Re: [PATCH 1/5] drm/format-helper: Rename drm_fb_xrgb8888_to_mono_reversed()

On Tue, Mar 15, 2022 at 12:07:03PM +0100, Geert Uytterhoeven wrote:

There is no "reversed" handling in drm_fb_xrgb8888_to_mono_reversed(): the function just converts from color to grayscale, and reduces the number of grayscale levels from 256 to 2 (i.e. brightness 0-127 is mapped to 0, 128-255 to 1). All "reversed" handling is done in the repaper driver, where this function originated.

Hence make this clear by renaming drm_fb_xrgb8888_to_mono_reversed() to drm_fb_xrgb8888_to_mono(), and documenting the black/white pixel mapping.

W/ or w/o the below remark being addressed Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com

Fixes: bcf8b616deb87941 ("drm/format-helper: Add drm_fb_xrgb8888_to_mono_reversed()") Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org

---

drivers/gpu/drm/drm_format_helper.c | 32 ++++++++++++++--------------- drivers/gpu/drm/solomon/ssd130x.c | 2 +- drivers/gpu/drm/tiny/repaper.c | 2 +- include/drm/drm_format_helper.h | 5 ++--- 4 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c index bc0f49773868a9b0..b68aa857c6514529 100644 --- a/drivers/gpu/drm/drm_format_helper.c +++ b/drivers/gpu/drm/drm_format_helper.c @@ -594,8 +594,8 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for } 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)
  

+static void drm_fb_gray8_to_mono_line(u8 *dst, const u8 *src, unsigned int pixels,

• 		      unsigned int start_offset, unsigned int end_len)
  

{ unsigned int xb, i;

@@ -621,8 +621,8 @@ static void drm_fb_gray8_to_mono_reversed_line(u8 *dst, const u8 *src, unsigned }

/**

• • drm_fb_xrgb8888_to_mono_reversed - Convert XRGB8888 to reversed monochrome
• • @dst: reversed monochrome destination buffer

• • drm_fb_xrgb8888_to_mono - Convert XRGB8888 to monochrome
• • @dst: monochrome destination buffer (0=black, 1=white)
  • @dst_pitch: Number of bytes between two consecutive scanlines within dst
  • @src: XRGB8888 source buffer
  • @fb: DRM framebuffer

@@ -633,10 +633,10 @@ static void drm_fb_gray8_to_mono_reversed_line(u8 *dst, const u8 *src, unsigned

• 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.

• • then the result is converted from grayscale to monochrome.
  */

-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)
  

+void drm_fb_xrgb8888_to_mono(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; @@ -652,8 +652,8 @@ void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const v return;

/*

• * The reversed mono destination buffer contains 1 bit per pixel
  

• * and destination scanlines have to be in multiple of 8 pixels.
  

• * The 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);

@@ -664,9 +664,9 @@ void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const v * 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.
  

• * Also, format conversion from XR24 to 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.

@@ -683,7 +683,7 @@ void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const v * 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.
  

• * offsets for the mono line conversion function to adjust.
  

  */ start_offset = clip->x1 % 8; end_len = clip->x2 % 8;

@@ -692,12 +692,12 @@ void drm_fb_xrgb8888_to_mono_reversed(void *dst, unsigned int dst_pitch, const v 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);
  

• drm_fb_gray8_to_mono_line(mono, gray8, dst_pitch, start_offset,
  

• 			  end_len);
  

Can be one line now (definition is already quite behind 80 limit).

vaddr += fb->pitches[0];
mono += dst_pitch;

}

kfree(src32); } -EXPORT_SYMBOL(drm_fb_xrgb8888_to_mono_reversed); +EXPORT_SYMBOL(drm_fb_xrgb8888_to_mono); diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index d08d86ef07bcbe7f..caee851efd5726e7 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -458,7 +458,7 @@ static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_m if (!buf) return -ENOMEM;

• drm_fb_xrgb8888_to_mono_reversed(buf, 0, vmap, fb, rect);

• drm_fb_xrgb8888_to_mono(buf, 0, vmap, fb, rect);

  ssd130x_update_rect(ssd130x, buf, rect);

diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c index 37b6bb90e46e1fe8..a096fb8b83e99dc8 100644 --- a/drivers/gpu/drm/tiny/repaper.c +++ b/drivers/gpu/drm/tiny/repaper.c @@ -540,7 +540,7 @@ static int repaper_fb_dirty(struct drm_framebuffer *fb) if (ret) goto out_free;

• drm_fb_xrgb8888_to_mono_reversed(buf, 0, cma_obj->vaddr, fb, &clip);

• drm_fb_xrgb8888_to_mono(buf, 0, cma_obj->vaddr, fb, &clip);

  drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);

diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h index 0b0937c0b2f6324e..55145eca07828321 100644 --- a/include/drm/drm_format_helper.h +++ b/include/drm/drm_format_helper.h @@ -43,8 +43,7 @@ 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);
  

+void drm_fb_xrgb8888_to_mono(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 */

2.25.1