From: Courtney Cavin <[email protected]>

This adds support for the WLED ('White' LED) block on Qualcomm's
PM8941 PMICs.

Signed-off-by: Courtney Cavin <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
---

The details surrounding the OVP spike issue that Stephen brought up during v2
review is still unkown, the patches provided on codeaurora msm-3.10 can with
ease be implemented as an incremental patch on top of this.
As the severity doesn't seem to high (the fixes are not done on all active msm
branches), I'm sending out v3 instead of waiting for a conclusion.

Changes since v2:
- Fix of parser return value on error
- Dropped THIS_MODULE

Changes since v1:
- Replace enum blob with defines
- Merged wled_context and wled structs
- Some style updates

 drivers/leds/Kconfig            |   8 +
 drivers/leds/Makefile           |   1 +
 drivers/leds/leds-pm8941-wled.c | 446 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 455 insertions(+)
 create mode 100644 drivers/leds/leds-pm8941-wled.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a6c3d2f..901b21a 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -516,6 +516,14 @@ config LEDS_VERSATILE
          This option enabled support for the LEDs on the ARM Versatile
          and RealView boards. Say Y to enabled these.
 
+config LEDS_PM8941_WLED
+       tristate "LED support for the Qualcomm PM8941 WLED block"
+       depends on LEDS_CLASS
+       select REGMAP
+       help
+         This option enables support for the 'White' LED block
+         on Qualcomm PM8941 PMICs.
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"
 
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 1c65a19..4325e49 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_LEDS_BLINKM)             += leds-blinkm.o
 obj-$(CONFIG_LEDS_SYSCON)              += leds-syscon.o
 obj-$(CONFIG_LEDS_VERSATILE)           += leds-versatile.o
 obj-$(CONFIG_LEDS_MENF21BMC)           += leds-menf21bmc.o
+obj-$(CONFIG_LEDS_PM8941_WLED)         += leds-pm8941-wled.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)          += leds-dac124s085.o
diff --git a/drivers/leds/leds-pm8941-wled.c b/drivers/leds/leds-pm8941-wled.c
new file mode 100644
index 0000000..9bf7358
--- /dev/null
+++ b/drivers/leds/leds-pm8941-wled.c
@@ -0,0 +1,446 @@
+/* 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/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+#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 {
+       struct regmap *regmap;
+       u16 addr;
+
+       struct led_classdev cdev;
+
+       struct pm8941_wled_config cfg;
+};
+
+static int pm8941_wled_set(struct led_classdev *cdev,
+                          enum led_brightness value)
+{
+       struct pm8941_wled *wled;
+       u8 ctrl = 0;
+       u16 val;
+       int rc;
+       int i;
+
+       wled = container_of(cdev, struct pm8941_wled, cdev);
+
+       if (value != 0)
+               ctrl = PM8941_WLED_REG_MOD_EN_BIT;
+
+       val = value * PM8941_WLED_REG_VAL_MAX / LED_FULL;
+
+       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 void pm8941_wled_set_brightness(struct led_classdev *cdev,
+                                      enum led_brightness value)
+{
+       if (pm8941_wled_set(cdev, value)) {
+               dev_err(cdev->dev, "Unable to set brightness\n");
+               return;
+       }
+       cdev->brightness = value;
+}
+
+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->cdev.name);
+       if (rc)
+               wled->cdev.name = dev->of_node->name;
+
+       wled->cdev.default_trigger = of_get_property(dev->of_node,
+                       "linux,default-trigger", NULL);
+
+       *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 int pm8941_wled_probe(struct platform_device *pdev)
+{
+       struct pm8941_wled *wled;
+       struct regmap *regmap;
+       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;
+
+       wled->cdev.brightness_set = pm8941_wled_set_brightness;
+
+       rc = led_classdev_register(&pdev->dev, &wled->cdev);
+       if (rc)
+               return rc;
+
+       platform_set_drvdata(pdev, wled);
+
+       return 0;
+};
+
+static int pm8941_wled_remove(struct platform_device *pdev)
+{
+       struct pm8941_wled *wled;
+
+       wled = platform_get_drvdata(pdev);
+       led_classdev_unregister(&wled->cdev);
+
+       return 0;
+}
+
+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,
+       .remove = pm8941_wled_remove,
+       .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");
+MODULE_ALIAS("platform:pm8941-wled");
-- 
1.9.1

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