1 /* 2 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ 3 * Andrew F. Davis <afd@ti.com> 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 10 * kind, whether expressed or implied; without even the implied warranty 11 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License version 2 for more details. 13 */ 14 15 #include <linux/gpio/driver.h> 16 #include <linux/i2c.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 20 #define TPIC2810_WS_COMMAND 0x44 21 22 /** 23 * struct tpic2810 - GPIO driver data 24 * @chip: GPIO controller chip 25 * @client: I2C device pointer 26 * @buffer: Buffer for device register 27 * @lock: Protects write sequences 28 */ 29 struct tpic2810 { 30 struct gpio_chip chip; 31 struct i2c_client *client; 32 u8 buffer; 33 struct mutex lock; 34 }; 35 36 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value); 37 38 static int tpic2810_get_direction(struct gpio_chip *chip, 39 unsigned offset) 40 { 41 /* This device always output */ 42 return 0; 43 } 44 45 static int tpic2810_direction_input(struct gpio_chip *chip, 46 unsigned offset) 47 { 48 /* This device is output only */ 49 return -EINVAL; 50 } 51 52 static int tpic2810_direction_output(struct gpio_chip *chip, 53 unsigned offset, int value) 54 { 55 /* This device always output */ 56 tpic2810_set(chip, offset, value); 57 return 0; 58 } 59 60 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value) 61 { 62 struct tpic2810 *gpio = gpiochip_get_data(chip); 63 64 mutex_lock(&gpio->lock); 65 66 if (value) 67 gpio->buffer |= BIT(offset); 68 else 69 gpio->buffer &= ~BIT(offset); 70 71 i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND, 72 gpio->buffer); 73 74 mutex_unlock(&gpio->lock); 75 } 76 77 static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask, 78 unsigned long *bits) 79 { 80 struct tpic2810 *gpio = gpiochip_get_data(chip); 81 82 mutex_lock(&gpio->lock); 83 84 /* clear bits under mask */ 85 gpio->buffer &= ~(*mask); 86 /* set bits under mask */ 87 gpio->buffer |= ((*mask) & (*bits)); 88 89 i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND, 90 gpio->buffer); 91 92 mutex_unlock(&gpio->lock); 93 } 94 95 static struct gpio_chip template_chip = { 96 .label = "tpic2810", 97 .owner = THIS_MODULE, 98 .get_direction = tpic2810_get_direction, 99 .direction_input = tpic2810_direction_input, 100 .direction_output = tpic2810_direction_output, 101 .set = tpic2810_set, 102 .set_multiple = tpic2810_set_multiple, 103 .base = -1, 104 .ngpio = 8, 105 .can_sleep = true, 106 }; 107 108 static const struct of_device_id tpic2810_of_match_table[] = { 109 { .compatible = "ti,tpic2810" }, 110 { /* sentinel */ } 111 }; 112 MODULE_DEVICE_TABLE(of, tpic2810_of_match_table); 113 114 static int tpic2810_probe(struct i2c_client *client, 115 const struct i2c_device_id *id) 116 { 117 struct tpic2810 *gpio; 118 int ret; 119 120 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); 121 if (!gpio) 122 return -ENOMEM; 123 124 i2c_set_clientdata(client, gpio); 125 126 gpio->chip = template_chip; 127 gpio->chip.parent = &client->dev; 128 129 gpio->client = client; 130 131 mutex_init(&gpio->lock); 132 133 ret = gpiochip_add_data(&gpio->chip, gpio); 134 if (ret < 0) { 135 dev_err(&client->dev, "Unable to register gpiochip\n"); 136 return ret; 137 } 138 139 return 0; 140 } 141 142 static int tpic2810_remove(struct i2c_client *client) 143 { 144 struct tpic2810 *gpio = i2c_get_clientdata(client); 145 146 gpiochip_remove(&gpio->chip); 147 148 return 0; 149 } 150 151 static const struct i2c_device_id tpic2810_id_table[] = { 152 { "tpic2810", }, 153 { /* sentinel */ } 154 }; 155 MODULE_DEVICE_TABLE(i2c, tpic2810_id_table); 156 157 static struct i2c_driver tpic2810_driver = { 158 .driver = { 159 .name = "tpic2810", 160 .of_match_table = tpic2810_of_match_table, 161 }, 162 .probe = tpic2810_probe, 163 .remove = tpic2810_remove, 164 .id_table = tpic2810_id_table, 165 }; 166 module_i2c_driver(tpic2810_driver); 167 168 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>"); 169 MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver"); 170 MODULE_LICENSE("GPL v2"); 171