]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/commitdiff
backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c
authorKiran Gunda <kgunda@codeaurora.org>
Fri, 1 Nov 2019 06:26:57 +0000 (11:56 +0530)
committerLee Jones <lee.jones@linaro.org>
Fri, 1 Nov 2019 08:03:29 +0000 (08:03 +0000)
pm8941-wled.c driver is supporting the WLED peripheral
on pm8941. Rename it to qcom-wled.c so that it can support
WLED on multiple PMICs.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt [deleted file]
Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt [new file with mode: 0644]
drivers/video/backlight/Kconfig
drivers/video/backlight/Makefile
drivers/video/backlight/pm8941-wled.c [deleted file]
drivers/video/backlight/qcom-wled.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt b/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
deleted file mode 100644 (file)
index e5b294d..0000000
+++ /dev/null
@@ -1,42 +0,0 @@
-Binding for Qualcomm PM8941 WLED driver
-
-Required properties:
-- compatible: should be "qcom,pm8941-wled"
-- reg: slave address
-
-Optional properties:
-- default-brightness: brightness value on boot, value from: 0-4095
-       default: 2048
-- label: The name of the backlight device
-- qcom,cs-out: bool; enable current sink output
-- qcom,cabc: bool; enable content adaptive backlight control
-- qcom,ext-gen: bool; use externally generated modulator signal to dim
-- qcom,current-limit: mA; per-string current limit; value from 0 to 25
-       default: 20mA
-- qcom,current-boost-limit: mA; boost current limit; one of:
-       105, 385, 525, 805, 980, 1260, 1400, 1680
-       default: 805mA
-- qcom,switching-freq: kHz; switching frequency; one of:
-       600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371,
-       1600, 1920, 2400, 3200, 4800, 9600,
-       default: 1600kHz
-- qcom,ovp: V; Over-voltage protection limit; one of:
-       27, 29, 32, 35
-       default: 29V
-- qcom,num-strings: #; number of led strings attached; value from 1 to 3
-       default: 2
-
-Example:
-
-pm8941-wled@d800 {
-       compatible = "qcom,pm8941-wled";
-       reg = <0xd800>;
-       label = "backlight";
-
-       qcom,cs-out;
-       qcom,current-limit = <20>;
-       qcom,current-boost-limit = <805>;
-       qcom,switching-freq = <1600>;
-       qcom,ovp = <29>;
-       qcom,num-strings = <2>;
-};
diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
new file mode 100644 (file)
index 0000000..fb39e32
--- /dev/null
@@ -0,0 +1,42 @@
+Binding for Qualcomm Technologies, Inc. WLED driver
+
+Required properties:
+- compatible: should be "qcom,pm8941-wled"
+- reg: slave address
+
+Optional properties:
+- default-brightness: brightness value on boot, value from: 0-4095
+       default: 2048
+- label: The name of the backlight device
+- qcom,cs-out: bool; enable current sink output
+- qcom,cabc: bool; enable content adaptive backlight control
+- qcom,ext-gen: bool; use externally generated modulator signal to dim
+- qcom,current-limit: mA; per-string current limit; value from 0 to 25
+       default: 20mA
+- qcom,current-boost-limit: mA; boost current limit; one of:
+       105, 385, 525, 805, 980, 1260, 1400, 1680
+       default: 805mA
+- qcom,switching-freq: kHz; switching frequency; one of:
+       600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371,
+       1600, 1920, 2400, 3200, 4800, 9600,
+       default: 1600kHz
+- qcom,ovp: V; Over-voltage protection limit; one of:
+       27, 29, 32, 35
+       default: 29V
+- qcom,num-strings: #; number of led strings attached; value from 1 to 3
+       default: 2
+
+Example:
+
+pm8941-wled@d800 {
+       compatible = "qcom,pm8941-wled";
+       reg = <0xd800>;
+       label = "backlight";
+
+       qcom,cs-out;
+       qcom,current-limit = <20>;
+       qcom,current-boost-limit = <805>;
+       qcom,switching-freq = <1600>;
+       qcom,ovp = <29>;
+       qcom,num-strings = <2>;
+};
index d09396393724b6ec267e03fedf08c1df9dbe6121..403707a3e503b125ab4afe088babc9bef62bea81 100644 (file)
@@ -282,12 +282,12 @@ config BACKLIGHT_TOSA
          If you have an Sharp SL-6000 Zaurus say Y to enable a driver
          for its backlight
 
-config BACKLIGHT_PM8941_WLED
-       tristate "Qualcomm PM8941 WLED Driver"
+config BACKLIGHT_QCOM_WLED
+       tristate "Qualcomm PMIC WLED Driver"
        select REGMAP
        help
-         If you have the Qualcomm PM8941, say Y to enable a driver for the
-         WLED block.
+         If you have the Qualcomm PMIC, say Y to enable a driver for the
+         WLED block. Currently it supports PM8941 and PMI8998.
 
 config BACKLIGHT_SAHARA
        tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
index 63c507c07437dd576d0c7f2a0c2585fae8336c08..6f8777037c372ef1765add544096a8d042f743f6 100644 (file)
@@ -48,8 +48,8 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)         += omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_OT200)          += ot200_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)                += pandora_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)       += pcf50633-backlight.o
-obj-$(CONFIG_BACKLIGHT_PM8941_WLED)    += pm8941-wled.o
 obj-$(CONFIG_BACKLIGHT_PWM)            += pwm_bl.o
+obj-$(CONFIG_BACKLIGHT_QCOM_WLED)      += qcom-wled.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)         += kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_SKY81452)       += sky81452-backlight.o
 obj-$(CONFIG_BACKLIGHT_TOSA)           += tosa_bl.o
diff --git a/drivers/video/backlight/pm8941-wled.c b/drivers/video/backlight/pm8941-wled.c
deleted file mode 100644 (file)
index 82b8572..0000000
+++ /dev/null
@@ -1,424 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2015, Sony Mobile Communications, AB.
- */
-
-#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 = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
-
-       *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");
diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
new file mode 100644 (file)
index 0000000..82b8572
--- /dev/null
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2015, Sony Mobile Communications, AB.
+ */
+
+#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 = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
+
+       *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");