Merge tag 'spi-fix-v4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A bunch of really small fixes here, all driver specific and mostly in
  error handling and remove paths.

  The most important fixes are for the a3700 clock configuration and a
  fix for a nasty stall which could potentially cause data corruption
  with the xilinx driver"

* tag 'spi-fix-v4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: atmel: fixed spin_lock usage inside atmel_spi_remove
  spi: sun4i: disable clocks in the remove function
  spi: rspi: Do not set SPCR_SPE in qspi_set_config_register()
  spi: Fix double "when"
  spi: a3700: Fix clk prescaling for coefficient over 15
  spi: xilinx: Detect stall with Unknown commands
  spi: imx: Update device tree binding documentation

7 files changed, 36 insertions, 11 deletions

diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
index 5bf13960f7f4..e3c48b20b1a6 100644
--- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
+++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt
@@ -12,24 +12,30 @@ Required properties:
   - "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc
 - reg : Offset and length of the register set for the device
 - interrupts : Should contain CSPI/eCSPI interrupt
-- cs-gpios : Specifies the gpio pins to be used for chipselects.
 - clocks : Clock specifiers for both ipg and per clocks.
 - clock-names : Clock names should include both "ipg" and "per"
 See the clock consumer binding,
 	Documentation/devicetree/bindings/clock/clock-bindings.txt
-- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
-		Documentation/devicetree/bindings/dma/dma.txt
-- dma-names: DMA request names should include "tx" and "rx" if present.
 
-Obsolete properties:
-- fsl,spi-num-chipselects : Contains the number of the chipselect
+Recommended properties:
+- cs-gpios : GPIOs to use as chip selects, see spi-bus.txt.  While the native chip
+select lines can be used, they appear to always generate a pulse between each
+word of a transfer.  Most use cases will require GPIO based chip selects to
+generate a valid transaction.
 
 Optional properties:
+- num-cs :  Number of total chip selects, see spi-bus.txt.
+- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
+Documentation/devicetree/bindings/dma/dma.txt.
+- dma-names: DMA request names, if present, should include "tx" and "rx".
 - fsl,spi-rdy-drctl: Integer, representing the value of DRCTL, the register
 controlling the SPI_READY handling. Note that to enable the DRCTL consideration,
 the SPI_READY mode-flag needs to be set too.
 Valid values are: 0 (disabled), 1 (edge-triggered burst) and 2 (level-triggered burst).
 
+Obsolete properties:
+- fsl,spi-num-chipselects : Contains the number of the chipselect
+
 Example:
 
 ecspi@70010000 {
diff --git a/drivers/spi/spi-armada-3700.c b/drivers/spi/spi-armada-3700.c
index 77fe55ce790c..d65345312527 100644
--- a/drivers/spi/spi-armada-3700.c
+++ b/drivers/spi/spi-armada-3700.c
@@ -79,6 +79,7 @@
 #define A3700_SPI_BYTE_LEN		BIT(5)
 #define A3700_SPI_CLK_PRESCALE		BIT(0)
 #define A3700_SPI_CLK_PRESCALE_MASK	(0x1f)
+#define A3700_SPI_CLK_EVEN_OFFS		(0x10)
 
 #define A3700_SPI_WFIFO_THRS_BIT	28
 #define A3700_SPI_RFIFO_THRS_BIT	24
@@ -220,6 +221,13 @@ static void a3700_spi_clock_set(struct a3700_spi *a3700_spi,
 
 	prescale = DIV_ROUND_UP(clk_get_rate(a3700_spi->clk), speed_hz);
 
+	/* For prescaler values over 15, we can only set it by steps of 2.
+	 * Starting from A3700_SPI_CLK_EVEN_OFFS, we set values from 0 up to
+	 * 30. We only use this range from 16 to 30.
+	 */
+	if (prescale > 15)
+		prescale = A3700_SPI_CLK_EVEN_OFFS + DIV_ROUND_UP(prescale, 2);
+
 	val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
 	val = val & ~A3700_SPI_CLK_PRESCALE_MASK;
 
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index f95da364c283..669470971023 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1661,12 +1661,12 @@ static int atmel_spi_remove(struct platform_device *pdev)
 	pm_runtime_get_sync(&pdev->dev);
 
 	/* reset the hardware and block queue progress */
-	spin_lock_irq(&as->lock);
 	if (as->use_dma) {
 		atmel_spi_stop_dma(master);
 		atmel_spi_release_dma(master);
 	}
 
+	spin_lock_irq(&as->lock);
 	spi_writel(as, CR, SPI_BIT(SWRST));
 	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
 	spi_readl(as, SR);
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 2ce875764ca6..0835a8d88fb8 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -377,8 +377,8 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
 	/* Sets SPCMD */
 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
 
-	/* Enables SPI function in master mode */
-	rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
+	/* Sets RSPI mode */
+	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
 
 	return 0;
 }
diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
index c5cd635c28f3..41410031f8e9 100644
--- a/drivers/spi/spi-sun4i.c
+++ b/drivers/spi/spi-sun4i.c
@@ -525,7 +525,7 @@ err_free_master:
 
 static int sun4i_spi_remove(struct platform_device *pdev)
 {
-	pm_runtime_disable(&pdev->dev);
+	pm_runtime_force_suspend(&pdev->dev);
 
 	return 0;
 }
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index bc7100b93dfc..e0b9fe1d0e37 100644
--- a/drivers/spi/spi-xilinx.c
+++ b/drivers/spi/spi-xilinx.c
@@ -271,6 +271,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 	while (remaining_words) {
 		int n_words, tx_words, rx_words;
 		u32 sr;
+		int stalled;
 
 		n_words = min(remaining_words, xspi->buffer_size);
 
@@ -299,7 +300,17 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 
 		/* Read out all the data from the Rx FIFO */
 		rx_words = n_words;
+		stalled = 10;
 		while (rx_words) {
+			if (rx_words == n_words && !(stalled--) &&
+			    !(sr & XSPI_SR_TX_EMPTY_MASK) &&
+			    (sr & XSPI_SR_RX_EMPTY_MASK)) {
+				dev_err(&spi->dev,
+					"Detected stall. Check C_SPI_MODE and C_SPI_MEMORY\n");
+				xspi_init_hw(xspi);
+				return -EIO;
+			}
+
 			if ((sr & XSPI_SR_TX_EMPTY_MASK) && (rx_words > 1)) {
 				xilinx_spi_rx(xspi);
 				rx_words--;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 7b2170bfd6e7..bc6bb325d1bf 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -126,7 +126,7 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
  *	for that name.  This appears in the sysfs "modalias" attribute
  *	for driver coldplugging, and in uevents used for hotplugging
  * @cs_gpio: gpio number of the chipselect line (optional, -ENOENT when
- *	when not using a GPIO line)
+ *	not using a GPIO line)
  *
  * @statistics: statistics for the spi_device
  *