diff options
Diffstat (limited to 'drivers/mfd/lp3943.c')
| -rw-r--r-- | drivers/mfd/lp3943.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/mfd/lp3943.c b/drivers/mfd/lp3943.c new file mode 100644 index 0000000..e322268 --- /dev/null +++ b/drivers/mfd/lp3943.c @@ -0,0 +1,167 @@ +/* + * TI/National Semiconductor LP3943 MFD Core Driver + * + * Copyright 2013 Texas Instruments + * + * Author: Milo Kim <milo.kim@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. + * + * Driver structure: + * LP3943 is an integrated device capable of driving 16 output channels. + * It can be used for a GPIO expander and PWM generators. + * + * LED control General usage for a device + * ___________ ____________________________ + * + * LP3943 MFD ---- GPIO expander leds-gpio eg) HW enable pin + * | + * --- PWM generator leds-pwm eg) PWM input + * + * Internal two PWM channels are used for LED dimming effect. + * And each output pin can be used as a GPIO as well. + * The LED functionality can work with GPIOs or PWMs. + * LEDs can be controlled with legacy leds-gpio(static brightness) or + * leds-pwm drivers(dynamic brightness control). + * Alternatively, it can be used for generic GPIO and PWM controller. + * For example, a GPIO is HW enable pin of a device. + * A PWM is input pin of a backlight device. + */ + +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/i2c.h> +#include <linux/mfd/core.h> +#include <linux/mfd/lp3943.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> + +#define LP3943_MAX_REGISTERS 0x09 + +/* Register configuration for pin MUX */ +static const struct lp3943_reg_cfg lp3943_mux_cfg[] = { + /* address, mask, shift */ + { LP3943_REG_MUX0, 0x03, 0 }, + { LP3943_REG_MUX0, 0x0C, 2 }, + { LP3943_REG_MUX0, 0x30, 4 }, + { LP3943_REG_MUX0, 0xC0, 6 }, + { LP3943_REG_MUX1, 0x03, 0 }, + { LP3943_REG_MUX1, 0x0C, 2 }, + { LP3943_REG_MUX1, 0x30, 4 }, + { LP3943_REG_MUX1, 0xC0, 6 }, + { LP3943_REG_MUX2, 0x03, 0 }, + { LP3943_REG_MUX2, 0x0C, 2 }, + { LP3943_REG_MUX2, 0x30, 4 }, + { LP3943_REG_MUX2, 0xC0, 6 }, + { LP3943_REG_MUX3, 0x03, 0 }, + { LP3943_REG_MUX3, 0x0C, 2 }, + { LP3943_REG_MUX3, 0x30, 4 }, + { LP3943_REG_MUX3, 0xC0, 6 }, +}; + +static struct mfd_cell lp3943_devs[] = { + { + .name = "lp3943-pwm", + .of_compatible = "ti,lp3943-pwm", + }, + { + .name = "lp3943-gpio", + .of_compatible = "ti,lp3943-gpio", + }, +}; + +int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read) +{ + int ret; + unsigned int val; + + ret = regmap_read(lp3943->regmap, reg, &val); + if (ret < 0) + return ret; + + *read = (u8)val; + return 0; +} +EXPORT_SYMBOL_GPL(lp3943_read_byte); + +int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data) +{ + return regmap_write(lp3943->regmap, reg, data); +} +EXPORT_SYMBOL_GPL(lp3943_write_byte); + +int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data) +{ + return regmap_update_bits(lp3943->regmap, reg, mask, data); +} +EXPORT_SYMBOL_GPL(lp3943_update_bits); + +static const struct regmap_config lp3943_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = LP3943_MAX_REGISTERS, +}; + +static int lp3943_probe(struct i2c_client *cl, const struct i2c_device_id *id) +{ + struct lp3943 *lp3943; + struct device *dev = &cl->dev; + + lp3943 = devm_kzalloc(dev, sizeof(*lp3943), GFP_KERNEL); + if (!lp3943) + return -ENOMEM; + + lp3943->regmap = devm_regmap_init_i2c(cl, &lp3943_regmap_config); + if (IS_ERR(lp3943->regmap)) + return PTR_ERR(lp3943->regmap); + + lp3943->pdata = dev_get_platdata(dev); + lp3943->dev = dev; + lp3943->mux_cfg = lp3943_mux_cfg; + i2c_set_clientdata(cl, lp3943); + + return mfd_add_devices(dev, -1, lp3943_devs, ARRAY_SIZE(lp3943_devs), + NULL, 0, NULL); +} + +static int lp3943_remove(struct i2c_client *cl) +{ + struct lp3943 *lp3943 = i2c_get_clientdata(cl); + + mfd_remove_devices(lp3943->dev); + return 0; +} + +static const struct i2c_device_id lp3943_ids[] = { + { "lp3943", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lp3943_ids); + +#ifdef CONFIG_OF +static const struct of_device_id lp3943_of_match[] = { + { .compatible = "ti,lp3943", }, + { } +}; +MODULE_DEVICE_TABLE(of, lp3943_of_match); +#endif + +static struct i2c_driver lp3943_driver = { + .probe = lp3943_probe, + .remove = lp3943_remove, + .driver = { + .name = "lp3943", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(lp3943_of_match), + }, + .id_table = lp3943_ids, +}; + +module_i2c_driver(lp3943_driver); + +MODULE_DESCRIPTION("LP3943 MFD Core Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); |