4 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
12 #include <linux/err.h>
13 #include <linux/gpio.h>
14 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/regmap.h>
19 #include <linux/mfd/syscon.h>
21 #define GPIO_SYSCON_FEAT_IN BIT(0)
22 #define GPIO_SYSCON_FEAT_OUT BIT(1)
23 #define GPIO_SYSCON_FEAT_DIR BIT(2)
25 /* SYSCON driver is designed to use 32-bit wide registers */
26 #define SYSCON_REG_SIZE (4)
27 #define SYSCON_REG_BITS (SYSCON_REG_SIZE * 8)
30 * struct syscon_gpio_data - Configuration for the device.
31 * compatible: SYSCON driver compatible string.
32 * flags: Set of GPIO_SYSCON_FEAT_ flags:
33 * GPIO_SYSCON_FEAT_IN: GPIOs supports input,
34 * GPIO_SYSCON_FEAT_OUT: GPIOs supports output,
35 * GPIO_SYSCON_FEAT_DIR: GPIOs supports switch direction.
36 * bit_count: Number of bits used as GPIOs.
37 * dat_bit_offset: Offset (in bits) to the first GPIO bit.
38 * dir_bit_offset: Optional offset (in bits) to the first bit to switch
39 * GPIO direction (Used with GPIO_SYSCON_FEAT_DIR flag).
40 * set: HW specific callback to assigns output value
44 struct syscon_gpio_data {
45 const char *compatible;
47 unsigned int bit_count;
48 unsigned int dat_bit_offset;
49 unsigned int dir_bit_offset;
50 void (*set)(struct gpio_chip *chip,
51 unsigned offset, int value);
54 struct syscon_gpio_priv {
55 struct gpio_chip chip;
56 struct regmap *syscon;
57 const struct syscon_gpio_data *data;
60 static inline struct syscon_gpio_priv *to_syscon_gpio(struct gpio_chip *chip)
62 return container_of(chip, struct syscon_gpio_priv, chip);
65 static int syscon_gpio_get(struct gpio_chip *chip, unsigned offset)
67 struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
68 unsigned int val, offs = priv->data->dat_bit_offset + offset;
71 ret = regmap_read(priv->syscon,
72 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE, &val);
76 return !!(val & BIT(offs % SYSCON_REG_BITS));
79 static void syscon_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
81 struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
82 unsigned int offs = priv->data->dat_bit_offset + offset;
84 regmap_update_bits(priv->syscon,
85 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
86 BIT(offs % SYSCON_REG_BITS),
87 val ? BIT(offs % SYSCON_REG_BITS) : 0);
90 static int syscon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
92 struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
94 if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
95 unsigned int offs = priv->data->dir_bit_offset + offset;
97 regmap_update_bits(priv->syscon,
98 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
99 BIT(offs % SYSCON_REG_BITS), 0);
105 static int syscon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int val)
107 struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
109 if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
110 unsigned int offs = priv->data->dir_bit_offset + offset;
112 regmap_update_bits(priv->syscon,
113 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
114 BIT(offs % SYSCON_REG_BITS),
115 BIT(offs % SYSCON_REG_BITS));
118 priv->data->set(chip, offset, val);
123 static const struct syscon_gpio_data clps711x_mctrl_gpio = {
124 /* ARM CLPS711X SYSFLG1 Bits 8-10 */
125 .compatible = "cirrus,clps711x-syscon1",
126 .flags = GPIO_SYSCON_FEAT_IN,
128 .dat_bit_offset = 0x40 * 8 + 8,
131 static const struct of_device_id syscon_gpio_ids[] = {
133 .compatible = "cirrus,clps711x-mctrl-gpio",
134 .data = &clps711x_mctrl_gpio,
138 MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
140 static int syscon_gpio_probe(struct platform_device *pdev)
142 struct device *dev = &pdev->dev;
143 const struct of_device_id *of_id = of_match_device(syscon_gpio_ids, dev);
144 struct syscon_gpio_priv *priv;
146 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
150 priv->data = of_id->data;
153 syscon_regmap_lookup_by_compatible(priv->data->compatible);
154 if (IS_ERR(priv->syscon))
155 return PTR_ERR(priv->syscon);
157 priv->chip.dev = dev;
158 priv->chip.owner = THIS_MODULE;
159 priv->chip.label = dev_name(dev);
160 priv->chip.base = -1;
161 priv->chip.ngpio = priv->data->bit_count;
162 priv->chip.get = syscon_gpio_get;
163 if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
164 priv->chip.direction_input = syscon_gpio_dir_in;
165 if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
166 priv->chip.set = priv->data->set ? : syscon_gpio_set;
167 priv->chip.direction_output = syscon_gpio_dir_out;
170 platform_set_drvdata(pdev, priv);
172 return gpiochip_add(&priv->chip);
175 static int syscon_gpio_remove(struct platform_device *pdev)
177 struct syscon_gpio_priv *priv = platform_get_drvdata(pdev);
179 gpiochip_remove(&priv->chip);
183 static struct platform_driver syscon_gpio_driver = {
185 .name = "gpio-syscon",
186 .owner = THIS_MODULE,
187 .of_match_table = syscon_gpio_ids,
189 .probe = syscon_gpio_probe,
190 .remove = syscon_gpio_remove,
192 module_platform_driver(syscon_gpio_driver);
194 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
195 MODULE_DESCRIPTION("SYSCON GPIO driver");
196 MODULE_LICENSE("GPL");