diff mbox series

[v3,8/8] leds: leds-mt6323: Add support for WLEDs and MT6332

Message ID 20230601110813.2373764-9-angelogioacchino.delregno@collabora.com
State New
Headers show
Series Add support for MT6331 and MT6332 LEDs | expand

Commit Message

AngeloGioacchino Del Regno June 1, 2023, 11:08 a.m. UTC 
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>
---
 drivers/leds/leds-mt6323.c | 171 +++++++++++++++++++++++++++++++++++--
 1 file changed, 164 insertions(+), 7 deletions(-)

Comments

Lee Jones June 9, 2023, 6:44 a.m. UTC | #1 
On Thu, 01 Jun 2023, AngeloGioacchino Del Regno wrote:

> 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>
> ---
>  drivers/leds/leds-mt6323.c | 171 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 164 insertions(+), 7 deletions(-)

Applied, thanks
Nathan Chancellor June 21, 2023, 9:31 p.m. UTC | #2 
Hi Angelo,

On Thu, Jun 01, 2023 at 01:08:13PM +0200, AngeloGioacchino Del Regno wrote:
> 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>

After this patch as commit 9bb0a9e0626c ("leds: leds-mt6323: Add support
for WLEDs and MT6332") in -next, I see the following warnings from
clang, which are basically flagging potential kernel Control Flow
Integrity [1] violations that will be visible at runtime (this warning
is not enabled for the kernel yet but we would like it to be):

  drivers/leds/leds-mt6323.c:598:49: error: incompatible function pointer types assigning to 'int (*)(struct led_classdev *, enum led_brightness)' from 'int (struct led_classdev *, unsigned int)' [-Werror,-Wincompatible-function-pointer-types-strict]
    598 |                         leds->led[reg]->cdev.brightness_set_blocking =
        |                                                                      ^
    599 |                                                 mt6323_wled_set_brightness;
        |                                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/leds/leds-mt6323.c:600:40: error: incompatible function pointer types assigning to 'enum led_brightness (*)(struct led_classdev *)' from 'unsigned int (struct led_classdev *)' [-Werror,-Wincompatible-function-pointer-types-strict]
    600 |                         leds->led[reg]->cdev.brightness_get =
        |                                                             ^
    601 |                                                 mt6323_get_wled_brightness;
        |                                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
  2 errors generated.
AngeloGioacchino Del Regno June 22, 2023, 9:10 a.m. UTC | #3 
Il 21/06/23 23:31, Nathan Chancellor ha scritto:
> Hi Angelo,
> 
> On Thu, Jun 01, 2023 at 01:08:13PM +0200, AngeloGioacchino Del Regno wrote:
>> 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>
> 
> After this patch as commit 9bb0a9e0626c ("leds: leds-mt6323: Add support
> for WLEDs and MT6332") in -next, I see the following warnings from
> clang, which are basically flagging potential kernel Control Flow
> Integrity [1] violations that will be visible at runtime (this warning
> is not enabled for the kernel yet but we would like it to be):
> 
>    drivers/leds/leds-mt6323.c:598:49: error: incompatible function pointer types assigning to 'int (*)(struct led_classdev *, enum led_brightness)' from 'int (struct led_classdev *, unsigned int)' [-Werror,-Wincompatible-function-pointer-types-strict]
>      598 |                         leds->led[reg]->cdev.brightness_set_blocking =
>          |                                                                      ^
>      599 |                                                 mt6323_wled_set_brightness;
>          |                                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
>    drivers/leds/leds-mt6323.c:600:40: error: incompatible function pointer types assigning to 'enum led_brightness (*)(struct led_classdev *)' from 'unsigned int (struct led_classdev *)' [-Werror,-Wincompatible-function-pointer-types-strict]
>      600 |                         leds->led[reg]->cdev.brightness_get =
>          |                                                             ^
>      601 |                                                 mt6323_get_wled_brightness;
>          |                                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
>    2 errors generated.
> 
>  From what I can tell/understand, 'enum led_brightness' is obsolete and
> the value that is passed via ->brightness_set_blocking() is an 'unsigned
> int' as well but it seems 'enum led_brightness' is used as the parameter
> in a lot of different callback implementations, so the prototype cannot
> be easily updated without a lot of extra work. Is there any reason not
> to just do something like this to avoid this issue?
> 

I don't think that this would bring any issue to the table.

The rework will possibly be done globally, for all drivers, when time comes... so
feel free to send the proposed patch.

Thanks,
Angelo

> [1]: https://lwn.net/Articles/898040/
> 
> Cheers,
> Nathan
> 
> diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
> index e8fecfc2e90a..24f35bdb55fb 100644
> --- a/drivers/leds/leds-mt6323.c
> +++ b/drivers/leds/leds-mt6323.c
> @@ -76,7 +76,7 @@ struct mt6323_led {
>   	int			id;
>   	struct mt6323_leds	*parent;
>   	struct led_classdev	cdev;
> -	unsigned int		current_brightness;
> +	enum led_brightness	current_brightness;
>   };
>   
>   /**
> @@ -451,7 +451,7 @@ static int mtk_wled_hw_off(struct led_classdev *cdev)
>   	return 0;
>   }
>   
> -static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> +static enum led_brightness 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;
> @@ -471,7 +471,7 @@ static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
>   }
>   
>   static int mt6323_wled_set_brightness(struct led_classdev *cdev,
> -				      unsigned int brightness)
> +				      enum led_brightness brightness)
>   {
>   	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
>   	struct mt6323_leds *leds = led->parent;
diff mbox series

Patch

diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
index 85b056fcd94e..e8fecfc2e90a 100644
--- 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 @@  static int mt6323_led_set_brightness(struct led_classdev *cdev,
 	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);