1 files changed, 191 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-syscon.c b/drivers/gpio/gpio-syscon.c
new file mode 100644
index 000000000000..b50fe1297748
--- /dev/null
+++ b/drivers/gpio/gpio-syscon.c
@@ -0,0 +1,191 @@
+/*
+ *  SYSCON GPIO driver
+ *
+ *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#define GPIO_SYSCON_FEAT_IN     BIT(0)
+#define GPIO_SYSCON_FEAT_OUT    BIT(1)
+#define GPIO_SYSCON_FEAT_DIR    BIT(2)
+
+/* SYSCON driver is designed to use 32-bit wide registers */
+#define SYSCON_REG_SIZE         (4)
+#define SYSCON_REG_BITS         (SYSCON_REG_SIZE * 8)
+
+/**
+ * struct syscon_gpio_data - Configuration for the device.
+ * compatible:          SYSCON driver compatible string.
+ * flags:               Set of GPIO_SYSCON_FEAT_ flags:
+ *                      GPIO_SYSCON_FEAT_IN:    GPIOs supports input,
+ *                      GPIO_SYSCON_FEAT_OUT:   GPIOs supports output,
+ *                      GPIO_SYSCON_FEAT_DIR:   GPIOs supports switch direction.
+ * bit_count:           Number of bits used as GPIOs.
+ * dat_bit_offset:      Offset (in bits) to the first GPIO bit.
+ * dir_bit_offset:      Optional offset (in bits) to the first bit to switch
+ *                      GPIO direction (Used with GPIO_SYSCON_FEAT_DIR flag).
+ */
+
+struct syscon_gpio_data {
+        const char      *compatible;
+        unsigned int    flags;
+        unsigned int    bit_count;
+        unsigned int    dat_bit_offset;
+        unsigned int    dir_bit_offset;
+};
+
+struct syscon_gpio_priv {
+        struct gpio_chip                chip;
+        struct regmap                   *syscon;
+        const struct syscon_gpio_data   *data;
+};
+
+static inline struct syscon_gpio_priv *to_syscon_gpio(struct gpio_chip *chip)
+{
+        return container_of(chip, struct syscon_gpio_priv, chip);
+}
+
+static int syscon_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
+        unsigned int val, offs = priv->data->dat_bit_offset + offset;
+        int ret;
+
+        ret = regmap_read(priv->syscon,
+                          (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE, &val);
+        if (ret)
+                return ret;
+
+        return !!(val & BIT(offs % SYSCON_REG_BITS));
+}
+
+static void syscon_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+        struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
+        unsigned int offs = priv->data->dat_bit_offset + offset;
+
+        regmap_update_bits(priv->syscon,
+                           (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
+                           BIT(offs % SYSCON_REG_BITS),
+                           val ? BIT(offs % SYSCON_REG_BITS) : 0);
+}
+
+static int syscon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+        struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
+
+        if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
+                unsigned int offs = priv->data->dir_bit_offset + offset;
+
+                regmap_update_bits(priv->syscon,
+                                   (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
+                                   BIT(offs % SYSCON_REG_BITS), 0);
+        }
+
+        return 0;
+}
+
+static int syscon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int val)
+{
+        struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
+
+        if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
+                unsigned int offs = priv->data->dir_bit_offset + offset;
+
+                regmap_update_bits(priv->syscon,
+                                   (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
+                                   BIT(offs % SYSCON_REG_BITS),
+                                   BIT(offs % SYSCON_REG_BITS));
+        }
+
+        syscon_gpio_set(chip, offset, val);
+
+        return 0;
+}
+
+static const struct syscon_gpio_data clps711x_mctrl_gpio = {
+        /* ARM CLPS711X SYSFLG1 Bits 8-10 */
+        .compatible     = "cirrus,clps711x-syscon1",
+        .flags          = GPIO_SYSCON_FEAT_IN,
+        .bit_count      = 3,
+        .dat_bit_offset = 0x40 * 8 + 8,
+};
+
+static const struct of_device_id syscon_gpio_ids[] = {
+        {
+                .compatible     = "cirrus,clps711x-mctrl-gpio",
+                .data           = &clps711x_mctrl_gpio,
+        },
+        { }
+};
+MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
+
+static int syscon_gpio_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        const struct of_device_id *of_id = of_match_device(syscon_gpio_ids, dev);
+        struct syscon_gpio_priv *priv;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->data = of_id->data;
+
+        priv->syscon =
+                syscon_regmap_lookup_by_compatible(priv->data->compatible);
+        if (IS_ERR(priv->syscon))
+                return PTR_ERR(priv->syscon);
+
+        priv->chip.dev = dev;
+        priv->chip.owner = THIS_MODULE;
+        priv->chip.label = dev_name(dev);
+        priv->chip.base = -1;
+        priv->chip.ngpio = priv->data->bit_count;
+        priv->chip.get = syscon_gpio_get;
+        if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
+                priv->chip.direction_input = syscon_gpio_dir_in;
+        if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
+                priv->chip.set = syscon_gpio_set;
+                priv->chip.direction_output = syscon_gpio_dir_out;
+        }
+
+        platform_set_drvdata(pdev, priv);
+
+        return gpiochip_add(&priv->chip);
+}
+
+static int syscon_gpio_remove(struct platform_device *pdev)
+{
+        struct syscon_gpio_priv *priv = platform_get_drvdata(pdev);
+
+        return gpiochip_remove(&priv->chip);
+}
+
+static struct platform_driver syscon_gpio_driver = {
+        .driver = {
+                .name           = "gpio-syscon",
+                .owner          = THIS_MODULE,
+                .of_match_table = syscon_gpio_ids,
+        },
+        .probe  = syscon_gpio_probe,
+        .remove = syscon_gpio_remove,
+};
+module_platform_driver(syscon_gpio_driver);
+
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("SYSCON GPIO driver");
+MODULE_LICENSE("GPL");