// SPDX-License-Identifier: GPL-2.0-only /* * Simple driver for Texas Instruments LM3630A Backlight driver chip * Copyright (C) 2012 Texas Instruments */ #include <linux/module.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/backlight.h> #include <linux/err.h> #include <linux/delay.h> #include <linux/uaccess.h> #include <linux/interrupt.h> #include <linux/regmap.h> #include <linux/gpio/consumer.h> #include <linux/pwm.h> #include <linux/platform_data/lm3630a_bl.h> #define REG_CTRL 0x00 #define REG_BOOST 0x02 #define REG_CONFIG 0x01 #define REG_BRT_A 0x03 #define REG_BRT_B 0x04 #define REG_I_A 0x05 #define REG_I_B 0x06 #define REG_INT_STATUS 0x09 #define REG_INT_EN 0x0A #define REG_FAULT 0x0B #define REG_PWM_OUTLOW 0x12 #define REG_PWM_OUTHIGH 0x13 #define REG_FILTER_STRENGTH 0x50 #define REG_MAX 0x50 #define INT_DEBOUNCE_MSEC 10 #define LM3630A_BANK_0 0 #define LM3630A_BANK_1 1 #define LM3630A_NUM_SINKS 2 #define LM3630A_SINK_0 0 #define LM3630A_SINK_1 1 struct lm3630a_chip { struct device *dev; struct delayed_work work; int irq; struct workqueue_struct *irqthread; struct lm3630a_platform_data *pdata; struct backlight_device *bleda; struct backlight_device *bledb; struct gpio_desc *enable_gpio; struct regmap *regmap; struct pwm_device *pwmd; struct pwm_state pwmd_state; }; /* i2c access */ static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg) { int rval; unsigned int reg_val; rval = regmap_read(pchip->regmap, reg, ®_val); if (rval < 0) return rval; return reg_val & 0xFF; } static int lm3630a_write(struct lm3630a_chip *pchip, unsigned int reg, unsigned int data) { return regmap_write(pchip->regmap, reg, data); } static int lm3630a_update(struct lm3630a_chip *pchip, unsigned int reg, unsigned int mask, unsigned int data) { return regmap_update_bits(pchip->regmap, reg, mask, data); } /* initialize chip */ static int lm3630a_chip_init(struct lm3630a_chip *pchip) { int rval; struct lm3630a_platform_data *pdata = pchip->pdata; usleep_range(1000, 2000); /* set Filter Strength Register */ rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03); /* set Cofig. register */ rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl); /* set boost control */ rval |= lm3630a_write(pchip, REG_BOOST, 0x38); /* set current A */ rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F); /* set current B */ rval |= lm3630a_write(pchip, REG_I_B, 0x1F); /* set control */ rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl); rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl); usleep_range(1000, 2000); /* set brightness A and B */ rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt); rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt); if (rval < 0) dev_err(pchip->dev, "i2c failed to access register\n"); return rval; } /* interrupt handling */ static void lm3630a_delayed_func(struct work_struct *work) { int rval; struct lm3630a_chip *pchip; pchip = container_of(work, struct lm3630a_chip, work.work); rval = lm3630a_read(pchip, REG_INT_STATUS); if (rval < 0) { dev_err(pchip->dev, "i2c failed to access REG_INT_STATUS Register\n"); return; } dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval); } static irqreturn_t lm3630a_isr_func(int irq, void *chip) { int rval; struct lm3630a_chip *pchip = chip; unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC); queue_delayed_work(pchip->irqthread, &pchip->work, delay); rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); if (rval < 0) { dev_err(pchip->dev, "i2c failed to access register\n"); return IRQ_NONE; } return IRQ_HANDLED; } static int lm3630a_intr_config(struct lm3630a_chip *pchip) { int rval; rval = lm3630a_write(pchip, REG_INT_EN, 0x87); if (rval < 0) return rval; INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func); pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd"); if (!pchip->irqthread) { dev_err(pchip->dev, "create irq thread fail\n"); return -ENOMEM; } if (request_threaded_irq (pchip->irq, NULL, lm3630a_isr_func, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) { dev_err(pchip->dev, "request threaded irq fail\n"); destroy_workqueue(pchip->irqthread); return -ENOMEM; } return rval; } static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max) { int err; pchip->pwmd_state.period = pchip->pdata->pwm_period; err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max); if (err) return err; pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false; return pwm_apply_might_sleep(pchip->pwmd, &pchip->pwmd_state); } /* update and get brightness */ static int lm3630a_bank_a_update_status(struct backlight_device *bl) { int ret; struct lm3630a_chip *pchip = bl_get_data(bl); enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; /* pwm control */ if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) return lm3630a_pwm_ctrl(pchip, bl->props.brightness, bl->props.max_brightness); /* disable sleep */ ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); if (ret < 0) goto out_i2c_err; usleep_range(1000, 2000); /* minimum brightness is 0x04 */ ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness); if (backlight_is_blank(bl) || (backlight_get_brightness(bl) < 0x4)) /* turn the string off */ ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0); else ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE); if (ret < 0) goto out_i2c_err; return 0; out_i2c_err: dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret)); return ret; } static int lm3630a_bank_a_get_brightness(struct backlight_device *bl) { int brightness, rval; struct lm3630a_chip *pchip = bl_get_data(bl); enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) { rval = lm3630a_read(pchip, REG_PWM_OUTHIGH); if (rval < 0) goto out_i2c_err; brightness = (rval & 0x01) << 8; rval = lm3630a_read(pchip, REG_PWM_OUTLOW); if (rval < 0) goto out_i2c_err; brightness |= rval; return brightness; } /* disable sleep */ rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); if (rval < 0) goto out_i2c_err; usleep_range(1000, 2000); rval = lm3630a_read(pchip, REG_BRT_A); if (rval < 0) goto out_i2c_err; return rval; out_i2c_err: dev_err(pchip->dev, "i2c failed to access register\n"); return 0; } static const struct backlight_ops lm3630a_bank_a_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = lm3630a_bank_a_update_status, .get_brightness = lm3630a_bank_a_get_brightness, }; /* update and get brightness */ static int lm3630a_bank_b_update_status(struct backlight_device *bl) { int ret; struct lm3630a_chip *pchip = bl_get_data(bl); enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; /* pwm control */ if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) return lm3630a_pwm_ctrl(pchip, bl->props.brightness, bl->props.max_brightness); /* disable sleep */ ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); if (ret < 0) goto out_i2c_err; usleep_range(1000, 2000); /* minimum brightness is 0x04 */ ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness); if (backlight_is_blank(bl) || (backlight_get_brightness(bl) < 0x4)) /* turn the string off */ ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0); else ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE); if (ret < 0) goto out_i2c_err; return 0; out_i2c_err: dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret)); return ret; } static int lm3630a_bank_b_get_brightness(struct backlight_device *bl) { int brightness, rval; struct lm3630a_chip *pchip = bl_get_data(bl); enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) { rval = lm3630a_read(pchip, REG_PWM_OUTHIGH); if (rval < 0) goto out_i2c_err; brightness = (rval & 0x01) << 8; rval = lm3630a_read(pchip, REG_PWM_OUTLOW); if (rval < 0) goto out_i2c_err; brightness |= rval; return brightness; } /* disable sleep */ rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); if (rval < 0) goto out_i2c_err; usleep_range(1000, 2000); rval = lm3630a_read(pchip, REG_BRT_B); if (rval < 0) goto out_i2c_err; return rval; out_i2c_err: dev_err(pchip->dev, "i2c failed to access register\n"); return 0; } static const struct backlight_ops lm3630a_bank_b_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = lm3630a_bank_b_update_status, .get_brightness = lm3630a_bank_b_get_brightness, }; static int lm3630a_backlight_register(struct lm3630a_chip *pchip) { struct lm3630a_platform_data *pdata = pchip->pdata; struct backlight_properties props; const char *label; memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) { props.brightness = pdata->leda_init_brt; props.max_brightness = pdata->leda_max_brt; label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda"; pchip->bleda = devm_backlight_device_register(pchip->dev, label, pchip->dev, pchip, &lm3630a_bank_a_ops, &props); if (IS_ERR(pchip->bleda)) return PTR_ERR(pchip->bleda); } if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) && (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) { props.brightness = pdata->ledb_init_brt; props.max_brightness = pdata->ledb_max_brt; label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb"; pchip->bledb = devm_backlight_device_register(pchip->dev, label, pchip->dev, pchip, &lm3630a_bank_b_ops, &props); if (IS_ERR(pchip->bledb)) return PTR_ERR(pchip->bledb); } return 0; } static const struct regmap_config lm3630a_regmap = { .reg_bits = 8, .val_bits = 8, .max_register = REG_MAX, }; static int lm3630a_parse_led_sources(struct fwnode_handle *node, int default_led_sources) { u32 sources[LM3630A_NUM_SINKS]; int ret, num_sources, i; num_sources = fwnode_property_count_u32(node, "led-sources"); if (num_sources < 0) return default_led_sources; else if (num_sources > ARRAY_SIZE(sources)) return -EINVAL; ret = fwnode_property_read_u32_array(node, "led-sources", sources, num_sources); if (ret) return ret; for (i = 0; i < num_sources; i++) { if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1) return -EINVAL; ret |= BIT(sources[i]); } return ret; } static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata, struct fwnode_handle *node, int *seen_led_sources) { int led_sources, ret; const char *label; u32 bank, val; bool linear; ret = fwnode_property_read_u32(node, "reg", &bank); if (ret) return ret; if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1) return -EINVAL; led_sources = lm3630a_parse_led_sources(node, BIT(bank)); if (led_sources < 0) return led_sources; if (*seen_led_sources & led_sources) return -EINVAL; *seen_led_sources |= led_sources; linear = fwnode_property_read_bool(node, "ti,linear-mapping-mode"); if (bank) { if (led_sources & BIT(LM3630A_SINK_0) || !(led_sources & BIT(LM3630A_SINK_1))) return -EINVAL; pdata->ledb_ctrl = linear ? LM3630A_LEDB_ENABLE_LINEAR : LM3630A_LEDB_ENABLE; } else { if (!(led_sources & BIT(LM3630A_SINK_0))) return -EINVAL; pdata->leda_ctrl = linear ? LM3630A_LEDA_ENABLE_LINEAR : LM3630A_LEDA_ENABLE; if (led_sources & BIT(LM3630A_SINK_1)) pdata->ledb_ctrl = LM3630A_LEDB_ON_A; } ret = fwnode_property_read_string(node, "label", &label); if (!ret) { if (bank) pdata->ledb_label = label; else pdata->leda_label = label; } ret = fwnode_property_read_u32(node, "default-brightness", &val); if (!ret) { if (bank) pdata->ledb_init_brt = val; else pdata->leda_init_brt = val; } ret = fwnode_property_read_u32(node, "max-brightness", &val); if (!ret) { if (bank) pdata->ledb_max_brt = val; else pdata->leda_max_brt = val; } return 0; } static int lm3630a_parse_node(struct lm3630a_chip *pchip, struct lm3630a_platform_data *pdata) { int ret = -ENODEV, seen_led_sources = 0; struct fwnode_handle *node; device_for_each_child_node(pchip->dev, node) { ret = lm3630a_parse_bank(pdata, node, &seen_led_sources); if (ret) { fwnode_handle_put(node); return ret; } } return ret; } static int lm3630a_probe(struct i2c_client *client) { struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev); struct lm3630a_chip *pchip; int rval; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { dev_err(&client->dev, "fail : i2c functionality check\n"); return -EOPNOTSUPP; } pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip), GFP_KERNEL); if (!pchip) return -ENOMEM; pchip->dev = &client->dev; pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap); if (IS_ERR(pchip->regmap)) { rval = PTR_ERR(pchip->regmap); dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval); return rval; } i2c_set_clientdata(client, pchip); if (pdata == NULL) { pdata = devm_kzalloc(pchip->dev, sizeof(struct lm3630a_platform_data), GFP_KERNEL); if (pdata == NULL) return -ENOMEM; /* default values */ pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS; pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS; pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS; pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS; rval = lm3630a_parse_node(pchip, pdata); if (rval) { dev_err(&client->dev, "fail : parse node\n"); return rval; } } pchip->pdata = pdata; pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH); if (IS_ERR(pchip->enable_gpio)) { rval = PTR_ERR(pchip->enable_gpio); return rval; } /* chip initialize */ rval = lm3630a_chip_init(pchip); if (rval < 0) { dev_err(&client->dev, "fail : init chip\n"); return rval; } /* backlight register */ rval = lm3630a_backlight_register(pchip); if (rval < 0) { dev_err(&client->dev, "fail : backlight register.\n"); return rval; } /* pwm */ if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) { pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm"); if (IS_ERR(pchip->pwmd)) { dev_err(&client->dev, "fail : get pwm device\n"); return PTR_ERR(pchip->pwmd); } pwm_init_state(pchip->pwmd, &pchip->pwmd_state); } /* interrupt enable : irq 0 is not allowed */ pchip->irq = client->irq; if (pchip->irq) { rval = lm3630a_intr_config(pchip); if (rval < 0) return rval; } dev_info(&client->dev, "LM3630A backlight register OK.\n"); return 0; } static void lm3630a_remove(struct i2c_client *client) { int rval; struct lm3630a_chip *pchip = i2c_get_clientdata(client); rval = lm3630a_write(pchip, REG_BRT_A, 0); if (rval < 0) dev_err(pchip->dev, "i2c failed to access register\n"); rval = lm3630a_write(pchip, REG_BRT_B, 0); if (rval < 0) dev_err(pchip->dev, "i2c failed to access register\n"); if (pchip->irq) { free_irq(pchip->irq, pchip); destroy_workqueue(pchip->irqthread); } } static const struct i2c_device_id lm3630a_id[] = { {LM3630A_NAME, 0}, {} }; MODULE_DEVICE_TABLE(i2c, lm3630a_id); static const struct of_device_id lm3630a_match_table[] = { { .compatible = "ti,lm3630a", }, { }, }; MODULE_DEVICE_TABLE(of, lm3630a_match_table); static struct i2c_driver lm3630a_i2c_driver = { .driver = { .name = LM3630A_NAME, .of_match_table = lm3630a_match_table, }, .probe = lm3630a_probe, .remove = lm3630a_remove, .id_table = lm3630a_id, }; module_i2c_driver(lm3630a_i2c_driver); MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A"); MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>"); MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>"); MODULE_LICENSE("GPL v2");