diff options
author | Milo Kim <milo.kim@ti.com> | 2013-12-06 11:18:41 +0900 |
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committer | Lee Jones <lee.jones@linaro.org> | 2014-01-21 08:27:59 +0000 |
commit | 470eca47bded10f2e1a425b44d6f2b1418271a9f (patch) | |
tree | 9e302eabaeb9fd2edd3dfd3c28d821c109f60487 | |
parent | 0cc59b9d98d554168915b3765a14e8b4ad75918c (diff) | |
download | linux-470eca47bded10f2e1a425b44d6f2b1418271a9f.tar.gz linux-470eca47bded10f2e1a425b44d6f2b1418271a9f.tar.bz2 linux-470eca47bded10f2e1a425b44d6f2b1418271a9f.zip |
mfd: Add LP3943 MFD driver
LP3943 has 16 output pins which can be used as GPIO expander and PWM generator.
* Regmap I2C interface for R/W LP3943 registers
* Atomic operations for output pin assignment
The driver should check whether requested pin is available or not.
If the pin is already used, pin request returns as a failure.
A driver data, 'pin_used' is checked when gpio_request() and
pwm_request() are called. If the pin is available, then pin_used is set.
And it is cleared when gpio_free() and pwm_free().
* Device tree support
Compatible strings for GPIO and PWM driver.
LP3943 platform data is PWM related, so parsing the device tree is
implemented in the PWM driver.
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
-rw-r--r-- | drivers/mfd/Kconfig | 11 | ||||
-rw-r--r-- | drivers/mfd/Makefile | 1 | ||||
-rw-r--r-- | drivers/mfd/lp3943.c | 167 | ||||
-rw-r--r-- | include/linux/mfd/lp3943.h | 114 |
4 files changed, 293 insertions, 0 deletions
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index e54a6fd2a5bd..1c2a389e6dc2 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -738,6 +738,17 @@ config MFD_DM355EVM_MSP boards. MSP430 firmware manages resets and power sequencing, inputs from buttons and the IR remote, LEDs, an RTC, and more. +config MFD_LP3943 + tristate "TI/National Semiconductor LP3943 MFD Driver" + depends on I2C + select MFD_CORE + select REGMAP_I2C + help + Support for the TI/National Semiconductor LP3943. + This driver consists of GPIO and PWM drivers. + With these functionalities, it can be used for LED string control or + general usage such like a GPIO controller and a PWM controller. + config MFD_LP8788 bool "TI LP8788 Power Management Unit Driver" depends on I2C=y diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 2e18b05017d9..5aea5ef0a62f 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -102,6 +102,7 @@ obj-$(CONFIG_PMIC_DA9052) += da9052-core.o obj-$(CONFIG_MFD_DA9052_SPI) += da9052-spi.o obj-$(CONFIG_MFD_DA9052_I2C) += da9052-i2c.o +obj-$(CONFIG_MFD_LP3943) += lp3943.o obj-$(CONFIG_MFD_LP8788) += lp8788.o lp8788-irq.o da9055-objs := da9055-core.o da9055-i2c.o diff --git a/drivers/mfd/lp3943.c b/drivers/mfd/lp3943.c new file mode 100644 index 000000000000..e32226836fb4 --- /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"); diff --git a/include/linux/mfd/lp3943.h b/include/linux/mfd/lp3943.h new file mode 100644 index 000000000000..3490db782988 --- /dev/null +++ b/include/linux/mfd/lp3943.h @@ -0,0 +1,114 @@ +/* + * TI/National Semiconductor LP3943 Device + * + * 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. + * + */ + +#ifndef __MFD_LP3943_H__ +#define __MFD_LP3943_H__ + +#include <linux/gpio.h> +#include <linux/pwm.h> +#include <linux/regmap.h> + +/* Registers */ +#define LP3943_REG_GPIO_A 0x00 +#define LP3943_REG_GPIO_B 0x01 +#define LP3943_REG_PRESCALE0 0x02 +#define LP3943_REG_PWM0 0x03 +#define LP3943_REG_PRESCALE1 0x04 +#define LP3943_REG_PWM1 0x05 +#define LP3943_REG_MUX0 0x06 +#define LP3943_REG_MUX1 0x07 +#define LP3943_REG_MUX2 0x08 +#define LP3943_REG_MUX3 0x09 + +/* Bit description for LP3943_REG_MUX0 ~ 3 */ +#define LP3943_GPIO_IN 0x00 +#define LP3943_GPIO_OUT_HIGH 0x00 +#define LP3943_GPIO_OUT_LOW 0x01 +#define LP3943_DIM_PWM0 0x02 +#define LP3943_DIM_PWM1 0x03 + +#define LP3943_NUM_PWMS 2 + +enum lp3943_pwm_output { + LP3943_PWM_OUT0, + LP3943_PWM_OUT1, + LP3943_PWM_OUT2, + LP3943_PWM_OUT3, + LP3943_PWM_OUT4, + LP3943_PWM_OUT5, + LP3943_PWM_OUT6, + LP3943_PWM_OUT7, + LP3943_PWM_OUT8, + LP3943_PWM_OUT9, + LP3943_PWM_OUT10, + LP3943_PWM_OUT11, + LP3943_PWM_OUT12, + LP3943_PWM_OUT13, + LP3943_PWM_OUT14, + LP3943_PWM_OUT15, +}; + +/* + * struct lp3943_pwm_map + * @output: Output pins which are mapped to each PWM channel + * @num_outputs: Number of outputs + */ +struct lp3943_pwm_map { + enum lp3943_pwm_output *output; + int num_outputs; +}; + +/* + * struct lp3943_platform_data + * @pwms: Output channel definitions for PWM channel 0 and 1 + */ +struct lp3943_platform_data { + struct lp3943_pwm_map *pwms[LP3943_NUM_PWMS]; +}; + +/* + * struct lp3943_reg_cfg + * @reg: Register address + * @mask: Register bit mask to be updated + * @shift: Register bit shift + */ +struct lp3943_reg_cfg { + u8 reg; + u8 mask; + u8 shift; +}; + +/* + * struct lp3943 + * @dev: Parent device pointer + * @regmap: Used for I2C communication on accessing registers + * @pdata: LP3943 platform specific data + * @mux_cfg: Register configuration for pin MUX + * @pin_used: Bit mask for output pin used. + * This bitmask is used for pin assignment management. + * 1 = pin used, 0 = available. + * Only LSB 16 bits are used, but it is unsigned long type + * for atomic bitwise operations. + */ +struct lp3943 { + struct device *dev; + struct regmap *regmap; + struct lp3943_platform_data *pdata; + const struct lp3943_reg_cfg *mux_cfg; + unsigned long pin_used; +}; + +int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read); +int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data); +int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data); +#endif |