[PATCH v4] gpio: Add MOXA ART GPIO driver

From: Jonas Jensen
Date: Mon Jul 29 2013 - 09:06:34 EST

Add GPIO driver for MOXA ART SoCs.

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

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@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@xxxxxxxxx>
+ *
+ * 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@xxxxxxxxx>");
--
1.8.2.1

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