->transfer_one = at91_usart_spi_transfer_one;
 	controller->prepare_message = at91_usart_spi_prepare_message;
 	controller->unprepare_message = at91_usart_spi_unprepare_message;
+	controller->can_dma = at91_usart_spi_can_dma;
 	controller->cleanup = at91_usart_spi_cleanup;
 	controller->max_speed_hz = DIV_ROUND_UP(clk_get_rate(clk),
 						US_MIN_CLK_DIV);
@@ -376,7 +580,17 @@ static int at91_usart_spi_probe(struct platform_device *pdev)
 	aus->spi_clk = clk_get_rate(clk);
 	at91_usart_spi_init(aus);
 
+	aus->phybase = regs->start;
+
+	aus->mpdev = to_platform_device(pdev->dev.parent);
+
+	ret = at91_usart_spi_configure_dma(controller, aus);
+	if (ret)
+		goto at91_usart_fail_dma;
+
 	spin_lock_init(&aus->lock);
+	init_completion(&aus->xfer_completion);
+
 	ret = devm_spi_register_master(&pdev->dev, controller);
 	if (ret)
 		goto at91_usart_fail_register_master;
@@ -389,6 +603,8 @@ static int at91_usart_spi_probe(struct platform_device *pdev)
 	return 0;
 
 at91_usart_fail_register_master:
+	at91_usart_spi_release_dma(controller);
+at91_usart_fail_dma:
 	clk_disable_unprepare(clk);
 at91_usart_spi_probe_fail:
 	spi_master_put(controller);
@@ -453,6 +669,7 @@ static int at91_usart_spi_remove(struct platform_device *pdev)
 	struct spi_controller *ctlr = platform_get_drvdata(pdev);
 	struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
 
+	at91_usart_spi_release_dma(ctlr);
 	clk_disable_unprepare(aus->clk);
 
 	return 0;
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 402c1efcd762..6f243a90c844 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -13,6 +13,7 @@
 
 #include <linux/clk.h>
 #include <linux/completion.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
@@ -64,14 +65,18 @@
 
 #define BCM2835_SPI_FIFO_SIZE		64
 #define BCM2835_SPI_FIFO_SIZE_3_4	48
-#define BCM2835_SPI_POLLING_LIMIT_US	30
-#define BCM2835_SPI_POLLING_JIFFIES	2
 #define BCM2835_SPI_DMA_MIN_LENGTH	96
 #define BCM2835_SPI_MODE_BITS	(SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
 				| SPI_NO_CS | SPI_3WIRE)
 
 #define DRV_NAME	"spi-bcm2835"
 
+/* define polling limits */
+unsigned int polling_limit_us = 30;
+module_param(polling_limit_us, uint, 0664);
+MODULE_PARM_DESC(polling_limit_us,
+		 "time in us to run a transfer in polling mode\n");
+
 /**
  * struct bcm2835_spi - BCM2835 SPI controller
  * @regs: base address of register map
@@ -88,6 +93,15 @@
  *	length is not a multiple of 4 (to overcome hardware limitation)
  * @tx_spillover: whether @tx_prologue spills over to second TX sglist entry
  * @dma_pending: whether a DMA transfer is in progress
+ * @debugfs_dir: the debugfs directory - neede to remove debugfs when
+ *      unloading the module
+ * @count_transfer_polling: count of how often polling mode is used
+ * @count_transfer_irq: count of how often interrupt mode is used
+ * @count_transfer_irq_after_polling: count of how often we fall back to
+ *      interrupt mode after starting in polling mode.
+ *      These are counted as well in @count_transfer_polling and
+ *      @count_transfer_irq
+ * @count_transfer_dma: count how often dma mode is used
  */
 struct bcm2835_spi {
 	void __iomem *regs;
@@ -102,8 +116,55 @@ struct bcm2835_spi {
 	int rx_prologue;
 	unsigned int tx_spillover;
 	unsigned int dma_pending;
+
+	struct dentry *debugfs_dir;
+	u64 count_transfer_polling;
+	u64 count_transfer_irq;
+	u64 count_transfer_irq_after_polling;
+	u64 count_transfer_dma;
 };
 
+#if defined(CONFIG_DEBUG_FS)
+static void bcm2835_debugfs_create(struct bcm2835_spi *bs,
+				   const char *dname)
+{
+	char name[64];
+	struct dentry *dir;
+
+	/* get full name */
+	snprintf(name, sizeof(name), "spi-bcm2835-%s", dname);
+
+	/* the base directory */
+	dir = debugfs_create_dir(name, NULL);
+	bs->debugfs_dir = dir;
+
+	/* the counters */
+	debugfs_create_u64("count_transfer_polling", 0444, dir,
+			   &bs->count_transfer_polling);
+	debugfs_create_u64("count_transfer_irq", 0444, dir,
+			   &bs->count_transfer_irq);
+	debugfs_create_u64("count_transfer_irq_after_polling", 0444, dir,
+			   &bs->count_transfer_irq_after_polling);
+	debugfs_create_u64("count_transfer_dma", 0444, dir,
+			   &bs->count_transfer_dma);
+}
+
+static void bcm2835_debugfs_remove(struct bcm2835_spi *bs)
+{
+	debugfs_remove_recursive(bs->debugfs_dir);
+	bs->debugfs_dir = NULL;
+}
+#else
+static void bcm2835_debugfs_create(struct bcm2835_spi *bs,
+				   const char *dname)
+{
+}
+
+static void bcm2835_debugfs_remove(struct bcm2835_spi *bs)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
 static inline u32 bcm2835_rd(struct bcm2835_spi *bs, unsigned reg)
 {
 	return readl(bs->regs + reg);
@@ -248,9 +309,9 @@ static inline void bcm2835_wr_fifo_blind(struct bcm2835_spi *bs, int count)
 	}
 }
 
-static void bcm2835_spi_reset_hw(struct spi_master *master)
+static void bcm2835_spi_reset_hw(struct spi_controller *ctlr)
 {
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
 	u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
 
 	/* Disable SPI interrupts and transfer */
@@ -269,8 +330,8 @@ static void bcm2835_spi_reset_hw(struct spi_master *master)
 
 static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
 {
-	struct spi_master *master = dev_id;
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct spi_controller *ctlr = dev_id;
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
 	u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
 
 	/*
@@ -292,20 +353,23 @@ static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
 
 	if (!bs->rx_len) {
 		/* Transfer complete - reset SPI HW */
-		bcm2835_spi_reset_hw(master);
+		bcm2835_spi_reset_hw(ctlr);
 		/* wake up the framework */
-		complete(&master->xfer_completion);
+		complete(&ctlr->xfer_completion);
 	}
 
 	return IRQ_HANDLED;
 }
 
-static int bcm2835_spi_transfer_one_irq(struct spi_master *master,
+static int bcm2835_spi_transfer_one_irq(struct spi_controller *ctlr,
 					struct spi_device *spi,
 					struct spi_transfer *tfr,
 					u32 cs, bool fifo_empty)
 {
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
+
+	/* update usage statistics */
+	bs->count_transfer_irq++;
 
 	/*
 	 * Enable HW block, but with interrupts still disabled.
@@ -328,7 +392,7 @@ static int bcm2835_spi_transfer_one_irq(struct spi_master *master,
 
 /**
  * bcm2835_spi_transfer_prologue() - transfer first few bytes without DMA
- * @master: SPI master
+ * @ctlr: SPI master controller
  * @tfr: SPI transfer
  * @bs: BCM2835 SPI controller
  * @cs: CS register
@@ -372,7 +436,7 @@ static int bcm2835_spi_transfer_one_irq(struct spi_master *master,
  * be transmitted in 32-bit width to ensure that the following DMA transfer can
  * pick up the residue in the RX FIFO in ungarbled form.
  */
-static void bcm2835_spi_transfer_prologue(struct spi_master *master,
+static void bcm2835_spi_transfer_prologue(struct spi_controller *ctlr,
 					  struct spi_transfer *tfr,
 					  struct bcm2835_spi *bs,
 					  u32 cs)
@@ -413,9 +477,9 @@ static void bcm2835_spi_transfer_prologue(struct spi_master *master,
 		bcm2835_wr_fifo_count(bs, bs->rx_prologue);
 		bcm2835_wait_tx_fifo_empty(bs);
 		bcm2835_rd_fifo_count(bs, bs->rx_prologue);
-		bcm2835_spi_reset_hw(master);
+		bcm2835_spi_reset_hw(ctlr);
 
-		dma_sync_single_for_device(master->dma_rx->device->dev,
+		dma_sync_single_for_device(ctlr->dma_rx->device->dev,
 					   sg_dma_address(&tfr->rx_sg.sgl[0]),
 					   bs->rx_prologue, DMA_FROM_DEVICE);
 
@@ -479,11 +543,11 @@ static void bcm2835_spi_undo_prologue(struct bcm2835_spi *bs)
 
 static void bcm2835_spi_dma_done(void *data)
 {
-	struct spi_master *master = data;
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct spi_controller *ctlr = data;
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
 
 	/* reset fifo and HW */
-	bcm2835_spi_reset_hw(master);
+	bcm2835_spi_reset_hw(ctlr);
 
 	/* and terminate tx-dma as we do not have an irq for it
 	 * because when the rx dma will terminate and this callback
@@ -491,15 +555,15 @@ static void bcm2835_spi_dma_done(void *data)
 	 * situation otherwise...
 	 */
 	if (cmpxchg(&bs->dma_pending, true, false)) {
-		dmaengine_terminate_async(master->dma_tx);
+		dmaengine_terminate_async(ctlr->dma_tx);
 		bcm2835_spi_undo_prologue(bs);
 	}
 
 	/* and mark as completed */;
-	complete(&master->xfer_completion);
+	complete(&ctlr->xfer_completion);
 }
 
-static int bcm2835_spi_prepare_sg(struct spi_master *master,
+static int bcm2835_spi_prepare_sg(struct spi_controller *ctlr,
 				  struct spi_transfer *tfr,
 				  bool is_tx)
 {
@@ -514,14 +578,14 @@ static int bcm2835_spi_prepare_sg(struct spi_master *master,
 
 	if (is_tx) {
 		dir   = DMA_MEM_TO_DEV;
-		chan  = master->dma_tx;
+		chan  = ctlr->dma_tx;
 		nents = tfr->tx_sg.nents;
 		sgl   = tfr->tx_sg.sgl;
 		flags = 0 /* no  tx interrupt */;
 
 	} else {
 		dir   = DMA_DEV_TO_MEM;
-		chan  = master->dma_rx;
+		chan  = ctlr->dma_rx;
 		nents = tfr->rx_sg.nents;
 		sgl   = tfr->rx_sg.sgl;
 		flags = DMA_PREP_INTERRUPT;
@@ -534,7 +598,7 @@ static int bcm2835_spi_prepare_sg(struct spi_master *master,
 	/* set callback for rx */
 	if (!is_tx) {
 		desc->callback = bcm2835_spi_dma_done;
-		desc->callback_param = master;
+		desc->callback_param = ctlr;
 	}
 
 	/* submit it to DMA-engine */
@@ -543,27 +607,30 @@ static int bcm2835_spi_prepare_sg(struct spi_master *master,
 	return dma_submit_error(cookie);
 }
 
-static int bcm2835_spi_transfer_one_dma(struct spi_master *master,
+static int bcm2835_spi_transfer_one_dma(struct spi_controller *ctlr,
 					struct spi_device *spi,
 					struct spi_transfer *tfr,
 					u32 cs)
 {
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
 	int ret;
 
+	/* update usage statistics */
+	bs->count_transfer_dma++;
+
 	/*
 	 * Transfer first few bytes without DMA if length of first TX or RX
 	 * sglist entry is not a multiple of 4 bytes (hardware limitation).
 	 */
-	bcm2835_spi_transfer_prologue(master, tfr, bs, cs);
+	bcm2835_spi_transfer_prologue(ctlr, tfr, bs, cs);
 
 	/* setup tx-DMA */
-	ret = bcm2835_spi_prepare_sg(master, tfr, true);
+	ret = bcm2835_spi_prepare_sg(ctlr, tfr, true);
 	if (ret)
 		goto err_reset_hw;
 
 	/* start TX early */
-	dma_async_issue_pending(master->dma_tx);
+	dma_async_issue_pending(ctlr->dma_tx);
 
 	/* mark as dma pending */
 	bs->dma_pending = 1;
@@ -579,27 +646,27 @@ static int bcm2835_spi_transfer_one_dma(struct spi_master *master,
 	 * mapping of the rx buffers still takes place
 	 * this saves 10us or more.
 	 */
-	ret = bcm2835_spi_prepare_sg(master, tfr, false);
+	ret = bcm2835_spi_prepare_sg(ctlr, tfr, false);
 	if (ret) {
 		/* need to reset on errors */
-		dmaengine_terminate_sync(master->dma_tx);
+		dmaengine_terminate_sync(ctlr->dma_tx);
 		bs->dma_pending = false;
 		goto err_reset_hw;
 	}
 
 	/* start rx dma late */
-	dma_async_issue_pending(master->dma_rx);
+	dma_async_issue_pending(ctlr->dma_rx);
 
 	/* wait for wakeup in framework */
 	return 1;
 
 err_reset_hw:
-	bcm2835_spi_reset_hw(master);
+	bcm2835_spi_reset_hw(ctlr);
 	bcm2835_spi_undo_prologue(bs);
 	return ret;
 }
 
-static bool bcm2835_spi_can_dma(struct spi_master *master,
+static bool bcm2835_spi_can_dma(struct spi_controller *ctlr,
 				struct spi_device *spi,
 				struct spi_transfer *tfr)
 {
@@ -611,21 +678,21 @@ static bool bcm2835_spi_can_dma(struct spi_master *master,
 	return true;
 }
 
-static void bcm2835_dma_release(struct spi_master *master)
+static void bcm2835_dma_release(struct spi_controller *ctlr)
 {
-	if (master->dma_tx) {
-		dmaengine_terminate_sync(master->dma_tx);
-		dma_release_channel(master->dma_tx);
-		master->dma_tx = NULL;
+	if (ctlr->dma_tx) {
+		dmaengine_terminate_sync(ctlr->dma_tx);
+		dma_release_channel(ctlr->dma_tx);
+		ctlr->dma_tx = NULL;
 	}
-	if (master->dma_rx) {
-		dmaengine_terminate_sync(master->dma_rx);
-		dma_release_channel(master->dma_rx);
-		master->dma_rx = NULL;
+	if (ctlr->dma_rx) {
+		dmaengine_terminate_sync(ctlr->dma_rx);
+		dma_release_channel(ctlr->dma_rx);
+		ctlr->dma_rx = NULL;
 	}
 }
 
-static void bcm2835_dma_init(struct spi_master *master, struct device *dev)
+static void bcm2835_dma_init(struct spi_controller *ctlr, struct device *dev)
 {
 	struct dma_slave_config slave_config;
 	const __be32 *addr;
@@ -633,7 +700,7 @@ static void bcm2835_dma_init(struct spi_master *master, struct device *dev)
 	int ret;
 
 	/* base address in dma-space */
-	addr = of_get_address(master->dev.of_node, 0, NULL, NULL);
+	addr = of_get_address(ctlr->dev.of_node, 0, NULL, NULL);
 	if (!addr) {
 		dev_err(dev, "could not get DMA-register address - not using dma mode\n");
 		goto err;
@@ -641,38 +708,36 @@ static void bcm2835_dma_init(struct spi_master *master, struct device *dev)
 	dma_reg_base = be32_to_cpup(addr);
 
 	/* get tx/rx dma */
-	master->dma_tx = dma_request_slave_channel(dev, "tx");
-	if (!master->dma_tx) {
+	ctlr->dma_tx = dma_request_slave_channel(dev, "tx");
+	if (!ctlr->dma_tx) {
 		dev_err(dev, "no tx-dma configuration found - not using dma mode\n");
 		goto err;
 	}
-	master->dma_rx = dma_request_slave_channel(dev, "rx");
-	if (!master->dma_rx) {
+	ctlr->dma_rx = dma_request_slave_channel(dev, "rx");
+	if (!ctlr->dma_rx) {
 		dev_err(dev, "no rx-dma configuration found - not using dma mode\n");
 		goto err_release;
 	}
 
 	/* configure DMAs */
-	slave_config.direction = DMA_MEM_TO_DEV;
 	slave_config.dst_addr = (u32)(dma_reg_base + BCM2835_SPI_FIFO);
 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 
-	ret = dmaengine_slave_config(master->dma_tx, &slave_config);
+	ret = dmaengine_slave_config(ctlr->dma_tx, &slave_config);
 	if (ret)
 		goto err_config;
 
-	slave_config.direction = DMA_DEV_TO_MEM;
 	slave_config.src_addr = (u32)(dma_reg_base + BCM2835_SPI_FIFO);
 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 
-	ret = dmaengine_slave_config(master->dma_rx, &slave_config);
+	ret = dmaengine_slave_config(ctlr->dma_rx, &slave_config);
 	if (ret)
 		goto err_config;
 
 	/* all went well, so set can_dma */
-	master->can_dma = bcm2835_spi_can_dma;
+	ctlr->can_dma = bcm2835_spi_can_dma;
 	/* need to do TX AND RX DMA, so we need dummy buffers */
-	master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
+	ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
 
 	return;
 
@@ -680,20 +745,22 @@ err_config:
 	dev_err(dev, "issue configuring dma: %d - not using DMA mode\n",
 		ret);
 err_release:
-	bcm2835_dma_release(master);
+	bcm2835_dma_release(ctlr);
 err:
 	return;
 }
 
-static int bcm2835_spi_transfer_one_poll(struct spi_master *master,
+static int bcm2835_spi_transfer_one_poll(struct spi_controller *ctlr,
 					 struct spi_device *spi,
 					 struct spi_transfer *tfr,
-					 u32 cs,
-					 unsigned long long xfer_time_us)
+					 u32 cs)
 {
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
 	unsigned long timeout;
 
+	/* update usage statistics */
+	bs->count_transfer_polling++;
+
 	/* enable HW block without interrupts */
 	bcm2835_wr(bs, BCM2835_SPI_CS, cs | BCM2835_SPI_CS_TA);
 
@@ -703,8 +770,8 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master,
 	 */
 	bcm2835_wr_fifo_blind(bs, BCM2835_SPI_FIFO_SIZE);
 
-	/* set the timeout */
-	timeout = jiffies + BCM2835_SPI_POLLING_JIFFIES;
+	/* set the timeout to at least 2 jiffies */
+	timeout = jiffies + 2 + HZ * polling_limit_us / 1000000;
 
 	/* loop until finished the transfer */
 	while (bs->rx_len) {
@@ -723,25 +790,28 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master,
 					    jiffies - timeout,
 					    bs->tx_len, bs->rx_len);
 			/* fall back to interrupt mode */
-			return bcm2835_spi_transfer_one_irq(master, spi,
+
+			/* update usage statistics */
+			bs->count_transfer_irq_after_polling++;
+
+			return bcm2835_spi_transfer_one_irq(ctlr, spi,
 							    tfr, cs, false);
 		}
 	}
 
 	/* Transfer complete - reset SPI HW */
-	bcm2835_spi_reset_hw(master);
+	bcm2835_spi_reset_hw(ctlr);
 	/* and return without waiting for completion */
 	return 0;
 }
 
-static int bcm2835_spi_transfer_one(struct spi_master *master,
+static int bcm2835_spi_transfer_one(struct spi_controller *ctlr,
 				    struct spi_device *spi,
 				    struct spi_transfer *tfr)
 {
-	struct bcm2835_spi *bs = spi_master_get_devdata(master);
-	unsigned long spi_hz, clk_hz, cdiv;
-	unsigned long spi_used_hz;
-	unsigned long long xfer_time_us;
+	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
+	unsigned long spi_hz, clk_hz, cdiv, spi_used_hz;
+	unsigned long hz_per_byte, byte_limit;
 	u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
 
 	/* set clock */
@@ -782,42 +852,49 @@ static int bcm2835_spi_transfer_one(struct spi_master *master,
 	bs->tx_len = tfr->len;
 	bs->rx_len = tfr->len;
 
-	/* calculate the estimated time in us the transfer runs */
-	xfer_time_us = (unsigned long long)tfr->len
-		* 9 /* clocks/byte - SPI-HW waits 1 clock after each byte */
-		* 1000000;
-	do_div(xfer_time_us, spi_used_hz);
+	/* Calculate the estimated time in us the transfer runs.  Note that
+	 * there is 1 idle clocks cycles after each byte getting transferred
+