Merge tag 'spi-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/broonie/spi

Pull spi updates from Mark Brown:
 "Quite a quiet release for SPI, there are no changes at all to the core
  and not that many changes to drivers. Highlights of those driver
  changes include:

   - SH MSIOF support for GPIO chip selects contributed by Geert
     Uytterhoeven.

   - Full duplex support for a3700 contributed by Maxime Chevallier.

   - Support for DMA transfers on Atmel devices that require a bounce
     buffer contributed by Radu Pirea"

* tag 'spi-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (31 commits)
  spi: dw: Remove unused members from struct chip_data
  spi: orion: Fix a resource leak if the optional "axi" clk is deferred
  spi: a3700: Remove endianness swapping for full-duplex transfers
  spi: a3700: Remove endianness swapping functions when accessing FIFOs
  spi: a3700: Add full-duplex support
  spi: a3700: Allow to enable or disable FIFO mode
  spi: a3700: Set frequency limits at startup
  spi: a3700: Clear DATA_OUT when performing a read
  spi: orion: Fix clock resource by adding an optional bus clock
  spi: s3c64xx: add SPDX identifier
  spi: imx: do not access registers while clocks disabled
  spi: atmel: Implements transfers with bounce buffer
  spi: sh-msiof: Fix timeout failures for TX-only DMA transfers
  spi: spi-fsl-dspi: account for const type of of_device_id.data
  spi: bcm53xx: simplify reading SPI data
  spi: sirf: account for const type of of_device_id.data
  spi: pxa2xx: Use gpiod_put() not gpiod_free()
  spi: pxa2xx: avoid redundant gpio_to_desc(desc_to_gpio()) round-trip
  spi: sh-msiof: Document hardware limitations related to chip selects
  spi: sh-msiof: Implement cs-gpios configuration
  ...

Documentation/devicetree/bindings/spi/sh-msiof.txt

@@ -36,7 +36,21 @@ Required properties:
 
 Optional properties:
 - clocks               : Must contain a reference to the functional clock.
-- num-cs               : Total number of chip-selects (default is 1)
+- num-cs               : Total number of chip selects (default is 1).
+			 Up to 3 native chip selects are supported:
+			   0: MSIOF_SYNC
+			   1: MSIOF_SS1
+			   2: MSIOF_SS2
+			 Hardware limitations related to chip selects:
+			   - Native chip selects are always deasserted in
+			     between transfers that are part of the same
+			     message.  Use cs-gpios to work around this.
+			   - All slaves using native chip selects must use the
+			     same spi-cs-high configuration.  Use cs-gpios to
+			     work around this.
+			   - When using GPIO chip selects, at least one native
+			     chip select must be left unused, as it will be
+			     driven anyway.
 - dmas                 : Must contain a list of two references to DMA
 			 specifiers, one for transmission, and one for
 			 reception.

Documentation/devicetree/bindings/spi/spi-meson.txt

@@ -27,7 +27,9 @@ The Meson SPICC is generic SPI controller for general purpose Full-Duplex
 communications with dedicated 16 words RX/TX PIO FIFOs.
 
 Required properties:
- - compatible: should be "amlogic,meson-gx-spicc" on Amlogic GX SoCs.
+ - compatible: should be:
+	"amlogic,meson-gx-spicc" on Amlogic GX and compatible SoCs.
+	"amlogic,meson-axg-spicc" on Amlogic AXG and compatible SoCs
  - reg: physical base address and length of the controller registers
  - interrupts: The interrupt specifier
  - clock-names: Must contain "core"

Documentation/devicetree/bindings/spi/spi-orion.txt

@@ -18,8 +18,17 @@ Required properties:
 	The eight register sets following the control registers refer to
 	chip-select lines 0 through 7 respectively.
 - cell-index : Which of multiple SPI controllers is this.
+- clocks : pointers to the reference clocks for this device, the first
+	   one is the one used for the clock on the spi bus, the
+	   second one is optional and is the clock used for the
+	   functional part of the controller
+
 Optional properties:
 - interrupts : Is currently not used.
+- clock-names : names of used clocks, mandatory if the second clock is
+		used, the name must be "core", and "axi" (the latter
+		is only for Armada 7K/8K).
+
 
 Example:
        spi@10600 {

Documentation/devicetree/bindings/spi/spi-xilinx.txt

@@ -2,7 +2,7 @@ Xilinx SPI controller Device Tree Bindings
 -------------------------------------------------
 
 Required properties:
-- compatible		: Should be "xlnx,xps-spi-2.00.a" or "xlnx,xps-spi-2.00.b"
+- compatible		: Should be "xlnx,xps-spi-2.00.a", "xlnx,xps-spi-2.00.b" or "xlnx,axi-quad-spi-1.00.a"
 - reg			: Physical base address and size of SPI registers map.
 - interrupts		: Property with a value describing the interrupt
 			  number.

drivers/spi/spi-armada-3700.c

@@ -27,6 +27,8 @@
 
 #define DRIVER_NAME			"armada_3700_spi"
 
+#define A3700_SPI_MAX_SPEED_HZ		100000000
+#define A3700_SPI_MAX_PRESCALE		30
 #define A3700_SPI_TIMEOUT		10
 
 /* SPI Register Offest */
@@ -184,12 +186,15 @@ static int a3700_spi_pin_mode_set(struct a3700_spi *a3700_spi,
 	return 0;
 }
 
-static void a3700_spi_fifo_mode_set(struct a3700_spi *a3700_spi)
+static void a3700_spi_fifo_mode_set(struct a3700_spi *a3700_spi, bool enable)
 {
 	u32 val;
 
 	val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
-	val |= A3700_SPI_FIFO_MODE;
+	if (enable)
+		val |= A3700_SPI_FIFO_MODE;
+	else
+		val &= ~A3700_SPI_FIFO_MODE;
 	spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
 }
 
@@ -297,7 +302,7 @@ static int a3700_spi_init(struct a3700_spi *a3700_spi)
 		a3700_spi_deactivate_cs(a3700_spi, i);
 
 	/* Enable FIFO mode */
-	a3700_spi_fifo_mode_set(a3700_spi);
+	a3700_spi_fifo_mode_set(a3700_spi, true);
 
 	/* Set SPI mode */
 	a3700_spi_mode_set(a3700_spi, master->mode_bits);
@@ -416,15 +421,20 @@ static void a3700_spi_transfer_setup(struct spi_device *spi,
 				     struct spi_transfer *xfer)
 {
 	struct a3700_spi *a3700_spi;
-	unsigned int byte_len;
 
 	a3700_spi = spi_master_get_devdata(spi->master);
 
 	a3700_spi_clock_set(a3700_spi, xfer->speed_hz);
 
-	byte_len = xfer->bits_per_word >> 3;
+	/* Use 4 bytes long transfers. Each transfer method has its way to deal
+	 * with the remaining bytes for non 4-bytes aligned transfers.
+	 */
+	a3700_spi_bytelen_set(a3700_spi, 4);
 
-	a3700_spi_fifo_thres_set(a3700_spi, byte_len);
+	/* Initialize the working buffers */
+	a3700_spi->tx_buf  = xfer->tx_buf;
+	a3700_spi->rx_buf  = xfer->rx_buf;
+	a3700_spi->buf_len = xfer->len;
 }
 
 static void a3700_spi_set_cs(struct spi_device *spi, bool enable)
@@ -491,7 +501,7 @@ static int a3700_spi_fifo_write(struct a3700_spi *a3700_spi)
 	u32 val;
 
 	while (!a3700_is_wfifo_full(a3700_spi) && a3700_spi->buf_len) {
-		val = cpu_to_le32(*(u32 *)a3700_spi->tx_buf);
+		val = *(u32 *)a3700_spi->tx_buf;
 		spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, val);
 		a3700_spi->buf_len -= 4;
 		a3700_spi->tx_buf += 4;
@@ -514,9 +524,8 @@ static int a3700_spi_fifo_read(struct a3700_spi *a3700_spi)
 	while (!a3700_is_rfifo_empty(a3700_spi) && a3700_spi->buf_len) {
 		val = spireg_read(a3700_spi, A3700_SPI_DATA_IN_REG);
 		if (a3700_spi->buf_len >= 4) {
-			u32 data = le32_to_cpu(val);
 
-			memcpy(a3700_spi->rx_buf, &data, 4);
+			memcpy(a3700_spi->rx_buf, &val, 4);
 
 			a3700_spi->buf_len -= 4;
 			a3700_spi->rx_buf += 4;
@@ -579,27 +588,26 @@ static int a3700_spi_prepare_message(struct spi_master *master,
 	if (ret)
 		return ret;
 
-	a3700_spi_bytelen_set(a3700_spi, 4);
-
 	a3700_spi_mode_set(a3700_spi, spi->mode);
 
 	return 0;
 }
 
-static int a3700_spi_transfer_one(struct spi_master *master,
+static int a3700_spi_transfer_one_fifo(struct spi_master *master,
 				  struct spi_device *spi,
 				  struct spi_transfer *xfer)
 {
 	struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
 	int ret = 0, timeout = A3700_SPI_TIMEOUT;
-	unsigned int nbits = 0;
+	unsigned int nbits = 0, byte_len;
 	u32 val;
 
-	a3700_spi_transfer_setup(spi, xfer);
+	/* Make sure we use FIFO mode */
+	a3700_spi_fifo_mode_set(a3700_spi, true);
 
-	a3700_spi->tx_buf  = xfer->tx_buf;
-	a3700_spi->rx_buf  = xfer->rx_buf;
-	a3700_spi->buf_len = xfer->len;
+	/* Configure FIFO thresholds */
+	byte_len = xfer->bits_per_word >> 3;
+	a3700_spi_fifo_thres_set(a3700_spi, byte_len);
 
 	if (xfer->tx_buf)
 		nbits = xfer->tx_nbits;
@@ -615,6 +623,11 @@ static int a3700_spi_transfer_one(struct spi_master *master,
 	a3700_spi_header_set(a3700_spi);
 
 	if (xfer->rx_buf) {
+		/* Clear WFIFO, since it's last 2 bytes are shifted out during
+		 * a read operation
+		 */
+		spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, 0);
+
 		/* Set read data length */
 		spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG,
 			     a3700_spi->buf_len);
@@ -729,6 +742,63 @@ static int a3700_spi_transfer_one(struct spi_master *master,
 	return ret;
 }
 
+static int a3700_spi_transfer_one_full_duplex(struct spi_master *master,
+				  struct spi_device *spi,
+				  struct spi_transfer *xfer)
+{
+	struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
+	u32 val;
+
+	/* Disable FIFO mode */
+	a3700_spi_fifo_mode_set(a3700_spi, false);
+
+	while (a3700_spi->buf_len) {
+
+		/* When we have less than 4 bytes to transfer, switch to 1 byte
+		 * mode. This is reset after each transfer
+		 */
+		if (a3700_spi->buf_len < 4)
+			a3700_spi_bytelen_set(a3700_spi, 1);
+
+		if (a3700_spi->byte_len == 1)
+			val = *a3700_spi->tx_buf;
+		else
+			val = *(u32 *)a3700_spi->tx_buf;
+
+		spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, val);
+
+		/* Wait for all the data to be shifted in / out */
+		while (!(spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG) &
+				A3700_SPI_XFER_DONE))
+			cpu_relax();
+
+		val = spireg_read(a3700_spi, A3700_SPI_DATA_IN_REG);
+
+		memcpy(a3700_spi->rx_buf, &val, a3700_spi->byte_len);
+
+		a3700_spi->buf_len -= a3700_spi->byte_len;
+		a3700_spi->tx_buf += a3700_spi->byte_len;
+		a3700_spi->rx_buf += a3700_spi->byte_len;
+
+	}
+
+	spi_finalize_current_transfer(master);
+
+	return 0;
+}
+
+static int a3700_spi_transfer_one(struct spi_master *master,
+				  struct spi_device *spi,
+				  struct spi_transfer *xfer)
+{
+	a3700_spi_transfer_setup(spi, xfer);
+
+	if (xfer->tx_buf && xfer->rx_buf)
+		return a3700_spi_transfer_one_full_duplex(master, spi, xfer);
+
+	return a3700_spi_transfer_one_fifo(master, spi, xfer);
+}
+
 static int a3700_spi_unprepare_message(struct spi_master *master,
 				       struct spi_message *message)
 {
@@ -778,7 +848,6 @@ static int a3700_spi_probe(struct platform_device *pdev)
 	master->transfer_one = a3700_spi_transfer_one;
 	master->unprepare_message = a3700_spi_unprepare_message;
 	master->set_cs = a3700_spi_set_cs;
-	master->flags = SPI_MASTER_HALF_DUPLEX;
 	master->mode_bits |= (SPI_RX_DUAL | SPI_TX_DUAL |
 			      SPI_RX_QUAD | SPI_TX_QUAD);
 
@@ -818,6 +887,11 @@ static int a3700_spi_probe(struct platform_device *pdev)
 		goto error;
 	}
 
+	master->max_speed_hz = min_t(unsigned long, A3700_SPI_MAX_SPEED_HZ,
+					clk_get_rate(spi->clk));
+	master->min_speed_hz = DIV_ROUND_UP(clk_get_rate(spi->clk),
+						A3700_SPI_MAX_PRESCALE);
+
 	ret = a3700_spi_init(spi);
 	if (ret)
 		goto error_clk;