[PATCH v4] gpio: Add MOXA ART GPIO driver

[jonas.jensen@gmail.com (Jonas Jensen)]

Add GPIO driver for MOXA ART SoCs.

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
---

Notes:
    Changes since v3:
    
    1. use local struct device *dev pointer, replace "&pdev->dev" with "dev"
    
    device tree bindings document:
    2. describe compatible variable "Must be" instead of "Should be".
    
    Applies to next-20130729

 .../devicetree/bindings/gpio/moxa,moxart-gpio.txt  |  23 +++
 drivers/gpio/Kconfig                               |   7 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-moxart.c                         | 189 +++++++++++++++++++++
 4 files changed, 220 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt
 create mode 100644 drivers/gpio/gpio-moxart.c

diff --git a/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt b/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt
new file mode 100644
index 0000000..795afab
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt
@@ -0,0 +1,23 @@
+MOXA ART GPIO Controller
+
+Required properties:
+
+- #gpio-cells : Should be 2
+- compatible : Must be "moxa,moxart-gpio"
+- reg : Should contain registers location and length
+	index 0 : input, output, and direction control
+	index 1 : enable/disable individual pins, pin 0-31
+- gpio-ready-led : ready LED gpio, with zero flags
+- gpio-reset-switch : reset switch gpio, with zero flags
+
+Example:
+
+	gpio: gpio at 98700000 {
+		gpio-controller;
+		#gpio-cells = <2>;
+		compatible = "moxa,moxart-gpio";
+		reg =	<0x98700000 0xC>,
+			<0x98100100 0x4>;
+		gpio-ready-led = <&gpio 27 0>;
+		gpio-reset-switch = <&gpio 25 0>;
+	};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 4b7ba53..5419413 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -741,6 +741,13 @@ config GPIO_MSIC
 	  Enable support for GPIO on intel MSIC controllers found in
 	  intel MID devices
 
+config GPIO_MOXART
+	bool "MOXART GPIO support"
+	depends on ARCH_MOXART
+	help
+	  Select this option to enable GPIO driver for
+	  MOXA ART SoC devices.
+
 comment "USB GPIO expanders:"
 
 config GPIO_VIPERBOARD
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 156fd28..c7a7a2b 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_GPIO_MC9S08DZ60)	+= gpio-mc9s08dz60.o
 obj-$(CONFIG_GPIO_MCP23S08)	+= gpio-mcp23s08.o
 obj-$(CONFIG_GPIO_ML_IOH)	+= gpio-ml-ioh.o
 obj-$(CONFIG_GPIO_MM_LANTIQ)	+= gpio-mm-lantiq.o
+obj-$(CONFIG_GPIO_MOXART)	+= gpio-moxart.o
 obj-$(CONFIG_GPIO_MPC5200)	+= gpio-mpc5200.o
 obj-$(CONFIG_GPIO_MPC8XXX)	+= gpio-mpc8xxx.o
 obj-$(CONFIG_GPIO_MSIC)		+= gpio-msic.o
diff --git a/drivers/gpio/gpio-moxart.c b/drivers/gpio/gpio-moxart.c
new file mode 100644
index 0000000..a5bdbca
--- /dev/null
+++ b/drivers/gpio/gpio-moxart.c
@@ -0,0 +1,189 @@
+/*
+ * MOXA ART SoCs GPIO driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/delay.h>
+#include <linux/timer.h>
+
+#define GPIO_DATA_OUT		0x00
+#define GPIO_DATA_IN		0x04
+#define GPIO_PIN_DIRECTION	0x08
+
+static void __iomem *moxart_pincontrol_base;
+static void __iomem *moxart_gpio_base;
+
+void moxart_gpio_enable(u32 gpio)
+{
+	writel(readl(moxart_pincontrol_base) | gpio, moxart_pincontrol_base);
+}
+
+void moxart_gpio_disable(u32 gpio)
+{
+	writel(readl(moxart_pincontrol_base) & ~gpio, moxart_pincontrol_base);
+}
+
+static int moxart_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	moxart_gpio_enable(1 << offset);
+	return pinctrl_request_gpio(offset);
+}
+
+static void moxart_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_free_gpio(offset);
+	moxart_gpio_disable(1 << offset);
+}
+
+static int moxart_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	void __iomem *ioaddr = moxart_gpio_base + GPIO_PIN_DIRECTION;
+
+	writel(readl(ioaddr) & ~(1 << offset), ioaddr);
+	return 0;
+}
+
+static int moxart_gpio_direction_output(struct gpio_chip *chip,
+					unsigned offset, int value)
+{
+	void __iomem *ioaddr = moxart_gpio_base + GPIO_PIN_DIRECTION;
+
+	writel(readl(ioaddr) | (1 << offset), ioaddr);
+	return 0;
+}
+
+static void moxart_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	void __iomem *ioaddr = moxart_gpio_base + GPIO_DATA_OUT;
+	u32 reg = readl(ioaddr);
+
+	(value) ?	writel(reg | (1 << offset), ioaddr) :
+			writel(reg & ~(1 << offset), ioaddr);
+}
+
+static int moxart_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	u32 ret = readl(moxart_gpio_base + GPIO_PIN_DIRECTION);
+
+	if (ret & (1 << offset))
+		ret = readl(moxart_gpio_base + GPIO_DATA_OUT) & (1 << offset);
+	else
+		ret = readl(moxart_gpio_base + GPIO_DATA_IN) & (1 << offset);
+
+	return ret;
+}
+
+static struct gpio_chip moxart_gpio_chip = {
+	.label			= "moxart-gpio",
+	.request		= moxart_gpio_request,
+	.free			= moxart_gpio_free,
+	.direction_input	= moxart_gpio_direction_input,
+	.direction_output	= moxart_gpio_direction_output,
+	.set			= moxart_gpio_set,
+	.get			= moxart_gpio_get,
+	.base			= 0,
+	.ngpio			= 32,
+	.can_sleep		= 0,
+};
+
+static int moxart_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	int ret, gpio_ready_led, gpio_reset_switch;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	moxart_gpio_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(moxart_gpio_base)) {
+		dev_err(dev, "%s: devm_ioremap_resource res_gpio failed\n",
+			dev->of_node->full_name);
+		return PTR_ERR(moxart_gpio_base);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	moxart_pincontrol_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(moxart_pincontrol_base)) {
+		dev_err(dev, "%s: devm_ioremap_resource res_pmu failed\n",
+			dev->of_node->full_name);
+		return PTR_ERR(moxart_pincontrol_base);
+	}
+
+	moxart_gpio_chip.dev = dev;
+
+	ret = gpiochip_add(&moxart_gpio_chip);
+	if (ret)
+		dev_err(dev, "%s: gpiochip_add failed\n",
+			dev->of_node->full_name);
+
+
+	gpio_ready_led = of_get_named_gpio(dev->of_node,
+					   "gpio-ready-led", 0);
+	if (!gpio_is_valid(gpio_ready_led)) {
+		dev_err(dev, "invalid gpio (gpio-ready-led): %d\n",
+			gpio_ready_led);
+		return gpio_ready_led;
+	}
+
+	gpio_reset_switch = of_get_named_gpio(dev->of_node,
+					      "gpio-reset-switch", 0);
+	if (!gpio_is_valid(gpio_reset_switch)) {
+		dev_err(dev, "invalid gpio (gpio-reset-switch): %d\n",
+			gpio_reset_switch);
+		return gpio_reset_switch;
+	}
+
+	moxart_gpio_enable(gpio_ready_led | gpio_reset_switch);
+
+	moxart_gpio_direction_input(&moxart_gpio_chip, gpio_reset_switch);
+
+	/*
+	 * gpio_ready_led=0 ready LED on
+	 * gpio_ready_led=1 ready LED off
+	 */
+	moxart_gpio_direction_output(&moxart_gpio_chip, gpio_ready_led, 0);
+	moxart_gpio_set(&moxart_gpio_chip, gpio_ready_led, 0);
+
+	return 0;
+}
+
+static const struct of_device_id moxart_gpio_match[] = {
+	{ .compatible = "moxa,moxart-gpio" },
+	{ }
+};
+
+static struct platform_driver moxart_gpio_driver = {
+	.driver	= {
+		.name		= "moxart-gpio",
+		.owner		= THIS_MODULE,
+		.of_match_table	= moxart_gpio_match,
+	},
+	.probe	= moxart_gpio_probe,
+};
+
+static int __init moxart_gpio_init(void)
+{
+	return platform_driver_register(&moxart_gpio_driver);
+}
+
+postcore_initcall(moxart_gpio_init);
+
+MODULE_DESCRIPTION("MOXART GPIO chip driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
-- 
1.8.2.1