gpio: Add support for Qualcomm gpio controller

Add support for gpio controllers on Qualcomm Snapdragon devices.
This devices are usually called Top Level Mode Multiplexing in
Qualcomm documentation.

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

doc/device-tree-bindings/gpio/gpio-msm.txt

@@ -0,0 +1,22 @@
+Qualcomm Snapdragon GPIO controller
+
+Required properties:
+- compatible : "qcom,msm8916-pinctrl" or "qcom,apq8016-pinctrl"
+- reg : Physical base address and length of the controller's registers.
+	This controller is called "Top Level Mode Multiplexing" in
+	Qualcomm documentation.
+- #gpio-cells : Should be one (pin number).
+- gpio-controller : Marks the device node as a GPIO controller.
+- gpio-count: Number of GPIO pins.
+- gpio-bank-name: (optional) name of gpio bank. As default "soc" is used.
+
+Example:
+
+soc_gpios: pinctrl@1000000 {
+	compatible = "qcom,msm8916-pinctrl";
+	reg = <0x1000000 0x300000>;
+	gpio-controller;
+	gpio-count = <122>;
+	gpio-bank-name="soc";
+	#gpio-cells = <1>;
+};

drivers/gpio/Kconfig

@@ -55,6 +55,20 @@ config LPC32XX_GPIO
 	help
 	  Support for the LPC32XX GPIO driver.
 
+config MSM_GPIO
+	bool "Qualcomm GPIO driver"
+	depends on DM_GPIO
+	default n
+	help
+	  Support GPIO controllers on Qualcomm Snapdragon family of SoCs.
+	  This controller have single bank (default name "soc"), every
+	  gpio has it's own set of registers.
+	  Only simple GPIO operations are supported (get/set, change of
+	  direction and checking pin function).
+	  Supported devices:
+	  - APQ8016
+	  - MSM8916
+
 config ROCKCHIP_GPIO
 	bool "Rockchip GPIO driver"
 	depends on DM_GPIO

drivers/gpio/Makefile

@@ -50,3 +50,4 @@ obj-$(CONFIG_VYBRID_GPIO)	+= vybrid_gpio.o
 obj-$(CONFIG_HIKEY_GPIO)	+= hi6220_gpio.o
 obj-$(CONFIG_PIC32_GPIO)	+= pic32_gpio.o
 obj-$(CONFIG_MVEBU_GPIO)	+= mvebu_gpio.o
+obj-$(CONFIG_MSM_GPIO)		+= msm_gpio.o

drivers/gpio/msm_gpio.c

@@ -0,0 +1,133 @@
+/*
+ * Qualcomm GPIO driver
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Register offsets */
+#define GPIO_CONFIG_OFF(no)         ((no) * 0x1000)
+#define GPIO_IN_OUT_OFF(no)         ((no) * 0x1000 + 0x4)
+
+/* OE */
+#define GPIO_OE_DISABLE  (0x0 << 9)
+#define GPIO_OE_ENABLE   (0x1 << 9)
+#define GPIO_OE_MASK     (0x1 << 9)
+
+/* GPIO_IN_OUT register shifts. */
+#define GPIO_IN          0
+#define GPIO_OUT         1
+
+struct msm_gpio_bank {
+	phys_addr_t base;
+};
+
+static int msm_gpio_direction_input(struct udevice *dev, unsigned int gpio)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+	phys_addr_t reg = priv->base + GPIO_CONFIG_OFF(gpio);
+
+	/* Disable OE bit */
+	clrsetbits_le32(reg, GPIO_OE_MASK, GPIO_OE_DISABLE);
+
+	return 0;
+}
+
+static int msm_gpio_set_value(struct udevice *dev, unsigned gpio, int value)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+
+	value = !!value;
+	/* set value */
+	writel(value << GPIO_OUT, priv->base + GPIO_IN_OUT_OFF(gpio));
+
+	return 0;
+}
+
+static int msm_gpio_direction_output(struct udevice *dev, unsigned gpio,
+				     int value)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+	phys_addr_t reg = priv->base + GPIO_CONFIG_OFF(gpio);
+
+	value = !!value;
+	/* set value */
+	writel(value << GPIO_OUT, priv->base + GPIO_IN_OUT_OFF(gpio));
+	/* switch direction */
+	clrsetbits_le32(reg, GPIO_OE_MASK, GPIO_OE_ENABLE);
+
+	return 0;
+}
+
+static int msm_gpio_get_value(struct udevice *dev, unsigned gpio)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+
+	return !!(readl(priv->base + GPIO_IN_OUT_OFF(gpio)) >> GPIO_IN);
+}
+
+static int msm_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+
+	if (readl(priv->base + GPIO_CONFIG_OFF(offset)) & GPIO_OE_ENABLE)
+		return GPIOF_OUTPUT;
+
+	return GPIOF_INPUT;
+}
+
+static const struct dm_gpio_ops gpio_msm_ops = {
+	.direction_input	= msm_gpio_direction_input,
+	.direction_output	= msm_gpio_direction_output,
+	.get_value		= msm_gpio_get_value,
+	.set_value		= msm_gpio_set_value,
+	.get_function		= msm_gpio_get_function,
+};
+
+static int msm_gpio_probe(struct udevice *dev)
+{
+	struct msm_gpio_bank *priv = dev_get_priv(dev);
+
+	priv->base = dev_get_addr(dev);
+
+	return priv->base == FDT_ADDR_T_NONE ? -EINVAL : 0;
+}
+
+static int msm_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	uc_priv->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+					     "gpio-count", 0);
+	uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset,
+					 "gpio-bank-name", NULL);
+	if (uc_priv->bank_name == NULL)
+		uc_priv->bank_name = "soc";
+
+	return 0;
+}
+
+static const struct udevice_id msm_gpio_ids[] = {
+	{ .compatible = "qcom,msm8916-pinctrl" },
+	{ .compatible = "qcom,apq8016-pinctrl" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_msm) = {
+	.name	= "gpio_msm",
+	.id	= UCLASS_GPIO,
+	.of_match = msm_gpio_ids,
+	.ofdata_to_platdata = msm_gpio_ofdata_to_platdata,
+	.probe	= msm_gpio_probe,
+	.ops	= &gpio_msm_ops,
+	.priv_auto_alloc_size = sizeof(struct msm_gpio_bank),
+};