leds: add Qualcomm PM8941 WLED driver
authorCourtney Cavin <courtney.cavin@sonymobile.com>
Thu, 12 Mar 2015 15:47:08 +0000 (08:47 -0700)
committerBryan Wu <cooloney@gmail.com>
Mon, 30 Mar 2015 18:55:49 +0000 (11:55 -0700)
This adds support for the WLED ('White' LED) block on Qualcomm's
PM8941 PMICs.

(cooloney@gmail.com: remove unneeded semicolon)

Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-pm8941-wled.c [new file with mode: 0644]

index 25b320d64e2609cfa1380e316ae7fee74f1e9cbd..966b9605f5f0660cf347acfdf012b1d2d303fe8a 100644 (file)
@@ -526,6 +526,14 @@ 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"
 
index cbba921b6f1c48a2dbfca3d4d4a47d49419c65e1..bf4609338e1047fee8119d690c376a31a0eb9074 100644 (file)
@@ -58,6 +58,7 @@ 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 (file)
index 0000000..bf64a59
--- /dev/null
@@ -0,0 +1,435 @@
+/* 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 = devm_led_classdev_register(&pdev->dev, &wled->cdev);
+       if (rc)
+               return rc;
+
+       platform_set_drvdata(pdev, wled);
+
+       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,
+       .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");