// SPDX-License-Identifier: GPL-2.0-only /* * sky81452-backlight.c SKY81452 backlight driver * * Copyright 2014 Skyworks Solutions Inc. * Author : Gyungoh Yoo */ #include #include #include #include #include #include #include #include #include #include #include /* registers */ #define SKY81452_REG0 0x00 #define SKY81452_REG1 0x01 #define SKY81452_REG2 0x02 #define SKY81452_REG4 0x04 #define SKY81452_REG5 0x05 /* bit mask */ #define SKY81452_CS 0xFF #define SKY81452_EN 0x3F #define SKY81452_IGPW 0x20 #define SKY81452_PWMMD 0x10 #define SKY81452_PHASE 0x08 #define SKY81452_ILIM 0x04 #define SKY81452_VSHRT 0x03 #define SKY81452_OCP 0x80 #define SKY81452_OTMP 0x40 #define SKY81452_SHRT 0x3F #define SKY81452_OPN 0x3F #define SKY81452_DEFAULT_NAME "lcd-backlight" #define SKY81452_MAX_BRIGHTNESS (SKY81452_CS + 1) #define CTZ(b) __builtin_ctz(b) static int sky81452_bl_update_status(struct backlight_device *bd) { const struct sky81452_bl_platform_data *pdata = dev_get_platdata(bd->dev.parent); const unsigned int brightness = (unsigned int)bd->props.brightness; struct regmap *regmap = bl_get_data(bd); int ret; if (brightness > 0) { ret = regmap_write(regmap, SKY81452_REG0, brightness - 1); if (ret < 0) return ret; return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, pdata->enable << CTZ(SKY81452_EN)); } return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, 0); } static const struct backlight_ops sky81452_bl_ops = { .update_status = sky81452_bl_update_status, }; static ssize_t sky81452_bl_store_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct regmap *regmap = bl_get_data(to_backlight_device(dev)); unsigned long value; int ret; ret = kstrtoul(buf, 16, &value); if (ret < 0) return ret; ret = regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, value << CTZ(SKY81452_EN)); if (ret < 0) return ret; return count; } static ssize_t sky81452_bl_show_open_short(struct device *dev, struct device_attribute *attr, char *buf) { struct regmap *regmap = bl_get_data(to_backlight_device(dev)); unsigned int reg, value = 0; char tmp[3]; int i, ret; reg = !strcmp(attr->attr.name, "open") ? SKY81452_REG5 : SKY81452_REG4; ret = regmap_read(regmap, reg, &value); if (ret < 0) return ret; if (value & SKY81452_SHRT) { *buf = 0; for (i = 0; i < 6; i++) { if (value & 0x01) { sprintf(tmp, "%d ", i + 1); strcat(buf, tmp); } value >>= 1; } strcat(buf, "\n"); } else { strcpy(buf, "none\n"); } return strlen(buf); } static ssize_t sky81452_bl_show_fault(struct device *dev, struct device_attribute *attr, char *buf) { struct regmap *regmap = bl_get_data(to_backlight_device(dev)); unsigned int value = 0; int ret; ret = regmap_read(regmap, SKY81452_REG4, &value); if (ret < 0) return ret; *buf = 0; if (value & SKY81452_OCP) strcat(buf, "over-current "); if (value & SKY81452_OTMP) strcat(buf, "over-temperature"); strcat(buf, "\n"); return strlen(buf); } static DEVICE_ATTR(enable, S_IWGRP | S_IWUSR, NULL, sky81452_bl_store_enable); static DEVICE_ATTR(open, S_IRUGO, sky81452_bl_show_open_short, NULL); static DEVICE_ATTR(short, S_IRUGO, sky81452_bl_show_open_short, NULL); static DEVICE_ATTR(fault, S_IRUGO, sky81452_bl_show_fault, NULL); static struct attribute *sky81452_bl_attribute[] = { &dev_attr_enable.attr, &dev_attr_open.attr, &dev_attr_short.attr, &dev_attr_fault.attr, NULL }; static const struct attribute_group sky81452_bl_attr_group = { .attrs = sky81452_bl_attribute, }; #ifdef CONFIG_OF static struct sky81452_bl_platform_data *sky81452_bl_parse_dt( struct device *dev) { struct device_node *np = of_node_get(dev->of_node); struct sky81452_bl_platform_data *pdata; int num_entry; unsigned int sources[6]; int ret; if (!np) { dev_err(dev, "backlight node not found.\n"); return ERR_PTR(-ENODATA); } pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) { of_node_put(np); return ERR_PTR(-ENOMEM); } of_property_read_string(np, "name", &pdata->name); pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm"); pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode"); pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift"); pdata->gpiod_enable = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH); ret = of_property_count_u32_elems(np, "led-sources"); if (ret < 0) { pdata->enable = SKY81452_EN >> CTZ(SKY81452_EN); } else { num_entry = ret; if (num_entry > 6) num_entry = 6; ret = of_property_read_u32_array(np, "led-sources", sources, num_entry); if (ret < 0) { dev_err(dev, "led-sources node is invalid.\n"); return ERR_PTR(-EINVAL); } pdata->enable = 0; while (--num_entry) pdata->enable |= (1 << sources[num_entry]); } ret = of_property_read_u32(np, "skyworks,short-detection-threshold-volt", &pdata->short_detection_threshold); if (ret < 0) pdata->short_detection_threshold = 7; ret = of_property_read_u32(np, "skyworks,current-limit-mA", &pdata->boost_current_limit); if (ret < 0) pdata->boost_current_limit = 2750; of_node_put(np); return pdata; } #else static struct sky81452_bl_platform_data *sky81452_bl_parse_dt( struct device *dev) { return ERR_PTR(-EINVAL); } #endif static int sky81452_bl_init_device(struct regmap *regmap, struct sky81452_bl_platform_data *pdata) { unsigned int value; value = pdata->ignore_pwm ? SKY81452_IGPW : 0; value |= pdata->dpwm_mode ? SKY81452_PWMMD : 0; value |= pdata->phase_shift ? 0 : SKY81452_PHASE; if (pdata->boost_current_limit == 2300) value |= SKY81452_ILIM; else if (pdata->boost_current_limit != 2750) return -EINVAL; if (pdata->short_detection_threshold < 4 || pdata->short_detection_threshold > 7) return -EINVAL; value |= (7 - pdata->short_detection_threshold) << CTZ(SKY81452_VSHRT); return regmap_write(regmap, SKY81452_REG2, value); } static int sky81452_bl_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct regmap *regmap = dev_get_drvdata(dev->parent); struct sky81452_bl_platform_data *pdata = dev_get_platdata(dev); struct backlight_device *bd; struct backlight_properties props; const char *name; int ret; if (!pdata) { pdata = sky81452_bl_parse_dt(dev); if (IS_ERR(pdata)) return PTR_ERR(pdata); } ret = sky81452_bl_init_device(regmap, pdata); if (ret < 0) { dev_err(dev, "failed to initialize. err=%d\n", ret); return ret; } memset(&props, 0, sizeof(props)); props.max_brightness = SKY81452_MAX_BRIGHTNESS, name = pdata->name ? pdata->name : SKY81452_DEFAULT_NAME; bd = devm_backlight_device_register(dev, name, dev, regmap, &sky81452_bl_ops, &props); if (IS_ERR(bd)) { dev_err(dev, "failed to register. err=%ld\n", PTR_ERR(bd)); return PTR_ERR(bd); } platform_set_drvdata(pdev, bd); ret = sysfs_create_group(&bd->dev.kobj, &sky81452_bl_attr_group); if (ret < 0) { dev_err(dev, "failed to create attribute. err=%d\n", ret); return ret; } return ret; } static int sky81452_bl_remove(struct platform_device *pdev) { const struct sky81452_bl_platform_data *pdata = dev_get_platdata(&pdev->dev); struct backlight_device *bd = platform_get_drvdata(pdev); sysfs_remove_group(&bd->dev.kobj, &sky81452_bl_attr_group); bd->props.power = FB_BLANK_UNBLANK; bd->props.brightness = 0; backlight_update_status(bd); if (pdata->gpiod_enable) gpiod_set_value_cansleep(pdata->gpiod_enable, 0); return 0; } #ifdef CONFIG_OF static const struct of_device_id sky81452_bl_of_match[] = { { .compatible = "skyworks,sky81452-backlight", }, { } }; MODULE_DEVICE_TABLE(of, sky81452_bl_of_match); #endif static struct platform_driver sky81452_bl_driver = { .driver = { .name = "sky81452-backlight", .of_match_table = of_match_ptr(sky81452_bl_of_match), }, .probe = sky81452_bl_probe, .remove = sky81452_bl_remove, }; module_platform_driver(sky81452_bl_driver); MODULE_DESCRIPTION("Skyworks SKY81452 backlight driver"); MODULE_AUTHOR("Gyungoh Yoo "); MODULE_LICENSE("GPL v2");