diff options
Diffstat (limited to 'kernel/drivers/video/backlight/pm8941-wled.c')
| -rw-r--r-- | kernel/drivers/video/backlight/pm8941-wled.c | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/kernel/drivers/video/backlight/pm8941-wled.c b/kernel/drivers/video/backlight/pm8941-wled.c new file mode 100644 index 000000000..0b6d21955 --- /dev/null +++ b/kernel/drivers/video/backlight/pm8941-wled.c @@ -0,0 +1,432 @@ +/* Copyright (c) 2015, Sony Mobile Communications, AB. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only 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. + */ + +#include <linux/kernel.h> +#include <linux/backlight.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +/* From DT binding */ +#define PM8941_WLED_DEFAULT_BRIGHTNESS 2048 + +#define PM8941_WLED_REG_VAL_BASE 0x40 +#define PM8941_WLED_REG_VAL_MAX 0xFFF + +#define PM8941_WLED_REG_MOD_EN 0x46 +#define PM8941_WLED_REG_MOD_EN_BIT BIT(7) +#define PM8941_WLED_REG_MOD_EN_MASK BIT(7) + +#define PM8941_WLED_REG_SYNC 0x47 +#define PM8941_WLED_REG_SYNC_MASK 0x07 +#define PM8941_WLED_REG_SYNC_LED1 BIT(0) +#define PM8941_WLED_REG_SYNC_LED2 BIT(1) +#define PM8941_WLED_REG_SYNC_LED3 BIT(2) +#define PM8941_WLED_REG_SYNC_ALL 0x07 +#define PM8941_WLED_REG_SYNC_CLEAR 0x00 + +#define PM8941_WLED_REG_FREQ 0x4c +#define PM8941_WLED_REG_FREQ_MASK 0x0f + +#define PM8941_WLED_REG_OVP 0x4d +#define PM8941_WLED_REG_OVP_MASK 0x03 + +#define PM8941_WLED_REG_BOOST 0x4e +#define PM8941_WLED_REG_BOOST_MASK 0x07 + +#define PM8941_WLED_REG_SINK 0x4f +#define PM8941_WLED_REG_SINK_MASK 0xe0 +#define PM8941_WLED_REG_SINK_SHFT 0x05 + +/* Per-'string' registers below */ +#define PM8941_WLED_REG_STR_OFFSET 0x10 + +#define PM8941_WLED_REG_STR_MOD_EN_BASE 0x60 +#define PM8941_WLED_REG_STR_MOD_MASK BIT(7) +#define PM8941_WLED_REG_STR_MOD_EN BIT(7) + +#define PM8941_WLED_REG_STR_SCALE_BASE 0x62 +#define PM8941_WLED_REG_STR_SCALE_MASK 0x1f + +#define PM8941_WLED_REG_STR_MOD_SRC_BASE 0x63 +#define PM8941_WLED_REG_STR_MOD_SRC_MASK 0x01 +#define PM8941_WLED_REG_STR_MOD_SRC_INT 0x00 +#define PM8941_WLED_REG_STR_MOD_SRC_EXT 0x01 + +#define PM8941_WLED_REG_STR_CABC_BASE 0x66 +#define PM8941_WLED_REG_STR_CABC_MASK BIT(7) +#define PM8941_WLED_REG_STR_CABC_EN BIT(7) + +struct pm8941_wled_config { + u32 i_boost_limit; + u32 ovp; + u32 switch_freq; + u32 num_strings; + u32 i_limit; + bool cs_out_en; + bool ext_gen; + bool cabc_en; +}; + +struct pm8941_wled { + const char *name; + struct regmap *regmap; + u16 addr; + + struct pm8941_wled_config cfg; +}; + +static int pm8941_wled_update_status(struct backlight_device *bl) +{ + struct pm8941_wled *wled = bl_get_data(bl); + u16 val = bl->props.brightness; + u8 ctrl = 0; + int rc; + int i; + + if (bl->props.power != FB_BLANK_UNBLANK || + bl->props.fb_blank != FB_BLANK_UNBLANK || + bl->props.state & BL_CORE_FBBLANK) + val = 0; + + if (val != 0) + ctrl = PM8941_WLED_REG_MOD_EN_BIT; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_MOD_EN, + PM8941_WLED_REG_MOD_EN_MASK, ctrl); + if (rc) + return rc; + + for (i = 0; i < wled->cfg.num_strings; ++i) { + u8 v[2] = { val & 0xff, (val >> 8) & 0xf }; + + rc = regmap_bulk_write(wled->regmap, + wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i, + v, 2); + if (rc) + return rc; + } + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_SYNC, + PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL); + if (rc) + return rc; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_SYNC, + PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR); + return rc; +} + +static int pm8941_wled_setup(struct pm8941_wled *wled) +{ + int rc; + int i; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_OVP, + PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp); + if (rc) + return rc; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_BOOST, + PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit); + if (rc) + return rc; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_FREQ, + PM8941_WLED_REG_FREQ_MASK, wled->cfg.switch_freq); + if (rc) + return rc; + + if (wled->cfg.cs_out_en) { + u8 all = (BIT(wled->cfg.num_strings) - 1) + << PM8941_WLED_REG_SINK_SHFT; + + rc = regmap_update_bits(wled->regmap, + wled->addr + PM8941_WLED_REG_SINK, + PM8941_WLED_REG_SINK_MASK, all); + if (rc) + return rc; + } + + for (i = 0; i < wled->cfg.num_strings; ++i) { + u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i; + + rc = regmap_update_bits(wled->regmap, + addr + PM8941_WLED_REG_STR_MOD_EN_BASE, + PM8941_WLED_REG_STR_MOD_MASK, + PM8941_WLED_REG_STR_MOD_EN); + if (rc) + return rc; + + if (wled->cfg.ext_gen) { + rc = regmap_update_bits(wled->regmap, + addr + PM8941_WLED_REG_STR_MOD_SRC_BASE, + PM8941_WLED_REG_STR_MOD_SRC_MASK, + PM8941_WLED_REG_STR_MOD_SRC_EXT); + if (rc) + return rc; + } + + rc = regmap_update_bits(wled->regmap, + addr + PM8941_WLED_REG_STR_SCALE_BASE, + PM8941_WLED_REG_STR_SCALE_MASK, + wled->cfg.i_limit); + if (rc) + return rc; + + rc = regmap_update_bits(wled->regmap, + addr + PM8941_WLED_REG_STR_CABC_BASE, + PM8941_WLED_REG_STR_CABC_MASK, + wled->cfg.cabc_en ? + PM8941_WLED_REG_STR_CABC_EN : 0); + if (rc) + return rc; + } + + return 0; +} + +static const struct pm8941_wled_config pm8941_wled_config_defaults = { + .i_boost_limit = 3, + .i_limit = 20, + .ovp = 2, + .switch_freq = 5, + .num_strings = 0, + .cs_out_en = false, + .ext_gen = false, + .cabc_en = false, +}; + +struct pm8941_wled_var_cfg { + const u32 *values; + u32 (*fn)(u32); + int size; +}; + +static const u32 pm8941_wled_i_boost_limit_values[] = { + 105, 385, 525, 805, 980, 1260, 1400, 1680, +}; + +static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = { + .values = pm8941_wled_i_boost_limit_values, + .size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values), +}; + +static const u32 pm8941_wled_ovp_values[] = { + 35, 32, 29, 27, +}; + +static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = { + .values = pm8941_wled_ovp_values, + .size = ARRAY_SIZE(pm8941_wled_ovp_values), +}; + +static u32 pm8941_wled_num_strings_values_fn(u32 idx) +{ + return idx + 1; +} + +static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = { + .fn = pm8941_wled_num_strings_values_fn, + .size = 3, +}; + +static u32 pm8941_wled_switch_freq_values_fn(u32 idx) +{ + return 19200 / (2 * (1 + idx)); +} + +static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = { + .fn = pm8941_wled_switch_freq_values_fn, + .size = 16, +}; + +static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = { + .size = 26, +}; + +static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx) +{ + if (idx >= cfg->size) + return UINT_MAX; + if (cfg->fn) + return cfg->fn(idx); + if (cfg->values) + return cfg->values[idx]; + return idx; +} + +static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev) +{ + struct pm8941_wled_config *cfg = &wled->cfg; + u32 val; + int rc; + u32 c; + int i; + int j; + + const struct { + const char *name; + u32 *val_ptr; + const struct pm8941_wled_var_cfg *cfg; + } u32_opts[] = { + { + "qcom,current-boost-limit", + &cfg->i_boost_limit, + .cfg = &pm8941_wled_i_boost_limit_cfg, + }, + { + "qcom,current-limit", + &cfg->i_limit, + .cfg = &pm8941_wled_i_limit_cfg, + }, + { + "qcom,ovp", + &cfg->ovp, + .cfg = &pm8941_wled_ovp_cfg, + }, + { + "qcom,switching-freq", + &cfg->switch_freq, + .cfg = &pm8941_wled_switch_freq_cfg, + }, + { + "qcom,num-strings", + &cfg->num_strings, + .cfg = &pm8941_wled_num_strings_cfg, + }, + }; + const struct { + const char *name; + bool *val_ptr; + } bool_opts[] = { + { "qcom,cs-out", &cfg->cs_out_en, }, + { "qcom,ext-gen", &cfg->ext_gen, }, + { "qcom,cabc", &cfg->cabc_en, }, + }; + + rc = of_property_read_u32(dev->of_node, "reg", &val); + if (rc || val > 0xffff) { + dev_err(dev, "invalid IO resources\n"); + return rc ? rc : -EINVAL; + } + wled->addr = val; + + rc = of_property_read_string(dev->of_node, "label", &wled->name); + if (rc) + wled->name = dev->of_node->name; + + *cfg = pm8941_wled_config_defaults; + for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) { + rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val); + if (rc == -EINVAL) { + continue; + } else if (rc) { + dev_err(dev, "error reading '%s'\n", u32_opts[i].name); + return rc; + } + + c = UINT_MAX; + for (j = 0; c != val; j++) { + c = pm8941_wled_values(u32_opts[i].cfg, j); + if (c == UINT_MAX) { + dev_err(dev, "invalid value for '%s'\n", + u32_opts[i].name); + return -EINVAL; + } + } + + dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c); + *u32_opts[i].val_ptr = j; + } + + for (i = 0; i < ARRAY_SIZE(bool_opts); ++i) { + if (of_property_read_bool(dev->of_node, bool_opts[i].name)) + *bool_opts[i].val_ptr = true; + } + + cfg->num_strings = cfg->num_strings + 1; + + return 0; +} + +static const struct backlight_ops pm8941_wled_ops = { + .update_status = pm8941_wled_update_status, +}; + +static int pm8941_wled_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct backlight_device *bl; + struct pm8941_wled *wled; + struct regmap *regmap; + u32 val; + int rc; + + regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!regmap) { + dev_err(&pdev->dev, "Unable to get regmap\n"); + return -EINVAL; + } + + wled = devm_kzalloc(&pdev->dev, sizeof(*wled), GFP_KERNEL); + if (!wled) + return -ENOMEM; + + wled->regmap = regmap; + + rc = pm8941_wled_configure(wled, &pdev->dev); + if (rc) + return rc; + + rc = pm8941_wled_setup(wled); + if (rc) + return rc; + + val = PM8941_WLED_DEFAULT_BRIGHTNESS; + of_property_read_u32(pdev->dev.of_node, "default-brightness", &val); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.brightness = val; + props.max_brightness = PM8941_WLED_REG_VAL_MAX; + bl = devm_backlight_device_register(&pdev->dev, wled->name, + &pdev->dev, wled, + &pm8941_wled_ops, &props); + return PTR_ERR_OR_ZERO(bl); +}; + +static const struct of_device_id pm8941_wled_match_table[] = { + { .compatible = "qcom,pm8941-wled" }, + {} +}; +MODULE_DEVICE_TABLE(of, pm8941_wled_match_table); + +static struct platform_driver pm8941_wled_driver = { + .probe = pm8941_wled_probe, + .driver = { + .name = "pm8941-wled", + .of_match_table = pm8941_wled_match_table, + }, +}; + +module_platform_driver(pm8941_wled_driver); + +MODULE_DESCRIPTION("pm8941 wled driver"); +MODULE_LICENSE("GPL v2"); |