leds: leds-mt6323: Add support for WLEDs and MT6332

Add basic code to turn on and off WLEDs and wire up MT6332 support
to take advantage of it.
This is a simple approach due to the aforementioned PMIC supporting
only on/off status so, at the time of writing, it is impossible for me
to validate more advanced functionality due to lack of hardware.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230601110813.2373764-9-angelogioacchino.delregno@collabora.com

diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
index 85b056f..e8fecfc 100644 (file)
--- a/drivers/leds/leds-mt6323.c
+++ b/drivers/leds/leds-mt6323.c
@@ -20,6 +20,11 @@
 #define RG_DRV_32K_CK_PDN              BIT(11)
 #define RG_DRV_32K_CK_PDN_MASK         BIT(11)
 
+/* 32K/1M/6M clock common for WLED device */
+#define RG_VWLED_1M_CK_PDN             BIT(0)
+#define RG_VWLED_32K_CK_PDN            BIT(12)
+#define RG_VWLED_6M_CK_PDN             BIT(13)
+
 /*
  * Register field for TOP_CKPDN2 to enable
  * individual clock for LED device.
@@ -71,7 +76,7 @@ struct mt6323_led {
        int                     id;
        struct mt6323_leds      *parent;
        struct led_classdev     cdev;
-       enum led_brightness     current_brightness;
+       unsigned int            current_brightness;
 };
 
 /**
@@ -84,6 +89,7 @@ struct mt6323_led {
  * @num_isink_con:     Number of ISINKx_CON registers
  * @isink_max_regs:    Number of ISINK[0..x] registers
  * @isink_en_ctrl:     Offset to ISINK_EN_CTRL register
+ * @iwled_en_ctrl:     Offset to IWLED_EN_CTRL register
  */
 struct mt6323_regs {
        const u16 *top_ckpdn;
@@ -94,18 +100,21 @@ struct mt6323_regs {
        u8 num_isink_con;
        u8 isink_max_regs;
        u16 isink_en_ctrl;
+       u16 iwled_en_ctrl;
 };
 
 /**
  * struct mt6323_hwspec - hardware specific parameters
  * @max_period:                Maximum period for all LEDs
  * @max_leds:          Maximum number of supported LEDs
+ * @max_wleds:         Maximum number of WLEDs
  * @max_brightness:    Maximum brightness for all LEDs
  * @unit_duty:         Steps of duty per period
  */
 struct mt6323_hwspec {
        u16 max_period;
        u8 max_leds;
+       u8 max_wleds;
        u16 max_brightness;
        u16 unit_duty;
 };
@@ -377,6 +386,117 @@ out:
        return ret;
 }
 
+static int mtk_wled_hw_on(struct led_classdev *cdev)
+{
+       struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
+       struct mt6323_leds *leds = led->parent;
+       const struct mt6323_regs *regs = leds->pdata->regs;
+       struct regmap *regmap = leds->hw->regmap;
+       int ret;
+
+       ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_32K_CK_PDN);
+       if (ret)
+               return ret;
+
+       ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_6M_CK_PDN);
+       if (ret)
+               return ret;
+
+       ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_1M_CK_PDN);
+       if (ret)
+               return ret;
+
+       usleep_range(5000, 6000);
+
+       /* Enable WLED channel pair */
+       ret = regmap_set_bits(regmap, regs->iwled_en_ctrl, BIT(led->id));
+       if (ret)
+               return ret;
+
+       ret = regmap_set_bits(regmap, regs->iwled_en_ctrl, BIT(led->id + 1));
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static int mtk_wled_hw_off(struct led_classdev *cdev)
+{
+       struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
+       struct mt6323_leds *leds = led->parent;
+       const struct mt6323_regs *regs = leds->pdata->regs;
+       struct regmap *regmap = leds->hw->regmap;
+       int ret;
+
+       ret = regmap_clear_bits(regmap, regs->iwled_en_ctrl, BIT(led->id + 1));
+       if (ret)
+               return ret;
+
+       ret = regmap_clear_bits(regmap, regs->iwled_en_ctrl, BIT(led->id));
+       if (ret)
+               return ret;
+
+       ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_32K_CK_PDN);
+       if (ret)
+               return ret;
+
+       ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_6M_CK_PDN);
+       if (ret)
+               return ret;
+
+       ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_1M_CK_PDN);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
+{
+       struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
+       struct mt6323_leds *leds = led->parent;
+       const struct mt6323_regs *regs = leds->pdata->regs;
+       struct regmap *regmap = leds->hw->regmap;
+       unsigned int status;
+       int ret;
+
+       ret = regmap_read(regmap, regs->iwled_en_ctrl, &status);
+       if (ret)
+               return 0;
+
+       /* Always two channels per WLED */
+       status &= BIT(led->id) | BIT(led->id + 1);
+
+       return status ? led->current_brightness : 0;
+}
+
+static int mt6323_wled_set_brightness(struct led_classdev *cdev,
+                                     unsigned int brightness)
+{
+       struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
+       struct mt6323_leds *leds = led->parent;
+       int ret = 0;
+
+       mutex_lock(&leds->lock);
+
+       if (brightness) {
+               if (!led->current_brightness)
+                       ret = mtk_wled_hw_on(cdev);
+               if (ret)
+                       goto out;
+       } else {
+               ret = mtk_wled_hw_off(cdev);
+               if (ret)
+                       goto out;
+       }
+
+       led->current_brightness = brightness;
+out:
+       mutex_unlock(&leds->lock);
+
+       return ret;
+}
+
 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
                                     struct device_node *np)
 {
@@ -416,6 +536,7 @@ static int mt6323_led_probe(struct platform_device *pdev)
        int ret;
        unsigned int status;
        u32 reg;
+       u8 max_leds;
 
        leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
        if (!leds)
@@ -426,6 +547,7 @@ static int mt6323_led_probe(struct platform_device *pdev)
        leds->pdata = device_get_match_data(dev);
        regs = leds->pdata->regs;
        spec = leds->pdata->spec;
+       max_leds = spec->max_leds + spec->max_wleds;
 
        /*
         * leds->hw points to the underlying bus for the register
@@ -445,6 +567,7 @@ static int mt6323_led_probe(struct platform_device *pdev)
 
        for_each_available_child_of_node(np, child) {
                struct led_init_data init_data = {};
+               bool is_wled;
 
                ret = of_property_read_u32(child, "reg", &reg);
                if (ret) {
@@ -452,7 +575,7 @@ static int mt6323_led_probe(struct platform_device *pdev)
                        goto put_child_node;
                }
 
-               if (reg >= spec->max_leds || reg >= MAX_SUPPORTED_LEDS ||
+               if (reg >= max_leds || reg >= MAX_SUPPORTED_LEDS ||
                    leds->led[reg]) {
                        dev_err(dev, "Invalid led reg %u\n", reg);
                        ret = -EINVAL;
@@ -465,14 +588,24 @@ static int mt6323_led_probe(struct platform_device *pdev)
                        goto put_child_node;
                }
 
+               is_wled = of_property_read_bool(child, "mediatek,is-wled");
+
                leds->led[reg] = led;
                leds->led[reg]->id = reg;
                leds->led[reg]->cdev.max_brightness = spec->max_brightness;
-               leds->led[reg]->cdev.brightness_set_blocking =
-                                       mt6323_led_set_brightness;
-               leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
-               leds->led[reg]->cdev.brightness_get =
-                                       mt6323_get_led_hw_brightness;
+
+               if (is_wled) {
+                       leds->led[reg]->cdev.brightness_set_blocking =
+                                               mt6323_wled_set_brightness;
+                       leds->led[reg]->cdev.brightness_get =
+                                               mt6323_get_wled_brightness;
+               } else {
+                       leds->led[reg]->cdev.brightness_set_blocking =
+                                               mt6323_led_set_brightness;
+                       leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
+                       leds->led[reg]->cdev.brightness_get =
+                                               mt6323_get_led_hw_brightness;
+               }
                leds->led[reg]->parent = leds;
 
                ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
@@ -540,6 +673,17 @@ static const struct mt6323_regs mt6331_registers = {
        .isink_en_ctrl = 0x43a,
 };
 
+static const struct mt6323_regs mt6332_registers = {
+       .top_ckpdn = (const u16[]){ 0x8094, 0x809a, 0x80a0 },
+       .num_top_ckpdn = 3,
+       .top_ckcon = (const u16[]){ 0x80a6, 0x80ac },
+       .num_top_ckcon = 2,
+       .isink_con = (const u16[]){ 0x8cd4 },
+       .num_isink_con = 1,
+       .isink_max_regs = 12, /* IWLED[0..2, 3..9] */
+       .iwled_en_ctrl = 0x8cda,
+};
+
 static const struct mt6323_hwspec mt6323_spec = {
        .max_period = 10000,
        .max_leds = 4,
@@ -547,6 +691,13 @@ static const struct mt6323_hwspec mt6323_spec = {
        .unit_duty = 3125,
 };
 
+static const struct mt6323_hwspec mt6332_spec = {
+       /* There are no LEDs in MT6332. Only WLEDs are present. */
+       .max_leds = 0,
+       .max_wleds = 1,
+       .max_brightness = 1024,
+};
+
 static const struct mt6323_data mt6323_pdata = {
        .regs = &mt6323_registers,
        .spec = &mt6323_spec,
@@ -557,9 +708,15 @@ static const struct mt6323_data mt6331_pdata = {
        .spec = &mt6323_spec,
 };
 
+static const struct mt6323_data mt6332_pdata = {
+       .regs = &mt6332_registers,
+       .spec = &mt6332_spec,
+};
+
 static const struct of_device_id mt6323_led_dt_match[] = {
        { .compatible = "mediatek,mt6323-led", .data = &mt6323_pdata},
        { .compatible = "mediatek,mt6331-led", .data = &mt6331_pdata },
+       { .compatible = "mediatek,mt6332-led", .data = &mt6332_pdata },
        {},
 };
 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);