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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for PCA9570 I2C GPO expander4 *5 * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run>6 *7 * Based on gpio-tpic2810.c8 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/9 * Andrew F. Davis <afd@ti.com>10 */11 12#include <linux/gpio/driver.h>13#include <linux/i2c.h>14#include <linux/module.h>15#include <linux/mutex.h>16#include <linux/property.h>17 18#define SLG7XL45106_GPO_REG 0xDB19 20/**21 * struct pca9570_chip_data - GPIO platformdata22 * @ngpio: no of gpios23 * @command: Command to be sent24 */25struct pca9570_chip_data {26 u16 ngpio;27 u32 command;28};29 30/**31 * struct pca9570 - GPIO driver data32 * @chip: GPIO controller chip33 * @chip_data: GPIO controller platform data34 * @lock: Protects write sequences35 * @out: Buffer for device register36 */37struct pca9570 {38 struct gpio_chip chip;39 const struct pca9570_chip_data *chip_data;40 struct mutex lock;41 u8 out;42};43 44static int pca9570_read(struct pca9570 *gpio, u8 *value)45{46 struct i2c_client *client = to_i2c_client(gpio->chip.parent);47 int ret;48 49 if (gpio->chip_data->command != 0)50 ret = i2c_smbus_read_byte_data(client, gpio->chip_data->command);51 else52 ret = i2c_smbus_read_byte(client);53 54 if (ret < 0)55 return ret;56 57 *value = ret;58 return 0;59}60 61static int pca9570_write(struct pca9570 *gpio, u8 value)62{63 struct i2c_client *client = to_i2c_client(gpio->chip.parent);64 65 if (gpio->chip_data->command != 0)66 return i2c_smbus_write_byte_data(client, gpio->chip_data->command, value);67 68 return i2c_smbus_write_byte(client, value);69}70 71static int pca9570_get_direction(struct gpio_chip *chip,72 unsigned offset)73{74 /* This device always output */75 return GPIO_LINE_DIRECTION_OUT;76}77 78static int pca9570_get(struct gpio_chip *chip, unsigned offset)79{80 struct pca9570 *gpio = gpiochip_get_data(chip);81 u8 buffer;82 int ret;83 84 ret = pca9570_read(gpio, &buffer);85 if (ret)86 return ret;87 88 return !!(buffer & BIT(offset));89}90 91static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value)92{93 struct pca9570 *gpio = gpiochip_get_data(chip);94 u8 buffer;95 int ret;96 97 mutex_lock(&gpio->lock);98 99 buffer = gpio->out;100 if (value)101 buffer |= BIT(offset);102 else103 buffer &= ~BIT(offset);104 105 ret = pca9570_write(gpio, buffer);106 if (ret)107 goto out;108 109 gpio->out = buffer;110 111out:112 mutex_unlock(&gpio->lock);113}114 115static int pca9570_probe(struct i2c_client *client)116{117 struct pca9570 *gpio;118 119 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);120 if (!gpio)121 return -ENOMEM;122 123 gpio->chip.label = client->name;124 gpio->chip.parent = &client->dev;125 gpio->chip.owner = THIS_MODULE;126 gpio->chip.get_direction = pca9570_get_direction;127 gpio->chip.get = pca9570_get;128 gpio->chip.set = pca9570_set;129 gpio->chip.base = -1;130 gpio->chip_data = device_get_match_data(&client->dev);131 gpio->chip.ngpio = gpio->chip_data->ngpio;132 gpio->chip.can_sleep = true;133 134 mutex_init(&gpio->lock);135 136 /* Read the current output level */137 pca9570_read(gpio, &gpio->out);138 139 i2c_set_clientdata(client, gpio);140 141 return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);142}143 144static const struct pca9570_chip_data pca9570_gpio = {145 .ngpio = 4,146};147 148static const struct pca9570_chip_data pca9571_gpio = {149 .ngpio = 8,150};151 152static const struct pca9570_chip_data slg7xl45106_gpio = {153 .ngpio = 8,154 .command = SLG7XL45106_GPO_REG,155};156 157static const struct i2c_device_id pca9570_id_table[] = {158 { "pca9570", (kernel_ulong_t)&pca9570_gpio},159 { "pca9571", (kernel_ulong_t)&pca9571_gpio },160 { "slg7xl45106", (kernel_ulong_t)&slg7xl45106_gpio },161 { /* sentinel */ }162};163MODULE_DEVICE_TABLE(i2c, pca9570_id_table);164 165static const struct of_device_id pca9570_of_match_table[] = {166 { .compatible = "dlg,slg7xl45106", .data = &slg7xl45106_gpio},167 { .compatible = "nxp,pca9570", .data = &pca9570_gpio },168 { .compatible = "nxp,pca9571", .data = &pca9571_gpio },169 { /* sentinel */ }170};171MODULE_DEVICE_TABLE(of, pca9570_of_match_table);172 173static struct i2c_driver pca9570_driver = {174 .driver = {175 .name = "pca9570",176 .of_match_table = pca9570_of_match_table,177 },178 .probe = pca9570_probe,179 .id_table = pca9570_id_table,180};181module_i2c_driver(pca9570_driver);182 183MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>");184MODULE_DESCRIPTION("GPIO expander driver for PCA9570");185MODULE_LICENSE("GPL v2");186