Messages in this thread | | | Date | Fri, 11 Feb 2022 13:46:49 +0100 | Subject | Re: [PATCH v4 2/6] drm/format-helper: Add drm_fb_xrgb8888_to_mono_reversed() | From | Thomas Zimmermann <> |
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Hi
Am 11.02.22 um 10:19 schrieb Javier Martinez Canillas: > Add support to convert from XR24 to reversed monochrome for drivers that > control monochromatic display panels, that only have 1 bit per pixel. > > The function does a line-by-line conversion doing an intermediate step > first from XR24 to 8-bit grayscale and then to reversed monochrome. > > The drm_fb_gray8_to_mono_reversed_line() helper was based on code from > drivers/gpu/drm/tiny/repaper.c driver. > > Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> > Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> > --- > > Changes in v4: > - Rename end_offset to end_len (Thomas Zimmermann) > - Warn once if dst_pitch is not a multiple of 8 (Thomas Zimmermann) > - Drop drm_fb_gray8_to_mono_reversed() that's not used (Thomas Zimmermann) > - Allocate single buffer for both copy cma memory and gray8 (Thomas Zimmermann) > - Add Thomas Zimmermann Reviewed-by tag to patch adding XR24 -> mono helper. > > Changes in v3: > - Also add a drm_fb_xrgb8888_to_mono_reversed() helper (Thomas Zimmermann) > - Split lines copy to drm_fb_gray8_to_mono_reversed_line() (Thomas Zimmermann) > - Handle case where the source buffer is not aligned to 8 (Thomas Zimmermann) > > drivers/gpu/drm/drm_format_helper.c | 107 ++++++++++++++++++++++++++++ > include/drm/drm_format_helper.h | 4 ++ > 2 files changed, 111 insertions(+) > > diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c > index b981712623d3..ec4e3724ee79 100644 > --- a/drivers/gpu/drm/drm_format_helper.c > +++ b/drivers/gpu/drm/drm_format_helper.c > @@ -591,3 +591,110 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for > return -EINVAL; > } > EXPORT_SYMBOL(drm_fb_blit_toio); > + > +static void drm_fb_gray8_to_mono_reversed_line(u8 *dst, const u8 *src, unsigned int pixels, > + unsigned int start_offset, unsigned int end_len) > +{ > + unsigned int xb, i; > + > + for (xb = 0; xb < pixels; xb++) { > + unsigned int start = 0, end = 8; > + u8 byte = 0x00; > + > + if (xb == 0 && start_offset) > + start = start_offset; > + > + if (xb == pixels - 1 && end_len) > + end = end_len; > + > + for (i = start; i < end; i++) { > + unsigned int x = xb * 8 + i; > + > + byte >>= 1; > + if (src[x] >> 7) > + byte |= BIT(7); > + } > + *dst++ = byte; > + } > +} > + > +/** > + * drm_fb_xrgb8888_to_mono_reversed - Convert XRGB8888 to reversed monochrome > + * @dst: reversed monochrome destination buffer > + * @dst_pitch: Number of bytes between two consecutive scanlines within dst > + * @src: XRGB8888 source buffer > + * @fb: DRM framebuffer > + * @clip: Clip rectangle area to copy > + * > + * DRM doesn't have native monochrome support. > + * Such drivers can announce the commonly supported XR24 format to userspace > + * and use this function to convert to the native format. > + * > + * This function uses drm_fb_xrgb8888_to_gray8() to convert to grayscale and > + * then the result is converted from grayscale to reversed monohrome. > + */ > +void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const void *vaddr, > + const struct drm_framebuffer *fb, const struct drm_rect *clip) > +{ > + unsigned int linepixels = drm_rect_width(clip); > + unsigned int lines = clip->y2 - clip->y1; > + unsigned int cpp = fb->format->cpp[0]; > + unsigned int len_src32 = linepixels * cpp; > + unsigned int start_offset, end_len; > + unsigned int y; > + u8 *mono = dst, *gray8; > + u32 *src32; > + > + if (WARN_ON(fb->format->format != DRM_FORMAT_XRGB8888)) > + return;
These WARN macros are deprecated. Use drm_warn, drm_WARN_ONCE, etc instead.
Best regards Thomas
> + > + /* > + * The reversed mono destination buffer contains 1 bit per pixel > + * and destination scanlines have to be in multiple of 8 pixels. > + */ > + if (!dst_pitch) > + dst_pitch = DIV_ROUND_UP(linepixels, 8); > + > + WARN_ONCE(dst_pitch % 8 != 0, "dst_pitch is not a multiple of 8\n"); > + > + /* > + * The cma memory is write-combined so reads are uncached. > + * Speed up by fetching one line at a time. > + * > + * Also, format conversion from XR24 to reversed monochrome > + * are done line-by-line but are converted to 8-bit grayscale > + * as an intermediate step. > + * > + * Allocate a buffer to be used for both copying from the cma > + * memory and to store the intermediate grayscale line pixels. > + */ > + src32 = kmalloc(len_src32 + linepixels, GFP_KERNEL); > + if (!src32) > + return; > + > + gray8 = (u8 *)src32 + len_src32; > + > + /* > + * For damage handling, it is possible that only parts of the source > + * buffer is copied and this could lead to start and end pixels that > + * are not aligned to multiple of 8. > + * > + * Calculate if the start and end pixels are not aligned and set the > + * offsets for the reversed mono line conversion function to adjust. > + */ > + start_offset = clip->x1 % 8; > + end_len = clip->x2 % 8; > + > + vaddr += clip_offset(clip, fb->pitches[0], cpp); > + for (y = 0; y < lines; y++) { > + src32 = memcpy(src32, vaddr, len_src32); > + drm_fb_xrgb8888_to_gray8_line(gray8, src32, linepixels); > + drm_fb_gray8_to_mono_reversed_line(mono, gray8, dst_pitch, > + start_offset, end_len); > + vaddr += fb->pitches[0]; > + mono += dst_pitch; > + } > + > + kfree(src32); > +} > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_mono_reversed); > diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h > index b30ed5de0a33..0b0937c0b2f6 100644 > --- a/include/drm/drm_format_helper.h > +++ b/include/drm/drm_format_helper.h > @@ -43,4 +43,8 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for > const void *vmap, const struct drm_framebuffer *fb, > const struct drm_rect *rect); > > +void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const void *src, > + const struct drm_framebuffer *fb, > + const struct drm_rect *clip); > + > #endif /* __LINUX_DRM_FORMAT_HELPER_H */
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev [unhandled content-type:application/pgp-signature] | |