drivers/gpio/gpio-tpic2810.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
0004  *  Andrew F. Davis <afd@ti.com>
0005  */
0006
0007 #include <linux/gpio/driver.h>
0008 #include <linux/i2c.h>
0009 #include <linux/module.h>
0010 #include <linux/mutex.h>
0011
0012 #define TPIC2810_WS_COMMAND 0x44
0013
0014 /**
0015  * struct tpic2810 - GPIO driver data
0016  * @chip: GPIO controller chip
0017  * @client: I2C device pointer
0018  * @buffer: Buffer for device register
0019  * @lock: Protects write sequences
0020  */
0021 struct tpic2810 {
0022     struct gpio_chip chip;
0023     struct i2c_client *client;
0024     u8 buffer;
0025     struct mutex lock;
0026 };
0027
0028 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value);
0029
0030 static int tpic2810_get_direction(struct gpio_chip *chip,
0031                   unsigned offset)
0032 {
0033     /* This device always output */
0034     return GPIO_LINE_DIRECTION_OUT;
0035 }
0036
0037 static int tpic2810_direction_input(struct gpio_chip *chip,
0038                     unsigned offset)
0039 {
0040     /* This device is output only */
0041     return -EINVAL;
0042 }
0043
0044 static int tpic2810_direction_output(struct gpio_chip *chip,
0045                      unsigned offset, int value)
0046 {
0047     /* This device always output */
0048     tpic2810_set(chip, offset, value);
0049     return 0;
0050 }
0051
0052 static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
0053 {
0054     struct tpic2810 *gpio = gpiochip_get_data(chip);
0055     u8 buffer;
0056     int err;
0057
0058     mutex_lock(&gpio->lock);
0059
0060     buffer = gpio->buffer & ~mask;
0061     buffer |= (mask & bits);
0062
0063     err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
0064                     buffer);
0065     if (!err)
0066         gpio->buffer = buffer;
0067
0068     mutex_unlock(&gpio->lock);
0069 }
0070
0071 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value)
0072 {
0073     tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
0074 }
0075
0076 static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
0077                   unsigned long *bits)
0078 {
0079     tpic2810_set_mask_bits(chip, *mask, *bits);
0080 }
0081
0082 static const struct gpio_chip template_chip = {
0083     .label          = "tpic2810",
0084     .owner          = THIS_MODULE,
0085     .get_direction      = tpic2810_get_direction,
0086     .direction_input    = tpic2810_direction_input,
0087     .direction_output   = tpic2810_direction_output,
0088     .set            = tpic2810_set,
0089     .set_multiple       = tpic2810_set_multiple,
0090     .base           = -1,
0091     .ngpio          = 8,
0092     .can_sleep      = true,
0093 };
0094
0095 static const struct of_device_id tpic2810_of_match_table[] = {
0096     { .compatible = "ti,tpic2810" },
0097     { /* sentinel */ }
0098 };
0099 MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
0100
0101 static int tpic2810_probe(struct i2c_client *client,
0102               const struct i2c_device_id *id)
0103 {
0104     struct tpic2810 *gpio;
0105     int ret;
0106
0107     gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
0108     if (!gpio)
0109         return -ENOMEM;
0110
0111     i2c_set_clientdata(client, gpio);
0112
0113     gpio->chip = template_chip;
0114     gpio->chip.parent = &client->dev;
0115
0116     gpio->client = client;
0117
0118     mutex_init(&gpio->lock);
0119
0120     ret = gpiochip_add_data(&gpio->chip, gpio);
0121     if (ret < 0) {
0122         dev_err(&client->dev, "Unable to register gpiochip\n");
0123         return ret;
0124     }
0125
0126     return 0;
0127 }
0128
0129 static int tpic2810_remove(struct i2c_client *client)
0130 {
0131     struct tpic2810 *gpio = i2c_get_clientdata(client);
0132
0133     gpiochip_remove(&gpio->chip);
0134
0135     return 0;
0136 }
0137
0138 static const struct i2c_device_id tpic2810_id_table[] = {
0139     { "tpic2810", },
0140     { /* sentinel */ }
0141 };
0142 MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
0143
0144 static struct i2c_driver tpic2810_driver = {
0145     .driver = {
0146         .name = "tpic2810",
0147         .of_match_table = tpic2810_of_match_table,
0148     },
0149     .probe = tpic2810_probe,
0150     .remove = tpic2810_remove,
0151     .id_table = tpic2810_id_table,
0152 };
0153 module_i2c_driver(tpic2810_driver);
0154
0155 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
0156 MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
0157 MODULE_LICENSE("GPL v2");