[PATCH v3 15/15] drm/mxsfb: Add support for live pixel format change

[Robert Chiras]

This IP requires full stop and re-start when changing display timings,
but we can change the pixel format while running.

Signed-off-by: Robert Chiras <robert.chi...@nxp.com>
---
 drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c 
b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 317575e..5607fc0 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -494,6 +494,7 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private 
*mxsfb,
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_plane_state *new_state = pipe->plane.state;
        struct drm_framebuffer *fb = pipe->plane.state->fb;
+       struct drm_framebuffer *old_fb = state->fb;
        struct drm_pending_vblank_event *event;
        u32 fb_addr, src_off, src_w, stride, cpp = 0;
 
@@ -510,7 +511,7 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private 
*mxsfb,
        }
        spin_unlock_irq(&crtc->dev->event_lock);
 
-       if (!fb)
+       if (!fb || !old_fb)
                return;
 
        fb_addr = mxsfb_get_fb_paddr(mxsfb);
@@ -533,4 +534,17 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private 
*mxsfb,
                src_w = new_state->src_w >> 16;
                mxsfb_set_fb_hcrop(mxsfb, src_w, stride);
        }
+
+       if (old_fb->format->format != fb->format->format) {
+               struct drm_format_name_buf old_fmt_buf;
+               struct drm_format_name_buf new_fmt_buf;
+
+               DRM_DEV_DEBUG_DRIVER(crtc->dev->dev,
+                               "Switching pixel format: %s -> %s\n",
+                               drm_get_format_name(old_fb->format->format,
+                                                   &old_fmt_buf),
+                               drm_get_format_name(fb->format->format,
+                                                   &new_fmt_buf));
+               mxsfb_set_pixel_fmt(mxsfb, true);
+       }
 }
-- 
2.7.4