diff options
Diffstat (limited to 'drivers/leds/leds-lp8501.c')
| -rw-r--r-- | drivers/leds/leds-lp8501.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/leds/leds-lp8501.c b/drivers/leds/leds-lp8501.c new file mode 100644 index 000000000..d3098e395 --- /dev/null +++ b/drivers/leds/leds-lp8501.c @@ -0,0 +1,411 @@ +/* + * TI LP8501 9 channel LED Driver + * + * Copyright (C) 2013 Texas Instruments + * + * Author: Milo(Woogyom) 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. + * + */ + +#include <linux/delay.h> +#include <linux/firmware.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/platform_data/leds-lp55xx.h> +#include <linux/slab.h> + +#include "leds-lp55xx-common.h" + +#define LP8501_PROGRAM_LENGTH 32 +#define LP8501_MAX_LEDS 9 + +/* Registers */ +#define LP8501_REG_ENABLE 0x00 +#define LP8501_ENABLE BIT(6) +#define LP8501_EXEC_M 0x3F +#define LP8501_EXEC_ENG1_M 0x30 +#define LP8501_EXEC_ENG2_M 0x0C +#define LP8501_EXEC_ENG3_M 0x03 +#define LP8501_RUN_ENG1 0x20 +#define LP8501_RUN_ENG2 0x08 +#define LP8501_RUN_ENG3 0x02 + +#define LP8501_REG_OP_MODE 0x01 +#define LP8501_MODE_ENG1_M 0x30 +#define LP8501_MODE_ENG2_M 0x0C +#define LP8501_MODE_ENG3_M 0x03 +#define LP8501_LOAD_ENG1 0x10 +#define LP8501_LOAD_ENG2 0x04 +#define LP8501_LOAD_ENG3 0x01 + +#define LP8501_REG_PWR_CONFIG 0x05 +#define LP8501_PWR_CONFIG_M 0x03 + +#define LP8501_REG_LED_PWM_BASE 0x16 + +#define LP8501_REG_LED_CURRENT_BASE 0x26 + +#define LP8501_REG_CONFIG 0x36 +#define LP8501_PWM_PSAVE BIT(7) +#define LP8501_AUTO_INC BIT(6) +#define LP8501_PWR_SAVE BIT(5) +#define LP8501_CP_AUTO 0x18 +#define LP8501_INT_CLK BIT(0) +#define LP8501_DEFAULT_CFG \ + (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO) + +#define LP8501_REG_RESET 0x3D +#define LP8501_RESET 0xFF + +#define LP8501_REG_PROG_PAGE_SEL 0x4F +#define LP8501_PAGE_ENG1 0 +#define LP8501_PAGE_ENG2 1 +#define LP8501_PAGE_ENG3 2 + +#define LP8501_REG_PROG_MEM 0x50 + +#define LP8501_ENG1_IS_LOADING(mode) \ + ((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1) +#define LP8501_ENG2_IS_LOADING(mode) \ + ((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2) +#define LP8501_ENG3_IS_LOADING(mode) \ + ((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3) + +static inline void lp8501_wait_opmode_done(void) +{ + usleep_range(1000, 2000); +} + +static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current) +{ + led->led_current = led_current; + lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr, + led_current); +} + +static int lp8501_post_init_device(struct lp55xx_chip *chip) +{ + int ret; + u8 val = LP8501_DEFAULT_CFG; + + ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE); + if (ret) + return ret; + + /* Chip startup time is 500 us, 1 - 2 ms gives some margin */ + usleep_range(1000, 2000); + + if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT) + val |= LP8501_INT_CLK; + + ret = lp55xx_write(chip, LP8501_REG_CONFIG, val); + if (ret) + return ret; + + /* Power selection for each output */ + return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG, + LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel); +} + +static void lp8501_load_engine(struct lp55xx_chip *chip) +{ + enum lp55xx_engine_index idx = chip->engine_idx; + u8 mask[] = { + [LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M, + [LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M, + [LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M, + }; + + u8 val[] = { + [LP55XX_ENGINE_1] = LP8501_LOAD_ENG1, + [LP55XX_ENGINE_2] = LP8501_LOAD_ENG2, + [LP55XX_ENGINE_3] = LP8501_LOAD_ENG3, + }; + + u8 page_sel[] = { + [LP55XX_ENGINE_1] = LP8501_PAGE_ENG1, + [LP55XX_ENGINE_2] = LP8501_PAGE_ENG2, + [LP55XX_ENGINE_3] = LP8501_PAGE_ENG3, + }; + + lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]); + + lp8501_wait_opmode_done(); + + lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]); +} + +static void lp8501_stop_engine(struct lp55xx_chip *chip) +{ + lp55xx_write(chip, LP8501_REG_OP_MODE, 0); + lp8501_wait_opmode_done(); +} + +static void lp8501_turn_off_channels(struct lp55xx_chip *chip) +{ + int i; + + for (i = 0; i < LP8501_MAX_LEDS; i++) + lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0); +} + +static void lp8501_run_engine(struct lp55xx_chip *chip, bool start) +{ + int ret; + u8 mode; + u8 exec; + + /* stop engine */ + if (!start) { + lp8501_stop_engine(chip); + lp8501_turn_off_channels(chip); + return; + } + + /* + * To run the engine, + * operation mode and enable register should updated at the same time + */ + + ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode); + if (ret) + return; + + ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec); + if (ret) + return; + + /* change operation mode to RUN only when each engine is loading */ + if (LP8501_ENG1_IS_LOADING(mode)) { + mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1; + exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1; + } + + if (LP8501_ENG2_IS_LOADING(mode)) { + mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2; + exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2; + } + + if (LP8501_ENG3_IS_LOADING(mode)) { + mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3; + exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3; + } + + lp55xx_write(chip, LP8501_REG_OP_MODE, mode); + lp8501_wait_opmode_done(); + + lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec); +} + +static int lp8501_update_program_memory(struct lp55xx_chip *chip, + const u8 *data, size_t size) +{ + u8 pattern[LP8501_PROGRAM_LENGTH] = {0}; + unsigned cmd; + char c[3]; + int update_size; + int nrchars; + int offset = 0; + int ret; + int i; + + /* clear program memory before updating */ + for (i = 0; i < LP8501_PROGRAM_LENGTH; i++) + lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0); + + i = 0; + while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) { + /* separate sscanfs because length is working only for %s */ + ret = sscanf(data + offset, "%2s%n ", c, &nrchars); + if (ret != 1) + goto err; + + ret = sscanf(c, "%2x", &cmd); + if (ret != 1) + goto err; + + pattern[i] = (u8)cmd; + offset += nrchars; + i++; + } + + /* Each instruction is 16bit long. Check that length is even */ + if (i % 2) + goto err; + + update_size = i; + for (i = 0; i < update_size; i++) + lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]); + + return 0; + +err: + dev_err(&chip->cl->dev, "wrong pattern format\n"); + return -EINVAL; +} + +static void lp8501_firmware_loaded(struct lp55xx_chip *chip) +{ + const struct firmware *fw = chip->fw; + + if (fw->size > LP8501_PROGRAM_LENGTH) { + dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", + fw->size); + return; + } + + /* + * Program memory sequence + * 1) set engine mode to "LOAD" + * 2) write firmware data into program memory + */ + + lp8501_load_engine(chip); + lp8501_update_program_memory(chip, fw->data, fw->size); +} + +static void lp8501_led_brightness_work(struct work_struct *work) +{ + struct lp55xx_led *led = container_of(work, struct lp55xx_led, + brightness_work); + struct lp55xx_chip *chip = led->chip; + + mutex_lock(&chip->lock); + lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr, + led->brightness); + mutex_unlock(&chip->lock); +} + +/* Chip specific configurations */ +static struct lp55xx_device_config lp8501_cfg = { + .reset = { + .addr = LP8501_REG_RESET, + .val = LP8501_RESET, + }, + .enable = { + .addr = LP8501_REG_ENABLE, + .val = LP8501_ENABLE, + }, + .max_channel = LP8501_MAX_LEDS, + .post_init_device = lp8501_post_init_device, + .brightness_work_fn = lp8501_led_brightness_work, + .set_led_current = lp8501_set_led_current, + .firmware_cb = lp8501_firmware_loaded, + .run_engine = lp8501_run_engine, +}; + +static int lp8501_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct lp55xx_chip *chip; + struct lp55xx_led *led; + struct lp55xx_platform_data *pdata; + struct device_node *np = client->dev.of_node; + + if (!dev_get_platdata(&client->dev)) { + if (np) { + ret = lp55xx_of_populate_pdata(&client->dev, np); + if (ret < 0) + return ret; + } else { + dev_err(&client->dev, "no platform data\n"); + return -EINVAL; + } + } + pdata = dev_get_platdata(&client->dev); + + chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + led = devm_kzalloc(&client->dev, + sizeof(*led) * pdata->num_channels, GFP_KERNEL); + if (!led) + return -ENOMEM; + + chip->cl = client; + chip->pdata = pdata; + chip->cfg = &lp8501_cfg; + + mutex_init(&chip->lock); + + i2c_set_clientdata(client, led); + + ret = lp55xx_init_device(chip); + if (ret) + goto err_init; + + dev_info(&client->dev, "%s Programmable led chip found\n", id->name); + + ret = lp55xx_register_leds(led, chip); + if (ret) + goto err_register_leds; + + ret = lp55xx_register_sysfs(chip); + if (ret) { + dev_err(&client->dev, "registering sysfs failed\n"); + goto err_register_sysfs; + } + + return 0; + +err_register_sysfs: + lp55xx_unregister_leds(led, chip); +err_register_leds: + lp55xx_deinit_device(chip); +err_init: + return ret; +} + +static int lp8501_remove(struct i2c_client *client) +{ + struct lp55xx_led *led = i2c_get_clientdata(client); + struct lp55xx_chip *chip = led->chip; + + lp8501_stop_engine(chip); + lp55xx_unregister_sysfs(chip); + lp55xx_unregister_leds(led, chip); + lp55xx_deinit_device(chip); + + return 0; +} + +static const struct i2c_device_id lp8501_id[] = { + { "lp8501", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lp8501_id); + +#ifdef CONFIG_OF +static const struct of_device_id of_lp8501_leds_match[] = { + { .compatible = "ti,lp8501", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_lp8501_leds_match); +#endif + +static struct i2c_driver lp8501_driver = { + .driver = { + .name = "lp8501", + .of_match_table = of_match_ptr(of_lp8501_leds_match), + }, + .probe = lp8501_probe, + .remove = lp8501_remove, + .id_table = lp8501_id, +}; + +module_i2c_driver(lp8501_driver); + +MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); |