mcs814x: add support for 3.18

[openwrt/staging/yousong.git] / target / linux / mcs814x / files-3.18 / drivers / gpio / gpio-mcs814x.c

diff --git a/target/linux/mcs814x/files-3.18/drivers/gpio/gpio-mcs814x.c b/target/linux/mcs814x/files-3.18/drivers/gpio/gpio-mcs814x.c
new file mode 100644 (file)
index 0000000..c8a6509
--- /dev/null
+++ b/target/linux/mcs814x/files-3.18/drivers/gpio/gpio-mcs814x.c
@@ -0,0 +1,148 @@
+/*
+ * Moschip MCS814x GPIO support
+ *
+ * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
+ *
+ * Licensed under the GPLv2
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+struct mcs814x_gpio_chip {
+       void __iomem *regs;
+       struct gpio_chip chip;
+};
+
+#define GPIO_PIN       0x00
+#define GPIO_DIR       0x04
+
+#define to_mcs814x_gpio_chip(x)        container_of(x, struct mcs814x_gpio_chip, chip)
+
+static int mcs814x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+       struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
+
+       return readl_relaxed(mcs814x->regs + GPIO_PIN) & (1 << offset);
+}
+
+static void mcs814x_gpio_set(struct gpio_chip *chip,
+                               unsigned offset, int value)
+{
+       struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
+       u32 mask;
+
+       mask = readl_relaxed(mcs814x->regs + GPIO_PIN);
+       if (value)
+               mask |= (1 << offset);
+       else
+               mask &= ~(1 << offset);
+       writel_relaxed(mask, mcs814x->regs + GPIO_PIN);
+}
+
+static int mcs814x_gpio_direction_output(struct gpio_chip *chip,
+                                       unsigned offset, int value)
+{
+       struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
+       u32 mask;
+
+       mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
+       mask &= ~(1 << offset);
+       writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
+
+       return 0;
+}
+
+static int mcs814x_gpio_direction_input(struct gpio_chip *chip,
+                                       unsigned offset)
+{
+       struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
+       u32 mask;
+
+       mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
+       mask |= (1 << offset);
+       writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
+
+       return 0;
+}
+
+static int mcs814x_gpio_probe(struct platform_device *pdev)
+{
+       struct resource *res;
+       struct mcs814x_gpio_chip *mcs814x_chip;
+       int ret;
+       const unsigned int *num_gpios;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -ENODEV;
+
+       num_gpios = of_get_property(pdev->dev.of_node, "num-gpios", NULL);
+       if (!num_gpios)
+               dev_err(&pdev->dev, "FIXME: no num-gpios property\n");
+
+       mcs814x_chip = kzalloc(sizeof(*mcs814x_chip), GFP_KERNEL);
+       if (!mcs814x_chip)
+               return -ENOMEM;
+
+       mcs814x_chip->regs = devm_ioremap_resource(&pdev->dev, res);
+       if (!mcs814x_chip->regs) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       platform_set_drvdata(pdev, mcs814x_chip);
+
+#ifdef CONFIG_OF_GPIO
+       mcs814x_chip->chip.of_node = pdev->dev.of_node;
+#endif
+
+       mcs814x_chip->chip.label = pdev->name;
+       mcs814x_chip->chip.get = mcs814x_gpio_get;
+       mcs814x_chip->chip.set = mcs814x_gpio_set;
+       mcs814x_chip->chip.direction_input = mcs814x_gpio_direction_input;
+       mcs814x_chip->chip.direction_output = mcs814x_gpio_direction_output;
+       mcs814x_chip->chip.ngpio = be32_to_cpup(num_gpios);
+       /* we want dynamic base allocation */
+       mcs814x_chip->chip.base = -1;
+
+       ret = gpiochip_add(&mcs814x_chip->chip);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to register gpiochip\n");
+               goto out;
+       }
+
+       return 0;
+
+out:
+       platform_set_drvdata(pdev, NULL);
+       kfree(mcs814x_chip);
+       return ret;
+}
+
+static struct of_device_id mcs814x_gpio_ids[] = {
+       { .compatible = "moschip,mcs814x-gpio" },
+       { /* sentinel */ },
+};
+
+static struct platform_driver mcs814x_gpio_driver = {
+       .driver = {
+               .name   = "mcs814x-gpio",
+               .owner  = THIS_MODULE,
+               .of_match_table = mcs814x_gpio_ids,
+       },
+       .probe  = mcs814x_gpio_probe,
+};
+
+int __init mcs814x_gpio_init(void)
+{
+       return platform_driver_register(&mcs814x_gpio_driver);
+}
+postcore_initcall(mcs814x_gpio_init);