Re: [PATCH v5 4/4] leds: core: add support for RGB LED's
On 03/29/2016 10:42 PM, Heiner Kallweit wrote: Am 29.03.2016 um 12:05 schrieb Pavel Machek: On Tue 2016-03-01 22:36:12, Heiner Kallweit wrote: Export a function to convert HSV color values to RGB. It's intended to be called by drivers for RGB LEDs. Signed-off-by: Heiner Kallweit --- v2: - move hsv -> rgb conversion to separate file - remove flag LED_DEV_CAP_RGB v3: - call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set This is needed in cases when we have monochrome and color LEDs as well in a system. v4: - Export led_hsv_to_rgb and let the device driver call it instead of doing the conversion in the core v5: - don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB is set but warn --- drivers/leds/led-class.c| 7 +++ drivers/leds/led-rgb-core.c | 36 include/linux/leds.h| 8 3 files changed, 51 insertions(+) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 8a3748a..a4b144e 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) char name[64]; int ret; + /* +* for now reading back the color is not supported as multiple +* HSV -> RGB -> HSV conversions may distort the color due to +* rounding issues in the conversion algorithm +*/ + WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get); + Backtrace is useless here, you may want to add some ()s and you don't really want user to be causing messages in syslog this easily. I agree that the backtrace doesn't provide a benefit here. I requested it to provide a verbose notification for a LED RGB class driver developer, in case they try to implement a brightness_get op, which would be harmful in case of HSV interface for RGB LEDs. However I don't see how a user could create syslog entries. The warn condition can be true only for drivers implementing the RGB extension in a not supported way (by setting flag LED_DEV_CAP_RGB and implementing brightness_get). Pavel -- Best regards, Jacek Anaszewski -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v5 4/4] leds: core: add support for RGB LED's
Am 29.03.2016 um 12:05 schrieb Pavel Machek: > On Tue 2016-03-01 22:36:12, Heiner Kallweit wrote: >> Export a function to convert HSV color values to RGB. >> It's intended to be called by drivers for RGB LEDs. >> >> Signed-off-by: Heiner Kallweit >> --- >> v2: >> - move hsv -> rgb conversion to separate file >> - remove flag LED_DEV_CAP_RGB >> v3: >> - call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set >> This is needed in cases when we have monochrome and color LEDs >> as well in a system. >> v4: >> - Export led_hsv_to_rgb and let the device driver call it instead >> of doing the conversion in the core >> v5: >> - don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB >> is set but warn >> --- >> drivers/leds/led-class.c| 7 +++ >> drivers/leds/led-rgb-core.c | 36 >> include/linux/leds.h| 8 >> 3 files changed, 51 insertions(+) >> >> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c >> index 8a3748a..a4b144e 100644 >> --- a/drivers/leds/led-class.c >> +++ b/drivers/leds/led-class.c >> @@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct >> led_classdev *led_cdev) >> char name[64]; >> int ret; >> >> +/* >> + * for now reading back the color is not supported as multiple >> + * HSV -> RGB -> HSV conversions may distort the color due to >> + * rounding issues in the conversion algorithm >> + */ >> +WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get); >> + > > Backtrace is useless here, you may want to add some ()s and you don't > really want user to be causing messages in syslog this easily. > I agree that the backtrace doesn't provide a benefit here. However I don't see how a user could create syslog entries. The warn condition can be true only for drivers implementing the RGB extension in a not supported way (by setting flag LED_DEV_CAP_RGB and implementing brightness_get). Pavel > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v5 4/4] leds: core: add support for RGB LED's
On Tue 2016-03-01 22:36:12, Heiner Kallweit wrote: > Export a function to convert HSV color values to RGB. > It's intended to be called by drivers for RGB LEDs. > > Signed-off-by: Heiner Kallweit > --- > v2: > - move hsv -> rgb conversion to separate file > - remove flag LED_DEV_CAP_RGB > v3: > - call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set > This is needed in cases when we have monochrome and color LEDs > as well in a system. > v4: > - Export led_hsv_to_rgb and let the device driver call it instead > of doing the conversion in the core > v5: > - don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB > is set but warn > --- > drivers/leds/led-class.c| 7 +++ > drivers/leds/led-rgb-core.c | 36 > include/linux/leds.h| 8 > 3 files changed, 51 insertions(+) > > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c > index 8a3748a..a4b144e 100644 > --- a/drivers/leds/led-class.c > +++ b/drivers/leds/led-class.c > @@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct > led_classdev *led_cdev) > char name[64]; > int ret; > > + /* > + * for now reading back the color is not supported as multiple > + * HSV -> RGB -> HSV conversions may distort the color due to > + * rounding issues in the conversion algorithm > + */ > + WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get); > + Backtrace is useless here, you may want to add some ()s and you don't really want user to be causing messages in syslog this easily. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v5 4/4] leds: core: add support for RGB LED's
Am 04.03.2016 um 10:05 schrieb Jacek Anaszewski:
> On 03/01/2016 10:36 PM, Heiner Kallweit wrote:
>> Export a function to convert HSV color values to RGB.
>> It's intended to be called by drivers for RGB LEDs.
>>
>> Signed-off-by: Heiner Kallweit
>> ---
>> v2:
>> - move hsv -> rgb conversion to separate file
>> - remove flag LED_DEV_CAP_RGB
>> v3:
>> - call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set
>>This is needed in cases when we have monochrome and color LEDs
>>as well in a system.
>> v4:
>> - Export led_hsv_to_rgb and let the device driver call it instead
>>of doing the conversion in the core
>> v5:
>> - don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB
>>is set but warn
>> ---
>> drivers/leds/led-class.c| 7 +++
>> drivers/leds/led-rgb-core.c | 36
>> include/linux/leds.h| 8
>> 3 files changed, 51 insertions(+)
>>
>> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
>> index 8a3748a..a4b144e 100644
>> --- a/drivers/leds/led-class.c
>> +++ b/drivers/leds/led-class.c
>> @@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct
>> led_classdev *led_cdev)
>> char name[64];
>> int ret;
>>
>> +/*
>> + * for now reading back the color is not supported as multiple
>> + * HSV -> RGB -> HSV conversions may distort the color due to
>> + * rounding issues in the conversion algorithm
>> + */
>
> Does the "for now" mean that you plan on supporting it in the future?
>
It was meant as "until somebody has an idea how to implement the conversion
HSV -> RGB -> HSV in a way that always results in the original values".
I'll remove the "for now".
>> +WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get);
>> +
>
> Could you move this warning to the line 216?
>
>> ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
>> if (ret < 0)
>> return ret;
>> diff --git a/drivers/leds/led-rgb-core.c b/drivers/leds/led-rgb-core.c
>> index f6591f1..2b18d4c 100644
>> --- a/drivers/leds/led-rgb-core.c
>> +++ b/drivers/leds/led-rgb-core.c
>> @@ -38,3 +38,39 @@ enum led_brightness led_confine_brightness(struct
>> led_classdev *led_cdev,
>> return brightness |
>> min(value & LED_BRIGHTNESS_MASK, led_cdev->max_brightness);
>> }
>> +
>> +enum led_brightness led_hsv_to_rgb(enum led_brightness hsv)
>> +{
>> +int h = min_t(int, (hsv >> 16) & 0xff, 251);
>> +int s = (hsv >> 8) & 0xff;
>> +int v = hsv & 0xff;
>> +int f, p, q, t, r, g, b;
>> +
>> +if (!v)
>> +return 0;
>> +if (!s)
>> +return (v << 16) + (v << 8) + v;
>> +
>> +f = DIV_ROUND_CLOSEST((h % 42) * 255, 42);
>> +p = v - DIV_ROUND_CLOSEST(s * v, 255);
>> +q = v - DIV_ROUND_CLOSEST(f * s * v, 255 * 255);
>> +t = v - DIV_ROUND_CLOSEST((255 - f) * s * v, 255 * 255);
>> +
>> +switch (h / 42) {
>> +case 0:
>> +r = v; g = t; b = p; break;
>> +case 1:
>> +r = q; g = v; b = p; break;
>> +case 2:
>> +r = p; g = v; b = t; break;
>> +case 3:
>> +r = p; g = q; b = v; break;
>> +case 4:
>> +r = t; g = p; b = v; break;
>> +case 5:
>> +r = v; g = p; b = q; break;
>> +}
>> +
>> +return (r << 16) + (g << 8) + b;
>> +}
>> +EXPORT_SYMBOL_GPL(led_hsv_to_rgb);
>> diff --git a/include/linux/leds.h b/include/linux/leds.h
>> index bbf24bb..82b3477 100644
>> --- a/include/linux/leds.h
>> +++ b/include/linux/leds.h
>> @@ -226,6 +226,14 @@ static inline bool led_sysfs_is_disabled(struct
>> led_classdev *led_cdev)
>> return led_cdev->flags & LED_SYSFS_DISABLE;
>> }
>>
>> +/**
>> + * led_hsv_to_rgb - convert a hsv color value to rgb color model
>> + * @hsv: the hsv value to convert
>> + *
>> + * Returns: the resulting rgb value
>> + */
>> +enum led_brightness led_hsv_to_rgb(enum led_brightness hsv);
>> +
>> /*
>>* LED Triggers
>>*/
>>
>
>
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Re: [PATCH v5 4/4] leds: core: add support for RGB LED's
On 03/01/2016 10:36 PM, Heiner Kallweit wrote:
Export a function to convert HSV color values to RGB.
It's intended to be called by drivers for RGB LEDs.
Signed-off-by: Heiner Kallweit
---
v2:
- move hsv -> rgb conversion to separate file
- remove flag LED_DEV_CAP_RGB
v3:
- call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set
This is needed in cases when we have monochrome and color LEDs
as well in a system.
v4:
- Export led_hsv_to_rgb and let the device driver call it instead
of doing the conversion in the core
v5:
- don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB
is set but warn
---
drivers/leds/led-class.c| 7 +++
drivers/leds/led-rgb-core.c | 36
include/linux/leds.h| 8
3 files changed, 51 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 8a3748a..a4b144e 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct
led_classdev *led_cdev)
char name[64];
int ret;
+ /*
+* for now reading back the color is not supported as multiple
+* HSV -> RGB -> HSV conversions may distort the color due to
+* rounding issues in the conversion algorithm
+*/
Does the "for now" mean that you plan on supporting it in the future?
+ WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get);
+
Could you move this warning to the line 216?
ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
if (ret < 0)
return ret;
diff --git a/drivers/leds/led-rgb-core.c b/drivers/leds/led-rgb-core.c
index f6591f1..2b18d4c 100644
--- a/drivers/leds/led-rgb-core.c
+++ b/drivers/leds/led-rgb-core.c
@@ -38,3 +38,39 @@ enum led_brightness led_confine_brightness(struct
led_classdev *led_cdev,
return brightness |
min(value & LED_BRIGHTNESS_MASK, led_cdev->max_brightness);
}
+
+enum led_brightness led_hsv_to_rgb(enum led_brightness hsv)
+{
+ int h = min_t(int, (hsv >> 16) & 0xff, 251);
+ int s = (hsv >> 8) & 0xff;
+ int v = hsv & 0xff;
+ int f, p, q, t, r, g, b;
+
+ if (!v)
+ return 0;
+ if (!s)
+ return (v << 16) + (v << 8) + v;
+
+ f = DIV_ROUND_CLOSEST((h % 42) * 255, 42);
+ p = v - DIV_ROUND_CLOSEST(s * v, 255);
+ q = v - DIV_ROUND_CLOSEST(f * s * v, 255 * 255);
+ t = v - DIV_ROUND_CLOSEST((255 - f) * s * v, 255 * 255);
+
+ switch (h / 42) {
+ case 0:
+ r = v; g = t; b = p; break;
+ case 1:
+ r = q; g = v; b = p; break;
+ case 2:
+ r = p; g = v; b = t; break;
+ case 3:
+ r = p; g = q; b = v; break;
+ case 4:
+ r = t; g = p; b = v; break;
+ case 5:
+ r = v; g = p; b = q; break;
+ }
+
+ return (r << 16) + (g << 8) + b;
+}
+EXPORT_SYMBOL_GPL(led_hsv_to_rgb);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index bbf24bb..82b3477 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -226,6 +226,14 @@ static inline bool led_sysfs_is_disabled(struct
led_classdev *led_cdev)
return led_cdev->flags & LED_SYSFS_DISABLE;
}
+/**
+ * led_hsv_to_rgb - convert a hsv color value to rgb color model
+ * @hsv: the hsv value to convert
+ *
+ * Returns: the resulting rgb value
+ */
+enum led_brightness led_hsv_to_rgb(enum led_brightness hsv);
+
/*
* LED Triggers
*/
--
Best regards,
Jacek Anaszewski
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[PATCH v5 4/4] leds: core: add support for RGB LED's
Export a function to convert HSV color values to RGB.
It's intended to be called by drivers for RGB LEDs.
Signed-off-by: Heiner Kallweit
---
v2:
- move hsv -> rgb conversion to separate file
- remove flag LED_DEV_CAP_RGB
v3:
- call led_hsv_to_rgb only if LED_DEV_CAP_HSV is set
This is needed in cases when we have monochrome and color LEDs
as well in a system.
v4:
- Export led_hsv_to_rgb and let the device driver call it instead
of doing the conversion in the core
v5:
- don't ignore led_cdev->brightness_get silently if LED_DEV_CAP_RGB
is set but warn
---
drivers/leds/led-class.c| 7 +++
drivers/leds/led-rgb-core.c | 36
include/linux/leds.h| 8
3 files changed, 51 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 8a3748a..a4b144e 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -193,6 +193,13 @@ int led_classdev_register(struct device *parent, struct
led_classdev *led_cdev)
char name[64];
int ret;
+ /*
+* for now reading back the color is not supported as multiple
+* HSV -> RGB -> HSV conversions may distort the color due to
+* rounding issues in the conversion algorithm
+*/
+ WARN_ON(led_cdev->flags & LED_DEV_CAP_RGB && led_cdev->brightness_get);
+
ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
if (ret < 0)
return ret;
diff --git a/drivers/leds/led-rgb-core.c b/drivers/leds/led-rgb-core.c
index f6591f1..2b18d4c 100644
--- a/drivers/leds/led-rgb-core.c
+++ b/drivers/leds/led-rgb-core.c
@@ -38,3 +38,39 @@ enum led_brightness led_confine_brightness(struct
led_classdev *led_cdev,
return brightness |
min(value & LED_BRIGHTNESS_MASK, led_cdev->max_brightness);
}
+
+enum led_brightness led_hsv_to_rgb(enum led_brightness hsv)
+{
+ int h = min_t(int, (hsv >> 16) & 0xff, 251);
+ int s = (hsv >> 8) & 0xff;
+ int v = hsv & 0xff;
+ int f, p, q, t, r, g, b;
+
+ if (!v)
+ return 0;
+ if (!s)
+ return (v << 16) + (v << 8) + v;
+
+ f = DIV_ROUND_CLOSEST((h % 42) * 255, 42);
+ p = v - DIV_ROUND_CLOSEST(s * v, 255);
+ q = v - DIV_ROUND_CLOSEST(f * s * v, 255 * 255);
+ t = v - DIV_ROUND_CLOSEST((255 - f) * s * v, 255 * 255);
+
+ switch (h / 42) {
+ case 0:
+ r = v; g = t; b = p; break;
+ case 1:
+ r = q; g = v; b = p; break;
+ case 2:
+ r = p; g = v; b = t; break;
+ case 3:
+ r = p; g = q; b = v; break;
+ case 4:
+ r = t; g = p; b = v; break;
+ case 5:
+ r = v; g = p; b = q; break;
+ }
+
+ return (r << 16) + (g << 8) + b;
+}
+EXPORT_SYMBOL_GPL(led_hsv_to_rgb);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index bbf24bb..82b3477 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -226,6 +226,14 @@ static inline bool led_sysfs_is_disabled(struct
led_classdev *led_cdev)
return led_cdev->flags & LED_SYSFS_DISABLE;
}
+/**
+ * led_hsv_to_rgb - convert a hsv color value to rgb color model
+ * @hsv: the hsv value to convert
+ *
+ * Returns: the resulting rgb value
+ */
+enum led_brightness led_hsv_to_rgb(enum led_brightness hsv);
+
/*
* LED Triggers
*/
--
2.7.1
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