diff mbox

[DPU,2/2] drm/panel: add backlight control support for truly panel

Message ID 1523084813-858-2-git-send-email-abhinavk@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Abhinav Kumar April 7, 2018, 7:06 a.m. UTC
Register truly panel as a backlight led device and
provide methods to control its backlight operation.

Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
---
 drivers/gpu/drm/panel/panel-truly-dual-dsi.c | 96 +++++++++++++++++++++++++++-
 1 file changed, 94 insertions(+), 2 deletions(-)

Comments

Sean Paul April 13, 2018, 8:46 p.m. UTC | #1
On Sat, Apr 07, 2018 at 12:06:53AM -0700, Abhinav Kumar wrote:
> Register truly panel as a backlight led device and
> provide methods to control its backlight operation.
> 
> Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
> ---
>  drivers/gpu/drm/panel/panel-truly-dual-dsi.c | 96 +++++++++++++++++++++++++++-
>  1 file changed, 94 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
> index 47891ee..5d0ef90 100644
> --- a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
> +++ b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
> @@ -14,6 +14,7 @@
>  #include <linux/gpio/consumer.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/pinctrl/consumer.h>
> +#include <linux/leds.h>

Includes should be alphabetical.

>  
>  #include <video/mipi_display.h>
>  #include <video/of_videomode.h>
> @@ -23,6 +24,9 @@
>  #include <drm/drm_panel.h>
>  #include <drm/drm_mipi_dsi.h>
>  
> +#define BL_NODE_NAME_SIZE 32
> +#define PRIM_DISPLAY_NODE 0
> +
>  struct truly_wqxga {
>  	struct device *dev;
>  	struct drm_panel panel;
> @@ -33,6 +37,8 @@ struct truly_wqxga {
>  	struct gpio_desc *mode_gpio;
>  
>  	struct backlight_device *backlight;
> +	/* WLED params */
> +	struct led_trigger *wled;
>  	struct videomode vm;
>  
>  	struct mipi_dsi_device *dsi[2];
> @@ -447,6 +453,83 @@ static void truly_wqxga_panel_del(struct truly_wqxga *ctx)
>  		put_device(&ctx->dsi[1]->dev);
>  }
>  
> +static int truly_backlight_device_update_status(struct backlight_device *bd)
> +{
> +	int brightness;
> +	int max_brightness;
> +	int rc = 0;
> +
extra line

> +	struct truly_wqxga *ctx = dev_get_drvdata(&bd->dev);
> +
> +	brightness = bd->props.brightness;
> +	max_brightness = bd->props.max_brightness;
> +
> +	if ((bd->props.power != FB_BLANK_UNBLANK) ||
> +		(bd->props.state & BL_CORE_FBBLANK) ||
> +		  (bd->props.state & BL_CORE_SUSPENDED))
> +		brightness = 0;
> +
> +	if (brightness > max_brightness)
> +		brightness = max_brightness;
> +
> +	/* Need to check WLED driver capability upstream */
> +	if (ctx && ctx->wled)

ctx can't be NULL, so no need to check for that. And if ctx->wled is null, it
doesn't seem like this function will do anything. So how about just not
registering the backlight if wled == NULL (if that's possible).

> +		led_trigger_event(ctx->wled, brightness);
> +
> +	return rc;
> +}
> +
> +static int truly_backlight_device_get_brightness(struct backlight_device *bd)
> +{
> +	return bd->props.brightness;
> +}
> +
> +static const struct backlight_ops truly_backlight_device_ops = {
> +	.update_status = truly_backlight_device_update_status,
> +	.get_brightness = truly_backlight_device_get_brightness,
> +};
> +
> +static int truly_backlight_setup(struct truly_wqxga *ctx)
> +{
> +	struct backlight_properties props;
> +	char bl_node_name[BL_NODE_NAME_SIZE];
> +
> +	if (!ctx) {
> +		dev_err(ctx->dev, "invalid context\n");
> +		return -EINVAL;
> +	}

This can't happen.

> +
> +	if (!ctx->backlight) {
> +		memset(&props, 0, sizeof(props));
> +		props.type = BACKLIGHT_RAW;
> +		props.power = FB_BLANK_UNBLANK;
> +		props.max_brightness = 4096;
> +
> +		snprintf(bl_node_name, BL_NODE_NAME_SIZE, "panel%u-backlight",
> +				 PRIM_DISPLAY_NODE);

Given that PRIM_DISPLAY_NODE is always 0, this seems like overkill for a pretty
generic name "panel0-backlight". So let's just call it "truly_backlight" in the
register call.

> +
> +		ctx->backlight =  backlight_device_register(bl_node_name,
> +				ctx->dev, ctx,
> +				&truly_backlight_device_ops, &props);
> +
> +		if (IS_ERR_OR_NULL(ctx->backlight)) {
> +			pr_err("Failed to register backlight\n");
> +			ctx->backlight = NULL;
> +			return -ENODEV;
> +		}
> +
> +		/* Register with the LED driver interface */
> +		led_trigger_register_simple("bkl-trigger", &ctx->wled);
> +
> +		if (!ctx->wled) {
> +			pr_err("backlight led registration failed\n");
> +			return -ENODEV;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
>  {
>  	struct device *dev = &dsi->dev;
> @@ -466,10 +549,11 @@ static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
>  		secondary = of_find_mipi_dsi_device_by_node(np);
>  		of_node_put(np);
>  
> +		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> +

Why move this?

>  		if (!secondary)
>  			return -EPROBE_DEFER;
>  
> -		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>  		if (!ctx) {
>  			put_device(&secondary->dev);
>  			return -ENOMEM;
> @@ -485,6 +569,12 @@ static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
>  			put_device(&secondary->dev);
>  			return ret;
>  		}
> +
> +		ret = truly_backlight_setup(ctx);
> +		if (ret) {
> +			put_device(&secondary->dev);
> +			return ret;
> +		}
>  	}
>  
>  	ret = mipi_dsi_attach(dsi);
> @@ -504,8 +594,10 @@ static int truly_wqxga_remove(struct mipi_dsi_device *dsi)
>  	mipi_dsi_detach(dsi);
>  
>  	/* delete panel only for the DSI1 interface */
> -	if (ctx)
> +	if (ctx) {
>  		truly_wqxga_panel_del(ctx);
> +		kfree(ctx);
> +	}
>  
>  	return 0;
>  }
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
Abhinav Kumar April 13, 2018, 8:59 p.m. UTC | #2
Hi Sean

Thanks for the comments.

Some replies inline.

On 2018-04-13 13:46, Sean Paul wrote:
> On Sat, Apr 07, 2018 at 12:06:53AM -0700, Abhinav Kumar wrote:
>> Register truly panel as a backlight led device and
>> provide methods to control its backlight operation.
>> 
>> Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
>> ---
>>  drivers/gpu/drm/panel/panel-truly-dual-dsi.c | 96 
>> +++++++++++++++++++++++++++-
>>  1 file changed, 94 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c 
>> b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
>> index 47891ee..5d0ef90 100644
>> --- a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
>> +++ b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
>> @@ -14,6 +14,7 @@
>>  #include <linux/gpio/consumer.h>
>>  #include <linux/regulator/consumer.h>
>>  #include <linux/pinctrl/consumer.h>
>> +#include <linux/leds.h>
> 
> Includes should be alphabetical.
[Abhinav] Ok, will take care of this in v2.
> 
>> 
>>  #include <video/mipi_display.h>
>>  #include <video/of_videomode.h>
>> @@ -23,6 +24,9 @@
>>  #include <drm/drm_panel.h>
>>  #include <drm/drm_mipi_dsi.h>
>> 
>> +#define BL_NODE_NAME_SIZE 32
>> +#define PRIM_DISPLAY_NODE 0
>> +
>>  struct truly_wqxga {
>>  	struct device *dev;
>>  	struct drm_panel panel;
>> @@ -33,6 +37,8 @@ struct truly_wqxga {
>>  	struct gpio_desc *mode_gpio;
>> 
>>  	struct backlight_device *backlight;
>> +	/* WLED params */
>> +	struct led_trigger *wled;
>>  	struct videomode vm;
>> 
>>  	struct mipi_dsi_device *dsi[2];
>> @@ -447,6 +453,83 @@ static void truly_wqxga_panel_del(struct 
>> truly_wqxga *ctx)
>>  		put_device(&ctx->dsi[1]->dev);
>>  }
>> 
>> +static int truly_backlight_device_update_status(struct 
>> backlight_device *bd)
>> +{
>> +	int brightness;
>> +	int max_brightness;
>> +	int rc = 0;
>> +
> extra line
> 
[Abhinav] Ok, will remove it in v2.

>> +	struct truly_wqxga *ctx = dev_get_drvdata(&bd->dev);
>> +
>> +	brightness = bd->props.brightness;
>> +	max_brightness = bd->props.max_brightness;
>> +
>> +	if ((bd->props.power != FB_BLANK_UNBLANK) ||
>> +		(bd->props.state & BL_CORE_FBBLANK) ||
>> +		  (bd->props.state & BL_CORE_SUSPENDED))
>> +		brightness = 0;
>> +
>> +	if (brightness > max_brightness)
>> +		brightness = max_brightness;
>> +
>> +	/* Need to check WLED driver capability upstream */
>> +	if (ctx && ctx->wled)
> 
> ctx can't be NULL, so no need to check for that. And if ctx->wled is 
> null, it
> doesn't seem like this function will do anything. So how about just not
> registering the backlight if wled == NULL (if that's possible).
[Abhinav] Yes, will remove the NULL check.
We are registering the backlight in the backlight_setup(), this was more 
of
an additional check, to make sure ctx->wled is present before we 
trigger.
Not sure if we should register again here.
> 
>> +		led_trigger_event(ctx->wled, brightness);
>> +
>> +	return rc;
>> +}
>> +
>> +static int truly_backlight_device_get_brightness(struct 
>> backlight_device *bd)
>> +{
>> +	return bd->props.brightness;
>> +}
>> +
>> +static const struct backlight_ops truly_backlight_device_ops = {
>> +	.update_status = truly_backlight_device_update_status,
>> +	.get_brightness = truly_backlight_device_get_brightness,
>> +};
>> +
>> +static int truly_backlight_setup(struct truly_wqxga *ctx)
>> +{
>> +	struct backlight_properties props;
>> +	char bl_node_name[BL_NODE_NAME_SIZE];
>> +
>> +	if (!ctx) {
>> +		dev_err(ctx->dev, "invalid context\n");
>> +		return -EINVAL;
>> +	}
> 
> This can't happen.
[Abhinav] Will remove it.
> 
>> +
>> +	if (!ctx->backlight) {
>> +		memset(&props, 0, sizeof(props));
>> +		props.type = BACKLIGHT_RAW;
>> +		props.power = FB_BLANK_UNBLANK;
>> +		props.max_brightness = 4096;
>> +
>> +		snprintf(bl_node_name, BL_NODE_NAME_SIZE, "panel%u-backlight",
>> +				 PRIM_DISPLAY_NODE);
> 
> Given that PRIM_DISPLAY_NODE is always 0, this seems like overkill for 
> a pretty
> generic name "panel0-backlight". So let's just call it 
> "truly_backlight" in the
> register call.
> 
[Abhinav] The reason for keeping it "panel0-backlight" is because 
userspace is using
this node name to write the backlight. Changing the name will need more 
changes in our
userspace.

>> +
>> +		ctx->backlight =  backlight_device_register(bl_node_name,
>> +				ctx->dev, ctx,
>> +				&truly_backlight_device_ops, &props);
>> +
>> +		if (IS_ERR_OR_NULL(ctx->backlight)) {
>> +			pr_err("Failed to register backlight\n");
>> +			ctx->backlight = NULL;
>> +			return -ENODEV;
>> +		}
>> +
>> +		/* Register with the LED driver interface */
>> +		led_trigger_register_simple("bkl-trigger", &ctx->wled);
>> +
>> +		if (!ctx->wled) {
>> +			pr_err("backlight led registration failed\n");
>> +			return -ENODEV;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
>>  {
>>  	struct device *dev = &dsi->dev;
>> @@ -466,10 +549,11 @@ static int truly_wqxga_probe(struct 
>> mipi_dsi_device *dsi)
>>  		secondary = of_find_mipi_dsi_device_by_node(np);
>>  		of_node_put(np);
>> 
>> +		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> +
> 
> Why move this?
[Abhinav] Thanks for catching this, yes not required.
Will move it back.
> 
>>  		if (!secondary)
>>  			return -EPROBE_DEFER;
>> 
>> -		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>>  		if (!ctx) {
>>  			put_device(&secondary->dev);
>>  			return -ENOMEM;
>> @@ -485,6 +569,12 @@ static int truly_wqxga_probe(struct 
>> mipi_dsi_device *dsi)
>>  			put_device(&secondary->dev);
>>  			return ret;
>>  		}
>> +
>> +		ret = truly_backlight_setup(ctx);
>> +		if (ret) {
>> +			put_device(&secondary->dev);
>> +			return ret;
>> +		}
>>  	}
>> 
>>  	ret = mipi_dsi_attach(dsi);
>> @@ -504,8 +594,10 @@ static int truly_wqxga_remove(struct 
>> mipi_dsi_device *dsi)
>>  	mipi_dsi_detach(dsi);
>> 
>>  	/* delete panel only for the DSI1 interface */
>> -	if (ctx)
>> +	if (ctx) {
>>  		truly_wqxga_panel_del(ctx);
>> +		kfree(ctx);
>> +	}
>> 
>>  	return 0;
>>  }
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project
>> 
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Sean Paul April 16, 2018, 5 p.m. UTC | #3
On Fri, Apr 13, 2018 at 01:59:29PM -0700, abhinavk@codeaurora.org wrote:
> Hi Sean
> 
> Thanks for the comments.
> 
> Some replies inline.
> 
> On 2018-04-13 13:46, Sean Paul wrote:
> > On Sat, Apr 07, 2018 at 12:06:53AM -0700, Abhinav Kumar wrote:
> > > Register truly panel as a backlight led device and
> > > provide methods to control its backlight operation.
> > > 
> > > Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
> > > ---

<snip />

> > > +	if (!ctx->backlight) {
> > > +		memset(&props, 0, sizeof(props));
> > > +		props.type = BACKLIGHT_RAW;
> > > +		props.power = FB_BLANK_UNBLANK;
> > > +		props.max_brightness = 4096;
> > > +
> > > +		snprintf(bl_node_name, BL_NODE_NAME_SIZE, "panel%u-backlight",
> > > +				 PRIM_DISPLAY_NODE);
> > 
> > Given that PRIM_DISPLAY_NODE is always 0, this seems like overkill for a
> > pretty
> > generic name "panel0-backlight". So let's just call it "truly_backlight"
> > in the
> > register call.
> > 
> [Abhinav] The reason for keeping it "panel0-backlight" is because userspace
> is using
> this node name to write the backlight. Changing the name will need more
> changes in our
> userspace.
> 

Unless the userspace is opensource (I'm guessing it's not?), that's not
something we need to code around. It sounds like this is mostly a moot point
given Bjorn's comments on the v2.

Sean

<snip />
diff mbox

Patch

diff --git a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
index 47891ee..5d0ef90 100644
--- a/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
+++ b/drivers/gpu/drm/panel/panel-truly-dual-dsi.c
@@ -14,6 +14,7 @@ 
 #include <linux/gpio/consumer.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/leds.h>
 
 #include <video/mipi_display.h>
 #include <video/of_videomode.h>
@@ -23,6 +24,9 @@ 
 #include <drm/drm_panel.h>
 #include <drm/drm_mipi_dsi.h>
 
+#define BL_NODE_NAME_SIZE 32
+#define PRIM_DISPLAY_NODE 0
+
 struct truly_wqxga {
 	struct device *dev;
 	struct drm_panel panel;
@@ -33,6 +37,8 @@  struct truly_wqxga {
 	struct gpio_desc *mode_gpio;
 
 	struct backlight_device *backlight;
+	/* WLED params */
+	struct led_trigger *wled;
 	struct videomode vm;
 
 	struct mipi_dsi_device *dsi[2];
@@ -447,6 +453,83 @@  static void truly_wqxga_panel_del(struct truly_wqxga *ctx)
 		put_device(&ctx->dsi[1]->dev);
 }
 
+static int truly_backlight_device_update_status(struct backlight_device *bd)
+{
+	int brightness;
+	int max_brightness;
+	int rc = 0;
+
+	struct truly_wqxga *ctx = dev_get_drvdata(&bd->dev);
+
+	brightness = bd->props.brightness;
+	max_brightness = bd->props.max_brightness;
+
+	if ((bd->props.power != FB_BLANK_UNBLANK) ||
+		(bd->props.state & BL_CORE_FBBLANK) ||
+		  (bd->props.state & BL_CORE_SUSPENDED))
+		brightness = 0;
+
+	if (brightness > max_brightness)
+		brightness = max_brightness;
+
+	/* Need to check WLED driver capability upstream */
+	if (ctx && ctx->wled)
+		led_trigger_event(ctx->wled, brightness);
+
+	return rc;
+}
+
+static int truly_backlight_device_get_brightness(struct backlight_device *bd)
+{
+	return bd->props.brightness;
+}
+
+static const struct backlight_ops truly_backlight_device_ops = {
+	.update_status = truly_backlight_device_update_status,
+	.get_brightness = truly_backlight_device_get_brightness,
+};
+
+static int truly_backlight_setup(struct truly_wqxga *ctx)
+{
+	struct backlight_properties props;
+	char bl_node_name[BL_NODE_NAME_SIZE];
+
+	if (!ctx) {
+		dev_err(ctx->dev, "invalid context\n");
+		return -EINVAL;
+	}
+
+	if (!ctx->backlight) {
+		memset(&props, 0, sizeof(props));
+		props.type = BACKLIGHT_RAW;
+		props.power = FB_BLANK_UNBLANK;
+		props.max_brightness = 4096;
+
+		snprintf(bl_node_name, BL_NODE_NAME_SIZE, "panel%u-backlight",
+				 PRIM_DISPLAY_NODE);
+
+		ctx->backlight =  backlight_device_register(bl_node_name,
+				ctx->dev, ctx,
+				&truly_backlight_device_ops, &props);
+
+		if (IS_ERR_OR_NULL(ctx->backlight)) {
+			pr_err("Failed to register backlight\n");
+			ctx->backlight = NULL;
+			return -ENODEV;
+		}
+
+		/* Register with the LED driver interface */
+		led_trigger_register_simple("bkl-trigger", &ctx->wled);
+
+		if (!ctx->wled) {
+			pr_err("backlight led registration failed\n");
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
 static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
 {
 	struct device *dev = &dsi->dev;
@@ -466,10 +549,11 @@  static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
 		secondary = of_find_mipi_dsi_device_by_node(np);
 		of_node_put(np);
 
+		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+
 		if (!secondary)
 			return -EPROBE_DEFER;
 
-		ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 		if (!ctx) {
 			put_device(&secondary->dev);
 			return -ENOMEM;
@@ -485,6 +569,12 @@  static int truly_wqxga_probe(struct mipi_dsi_device *dsi)
 			put_device(&secondary->dev);
 			return ret;
 		}
+
+		ret = truly_backlight_setup(ctx);
+		if (ret) {
+			put_device(&secondary->dev);
+			return ret;
+		}
 	}
 
 	ret = mipi_dsi_attach(dsi);
@@ -504,8 +594,10 @@  static int truly_wqxga_remove(struct mipi_dsi_device *dsi)
 	mipi_dsi_detach(dsi);
 
 	/* delete panel only for the DSI1 interface */
-	if (ctx)
+	if (ctx) {
 		truly_wqxga_panel_del(ctx);
+		kfree(ctx);
+	}
 
 	return 0;
 }