Re: [PATCH v2 5/7] drm/ltdc: Use the panel-bridge helper.

From: Philippe CORNU
Date: Tue May 30 2017 - 12:56:12 EST

Hi Eric,

I took your patch for the panel-bridge and it works perfectly in both
DPI mode (panel RGB //) and DSI mode (bridge dw mipi dsi), bravo :-)

~160 lines have been removed from ltdc.c thanks to your panel-bridge code!

Many thanks
Philippe

On 05/11/2017 08:31 PM, Eric Anholt wrote:
> Another 100 lines of boilerplate gone. Bridges aren't supported yet,
> but will be trivial to add later.
>
> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> ---
>
> Also untested.
>
> drivers/gpu/drm/stm/ltdc.c | 128 +++++----------------------------------------
> drivers/gpu/drm/stm/ltdc.h | 2 +-
> 2 files changed, 13 insertions(+), 117 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index a40418cda74a..41a1c5d68f5b 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -269,11 +269,6 @@ static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
> return (struct ltdc_device *)enc->dev->dev_private;
> }
>
> -static inline struct ltdc_device *connector_to_ltdc(struct drm_connector *con)
> -{
> - return (struct ltdc_device *)con->dev->dev_private;
> -}
> -
> static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
> {
> enum ltdc_pix_fmt pf;
> @@ -815,22 +810,12 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
>
> static void ltdc_rgb_encoder_enable(struct drm_encoder *encoder)
> {
> - struct ltdc_device *ldev = encoder_to_ltdc(encoder);
> -
> DRM_DEBUG_DRIVER("\n");
> -
> - drm_panel_prepare(ldev->panel);
> - drm_panel_enable(ldev->panel);
> }
>
> static void ltdc_rgb_encoder_disable(struct drm_encoder *encoder)
> {
> - struct ltdc_device *ldev = encoder_to_ltdc(encoder);
> -
> DRM_DEBUG_DRIVER("\n");
> -
> - drm_panel_disable(ldev->panel);
> - drm_panel_unprepare(ldev->panel);
> }
>
> static const struct drm_encoder_helper_funcs ltdc_rgb_encoder_helper_funcs = {
> @@ -863,82 +848,6 @@ static struct drm_encoder *ltdc_rgb_encoder_create(struct drm_device *ddev)
> return encoder;
> }
>
> -/*
> - * DRM_CONNECTOR
> - */
> -
> -static int ltdc_rgb_connector_get_modes(struct drm_connector *connector)
> -{
> - struct drm_device *ddev = connector->dev;
> - struct ltdc_device *ldev = ddev->dev_private;
> - int ret = 0;
> -
> - DRM_DEBUG_DRIVER("\n");
> -
> - if (ldev->panel)
> - ret = drm_panel_get_modes(ldev->panel);
> -
> - return ret < 0 ? 0 : ret;
> -}
> -
> -static struct drm_connector_helper_funcs ltdc_rgb_connector_helper_funcs = {
> - .get_modes = ltdc_rgb_connector_get_modes,
> -};
> -
> -static enum drm_connector_status
> -ltdc_rgb_connector_detect(struct drm_connector *connector, bool force)
> -{
> - struct ltdc_device *ldev = connector_to_ltdc(connector);
> -
> - return ldev->panel ? connector_status_connected :
> - connector_status_disconnected;
> -}
> -
> -static void ltdc_rgb_connector_destroy(struct drm_connector *connector)
> -{
> - DRM_DEBUG_DRIVER("\n");
> -
> - drm_connector_unregister(connector);
> - drm_connector_cleanup(connector);
> -}
> -
> -static const struct drm_connector_funcs ltdc_rgb_connector_funcs = {
> - .dpms = drm_atomic_helper_connector_dpms,
> - .fill_modes = drm_helper_probe_single_connector_modes,
> - .detect = ltdc_rgb_connector_detect,
> - .destroy = ltdc_rgb_connector_destroy,
> - .reset = drm_atomic_helper_connector_reset,
> - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> - .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> -};
> -
> -struct drm_connector *ltdc_rgb_connector_create(struct drm_device *ddev)
> -{
> - struct drm_connector *connector;
> - int err;
> -
> - connector = devm_kzalloc(ddev->dev, sizeof(*connector), GFP_KERNEL);
> - if (!connector) {
> - DRM_ERROR("Failed to allocate connector\n");
> - return NULL;
> - }
> -
> - connector->polled = DRM_CONNECTOR_POLL_HPD;
> -
> - err = drm_connector_init(ddev, connector, &ltdc_rgb_connector_funcs,
> - DRM_MODE_CONNECTOR_DPI);
> - if (err) {
> - DRM_ERROR("Failed to initialize connector\n");
> - return NULL;
> - }
> -
> - drm_connector_helper_add(connector, &ltdc_rgb_connector_helper_funcs);
> -
> - DRM_DEBUG_DRIVER("RGB connector:%d created\n", connector->base.id);
> -
> - return connector;
> -}
> -
> static int ltdc_get_caps(struct drm_device *ddev)
> {
> struct ltdc_device *ldev = ddev->dev_private;
> @@ -972,7 +881,7 @@ static int ltdc_get_caps(struct drm_device *ddev)
> return 0;
> }
>
> -static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
> +static struct drm_bridge *ltdc_get_bridge(struct drm_device *ddev)
> {
> struct device *dev = ddev->dev;
> struct device_node *np = dev->of_node;
> @@ -1004,7 +913,10 @@ static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
> }
> }
>
> - return panel;
> + if (!panel)
> + return ERR_PTR(-ENODEV);
> +
> + return drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
> }
>
> int ltdc_load(struct drm_device *ddev)
> @@ -1014,7 +926,6 @@ int ltdc_load(struct drm_device *ddev)
> struct device *dev = ddev->dev;
> struct device_node *np = dev->of_node;
> struct drm_encoder *encoder;
> - struct drm_connector *connector = NULL;
> struct drm_crtc *crtc;
> struct reset_control *rstc;
> struct resource res;
> @@ -1022,8 +933,8 @@ int ltdc_load(struct drm_device *ddev)
>
> DRM_DEBUG_DRIVER("\n");
>
> - ldev->panel = ltdc_get_panel(ddev);
> - if (!ldev->panel)
> + ldev->bridge = ltdc_get_bridge(ddev);
> + if (!ldev->bridge)
> return -EPROBE_DEFER;
>
> rstc = of_reset_control_get(np, NULL);
> @@ -1082,28 +993,13 @@ int ltdc_load(struct drm_device *ddev)
>
> DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
>
> - if (ldev->panel) {
> + if (ldev->bridge) {
> encoder = ltdc_rgb_encoder_create(ddev);
> if (!encoder) {
> DRM_ERROR("Failed to create RGB encoder\n");
> ret = -EINVAL;
> goto err;
> }
> -
> - connector = ltdc_rgb_connector_create(ddev);
> - if (!connector) {
> - DRM_ERROR("Failed to create RGB connector\n");
> - ret = -EINVAL;
> - goto err;
> - }
> -
> - ret = drm_mode_connector_attach_encoder(connector, encoder);
> - if (ret) {
> - DRM_ERROR("Failed to attach connector to encoder\n");
> - goto err;
> - }
> -
> - drm_panel_attach(ldev->panel, connector);
> }
>
> crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
> @@ -1130,8 +1026,8 @@ int ltdc_load(struct drm_device *ddev)
>
> return 0;
> err:
> - if (ldev->panel)
> - drm_panel_detach(ldev->panel);
> + if (ldev->bridge)
> + drm_panel_bridge_remove(ldev->bridge);
>
> clk_disable_unprepare(ldev->pixel_clk);
>
> @@ -1146,8 +1042,8 @@ void ltdc_unload(struct drm_device *ddev)
>
> drm_vblank_cleanup(ddev);
>
> - if (ldev->panel)
> - drm_panel_detach(ldev->panel);
> + if (ldev->bridge)
> + drm_panel_bridge_remove(ldev->bridge);
>
> clk_disable_unprepare(ldev->pixel_clk);
> }
> diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
> index d7a9c736ac1e..d78cb0dd3200 100644
> --- a/drivers/gpu/drm/stm/ltdc.h
> +++ b/drivers/gpu/drm/stm/ltdc.h
> @@ -24,7 +24,7 @@ struct ltdc_device {
> struct drm_fbdev_cma *fbdev;
> void __iomem *regs;
> struct clk *pixel_clk; /* lcd pixel clock */
> - struct drm_panel *panel;
> + struct drm_bridge *bridge;
> struct mutex err_lock; /* protecting error_status */
> struct ltdc_caps caps;
> u32 clut[256]; /* color look up table */
>