drm/tinydrm: Generalize tinydrm_xrgb8888_to_gray8()

This adds parameters for vaddr and clip to tinydrm_xrgb8888_to_gray8() to
make it more generic.

dma_buf_{begin,end}_cpu_access() are moved out to the repaper driver.

Return type is change to void to simplify error handling by callers.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1502127581-10517-2-git-send-email-david@lechnology.com

2 files changed, 39 insertions, 31 deletions

diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
index 75808bb84c9a..bd6cce093a85 100644
--- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
@@ -185,7 +185,9 @@ EXPORT_SYMBOL(tinydrm_xrgb8888_to_rgb565);
 /**
  * tinydrm_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
  * @dst: 8-bit grayscale destination buffer
+ * @vaddr: XRGB8888 source buffer
  * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
  *
  * Drm doesn't have native monochrome or grayscale support.
  * Such drivers can announce the commonly supported XR24 format to userspace
@@ -195,41 +197,31 @@ EXPORT_SYMBOL(tinydrm_xrgb8888_to_rgb565);
  * where 1 means foreground color and 0 background color.
  *
  * ITU BT.601 is used for the RGB -> luma (brightness) conversion.
- *
- * Returns:
- * Zero on success, negative error code on failure.
  */
-int tinydrm_xrgb8888_to_gray8(u8 *dst, struct drm_framebuffer *fb)
+void tinydrm_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
+                               struct drm_clip_rect *clip)
 {
-        struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
-        struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
-        unsigned int x, y, pitch = fb->pitches[0];
-        int ret = 0;
+        unsigned int len = (clip->x2 - clip->x1) * sizeof(u32);
+        unsigned int x, y;
         void *buf;
         u32 *src;
 
         if (WARN_ON(fb->format->format != DRM_FORMAT_XRGB8888))
-                return -EINVAL;
+                return;
         /*
          * The cma memory is write-combined so reads are uncached.
          * Speed up by fetching one line at a time.
          */
-        buf = kmalloc(pitch, GFP_KERNEL);
+        buf = kmalloc(len, GFP_KERNEL);
         if (!buf)
-                return -ENOMEM;
-
-        if (import_attach) {
-                ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
-                                               DMA_FROM_DEVICE);
-                if (ret)
-                        goto err_free;
-        }
+                return;
 
-        for (y = 0; y < fb->height; y++) {
-                src = cma_obj->vaddr + (y * pitch);
-                memcpy(buf, src, pitch);
+        for (y = clip->y1; y < clip->y2; y++) {
+                src = vaddr + (y * fb->pitches[0]);
+                src += clip->x1;
+                memcpy(buf, src, len);
                 src = buf;
-                for (x = 0; x < fb->width; x++) {
+                for (x = clip->x1; x < clip->x2; x++) {
                         u8 r = (*src & 0x00ff0000) >> 16;
                         u8 g = (*src & 0x0000ff00) >> 8;
                         u8 b =  *src & 0x000000ff;
@@ -240,13 +232,7 @@ int tinydrm_xrgb8888_to_gray8(u8 *dst, struct drm_framebuffer *fb)
                 }
         }
 
-        if (import_attach)
-                ret = dma_buf_end_cpu_access(import_attach->dmabuf,
-                                             DMA_FROM_DEVICE);
-err_free:
         kfree(buf);
-
-        return ret;
 }
 EXPORT_SYMBOL(tinydrm_xrgb8888_to_gray8);
 
diff --git a/drivers/gpu/drm/tinydrm/repaper.c b/drivers/gpu/drm/tinydrm/repaper.c
index 3343d3f15a90..30dc97b3ff21 100644
--- a/drivers/gpu/drm/tinydrm/repaper.c
+++ b/drivers/gpu/drm/tinydrm/repaper.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/dma-buf.h>
 #include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
@@ -525,11 +526,20 @@ static int repaper_fb_dirty(struct drm_framebuffer *fb,
                             struct drm_clip_rect *clips,
                             unsigned int num_clips)
 {
+        struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+        struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
         struct tinydrm_device *tdev = fb->dev->dev_private;
         struct repaper_epd *epd = epd_from_tinydrm(tdev);
+        struct drm_clip_rect clip;
         u8 *buf = NULL;
         int ret = 0;
 
+        /* repaper can't do partial updates */
+        clip.x1 = 0;
+        clip.x2 = fb->width;
+        clip.y1 = 0;
+        clip.y2 = fb->height;
+
         mutex_lock(&tdev->dirty_lock);
 
         if (!epd->enabled)
@@ -550,9 +560,21 @@ static int repaper_fb_dirty(struct drm_framebuffer *fb,
                 goto out_unlock;
         }
 
-        ret = tinydrm_xrgb8888_to_gray8(buf, fb);
-        if (ret)
-                goto out_unlock;
+        if (import_attach) {
+                ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
+                                               DMA_FROM_DEVICE);
+                if (ret)
+                        goto out_unlock;
+        }
+
+        tinydrm_xrgb8888_to_gray8(buf, cma_obj->vaddr, fb, &clip);
+
+        if (import_attach) {
+                ret = dma_buf_end_cpu_access(import_attach->dmabuf,
+                                             DMA_FROM_DEVICE);
+                if (ret)
+                        goto out_unlock;
+        }
 
         repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);