--- /dev/null
+/*
+ * 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).
+ * set: HW specific callback to assigns output value
+ * for signal "offset"
+ */
+
+struct syscon_gpio_data {
+ const char *compatible;
+ unsigned int flags;
+ unsigned int bit_count;
+ unsigned int dat_bit_offset;
+ unsigned int dir_bit_offset;
+ void (*set)(struct gpio_chip *chip,
+ unsigned offset, int value);
+};
+
+struct syscon_gpio_priv {
+ struct gpio_chip chip;
+ struct regmap *syscon;
+ const struct syscon_gpio_data *data;
+ u32 dreg_offset;
+ u32 dir_reg_offset;
+};
+
+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;
+ int ret;
+
+ offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
+
+ 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;
+
+ offs = priv->dreg_offset + 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;
+
+ offs = priv->dir_reg_offset +
+ 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;
+
+ offs = priv->dir_reg_offset +
+ 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));
+ }
+
+ priv->data->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,
+};
+
+#define KEYSTONE_LOCK_BIT BIT(0)
+
+static void keystone_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+ struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
+ unsigned int offs;
+ int ret;
+
+ offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
+
+ if (!val)
+ return;
+
+ ret = regmap_update_bits(
+ priv->syscon,
+ (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
+ BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT,
+ BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT);
+ if (ret < 0)
+ dev_err(chip->dev, "gpio write failed ret(%d)\n", ret);
+}
+
+static const struct syscon_gpio_data keystone_dsp_gpio = {
+ /* ARM Keystone 2 */
+ .compatible = NULL,
+ .flags = GPIO_SYSCON_FEAT_OUT,
+ .bit_count = 28,
+ .dat_bit_offset = 4,
+ .set = keystone_gpio_set,
+};
+
+static const struct of_device_id syscon_gpio_ids[] = {
+ {
+ .compatible = "cirrus,clps711x-mctrl-gpio",
+ .data = &clps711x_mctrl_gpio,
+ },
+ {
+ .compatible = "ti,keystone-dsp-gpio",
+ .data = &keystone_dsp_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;
+ struct device_node *np = dev->of_node;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->data = of_id->data;
+
+ if (priv->data->compatible) {
+ priv->syscon = syscon_regmap_lookup_by_compatible(
+ priv->data->compatible);
+ if (IS_ERR(priv->syscon))
+ return PTR_ERR(priv->syscon);
+ } else {
+ priv->syscon =
+ syscon_regmap_lookup_by_phandle(np, "gpio,syscon-dev");
+ if (IS_ERR(priv->syscon))
+ return PTR_ERR(priv->syscon);
+
+ ret = of_property_read_u32_index(np, "gpio,syscon-dev", 1,
+ &priv->dreg_offset);
+ if (ret)
+ dev_err(dev, "can't read the data register offset!\n");
+
+ priv->dreg_offset <<= 3;
+
+ ret = of_property_read_u32_index(np, "gpio,syscon-dev", 2,
+ &priv->dir_reg_offset);
+ if (ret)
+ dev_dbg(dev, "can't read the dir register offset!\n");
+
+ priv->dir_reg_offset <<= 3;
+ }
+
+ 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 = priv->data->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);
+
+ gpiochip_remove(&priv->chip);
+ return 0;
+}
+
+static struct platform_driver syscon_gpio_driver = {
+ .driver = {
+ .name = "gpio-syscon",
+ .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");
Code Review / kvmfornfv.git / blobdiff