159 lines
4.1 KiB
C
159 lines
4.1 KiB
C
/*
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* TI/National Semiconductor LP3943 MFD Core Driver
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*
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* Copyright 2013 Texas Instruments
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*
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* Author: Milo Kim <milo.kim@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Driver structure:
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* LP3943 is an integrated device capable of driving 16 output channels.
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* It can be used for a GPIO expander and PWM generators.
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*
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* LED control General usage for a device
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* ___________ ____________________________
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*
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* LP3943 MFD ---- GPIO expander leds-gpio eg) HW enable pin
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* |
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* --- PWM generator leds-pwm eg) PWM input
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*
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* Internal two PWM channels are used for LED dimming effect.
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* And each output pin can be used as a GPIO as well.
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* The LED functionality can work with GPIOs or PWMs.
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* LEDs can be controlled with legacy leds-gpio(static brightness) or
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* leds-pwm drivers(dynamic brightness control).
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* Alternatively, it can be used for generic GPIO and PWM controller.
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* For example, a GPIO is HW enable pin of a device.
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* A PWM is input pin of a backlight device.
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*/
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/mfd/core.h>
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#include <linux/mfd/lp3943.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#define LP3943_MAX_REGISTERS 0x09
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/* Register configuration for pin MUX */
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static const struct lp3943_reg_cfg lp3943_mux_cfg[] = {
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/* address, mask, shift */
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{ LP3943_REG_MUX0, 0x03, 0 },
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{ LP3943_REG_MUX0, 0x0C, 2 },
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{ LP3943_REG_MUX0, 0x30, 4 },
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{ LP3943_REG_MUX0, 0xC0, 6 },
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{ LP3943_REG_MUX1, 0x03, 0 },
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{ LP3943_REG_MUX1, 0x0C, 2 },
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{ LP3943_REG_MUX1, 0x30, 4 },
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{ LP3943_REG_MUX1, 0xC0, 6 },
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{ LP3943_REG_MUX2, 0x03, 0 },
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{ LP3943_REG_MUX2, 0x0C, 2 },
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{ LP3943_REG_MUX2, 0x30, 4 },
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{ LP3943_REG_MUX2, 0xC0, 6 },
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{ LP3943_REG_MUX3, 0x03, 0 },
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{ LP3943_REG_MUX3, 0x0C, 2 },
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{ LP3943_REG_MUX3, 0x30, 4 },
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{ LP3943_REG_MUX3, 0xC0, 6 },
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};
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static const struct mfd_cell lp3943_devs[] = {
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{
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.name = "lp3943-pwm",
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.of_compatible = "ti,lp3943-pwm",
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},
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{
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.name = "lp3943-gpio",
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.of_compatible = "ti,lp3943-gpio",
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},
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};
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int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read)
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{
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int ret;
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unsigned int val;
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ret = regmap_read(lp3943->regmap, reg, &val);
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if (ret < 0)
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return ret;
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*read = (u8)val;
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return 0;
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}
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EXPORT_SYMBOL_GPL(lp3943_read_byte);
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int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data)
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{
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return regmap_write(lp3943->regmap, reg, data);
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}
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EXPORT_SYMBOL_GPL(lp3943_write_byte);
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int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data)
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{
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return regmap_update_bits(lp3943->regmap, reg, mask, data);
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}
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EXPORT_SYMBOL_GPL(lp3943_update_bits);
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static const struct regmap_config lp3943_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = LP3943_MAX_REGISTERS,
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};
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static int lp3943_probe(struct i2c_client *cl, const struct i2c_device_id *id)
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{
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struct lp3943 *lp3943;
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struct device *dev = &cl->dev;
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lp3943 = devm_kzalloc(dev, sizeof(*lp3943), GFP_KERNEL);
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if (!lp3943)
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return -ENOMEM;
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lp3943->regmap = devm_regmap_init_i2c(cl, &lp3943_regmap_config);
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if (IS_ERR(lp3943->regmap))
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return PTR_ERR(lp3943->regmap);
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lp3943->pdata = dev_get_platdata(dev);
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lp3943->dev = dev;
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lp3943->mux_cfg = lp3943_mux_cfg;
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i2c_set_clientdata(cl, lp3943);
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return devm_mfd_add_devices(dev, -1, lp3943_devs,
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ARRAY_SIZE(lp3943_devs),
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NULL, 0, NULL);
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}
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static const struct i2c_device_id lp3943_ids[] = {
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{ "lp3943", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, lp3943_ids);
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#ifdef CONFIG_OF
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static const struct of_device_id lp3943_of_match[] = {
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{ .compatible = "ti,lp3943", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lp3943_of_match);
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#endif
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static struct i2c_driver lp3943_driver = {
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.probe = lp3943_probe,
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.driver = {
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.name = "lp3943",
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.of_match_table = of_match_ptr(lp3943_of_match),
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},
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.id_table = lp3943_ids,
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};
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module_i2c_driver(lp3943_driver);
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MODULE_DESCRIPTION("LP3943 MFD Core Driver");
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MODULE_AUTHOR("Milo Kim");
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MODULE_LICENSE("GPL");
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