diff options
Diffstat (limited to 'drivers/gpio/gpio-tpic2810.c')
| -rw-r--r-- | drivers/gpio/gpio-tpic2810.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-tpic2810.c b/drivers/gpio/gpio-tpic2810.c new file mode 100644 index 000000000..c8b34d787 --- /dev/null +++ b/drivers/gpio/gpio-tpic2810.c @@ -0,0 +1,165 @@ +/* + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ + * Andrew F. Davis <afd@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether expressed or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License version 2 for more details. + */ + +#include <linux/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mutex.h> + +#define TPIC2810_WS_COMMAND 0x44 + +/** + * struct tpic2810 - GPIO driver data + * @chip: GPIO controller chip + * @client: I2C device pointer + * @buffer: Buffer for device register + * @lock: Protects write sequences + */ +struct tpic2810 { + struct gpio_chip chip; + struct i2c_client *client; + u8 buffer; + struct mutex lock; +}; + +static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value); + +static int tpic2810_get_direction(struct gpio_chip *chip, + unsigned offset) +{ + /* This device always output */ + return 0; +} + +static int tpic2810_direction_input(struct gpio_chip *chip, + unsigned offset) +{ + /* This device is output only */ + return -EINVAL; +} + +static int tpic2810_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + /* This device always output */ + tpic2810_set(chip, offset, value); + return 0; +} + +static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits) +{ + struct tpic2810 *gpio = gpiochip_get_data(chip); + u8 buffer; + int err; + + mutex_lock(&gpio->lock); + + buffer = gpio->buffer & ~mask; + buffer |= (mask & bits); + + err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND, + buffer); + if (!err) + gpio->buffer = buffer; + + mutex_unlock(&gpio->lock); +} + +static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value) +{ + tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0); +} + +static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + tpic2810_set_mask_bits(chip, *mask, *bits); +} + +static const struct gpio_chip template_chip = { + .label = "tpic2810", + .owner = THIS_MODULE, + .get_direction = tpic2810_get_direction, + .direction_input = tpic2810_direction_input, + .direction_output = tpic2810_direction_output, + .set = tpic2810_set, + .set_multiple = tpic2810_set_multiple, + .base = -1, + .ngpio = 8, + .can_sleep = true, +}; + +static const struct of_device_id tpic2810_of_match_table[] = { + { .compatible = "ti,tpic2810" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, tpic2810_of_match_table); + +static int tpic2810_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct tpic2810 *gpio; + int ret; + + gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + + i2c_set_clientdata(client, gpio); + + gpio->chip = template_chip; + gpio->chip.parent = &client->dev; + + gpio->client = client; + + mutex_init(&gpio->lock); + + ret = gpiochip_add_data(&gpio->chip, gpio); + if (ret < 0) { + dev_err(&client->dev, "Unable to register gpiochip\n"); + return ret; + } + + return 0; +} + +static int tpic2810_remove(struct i2c_client *client) +{ + struct tpic2810 *gpio = i2c_get_clientdata(client); + + gpiochip_remove(&gpio->chip); + + return 0; +} + +static const struct i2c_device_id tpic2810_id_table[] = { + { "tpic2810", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, tpic2810_id_table); + +static struct i2c_driver tpic2810_driver = { + .driver = { + .name = "tpic2810", + .of_match_table = tpic2810_of_match_table, + }, + .probe = tpic2810_probe, + .remove = tpic2810_remove, + .id_table = tpic2810_id_table, +}; +module_i2c_driver(tpic2810_driver); + +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>"); +MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver"); +MODULE_LICENSE("GPL v2"); |