/* * LP5521 LED chip driver. * * Copyright (C) 2010 Nokia Corporation * Copyright (C) 2012 Texas Instruments * * Contact: Samu Onkalo <samu.p.onkalo@nokia.com> * 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. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA */ #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/platform_data/leds-lp55xx.h> #include <linux/slab.h> #include "leds-lp55xx-common.h" #define LP5521_PROGRAM_LENGTH 32 #define LP5521_MAX_LEDS 3 #define LP5521_CMD_DIRECT 0x3F /* Registers */ #define LP5521_REG_ENABLE 0x00 #define LP5521_REG_OP_MODE 0x01 #define LP5521_REG_R_PWM 0x02 #define LP5521_REG_G_PWM 0x03 #define LP5521_REG_B_PWM 0x04 #define LP5521_REG_R_CURRENT 0x05 #define LP5521_REG_G_CURRENT 0x06 #define LP5521_REG_B_CURRENT 0x07 #define LP5521_REG_CONFIG 0x08 #define LP5521_REG_STATUS 0x0C #define LP5521_REG_RESET 0x0D #define LP5521_REG_R_PROG_MEM 0x10 #define LP5521_REG_G_PROG_MEM 0x30 #define LP5521_REG_B_PROG_MEM 0x50 /* Base register to set LED current */ #define LP5521_REG_LED_CURRENT_BASE LP5521_REG_R_CURRENT /* Base register to set the brightness */ #define LP5521_REG_LED_PWM_BASE LP5521_REG_R_PWM /* Bits in ENABLE register */ #define LP5521_MASTER_ENABLE 0x40 /* Chip master enable */ #define LP5521_LOGARITHMIC_PWM 0x80 /* Logarithmic PWM adjustment */ #define LP5521_EXEC_RUN 0x2A #define LP5521_ENABLE_DEFAULT \ (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM) #define LP5521_ENABLE_RUN_PROGRAM \ (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN) /* Status */ #define LP5521_EXT_CLK_USED 0x08 /* default R channel current register value */ #define LP5521_REG_R_CURR_DEFAULT 0xAF /* Reset register value */ #define LP5521_RESET 0xFF /* Program Memory Operations */ #define LP5521_MODE_R_M 0x30 /* Operation Mode Register */ #define LP5521_MODE_G_M 0x0C #define LP5521_MODE_B_M 0x03 #define LP5521_LOAD_R 0x10 #define LP5521_LOAD_G 0x04 #define LP5521_LOAD_B 0x01 #define LP5521_R_IS_LOADING(mode) \ ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R) #define LP5521_G_IS_LOADING(mode) \ ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G) #define LP5521_B_IS_LOADING(mode) \ ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B) #define LP5521_EXEC_R_M 0x30 /* Enable Register */ #define LP5521_EXEC_G_M 0x0C #define LP5521_EXEC_B_M 0x03 #define LP5521_EXEC_M 0x3F #define LP5521_RUN_R 0x20 #define LP5521_RUN_G 0x08 #define LP5521_RUN_B 0x02 static inline void lp5521_wait_opmode_done(void) { /* operation mode change needs to be longer than 153 us */ usleep_range(200, 300); } static inline void lp5521_wait_enable_done(void) { /* it takes more 488 us to update ENABLE register */ usleep_range(500, 600); } static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current) { led->led_current = led_current; lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr, led_current); } static void lp5521_load_engine(struct lp55xx_chip *chip) { enum lp55xx_engine_index idx = chip->engine_idx; u8 mask[] = { [LP55XX_ENGINE_1] = LP5521_MODE_R_M, [LP55XX_ENGINE_2] = LP5521_MODE_G_M, [LP55XX_ENGINE_3] = LP5521_MODE_B_M, }; u8 val[] = { [LP55XX_ENGINE_1] = LP5521_LOAD_R, [LP55XX_ENGINE_2] = LP5521_LOAD_G, [LP55XX_ENGINE_3] = LP5521_LOAD_B, }; lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]); lp5521_wait_opmode_done(); } static void lp5521_stop_engine(struct lp55xx_chip *chip) { lp55xx_write(chip, LP5521_REG_OP_MODE, 0); lp5521_wait_opmode_done(); } static void lp5521_run_engine(struct lp55xx_chip *chip, bool start) { int ret; u8 mode; u8 exec; /* stop engine */ if (!start) { lp5521_stop_engine(chip); lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); lp5521_wait_opmode_done(); return; } /* * To run the engine, * operation mode and enable register should updated at the same time */ ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode); if (ret) return; ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec); if (ret) return; /* change operation mode to RUN only when each engine is loading */ if (LP5521_R_IS_LOADING(mode)) { mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R; exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R; } if (LP5521_G_IS_LOADING(mode)) { mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G; exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G; } if (LP5521_B_IS_LOADING(mode)) { mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B; exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B; } lp55xx_write(chip, LP5521_REG_OP_MODE, mode); lp5521_wait_opmode_done(); lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec); lp5521_wait_enable_done(); } static int lp5521_update_program_memory(struct lp55xx_chip *chip, const u8 *data, size_t size) { enum lp55xx_engine_index idx = chip->engine_idx; u8 pattern[LP5521_PROGRAM_LENGTH] = {0}; u8 addr[] = { [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM, [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM, [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM, }; unsigned cmd; char c[3]; int program_size; int nrchars; int offset = 0; int ret; int i; /* clear program memory before updating */ for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) lp55xx_write(chip, addr[idx] + i, 0); i = 0; while ((offset < size - 1) && (i < LP5521_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; program_size = i; for (i = 0; i < program_size; i++) lp55xx_write(chip, addr[idx] + i, pattern[i]); return 0; err: dev_err(&chip->cl->dev, "wrong pattern format\n"); return -EINVAL; } static void lp5521_firmware_loaded(struct lp55xx_chip *chip) { const struct firmware *fw = chip->fw; if (fw->size > LP5521_PROGRAM_LENGTH) { dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", fw->size); return; } /* * Program momery sequence * 1) set engine mode to "LOAD" * 2) write firmware data into program memory */ lp5521_load_engine(chip); lp5521_update_program_memory(chip, fw->data, fw->size); } static int lp5521_post_init_device(struct lp55xx_chip *chip) { int ret; u8 val; /* * Make sure that the chip is reset by reading back the r channel * current reg. This is dummy read is required on some platforms - * otherwise further access to the R G B channels in the * LP5521_REG_ENABLE register will not have any effect - strange! */ ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val); if (ret) { dev_err(&chip->cl->dev, "error in resetting chip\n"); return ret; } if (val != LP5521_REG_R_CURR_DEFAULT) { dev_err(&chip->cl->dev, "unexpected data in register (expected 0x%x got 0x%x)\n", LP5521_REG_R_CURR_DEFAULT, val); ret = -EINVAL; return ret; } usleep_range(10000, 20000); /* Set all PWMs to direct control mode */ ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); val = chip->pdata->update_config ? : (LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT); ret = lp55xx_write(chip, LP5521_REG_CONFIG, val); if (ret) return ret; /* Initialize all channels PWM to zero -> leds off */ lp55xx_write(chip, LP5521_REG_R_PWM, 0); lp55xx_write(chip, LP5521_REG_G_PWM, 0); lp55xx_write(chip, LP5521_REG_B_PWM, 0); /* Set engines are set to run state when OP_MODE enables engines */ ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM); if (ret) return ret; lp5521_wait_enable_done(); return 0; } static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf) { struct lp55xx_platform_data *pdata = chip->pdata; int ret; u8 status; ret = lp55xx_read(chip, LP5521_REG_STATUS, &status); if (ret < 0) return ret; if (pdata->clock_mode != LP55XX_CLOCK_EXT) return 0; /* Check that ext clock is really in use if requested */ if ((status & LP5521_EXT_CLK_USED) == 0) return -EIO; return 0; } static void lp5521_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, LP5521_REG_LED_PWM_BASE + led->chan_nr, led->brightness); mutex_unlock(&chip->lock); } static ssize_t lp5521_selftest(struct device *dev, struct device_attribute *attr, char *buf) { struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); struct lp55xx_chip *chip = led->chip; int ret; mutex_lock(&chip->lock); ret = lp5521_run_selftest(chip, buf); mutex_unlock(&chip->lock); return sprintf(buf, "%s\n", ret ? "FAIL" : "OK"); } /* device attributes */ static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL); static struct attribute *lp5521_attributes[] = { &dev_attr_selftest.attr, NULL }; static const struct attribute_group lp5521_group = { .attrs = lp5521_attributes, }; /* Chip specific configurations */ static struct lp55xx_device_config lp5521_cfg = { .reset = { .addr = LP5521_REG_RESET, .val = LP5521_RESET, }, .enable = { .addr = LP5521_REG_ENABLE, .val = LP5521_ENABLE_DEFAULT, }, .max_channel = LP5521_MAX_LEDS, .post_init_device = lp5521_post_init_device, .brightness_work_fn = lp5521_led_brightness_work, .set_led_current = lp5521_set_led_current, .firmware_cb = lp5521_firmware_loaded, .run_engine = lp5521_run_engine, .dev_attr_group = &lp5521_group, }; static int lp5521_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 = client->dev.platform_data; if (!pdata) { dev_err(&client->dev, "no platform data\n"); return -EINVAL; } 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 = &lp5521_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 lp5521_remove(struct i2c_client *client) { struct lp55xx_led *led = i2c_get_clientdata(client); struct lp55xx_chip *chip = led->chip; lp5521_stop_engine(chip); lp55xx_unregister_sysfs(chip); lp55xx_unregister_leds(led, chip); lp55xx_deinit_device(chip); return 0; } static const struct i2c_device_id lp5521_id[] = { { "lp5521", 0 }, /* Three channel chip */ { } }; MODULE_DEVICE_TABLE(i2c, lp5521_id); static struct i2c_driver lp5521_driver = { .driver = { .name = "lp5521", }, .probe = lp5521_probe, .remove = lp5521_remove, .id_table = lp5521_id, }; module_i2c_driver(lp5521_driver); MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo"); MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); MODULE_DESCRIPTION("LP5521 LED engine"); MODULE_LICENSE("GPL v2");