168 lines
3.5 KiB
C
168 lines
3.5 KiB
C
/*
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* TI LP88XX I2C Backlight Driver
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*
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* Copyright 2016 Texas Instruments
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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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#include <linux/i2c.h>
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#include <linux/of.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include "lp88xx.h"
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#define LP88XX_SLAVE1_OFFSET 1
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#define LP88XX_SLAVE2_OFFSET 2
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#define LP88XX_SLAVE3_OFFSET 3
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#define LP88XX_NUM_SLAVES 4
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struct lp88xx_i2c {
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struct i2c_client *client[LP88XX_NUM_SLAVES];
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};
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static struct i2c_client *lp88xx_get_client(struct lp88xx_i2c *lpi2c,
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unsigned int reg)
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{
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switch (reg) {
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case 0 ... 0xff:
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return lpi2c->client[0];
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case 0x100 ... 0x1ff:
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return lpi2c->client[1];
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case 0x200 ... 0x2ff:
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return lpi2c->client[2];
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case 0x300 ... 0x3ff:
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return lpi2c->client[3];
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default:
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return NULL;
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}
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}
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static int lp88xx_reg_read(void *p, u16 reg, u16 *val)
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{
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struct lp88xx_i2c *lpi2c = p;
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struct i2c_client *cl = lp88xx_get_client(lpi2c, reg);
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int ret;
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if (!cl)
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return -EINVAL;
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ret = i2c_smbus_read_word_data(cl, (u8)reg);
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if (ret < 0)
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return ret;
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*val = (u16)ret;
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return 0;
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}
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static int lp88xx_reg_write(void *p, u16 reg, u16 val)
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{
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struct lp88xx_i2c *lpi2c = p;
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struct i2c_client *cl = lp88xx_get_client(lpi2c, reg);
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if (!cl)
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return -EINVAL;
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return i2c_smbus_write_word_data(cl, (u8)reg, val);
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}
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static int lp88xx_add_slave(struct i2c_client *cl)
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{
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struct lp88xx_i2c *lpi2c = i2c_get_clientdata(cl);
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struct i2c_client *client;
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struct i2c_board_info info[] = {
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{
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I2C_BOARD_INFO("lp88xx-bl",
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cl->addr + LP88XX_SLAVE1_OFFSET),
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},
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{
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I2C_BOARD_INFO("lp88xx-bl",
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cl->addr + LP88XX_SLAVE2_OFFSET),
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},
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{
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I2C_BOARD_INFO("lp88xx-bl",
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cl->addr + LP88XX_SLAVE3_OFFSET),
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},
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};
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int index = 0;
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for (index = 0; index < (LP88XX_NUM_SLAVES - 1); index++) {
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client = i2c_new_device(cl->adapter, &info[index]);
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if (!client)
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return -ENODEV;
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lpi2c->client[index + LP88XX_SLAVE1_OFFSET] = client;
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}
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return 0;
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}
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static int lp88xx_probe(struct i2c_client *cl, const struct i2c_device_id *id)
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{
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struct lp88xx *lp;
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struct lp88xx_i2c *lpi2c;
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struct device *dev = &cl->dev;
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int ret;
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if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
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return -EIO;
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lp = devm_kzalloc(dev, sizeof(*lp), GFP_KERNEL);
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if (!lp)
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return -ENOMEM;
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lpi2c = devm_kzalloc(dev, sizeof(*lpi2c), GFP_KERNEL);
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if (!lpi2c)
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return -ENOMEM;
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lp->dev = &cl->dev;
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lp->priv = lpi2c;
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lp->io.write = lp88xx_reg_write;
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lp->io.read = lp88xx_reg_read;
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i2c_set_clientdata(cl, lpi2c);
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/* LP88xx device has multiple I2C slave addresses */
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lpi2c->client[0] = cl;
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ret = lp88xx_add_slave(cl);
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if (ret) {
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dev_err(dev, "Failed to add I2C slave device: %d\n", ret);
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return ret;
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}
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return lp88xx_common_probe(dev, lp);
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}
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static const struct of_device_id lp88xx_dt_ids[] = {
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{ .compatible = "ti,lp8580", },
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{ .compatible = "ti,lp8863", },
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{ .compatible = "ti,lp8880", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lp88xx_dt_ids);
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static const struct i2c_device_id lp88xx_ids[] = {
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{ "lp88xx", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, lp88xx_ids);
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static struct i2c_driver lp88xx_driver = {
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.driver = {
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.name = "lp88xx",
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.of_match_table = of_match_ptr(lp88xx_dt_ids),
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},
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.probe = lp88xx_probe,
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.id_table = lp88xx_ids,
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};
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module_i2c_driver(lp88xx_driver);
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MODULE_DESCRIPTION("Texas Instruments LP88XX I2C Backlight driver");
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MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
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MODULE_LICENSE("GPL v2");
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