[PATCH v2 5/5] drm/ssd130x: Remove hardcoded bits-per-pixel in ssd130x_buf_alloc()

From: Javier Martinez Canillas
Date: Fri Jun 09 2023 - 13:11:26 EST


The driver only supports OLED controllers that have a native DRM_FORMAT_C1
pixel format and that is why it has harcoded a division of the width by 8.

But the driver might be extended to support devices that have a different
pixel format. So it's better to use the struct drm_format_info helpers to
compute the size of the buffer, used to store the pixels in native format.

Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---

(no changes since v1)

drivers/gpu/drm/solomon/ssd130x.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index 0be3b476dc60..b3dc1ca9dc10 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -150,9 +150,16 @@ static int ssd130x_buf_alloc(struct ssd130x_device *ssd130x)
{
unsigned int page_height = ssd130x->device_info->page_height;
unsigned int pages = DIV_ROUND_UP(ssd130x->height, page_height);
+ const struct drm_format_info *fi;
+ unsigned int pitch;

- ssd130x->buffer = kcalloc(DIV_ROUND_UP(ssd130x->width, 8),
- ssd130x->height, GFP_KERNEL);
+ fi = drm_format_info(DRM_FORMAT_C1);
+ if (!fi)
+ return -EINVAL;
+
+ pitch = drm_format_info_min_pitch(fi, 0, ssd130x->width);
+
+ ssd130x->buffer = kcalloc(pitch, ssd130x->height, GFP_KERNEL);
if (!ssd130x->buffer)
return -ENOMEM;

--
2.40.1