[PATCH v1 0/2] spi: npcm: add NPCM Peripheral SPI driver

[PATCH v1 0/2] spi: npcm: add NPCM Peripheral SPI driver

[Tomer Maimon]

This patch set adds Peripheral SPI (PSPI) support for the
Nuvoton NPCM Baseboard Management Controller (BMC).

The NPCM PSPI operates in master mode.

The NPCM750/730/715/710 supports up to two PSPI devices.

The NPCM PSPI driver tested on NPCM750 evaluation board.

Tomer Maimon (2):
  dt-binding: spi: add NPCM PSPI controller documentation
  spi: npcm: add NPCM PSPI controller driver

 .../devicetree/bindings/spi/nuvoton,npcm-pspi.txt  |  35 ++
 drivers/spi/Kconfig                                |   7 +
 drivers/spi/Makefile                               |   1 +
 drivers/spi/spi-npcm-pspi.c                        | 480 +++++++++++++++++++++
 4 files changed, 523 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
 create mode 100644 drivers/spi/spi-npcm-pspi.c

-- 
2.14.1

[PATCH v1 1/2] dt-binding: spi: add NPCM PSPI controller documentation

[Tomer Maimon]

Added device tree binding documentation for Nuvoton BMC
NPCM Peripheral SPI controller.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
---
 .../devicetree/bindings/spi/nuvoton,npcm-pspi.txt  | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt

diff --git a/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt b/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
new file mode 100644
index 000000000000..99606b22e5c2
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
@@ -0,0 +1,35 @@
+Nuvoton NPCM Peripheral Serial Peripheral Interface(PSPI) controller driver
+
+Nuvoton NPCM7xx SOC support two PSPI channels.
+
+Required properties:
+ - compatible : "nuvoton,npcm750-pspi" for NPCM7XX BMC
+ - #address-cells : should be 1. see spi-bus.txt
+ - #size-cells : should be 0. see spi-bus.txt
+ - specifies physical base address and size of the register.
+ - interrupts : contain PSPI interrupt.
+ - clocks : phandle of PSPI reference clock.
+ - clock-names: Should be "clk_apb5".
+ - pinctrl-names : a pinctrl state named "default" must be defined.
+ - pinctrl-0 : phandle referencing pin configuration of the device.
+ - cs-gpios: Specifies the gpio pins to be used for chipselects.
+            See: Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Optional properties:
+- clock-frequency : Input clock frequency to the PSPI block in Hz.
+		    Default is 25000000 Hz.
+
+Example:
+
+spi0: spi@f0200000 {
+	compatible = "nuvoton,npcm750-pspi";
+	reg = <0xf0200000 0x1000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pspi1_pins>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&clk NPCM7XX_CLK_APB5>;
+	clock-names = "clk_apb5";
+	cs-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>;
+};
-- 
2.14.1

[PATCH v1 2/2] spi: npcm: add NPCM PSPI controller driver

[Tomer Maimon]

Add Nuvoton NPCM BMC Peripheral SPI controller driver.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
---
 drivers/spi/Kconfig         |   7 +
 drivers/spi/Makefile        |   1 +
 drivers/spi/spi-npcm-pspi.c | 480 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 488 insertions(+)
 create mode 100644 drivers/spi/spi-npcm-pspi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7d3a5c94727e..21eb08405127 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -397,6 +397,13 @@ config SPI_MT65XX
 	  say Y or M here.If you are not sure, say N.
 	  SPI drivers for Mediatek MT65XX and MT81XX series ARM SoCs.
 
+config SPI_NPCM_PSPI
+	tristate "Nuvoton NPCM PSPI Controller"
+	depends on ARCH_NPCM || COMPILE_TEST
+	help
+	  This driver provides support for Nuvoton NPCM BMC
+	  Peripheral SPI controller in master mode.
+
 config SPI_NUC900
 	tristate "Nuvoton NUC900 series SPI"
 	depends on ARCH_W90X900
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3575205c5c27..d40a3611809c 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
 obj-$(CONFIG_SPI_MPC52xx)		+= spi-mpc52xx.o
 obj-$(CONFIG_SPI_MT65XX)                += spi-mt65xx.o
 obj-$(CONFIG_SPI_MXS)			+= spi-mxs.o
+obj-$(CONFIG_SPI_NPCM_PSPI)		+= spi-npcm-pspi.o
 obj-$(CONFIG_SPI_NUC900)		+= spi-nuc900.o
 obj-$(CONFIG_SPI_OC_TINY)		+= spi-oc-tiny.o
 spi-octeon-objs				:= spi-cavium.o spi-cavium-octeon.o
diff --git a/drivers/spi/spi-npcm-pspi.c b/drivers/spi/spi-npcm-pspi.c
new file mode 100644
index 000000000000..51777515c83f
--- /dev/null
+++ b/drivers/spi/spi-npcm-pspi.c
@@ -0,0 +1,480 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Nuvoton Technology corporation.
+
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+struct npcm_pspi {
+	struct completion xfer_done;
+	struct regmap *rst_regmap;
+	struct spi_master *master;
+	unsigned int tx_bytes;
+	unsigned int rx_bytes;
+	void __iomem *base;
+	bool is_save_param;
+	u8 bits_per_word;
+	const u8 *tx_buf;
+	struct clk *clk;
+	u32 speed_hz;
+	u8 *rx_buf;
+	u16 mode;
+	u32 id;
+};
+
+#define DRIVER_NAME "npcm-pspi"
+
+#define NPCM_PSPI_DATA		0x00
+#define NPCM_PSPI_CTL1		0x02
+#define NPCM_PSPI_STAT		0x04
+
+/* definitions for control and status register */
+#define NPCM_PSPI_CTL1_SPIEN	BIT(0)
+#define NPCM_PSPI_CTL1_MOD	BIT(2)
+#define NPCM_PSPI_CTL1_EIR	BIT(5)
+#define NPCM_PSPI_CTL1_EIW	BIT(6)
+#define NPCM_PSPI_CTL1_SCM	BIT(7)
+#define NPCM_PSPI_CTL1_SCIDL	BIT(8)
+#define NPCM_PSPI_CTL1_SCDV6_0	GENMASK(15, 9)
+
+#define NPCM_PSPI_STAT_BSY	BIT(0)
+#define NPCM_PSPI_STAT_RBF	BIT(1)
+
+/* general definitions */
+#define NPCM_PSPI_TIMEOUT_MS		2000
+#define NPCM_PSPI_MAX_CLK_DIVIDER	256
+#define NPCM_PSPI_MIN_CLK_DIVIDER	4
+#define NPCM_PSPI_DEFAULT_CLK		25000000
+
+/* reset register */
+#define NPCM7XX_IPSRST2_OFFSET	0x24
+
+#define NPCM7XX_PSPI1_RESET	BIT(22)
+#define NPCM7XX_PSPI2_RESET	BIT(23)
+
+static inline unsigned int bytes_per_word(unsigned int bits)
+{
+	return bits <= 8 ? 1 : 2;
+}
+
+static inline void npcm_pspi_irq_enable(struct npcm_pspi *priv, u16 mask)
+{
+	u16 val;
+
+	val = ioread16(priv->base + NPCM_PSPI_CTL1);
+	val |= mask;
+	iowrite16(val, priv->base + NPCM_PSPI_CTL1);
+}
+
+static inline void npcm_pspi_irq_disable(struct npcm_pspi *priv, u16 mask)
+{
+	u16 val;
+
+	val = ioread16(priv->base + NPCM_PSPI_CTL1);
+	val &= ~mask;
+	iowrite16(val, priv->base + NPCM_PSPI_CTL1);
+}
+
+static inline void npcm_pspi_enable(struct npcm_pspi *priv)
+{
+	u16 val;
+
+	val = ioread16(priv->base + NPCM_PSPI_CTL1);
+	val |= NPCM_PSPI_CTL1_SPIEN;
+	iowrite16(val, priv->base + NPCM_PSPI_CTL1);
+}
+
+static inline void npcm_pspi_disable(struct npcm_pspi *priv)
+{
+	u16 val;
+
+	val = ioread16(priv->base + NPCM_PSPI_CTL1);
+	val &= ~NPCM_PSPI_CTL1_SPIEN;
+	iowrite16(val, priv->base + NPCM_PSPI_CTL1);
+}
+
+static void npcm_pspi_set_mode(struct spi_device *spi)
+{
+	struct npcm_pspi *priv = spi_master_get_devdata(spi->master);
+	u16 regtemp;
+	u16 mode_val;
+
+	switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
+	case SPI_MODE_0:
+		mode_val = 0;
+		break;
+	case SPI_MODE_1:
+		mode_val = NPCM_PSPI_CTL1_SCIDL;
+		break;
+	case SPI_MODE_2:
+		mode_val = NPCM_PSPI_CTL1_SCM;
+		break;
+	case SPI_MODE_3:
+		mode_val = NPCM_PSPI_CTL1_SCIDL | NPCM_PSPI_CTL1_SCM;
+		break;
+	}
+
+	regtemp = ioread16(priv->base + NPCM_PSPI_CTL1);
+	regtemp &= ~(NPCM_PSPI_CTL1_SCM | NPCM_PSPI_CTL1_SCIDL);
+	iowrite16(regtemp | mode_val, priv->base + NPCM_PSPI_CTL1);
+}
+
+static void npcm_pspi_set_transfer_size(struct npcm_pspi *priv, int size)
+{
+	u16 regtemp;
+
+	regtemp = ioread16(NPCM_PSPI_CTL1 + priv->base);
+
+	switch (size) {
+	case 8:
+		regtemp &= ~NPCM_PSPI_CTL1_MOD;
+		break;
+	case 16:
+		regtemp |= NPCM_PSPI_CTL1_MOD;
+		break;
+	}
+
+	iowrite16(regtemp, NPCM_PSPI_CTL1 + priv->base);
+}
+
+static void npcm_pspi_set_baudrate(struct npcm_pspi *priv, unsigned int speed)
+{
+	u32 ckdiv;
+	u16 regtemp;
+
+	/* the supported rates are numbers from 4 to 256. */
+	ckdiv = DIV_ROUND_CLOSEST(clk_get_rate(priv->clk), (2 * speed)) - 1;
+
+	regtemp = ioread16(NPCM_PSPI_CTL1 + priv->base);
+	regtemp &= ~NPCM_PSPI_CTL1_SCDV6_0;
+	iowrite16(regtemp | (ckdiv << 9), NPCM_PSPI_CTL1 + priv->base);
+}
+
+static void npcm_pspi_setup_transfer(struct spi_device *spi,
+				     struct spi_transfer *t)
+{
+	struct npcm_pspi *priv = spi_master_get_devdata(spi->master);
+
+	priv->tx_buf = t->tx_buf;
+	priv->rx_buf = t->rx_buf;
+	priv->tx_bytes = t->len;
+	priv->rx_bytes = t->len;
+
+	if (!priv->is_save_param || priv->mode != spi->mode) {
+		npcm_pspi_set_mode(spi);
+		priv->mode = spi->mode;
+	}
+
+	if (!priv->is_save_param || priv->bits_per_word != t->bits_per_word) {
+		npcm_pspi_set_transfer_size(priv, t->bits_per_word);
+		priv->bits_per_word = t->bits_per_word;
+	}
+
+	if (!priv->is_save_param || priv->speed_hz != t->speed_hz) {
+		npcm_pspi_set_baudrate(priv, t->speed_hz);
+		priv->speed_hz = t->speed_hz;
+	}
+
+	if (!priv->is_save_param)
+		priv->is_save_param = true;
+}
+
+static void npcm_pspi_send(struct npcm_pspi *priv)
+{
+	int wsize;
+
+	wsize = min(bytes_per_word(priv->bits_per_word), priv->tx_bytes);
+	priv->tx_bytes -= wsize;
+
+	if (priv->tx_buf) {
+		if (wsize == 1)
+			iowrite8(*priv->tx_buf, NPCM_PSPI_DATA + priv->base);
+		if (wsize == 2)
+			iowrite16(*priv->tx_buf, NPCM_PSPI_DATA + priv->base);
+
+		priv->tx_buf += wsize;
+	}
+}
+
+static void npcm_pspi_recv(struct npcm_pspi *priv)
+{
+	int rsize;
+	u16 val;
+
+	rsize = min(bytes_per_word(priv->bits_per_word), priv->rx_bytes);
+	priv->rx_bytes -= rsize;
+
+	if (priv->rx_buf) {
+		if (rsize == 1)
+			val = ioread8(priv->base + NPCM_PSPI_DATA);
+		if (rsize == 2)
+			val = ioread16(priv->base + NPCM_PSPI_DATA);
+
+		*priv->rx_buf = val;
+		priv->rx_buf += rsize;
+	}
+}
+
+static int npcm_pspi_transfer_one(struct spi_master *master,
+				  struct spi_device *spi,
+				  struct spi_transfer *t)
+{
+	struct npcm_pspi *priv = spi_master_get_devdata(master);
+	int status;
+
+	npcm_pspi_setup_transfer(spi, t);
+	reinit_completion(&priv->xfer_done);
+	npcm_pspi_enable(priv);
+	status = wait_for_completion_timeout(&priv->xfer_done,
+					     msecs_to_jiffies
+					     (NPCM_PSPI_TIMEOUT_MS));
+	if (status == 0) {
+		npcm_pspi_disable(priv);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int npcm_pspi_prepare_transfer_hardware(struct spi_master *master)
+{
+	struct npcm_pspi *priv = spi_master_get_devdata(master);
+
+	npcm_pspi_irq_enable(priv, NPCM_PSPI_CTL1_EIR | NPCM_PSPI_CTL1_EIW);
+
+	return 0;
+}
+
+static int npcm_pspi_unprepare_transfer_hardware(struct spi_master *master)
+{
+	struct npcm_pspi *priv = spi_master_get_devdata(master);
+
+	npcm_pspi_irq_disable(priv, NPCM_PSPI_CTL1_EIR | NPCM_PSPI_CTL1_EIW);
+
+	return 0;
+}
+
+static void npcm_pspi_reset_hw(struct npcm_pspi *priv)
+{
+	regmap_write(priv->rst_regmap, NPCM7XX_IPSRST2_OFFSET,
+		     NPCM7XX_PSPI1_RESET << priv->id);
+	regmap_write(priv->rst_regmap, NPCM7XX_IPSRST2_OFFSET, 0x0);
+}
+
+static irqreturn_t npcm_pspi_handler(int irq, void *dev_id)
+{
+	struct npcm_pspi *priv = dev_id;
+	u16 val;
+	u8 stat;
+
+	stat = ioread8(priv->base + NPCM_PSPI_STAT);
+
+	if (!priv->tx_buf && !priv->rx_buf)
+		return IRQ_NONE;
+
+	if (priv->tx_buf) {
+		if (stat & NPCM_PSPI_STAT_RBF) {
+			val = ioread8(NPCM_PSPI_DATA + priv->base);
+			if (priv->tx_bytes == 0) {
+				npcm_pspi_disable(priv);
+				complete(&priv->xfer_done);
+				return IRQ_HANDLED;
+			}
+		}
+
+		if ((stat & NPCM_PSPI_STAT_BSY) == 0)
+			if (priv->tx_bytes)
+				npcm_pspi_send(priv);
+	}
+
+	if (priv->rx_buf) {
+		if (stat & NPCM_PSPI_STAT_RBF) {
+			if (!priv->rx_bytes)
+				return IRQ_NONE;
+
+			npcm_pspi_recv(priv);
+
+			if (!priv->rx_bytes) {
+				npcm_pspi_disable(priv);
+				complete(&priv->xfer_done);
+				return IRQ_HANDLED;
+			}
+		}
+
+		if (((stat & NPCM_PSPI_STAT_BSY) == 0) && !priv->tx_buf)
+			iowrite8(0x0, NPCM_PSPI_DATA + priv->base);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int npcm_pspi_probe(struct platform_device *pdev)
+{
+	struct npcm_pspi *priv;
+	struct spi_master *master;
+	struct resource *res;
+	unsigned long clk_hz;
+	struct device_node *np = pdev->dev.of_node;
+	int num_cs, i;
+	u32 csgpio;
+	int irq;
+	int ret;
+
+	num_cs = of_gpio_named_count(np, "cs-gpios");
+	if (num_cs < 0)
+		return num_cs;
+
+	pdev->id = of_alias_get_id(np, "spi");
+	if (pdev->id < 0)
+		pdev->id = 0;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*priv));
+	if (!master)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, master);
+
+	priv = spi_master_get_devdata(master);
+	priv->master = master;
+	priv->is_save_param = false;
+	priv->id = pdev->id;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->base)) {
+		ret = PTR_ERR(priv->base);
+		goto out_master_put;
+	}
+
+	priv->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(&pdev->dev, "failed to get clock\n");
+		ret = PTR_ERR(priv->clk);
+		goto out_master_put;
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		goto out_master_put;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ\n");
+		ret = irq;
+		goto out_disable_clk;
+	}
+
+	priv->rst_regmap =
+		syscon_regmap_lookup_by_compatible("nuvoton,npcm750-rst");
+	if (IS_ERR(priv->rst_regmap)) {
+		dev_err(&pdev->dev, "failed to find nuvoton,npcm750-rst\n");
+		return IS_ERR(priv->rst_regmap);
+	}
+
+	/* reset SPI-HW block */
+	npcm_pspi_reset_hw(priv);
+
+	ret = devm_request_irq(&pdev->dev, irq, npcm_pspi_handler, 0,
+			       "npcm-pspi", priv);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		goto out_disable_clk;
+	}
+
+	init_completion(&priv->xfer_done);
+
+	clk_hz = clk_get_rate(priv->clk);
+
+	master->max_speed_hz = DIV_ROUND_UP(clk_hz, NPCM_PSPI_MIN_CLK_DIVIDER);
+	master->min_speed_hz = DIV_ROUND_UP(clk_hz, NPCM_PSPI_MAX_CLK_DIVIDER);
+	master->mode_bits = SPI_CPHA | SPI_CPOL;
+	master->dev.of_node = pdev->dev.of_node;
+	master->bus_num = pdev->id;
+	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+	master->transfer_one = npcm_pspi_transfer_one;
+	master->prepare_transfer_hardware =
+		npcm_pspi_prepare_transfer_hardware;
+	master->unprepare_transfer_hardware =
+		npcm_pspi_unprepare_transfer_hardware;
+	master->num_chipselect = num_cs;
+
+	for (i = 0; i < num_cs; i++) {
+		csgpio = of_get_named_gpio(np, "cs-gpios", i);
+		if (csgpio < 0) {
+			dev_err(&pdev->dev, "failed to get csgpio#%u\n", i);
+			goto out_disable_clk;
+		}
+		dev_dbg(&pdev->dev, "csgpio#%u = %u\n", i, csgpio);
+		ret = devm_gpio_request_one(&pdev->dev, csgpio,
+					    GPIOF_OUT_INIT_HIGH, DRIVER_NAME);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+				"failed to configure csgpio#%u %u\n"
+				, i, csgpio);
+			goto out_disable_clk;
+		}
+	}
+
+	/* set to default clock rate */
+	npcm_pspi_set_baudrate(priv, NPCM_PSPI_DEFAULT_CLK);
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret)
+		goto out_disable_clk;
+
+	pr_info("NPCM Peripheral SPI %d probed\n", pdev->id);
+
+	return 0;
+
+out_disable_clk:
+	clk_disable_unprepare(priv->clk);
+
+out_master_put:
+	spi_master_put(master);
+	return ret;
+}
+
+static int npcm_pspi_remove(struct platform_device *pdev)
+{
+	struct npcm_pspi *priv = platform_get_drvdata(pdev);
+
+	npcm_pspi_reset_hw(priv);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static const struct of_device_id npcm_pspi_match[] = {
+	{ .compatible = "nuvoton,npcm750-pspi", .data = NULL },
+	{}
+};
+MODULE_DEVICE_TABLE(of, npcm_pspi_match);
+
+static struct platform_driver npcm_pspi_driver = {
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= npcm_pspi_match,
+		.owner		= THIS_MODULE,
+	},
+	.probe		= npcm_pspi_probe,
+	.remove		= npcm_pspi_remove,
+};
+module_platform_driver(npcm_pspi_driver);
+
+MODULE_DESCRIPTION("NPCM peripheral SPI Controller driver");
+MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
+MODULE_LICENSE("GPL v2");
+
-- 
2.14.1

Applied "dt-binding: spi: add NPCM PSPI controller documentation" to the spi tree

[Mark Brown]

The patch

   dt-binding: spi: add NPCM PSPI controller documentation

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 4ad26864df53b265976c4a3ae61b1e6cad92fe40 Mon Sep 17 00:00:00 2001
From: Tomer Maimon <tmaimon77@gmail.com>
Date: Mon, 12 Nov 2018 18:42:31 +0200
Subject: [PATCH] dt-binding: spi: add NPCM PSPI controller documentation

Added device tree binding documentation for Nuvoton BMC
NPCM Peripheral SPI controller.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../bindings/spi/nuvoton,npcm-pspi.txt        | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt

diff --git a/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt b/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
new file mode 100644
index 000000000000..99606b22e5c2
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
@@ -0,0 +1,35 @@
+Nuvoton NPCM Peripheral Serial Peripheral Interface(PSPI) controller driver
+
+Nuvoton NPCM7xx SOC support two PSPI channels.
+
+Required properties:
+ - compatible : "nuvoton,npcm750-pspi" for NPCM7XX BMC
+ - #address-cells : should be 1. see spi-bus.txt
+ - #size-cells : should be 0. see spi-bus.txt
+ - specifies physical base address and size of the register.
+ - interrupts : contain PSPI interrupt.
+ - clocks : phandle of PSPI reference clock.
+ - clock-names: Should be "clk_apb5".
+ - pinctrl-names : a pinctrl state named "default" must be defined.
+ - pinctrl-0 : phandle referencing pin configuration of the device.
+ - cs-gpios: Specifies the gpio pins to be used for chipselects.
+            See: Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Optional properties:
+- clock-frequency : Input clock frequency to the PSPI block in Hz.
+		    Default is 25000000 Hz.
+
+Example:
+
+spi0: spi@f0200000 {
+	compatible = "nuvoton,npcm750-pspi";
+	reg = <0xf0200000 0x1000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pspi1_pins>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&clk NPCM7XX_CLK_APB5>;
+	clock-names = "clk_apb5";
+	cs-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>;
+};
-- 
2.19.1