1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ 4 * Andrew F. 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 int ret; 105 106 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); 107 if (!gpio) 108 return -ENOMEM; 109 110 i2c_set_clientdata(client, gpio); 111 112 gpio->chip = template_chip; 113 gpio->chip.parent = &client->dev; 114 115 gpio->client = client; 116 117 mutex_init(&gpio->lock); 118 119 ret = gpiochip_add_data(&gpio->chip, gpio); 120 if (ret < 0) { 121 dev_err(&client->dev, "Unable to register gpiochip\n"); 122 return ret; 123 } 124 125 return 0; 126 } 127 128 static void tpic2810_remove(struct i2c_client *client) 129 { 130 struct tpic2810 *gpio = i2c_get_clientdata(client); 131 132 gpiochip_remove(&gpio->chip); 133 } 134 135 static const struct i2c_device_id tpic2810_id_table[] = { 136 { "tpic2810", }, 137 { /* sentinel */ } 138 }; 139 MODULE_DEVICE_TABLE(i2c, tpic2810_id_table); 140 141 static struct i2c_driver tpic2810_driver = { 142 .driver = { 143 .name = "tpic2810", 144 .of_match_table = tpic2810_of_match_table, 145 }, 146 .probe_new = tpic2810_probe, 147 .remove = tpic2810_remove, 148 .id_table = tpic2810_id_table, 149 }; 150 module_i2c_driver(tpic2810_driver); 151 152 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>"); 153 MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver"); 154 MODULE_LICENSE("GPL v2"); 155