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[PATCH v4 4/8] drm/vkms: Add support for RGB565 formats

Louis Chauvet posted 8 patches 6 months, 2 weeks ago
There is a newer version of this series
[PATCH v4 4/8] drm/vkms: Add support for RGB565 formats
Posted by Louis Chauvet 6 months, 2 weeks ago 
The format RGB565 was already supported. Add the support for:
- BGR565

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_formats.c | 23 +++++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_plane.c   |  1 +
 2 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 95771bff5202..2c5cc8d3a14c 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -259,6 +259,26 @@ static struct pixel_argb_u16 argb_u16_from_grayu16(u16 gray)
 	return argb_u16_from_u16161616(0xFFFF, gray, gray, gray);
 }
 
+static struct pixel_argb_u16 argb_u16_from_BGR565(const __le16 *pixel)
+{
+	struct pixel_argb_u16 out_pixel;
+
+	s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
+	s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
+
+	u16 rgb_565 = le16_to_cpu(*pixel);
+	s64 fp_b = drm_int2fixp((rgb_565 >> 11) & 0x1f);
+	s64 fp_g = drm_int2fixp((rgb_565 >> 5) & 0x3f);
+	s64 fp_r = drm_int2fixp(rgb_565 & 0x1f);
+
+	out_pixel.a = (u16)0xffff;
+	out_pixel.b = drm_fixp2int_round(drm_fixp_mul(fp_b, fp_rb_ratio));
+	out_pixel.g = drm_fixp2int_round(drm_fixp_mul(fp_g, fp_g_ratio));
+	out_pixel.r = drm_fixp2int_round(drm_fixp_mul(fp_r, fp_rb_ratio));
+
+	return out_pixel;
+}
+
 VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
 							    const struct conversion_matrix *matrix)
 {
@@ -447,6 +467,7 @@ READ_LINE_le16161616(XRGB16161616_read_line, px, cpu_to_le16(0xFFFF), px[2], px[
 READ_LINE_le16161616(XBGR16161616_read_line, px, cpu_to_le16(0xFFFF), px[0], px[1], px[2])
 
 READ_LINE(RGB565_read_line, px, __le16, argb_u16_from_RGB565, px)
+READ_LINE(BGR565_read_line, px, __le16, argb_u16_from_BGR565, px)
 
 READ_LINE(R8_read_line, px, u8, argb_u16_from_gray8, *px)
 
@@ -675,6 +696,8 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
 		return &XBGR16161616_read_line;
 	case DRM_FORMAT_RGB565:
 		return &RGB565_read_line;
+	case DRM_FORMAT_BGR565:
+		return &BGR565_read_line;
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV16:
 	case DRM_FORMAT_NV24:
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 505847ec8508..d3783a8f84c2 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -26,6 +26,7 @@ static const u32 vkms_formats[] = {
 	DRM_FORMAT_ARGB16161616,
 	DRM_FORMAT_ABGR16161616,
 	DRM_FORMAT_RGB565,
+	DRM_FORMAT_BGR565,
 	DRM_FORMAT_NV12,
 	DRM_FORMAT_NV16,
 	DRM_FORMAT_NV24,

-- 
2.49.0
Re: [PATCH v4 4/8] drm/vkms: Add support for RGB565 formats
Posted by Maíra Canal 6 months, 1 week ago 
Hi Louis,

On 5/30/25 11:05, Louis Chauvet wrote:
> The format RGB565 was already supported. Add the support for:
> - BGR565
> 
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>   drivers/gpu/drm/vkms/vkms_formats.c | 23 +++++++++++++++++++++++
>   drivers/gpu/drm/vkms/vkms_plane.c   |  1 +
>   2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> index 95771bff5202..2c5cc8d3a14c 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.c
> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> @@ -259,6 +259,26 @@ static struct pixel_argb_u16 argb_u16_from_grayu16(u16 gray)
>   	return argb_u16_from_u16161616(0xFFFF, gray, gray, gray);
>   }
>   
> +static struct pixel_argb_u16 argb_u16_from_BGR565(const __le16 *pixel)
> +{
> +	struct pixel_argb_u16 out_pixel;
> +
> +	s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
> +	s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
> +
> +	u16 rgb_565 = le16_to_cpu(*pixel);
> +	s64 fp_b = drm_int2fixp((rgb_565 >> 11) & 0x1f);
> +	s64 fp_g = drm_int2fixp((rgb_565 >> 5) & 0x3f);
> +	s64 fp_r = drm_int2fixp(rgb_565 & 0x1f);
> +
> +	out_pixel.a = (u16)0xffff;
> +	out_pixel.b = drm_fixp2int_round(drm_fixp_mul(fp_b, fp_rb_ratio));
> +	out_pixel.g = drm_fixp2int_round(drm_fixp_mul(fp_g, fp_g_ratio));
> +	out_pixel.r = drm_fixp2int_round(drm_fixp_mul(fp_r, fp_rb_ratio));
> +
> +	return out_pixel;
> +}

Instead of writing `argb_u16_from_BGR565()` from scratch, I wonder if
we could just call `argb_u16_from_RGB565()` and swap `out_pixel.b` with
`out_pixel.r` . For me, it looks like a cleaner approach.

Well, even without this suggestion,

Reviewed-by: Maíra Canal <mcanal@igalia.com>

Best Regards,
- Maíra

> +
>   VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
>   							    const struct conversion_matrix *matrix)
>   {
> @@ -447,6 +467,7 @@ READ_LINE_le16161616(XRGB16161616_read_line, px, cpu_to_le16(0xFFFF), px[2], px[
>   READ_LINE_le16161616(XBGR16161616_read_line, px, cpu_to_le16(0xFFFF), px[0], px[1], px[2])
>   
>   READ_LINE(RGB565_read_line, px, __le16, argb_u16_from_RGB565, px)
> +READ_LINE(BGR565_read_line, px, __le16, argb_u16_from_BGR565, px)
>   
>   READ_LINE(R8_read_line, px, u8, argb_u16_from_gray8, *px)
>   
> @@ -675,6 +696,8 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
>   		return &XBGR16161616_read_line;
>   	case DRM_FORMAT_RGB565:
>   		return &RGB565_read_line;
> +	case DRM_FORMAT_BGR565:
> +		return &BGR565_read_line;
>   	case DRM_FORMAT_NV12:
>   	case DRM_FORMAT_NV16:
>   	case DRM_FORMAT_NV24:
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 505847ec8508..d3783a8f84c2 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -26,6 +26,7 @@ static const u32 vkms_formats[] = {
>   	DRM_FORMAT_ARGB16161616,
>   	DRM_FORMAT_ABGR16161616,
>   	DRM_FORMAT_RGB565,
> +	DRM_FORMAT_BGR565,
>   	DRM_FORMAT_NV12,
>   	DRM_FORMAT_NV16,
>   	DRM_FORMAT_NV24,
>
Re: [PATCH v4 4/8] drm/vkms: Add support for RGB565 formats
Posted by Louis Chauvet 6 months ago 

Le 11/06/2025 à 22:02, Maíra Canal a écrit :
> Hi Louis,
> 
> On 5/30/25 11:05, Louis Chauvet wrote:
>> The format RGB565 was already supported. Add the support for:
>> - BGR565
>>
>> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
>> ---
>>    drivers/gpu/drm/vkms/vkms_formats.c | 23 +++++++++++++++++++++++
>>    drivers/gpu/drm/vkms/vkms_plane.c   |  1 +
>>    2 files changed, 24 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
>> index 95771bff5202..2c5cc8d3a14c 100644
>> --- a/drivers/gpu/drm/vkms/vkms_formats.c
>> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
>> @@ -259,6 +259,26 @@ static struct pixel_argb_u16 argb_u16_from_grayu16(u16 gray)
>>    	return argb_u16_from_u16161616(0xFFFF, gray, gray, gray);
>>    }
>>    
>> +static struct pixel_argb_u16 argb_u16_from_BGR565(const __le16 *pixel)
>> +{
>> +	struct pixel_argb_u16 out_pixel;
>> +
>> +	s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
>> +	s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
>> +
>> +	u16 rgb_565 = le16_to_cpu(*pixel);
>> +	s64 fp_b = drm_int2fixp((rgb_565 >> 11) & 0x1f);
>> +	s64 fp_g = drm_int2fixp((rgb_565 >> 5) & 0x3f);
>> +	s64 fp_r = drm_int2fixp(rgb_565 & 0x1f);
>> +
>> +	out_pixel.a = (u16)0xffff;
>> +	out_pixel.b = drm_fixp2int_round(drm_fixp_mul(fp_b, fp_rb_ratio));
>> +	out_pixel.g = drm_fixp2int_round(drm_fixp_mul(fp_g, fp_g_ratio));
>> +	out_pixel.r = drm_fixp2int_round(drm_fixp_mul(fp_r, fp_rb_ratio));
>> +
>> +	return out_pixel;
>> +}
> 
> Instead of writing `argb_u16_from_BGR565()` from scratch, I wonder if
> we could just call `argb_u16_from_RGB565()` and swap `out_pixel.b` with
> `out_pixel.r` . For me, it looks like a cleaner approach.

Thanks for the suggestion, I was looking to avoid code repetition, but I 
did not think about this kind of "post-processing".

I will do for the next revision.

> Well, even without this suggestion,
> 
> Reviewed-by: Maíra Canal <mcanal@igalia.com>
> 
> Best Regards,
> - Maíra
> 
>> +
>>    VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
>>    							    const struct conversion_matrix *matrix)
>>    {
>> @@ -447,6 +467,7 @@ READ_LINE_le16161616(XRGB16161616_read_line, px, cpu_to_le16(0xFFFF), px[2], px[
>>    READ_LINE_le16161616(XBGR16161616_read_line, px, cpu_to_le16(0xFFFF), px[0], px[1], px[2])
>>    
>>    READ_LINE(RGB565_read_line, px, __le16, argb_u16_from_RGB565, px)
>> +READ_LINE(BGR565_read_line, px, __le16, argb_u16_from_BGR565, px)
>>    
>>    READ_LINE(R8_read_line, px, u8, argb_u16_from_gray8, *px)
>>    
>> @@ -675,6 +696,8 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
>>    		return &XBGR16161616_read_line;
>>    	case DRM_FORMAT_RGB565:
>>    		return &RGB565_read_line;
>> +	case DRM_FORMAT_BGR565:
>> +		return &BGR565_read_line;
>>    	case DRM_FORMAT_NV12:
>>    	case DRM_FORMAT_NV16:
>>    	case DRM_FORMAT_NV24:
>> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
>> index 505847ec8508..d3783a8f84c2 100644
>> --- a/drivers/gpu/drm/vkms/vkms_plane.c
>> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
>> @@ -26,6 +26,7 @@ static const u32 vkms_formats[] = {
>>    	DRM_FORMAT_ARGB16161616,
>>    	DRM_FORMAT_ABGR16161616,
>>    	DRM_FORMAT_RGB565,
>> +	DRM_FORMAT_BGR565,
>>    	DRM_FORMAT_NV12,
>>    	DRM_FORMAT_NV16,
>>    	DRM_FORMAT_NV24,
>>
> 

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Patchew 2.1-devel-b67e4c2

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