drm/mipi-dbi: Remove dependency on GEM CMA helper library

The MIPI DBI helpers access struct drm_gem_cma_object.vaddr in a
few places. Replace all instances with the correct generic GEM
functions. Use drm_gem_fb_vmap() for mapping a framebuffer's GEM
objects and drm_gem_fb_vunmap() for unmapping them. This removes
the dependency on CMA helpers within MIPI DBI.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211106193509.17472-2-tzimmermann@suse.de

drivers/gpu/drm/drm_mipi_dbi.c

@@ -15,9 +15,10 @@
 #include <drm/drm_connector.h>
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_drv.h>
-#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_file.h>
 #include <drm/drm_format_helper.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_gem.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_mipi_dbi.h>
 #include <drm/drm_modes.h>
@@ -200,13 +201,19 @@ int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb,
 		      struct drm_rect *clip, bool swap)
 {
 	struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0);
-	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem);
-	void *src = cma_obj->vaddr;
+	struct dma_buf_map map[DRM_FORMAT_MAX_PLANES];
+	struct dma_buf_map data[DRM_FORMAT_MAX_PLANES];
+	void *src;
 	int ret;
 
 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 	if (ret)
 		return ret;
+	src = data[0].vaddr; /* TODO: Use mapping abstraction properly */
+
+	ret = drm_gem_fb_vmap(fb, map, data);
+	if (ret)
+		goto out_drm_gem_fb_end_cpu_access;
 
 	switch (fb->format->format) {
 	case DRM_FORMAT_RGB565:
@@ -221,9 +228,11 @@ int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb,
 	default:
 		drm_err_once(fb->dev, "Format is not supported: %p4cc\n",
 			     &fb->format->format);
-		return -EINVAL;
+		ret = -EINVAL;
 	}
 
+	drm_gem_fb_vunmap(fb, map);
+out_drm_gem_fb_end_cpu_access:
 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 
 	return ret;
@@ -249,8 +258,8 @@ static void mipi_dbi_set_window_address(struct mipi_dbi_dev *dbidev,
 
 static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 {
-	struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0);
-	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem);
+	struct dma_buf_map map[DRM_FORMAT_MAX_PLANES];
+	struct dma_buf_map data[DRM_FORMAT_MAX_PLANES];
 	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
 	unsigned int height = rect->y2 - rect->y1;
 	unsigned int width = rect->x2 - rect->x1;
@@ -266,6 +275,10 @@ static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 	if (!drm_dev_enter(fb->dev, &idx))
 		return;
 
+	ret = drm_gem_fb_vmap(fb, map, data);
+	if (ret)
+		goto err_drm_dev_exit;
+
 	full = width == fb->width && height == fb->height;
 
 	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
@@ -277,7 +290,7 @@ static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 		if (ret)
 			goto err_msg;
 	} else {
-		tr = cma_obj->vaddr;
+		tr = data[0].vaddr; /* TODO: Use mapping abstraction properly */
 	}
 
 	mipi_dbi_set_window_address(dbidev, rect->x1, rect->x2 - 1, rect->y1,
@@ -289,6 +302,9 @@ static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
 	if (ret)
 		drm_err_once(fb->dev, "Failed to update display %d\n", ret);
 
+	drm_gem_fb_vunmap(fb, map);
+
+err_drm_dev_exit:
 	drm_dev_exit(idx);
 }
 
@@ -1117,8 +1133,8 @@ int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *dbi,
 
 	/*
 	 * Even though it's not the SPI device that does DMA (the master does),
-	 * the dma mask is necessary for the dma_alloc_wc() in
-	 * drm_gem_cma_create(). The dma_addr returned will be a physical
+	 * the dma mask is necessary for the dma_alloc_wc() in the GEM code
+	 * (e.g., drm_gem_cma_create()). The dma_addr returned will be a physical
 	 * address which might be different from the bus address, but this is
 	 * not a problem since the address will not be used.
 	 * The virtual address is used in the transfer and the SPI core