// SPDX-License-Identifier: GPL-2.0-only /* * Backlight driver for ArcticSand ARC_X_C_0N_0N Devices * * Copyright 2016 ArcticSand, Inc. * Author : Brian Dodge */ #include #include #include #include #include #include enum arcxcnn_chip_id { ARC2C0608 }; /** * struct arcxcnn_platform_data * @name : Backlight driver name (NULL will use default) * @initial_brightness : initial value of backlight brightness * @leden : initial LED string enables, upper bit is global on/off * @led_config_0 : fading speed (period between intensity steps) * @led_config_1 : misc settings, see datasheet * @dim_freq : pwm dimming frequency if in pwm mode * @comp_config : misc config, see datasheet * @filter_config : RC/PWM filter config, see datasheet * @trim_config : full scale current trim, see datasheet */ struct arcxcnn_platform_data { const char *name; u16 initial_brightness; u8 leden; u8 led_config_0; u8 led_config_1; u8 dim_freq; u8 comp_config; u8 filter_config; u8 trim_config; }; #define ARCXCNN_CMD 0x00 /* Command Register */ #define ARCXCNN_CMD_STDBY 0x80 /* I2C Standby */ #define ARCXCNN_CMD_RESET 0x40 /* Reset */ #define ARCXCNN_CMD_BOOST 0x10 /* Boost */ #define ARCXCNN_CMD_OVP_MASK 0x0C /* --- Over Voltage Threshold */ #define ARCXCNN_CMD_OVP_XXV 0x0C /* Over Voltage Threshold */ #define ARCXCNN_CMD_OVP_20V 0x08 /* 20v Over Voltage Threshold */ #define ARCXCNN_CMD_OVP_24V 0x04 /* 24v Over Voltage Threshold */ #define ARCXCNN_CMD_OVP_31V 0x00 /* 31.4v Over Voltage Threshold */ #define ARCXCNN_CMD_EXT_COMP 0x01 /* part (0) or full (1) ext. comp */ #define ARCXCNN_CONFIG 0x01 /* Configuration */ #define ARCXCNN_STATUS1 0x02 /* Status 1 */ #define ARCXCNN_STATUS2 0x03 /* Status 2 */ #define ARCXCNN_FADECTRL 0x04 /* Fading Control */ #define ARCXCNN_ILED_CONFIG 0x05 /* ILED Configuration */ #define ARCXCNN_ILED_DIM_PWM 0x00 /* config dim mode pwm */ #define ARCXCNN_ILED_DIM_INT 0x04 /* config dim mode internal */ #define ARCXCNN_LEDEN 0x06 /* LED Enable Register */ #define ARCXCNN_LEDEN_ISETEXT 0x80 /* Full-scale current set extern */ #define ARCXCNN_LEDEN_MASK 0x3F /* LED string enables mask */ #define ARCXCNN_LEDEN_BITS 0x06 /* Bits of LED string enables */ #define ARCXCNN_LEDEN_LED1 0x01 #define ARCXCNN_LEDEN_LED2 0x02 #define ARCXCNN_LEDEN_LED3 0x04 #define ARCXCNN_LEDEN_LED4 0x08 #define ARCXCNN_LEDEN_LED5 0x10 #define ARCXCNN_LEDEN_LED6 0x20 #define ARCXCNN_WLED_ISET_LSB 0x07 /* LED ISET LSB (in upper nibble) */ #define ARCXCNN_WLED_ISET_LSB_SHIFT 0x04 /* ISET LSB Left Shift */ #define ARCXCNN_WLED_ISET_MSB 0x08 /* LED ISET MSB (8 bits) */ #define ARCXCNN_DIMFREQ 0x09 #define ARCXCNN_COMP_CONFIG 0x0A #define ARCXCNN_FILT_CONFIG 0x0B #define ARCXCNN_IMAXTUNE 0x0C #define ARCXCNN_ID_MSB 0x1E #define ARCXCNN_ID_LSB 0x1F #define MAX_BRIGHTNESS 4095 #define INIT_BRIGHT 60 struct arcxcnn { struct i2c_client *client; struct backlight_device *bl; struct device *dev; struct arcxcnn_platform_data *pdata; }; static int arcxcnn_update_field(struct arcxcnn *lp, u8 reg, u8 mask, u8 data) { int ret; u8 tmp; ret = i2c_smbus_read_byte_data(lp->client, reg); if (ret < 0) { dev_err(lp->dev, "failed to read 0x%.2x\n", reg); return ret; } tmp = (u8)ret; tmp &= ~mask; tmp |= data & mask; return i2c_smbus_write_byte_data(lp->client, reg, tmp); } static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness) { int ret; u8 val; /* lower nibble of brightness goes in upper nibble of LSB register */ val = (brightness & 0xF) << ARCXCNN_WLED_ISET_LSB_SHIFT; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_WLED_ISET_LSB, val); if (ret < 0) return ret; /* remaining 8 bits of brightness go in MSB register */ val = (brightness >> 4); return i2c_smbus_write_byte_data(lp->client, ARCXCNN_WLED_ISET_MSB, val); } static int arcxcnn_bl_update_status(struct backlight_device *bl) { struct arcxcnn *lp = bl_get_data(bl); u32 brightness = bl->props.brightness; int ret; if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) brightness = 0; ret = arcxcnn_set_brightness(lp, brightness); if (ret) return ret; /* set power-on/off/save modes */ return arcxcnn_update_field(lp, ARCXCNN_CMD, ARCXCNN_CMD_STDBY, (bl->props.power == 0) ? 0 : ARCXCNN_CMD_STDBY); } static const struct backlight_ops arcxcnn_bl_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = arcxcnn_bl_update_status, }; static int arcxcnn_backlight_register(struct arcxcnn *lp) { struct backlight_properties *props; const char *name = lp->pdata->name ? : "arctic_bl"; props = devm_kzalloc(lp->dev, sizeof(*props), GFP_KERNEL); if (!props) return -ENOMEM; props->type = BACKLIGHT_PLATFORM; props->max_brightness = MAX_BRIGHTNESS; if (lp->pdata->initial_brightness > props->max_brightness) lp->pdata->initial_brightness = props->max_brightness; props->brightness = lp->pdata->initial_brightness; lp->bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp, &arcxcnn_bl_ops, props); return PTR_ERR_OR_ZERO(lp->bl); } static void arcxcnn_parse_dt(struct arcxcnn *lp) { struct device *dev = lp->dev; struct device_node *node = dev->of_node; u32 prog_val, num_entry, entry, sources[ARCXCNN_LEDEN_BITS]; int ret; /* device tree entry isn't required, defaults are OK */ if (!node) return; ret = of_property_read_string(node, "label", &lp->pdata->name); if (ret < 0) lp->pdata->name = NULL; ret = of_property_read_u32(node, "default-brightness", &prog_val); if (ret == 0) lp->pdata->initial_brightness = prog_val; ret = of_property_read_u32(node, "arc,led-config-0", &prog_val); if (ret == 0) lp->pdata->led_config_0 = (u8)prog_val; ret = of_property_read_u32(node, "arc,led-config-1", &prog_val); if (ret == 0) lp->pdata->led_config_1 = (u8)prog_val; ret = of_property_read_u32(node, "arc,dim-freq", &prog_val); if (ret == 0) lp->pdata->dim_freq = (u8)prog_val; ret = of_property_read_u32(node, "arc,comp-config", &prog_val); if (ret == 0) lp->pdata->comp_config = (u8)prog_val; ret = of_property_read_u32(node, "arc,filter-config", &prog_val); if (ret == 0) lp->pdata->filter_config = (u8)prog_val; ret = of_property_read_u32(node, "arc,trim-config", &prog_val); if (ret == 0) lp->pdata->trim_config = (u8)prog_val; ret = of_property_count_u32_elems(node, "led-sources"); if (ret < 0) { lp->pdata->leden = ARCXCNN_LEDEN_MASK; /* all on is default */ } else { num_entry = ret; if (num_entry > ARCXCNN_LEDEN_BITS) num_entry = ARCXCNN_LEDEN_BITS; ret = of_property_read_u32_array(node, "led-sources", sources, num_entry); if (ret < 0) { dev_err(dev, "led-sources node is invalid.\n"); return; } lp->pdata->leden = 0; /* for each enable in source, set bit in led enable */ for (entry = 0; entry < num_entry; entry++) { u8 onbit = 1 << sources[entry]; lp->pdata->leden |= onbit; } } } static int arcxcnn_probe(struct i2c_client *cl, const struct i2c_device_id *id) { struct arcxcnn *lp; int ret; if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -EIO; lp = devm_kzalloc(&cl->dev, sizeof(*lp), GFP_KERNEL); if (!lp) return -ENOMEM; lp->client = cl; lp->dev = &cl->dev; lp->pdata = dev_get_platdata(&cl->dev); /* reset the device */ ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_CMD, ARCXCNN_CMD_RESET); if (ret) goto probe_err; if (!lp->pdata) { lp->pdata = devm_kzalloc(lp->dev, sizeof(*lp->pdata), GFP_KERNEL); if (!lp->pdata) return -ENOMEM; /* Setup defaults based on power-on defaults */ lp->pdata->name = NULL; lp->pdata->initial_brightness = INIT_BRIGHT; lp->pdata->leden = ARCXCNN_LEDEN_MASK; lp->pdata->led_config_0 = i2c_smbus_read_byte_data( lp->client, ARCXCNN_FADECTRL); lp->pdata->led_config_1 = i2c_smbus_read_byte_data( lp->client, ARCXCNN_ILED_CONFIG); /* insure dim mode is not default pwm */ lp->pdata->led_config_1 |= ARCXCNN_ILED_DIM_INT; lp->pdata->dim_freq = i2c_smbus_read_byte_data( lp->client, ARCXCNN_DIMFREQ); lp->pdata->comp_config = i2c_smbus_read_byte_data( lp->client, ARCXCNN_COMP_CONFIG); lp->pdata->filter_config = i2c_smbus_read_byte_data( lp->client, ARCXCNN_FILT_CONFIG); lp->pdata->trim_config = i2c_smbus_read_byte_data( lp->client, ARCXCNN_IMAXTUNE); if (IS_ENABLED(CONFIG_OF)) arcxcnn_parse_dt(lp); } i2c_set_clientdata(cl, lp); /* constrain settings to what is possible */ if (lp->pdata->initial_brightness > MAX_BRIGHTNESS) lp->pdata->initial_brightness = MAX_BRIGHTNESS; /* set initial brightness */ ret = arcxcnn_set_brightness(lp, lp->pdata->initial_brightness); if (ret) goto probe_err; /* set other register values directly */ ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FADECTRL, lp->pdata->led_config_0); if (ret) goto probe_err; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_ILED_CONFIG, lp->pdata->led_config_1); if (ret) goto probe_err; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_DIMFREQ, lp->pdata->dim_freq); if (ret) goto probe_err; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_COMP_CONFIG, lp->pdata->comp_config); if (ret) goto probe_err; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FILT_CONFIG, lp->pdata->filter_config); if (ret) goto probe_err; ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_IMAXTUNE, lp->pdata->trim_config); if (ret) goto probe_err; /* set initial LED Enables */ arcxcnn_update_field(lp, ARCXCNN_LEDEN, ARCXCNN_LEDEN_MASK, lp->pdata->leden); ret = arcxcnn_backlight_register(lp); if (ret) goto probe_register_err; backlight_update_status(lp->bl); return 0; probe_register_err: dev_err(lp->dev, "failed to register backlight.\n"); probe_err: dev_err(lp->dev, "failure ret: %d\n", ret); return ret; } static void arcxcnn_remove(struct i2c_client *cl) { struct arcxcnn *lp = i2c_get_clientdata(cl); /* disable all strings (ignore errors) */ i2c_smbus_write_byte_data(lp->client, ARCXCNN_LEDEN, 0x00); /* reset the device (ignore errors) */ i2c_smbus_write_byte_data(lp->client, ARCXCNN_CMD, ARCXCNN_CMD_RESET); lp->bl->props.brightness = 0; backlight_update_status(lp->bl); } static const struct of_device_id arcxcnn_dt_ids[] = { { .compatible = "arc,arc2c0608" }, { } }; MODULE_DEVICE_TABLE(of, arcxcnn_dt_ids); static const struct i2c_device_id arcxcnn_ids[] = { {"arc2c0608", ARC2C0608}, { } }; MODULE_DEVICE_TABLE(i2c, arcxcnn_ids); static struct i2c_driver arcxcnn_driver = { .driver = { .name = "arcxcnn_bl", .of_match_table = of_match_ptr(arcxcnn_dt_ids), }, .probe = arcxcnn_probe, .remove = arcxcnn_remove, .id_table = arcxcnn_ids, }; module_i2c_driver(arcxcnn_driver); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Brian Dodge "); MODULE_DESCRIPTION("ARCXCNN Backlight driver");