drivers/gpio/gpio-tpic2810.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015-2023 Texas Instruments Incorporated - https://www.ti.com/
   4  *      Andrew Davis <afd@ti.com>
   5  */
   6
   7 #include <linux/gpio/driver.h>
   8 #include <linux/i2c.h>
   9 #include <linux/module.h>
  10 #include <linux/mutex.h>
  11
  12 #define TPIC2810_WS_COMMAND 0x44
  13
  14 /**
  15  * struct tpic2810 - GPIO driver data
  16  * @chip: GPIO controller chip
  17  * @client: I2C device pointer
  18  * @buffer: Buffer for device register
  19  * @lock: Protects write sequences
  20  */
  21 struct tpic2810 {
  22         struct gpio_chip chip;
  23         struct i2c_client *client;
  24         u8 buffer;
  25         struct mutex lock;
  26 };
  27
  28 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value);
  29
  30 static int tpic2810_get_direction(struct gpio_chip *chip,
  31                                   unsigned offset)
  32 {
  33         /* This device always output */
  34         return GPIO_LINE_DIRECTION_OUT;
  35 }
  36
  37 static int tpic2810_direction_input(struct gpio_chip *chip,
  38                                     unsigned offset)
  39 {
  40         /* This device is output only */
  41         return -EINVAL;
  42 }
  43
  44 static int tpic2810_direction_output(struct gpio_chip *chip,
  45                                      unsigned offset, int value)
  46 {
  47         /* This device always output */
  48         tpic2810_set(chip, offset, value);
  49         return 0;
  50 }
  51
  52 static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
  53 {
  54         struct tpic2810 *gpio = gpiochip_get_data(chip);
  55         u8 buffer;
  56         int err;
  57
  58         mutex_lock(&gpio->lock);
  59
  60         buffer = gpio->buffer & ~mask;
  61         buffer |= (mask & bits);
  62
  63         err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
  64                                         buffer);
  65         if (!err)
  66                 gpio->buffer = buffer;
  67
  68         mutex_unlock(&gpio->lock);
  69 }
  70
  71 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value)
  72 {
  73         tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
  74 }
  75
  76 static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
  77                                   unsigned long *bits)
  78 {
  79         tpic2810_set_mask_bits(chip, *mask, *bits);
  80 }
  81
  82 static const struct gpio_chip template_chip = {
  83         .label                  = "tpic2810",
  84         .owner                  = THIS_MODULE,
  85         .get_direction          = tpic2810_get_direction,
  86         .direction_input        = tpic2810_direction_input,
  87         .direction_output       = tpic2810_direction_output,
  88         .set                    = tpic2810_set,
  89         .set_multiple           = tpic2810_set_multiple,
  90         .base                   = -1,
  91         .ngpio                  = 8,
  92         .can_sleep              = true,
  93 };
  94
  95 static const struct of_device_id tpic2810_of_match_table[] = {
  96         { .compatible = "ti,tpic2810" },
  97         { /* sentinel */ }
  98 };
  99 MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
 100
 101 static int tpic2810_probe(struct i2c_client *client)
 102 {
 103         struct tpic2810 *gpio;
 104
 105         gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
 106         if (!gpio)
 107                 return -ENOMEM;
 108
 109         gpio->chip = template_chip;
 110         gpio->chip.parent = &client->dev;
 111
 112         gpio->client = client;
 113
 114         mutex_init(&gpio->lock);
 115
 116         return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
 117 }
 118
 119 static const struct i2c_device_id tpic2810_id_table[] = {
 120         { "tpic2810", },
 121         { /* sentinel */ }
 122 };
 123 MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
 124
 125 static struct i2c_driver tpic2810_driver = {
 126         .driver = {
 127                 .name = "tpic2810",
 128                 .of_match_table = tpic2810_of_match_table,
 129         },
 130         .probe = tpic2810_probe,
 131         .id_table = tpic2810_id_table,
 132 };
 133 module_i2c_driver(tpic2810_driver);
 134
 135 MODULE_AUTHOR("Andrew Davis <afd@ti.com>");
 136 MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
 137 MODULE_LICENSE("GPL v2");