Re: [PATCH v3 3/7] drm: exynos: dsi: Convert to bridge driver

On 12.12.2021 19:14, Jagan Teki wrote:

Convert the encoders to bridge drivers in order to standardize on a single API with built-in dumb encoder support for compatibility with existing component drivers.

Driver bridge conversion will help to reuse the same bridge on different platforms as exynos dsi driver can be used as a Samsung DSIM and use it for i.MX8MM platform.

Bridge conversion,

• Drops drm_encoder_helper_funcs,

bridge_chain.

I wonder how it will behave on setup with two bridges after exynos_dsi.

• Adds drm_bridge_funcs and register a drm bridge.

Convert it.

Signed-off-by: Jagan Teki jagan@amarulasolutions.com

Changes for v3:

• move bridge add in host_attach
• move bridge remove in host_detach
• use flags, bridge in drm_bridge_attach in attch

Changes for v2:

• drop bridge_chain

  drivers/gpu/drm/exynos/exynos_drm_dsi.c | 82 +++++++++++++------------ 1 file changed, 43 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c index d1039628b6f2..1450187c1edc 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c @@ -259,7 +259,7 @@ struct exynos_dsi_driver_data { struct exynos_dsi { struct drm_encoder encoder; struct mipi_dsi_host dsi_host;

• struct list_head bridge_chain;

• struct drm_bridge bridge; struct drm_bridge *out_bridge; struct device *dev;

@@ -289,9 +289,9 @@ struct exynos_dsi {

#define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)

-static inline struct exynos_dsi *encoder_to_dsi(struct drm_encoder *e) +static inline struct exynos_dsi *bridge_to_dsi(struct drm_bridge *b) {

• return container_of(e, struct exynos_dsi, encoder);

• return container_of(b, struct exynos_dsi, bridge); }

  enum reg_idx {

@@ -882,9 +882,10 @@ static int exynos_dsi_init_link(struct exynos_dsi *dsi) return 0; }

-static void exynos_dsi_set_display_mode(struct exynos_dsi *dsi) +static void exynos_dsi_set_display_mode(struct drm_bridge *bridge) {

• struct drm_display_mode *m = &dsi->encoder.crtc->state->adjusted_mode;

• struct exynos_dsi *dsi = bridge_to_dsi(bridge);
• struct drm_display_mode *m = &bridge->encoder->crtc->state->adjusted_mode; unsigned int num_bits_resol = dsi->driver_data->num_bits_resol; u32 reg;

@@ -1376,10 +1377,10 @@ static void exynos_dsi_unregister_te_irq(struct exynos_dsi *dsi) } }

-static void exynos_dsi_enable(struct drm_encoder *encoder) +static void exynos_dsi_enable(struct drm_bridge *bridge) {

• struct exynos_dsi *dsi = encoder_to_dsi(encoder);
• struct drm_bridge *iter;

• struct exynos_dsi *dsi = bridge_to_dsi(bridge);
• const struct drm_bridge_funcs *funcs = dsi->out_bridge->funcs;

It will blow up in case there is no dsi->out_bridge, the same case in code below.

Beside this the conversion looks quite well, I hope tests will pass well :)

Regards

Andrzej

int ret;

if (dsi->state & DSIM_STATE_ENABLED) @@ -1393,52 +1394,53 @@ static void exynos_dsi_enable(struct drm_encoder *encoder)

dsi->state |= DSIM_STATE_ENABLED;

• list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {

• if (iter->funcs->pre_enable)
  

• 	iter->funcs->pre_enable(iter);
  

• }

• if (dsi->out_bridge)

• funcs->pre_enable(dsi->out_bridge);
  
  

• exynos_dsi_set_display_mode(dsi);

• exynos_dsi_set_display_mode(bridge); exynos_dsi_set_display_enable(dsi, true);

• list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {

• if (iter->funcs->enable)
  

• 	iter->funcs->enable(iter);
  

• }

• if (dsi->out_bridge)

• funcs->enable(dsi->out_bridge);
  
  

  dsi->state |= DSIM_STATE_VIDOUT_AVAILABLE; return; }

-static void exynos_dsi_disable(struct drm_encoder *encoder) +static void exynos_dsi_disable(struct drm_bridge *bridge) {

• struct exynos_dsi *dsi = encoder_to_dsi(encoder);
• struct drm_bridge *iter;

• struct exynos_dsi *dsi = bridge_to_dsi(bridge);

• const struct drm_bridge_funcs *funcs = dsi->out_bridge->funcs;

  if (!(dsi->state & DSIM_STATE_ENABLED)) return;

  dsi->state &= ~DSIM_STATE_VIDOUT_AVAILABLE;

• list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {

• if (iter->funcs->disable)
  

• 	iter->funcs->disable(iter);
  

• }

• if (dsi->out_bridge)

• funcs->disable(dsi->out_bridge);
  
  

  exynos_dsi_set_display_enable(dsi, false);

• list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {

• if (iter->funcs->post_disable)
  

• 	iter->funcs->post_disable(iter);
  

• }

• if (dsi->out_bridge)

• funcs->post_disable(dsi->out_bridge);
  
  

  dsi->state &= ~DSIM_STATE_ENABLED; pm_runtime_put_sync(dsi->dev); }

-static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {

• .enable = exynos_dsi_enable,
• .disable = exynos_dsi_disable,

+static int exynos_dsi_attach(struct drm_bridge *bridge,

• 	     enum drm_bridge_attach_flags flags)
  

+{

• struct exynos_dsi *dsi = bridge_to_dsi(bridge);
• return drm_bridge_attach(bridge->encoder, dsi->out_bridge, bridge, flags);

+}

+static const struct drm_bridge_funcs exynos_dsi_bridge_funcs = {

• .enable = exynos_dsi_enable,

• .disable = exynos_dsi_disable,

• .attach = exynos_dsi_attach, };

  MODULE_DEVICE_TABLE(of, exynos_dsi_of_match);

@@ -1460,8 +1462,9 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,

DRM_DEV_INFO(dsi->dev, "Attached %s device\n", device->name);

• drm_bridge_attach(encoder, dsi->out_bridge, NULL, 0);
• list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);

• drm_bridge_add(&dsi->bridge);

• drm_bridge_attach(encoder, &dsi->bridge, NULL, 0);

  /*

  • This is a temporary solution and should be made by more generic way.

@@ -1499,13 +1502,14 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,

if (dsi->out_bridge->funcs->detach) dsi->out_bridge->funcs->detach(dsi->out_bridge);

• INIT_LIST_HEAD(&dsi->bridge_chain);

  if (drm->mode_config.poll_enabled) drm_kms_helper_hotplug_event(drm);

  exynos_dsi_unregister_te_irq(dsi);

• drm_bridge_remove(&dsi->bridge);
• return 0; }

@@ -1591,8 +1595,6 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,

drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);

• drm_encoder_helper_add(encoder, &exynos_dsi_encoder_helper_funcs);
• ret = exynos_drm_set_possible_crtcs(encoder, EXYNOS_DISPLAY_TYPE_LCD); if (ret < 0) return ret;

@@ -1612,9 +1614,8 @@ static void exynos_dsi_unbind(struct device *dev, struct device *master, void *data) { struct exynos_dsi *dsi = dev_get_drvdata(dev);

• struct drm_encoder *encoder = &dsi->encoder;

• exynos_dsi_disable(encoder);

• exynos_dsi_disable(&dsi->bridge);

  mipi_dsi_host_unregister(&dsi->dsi_host); }

@@ -1640,7 +1641,6 @@ static int exynos_dsi_probe(struct platform_device *pdev) init_completion(&dsi->completed); spin_lock_init(&dsi->transfer_lock); INIT_LIST_HEAD(&dsi->transfer_list);

• INIT_LIST_HEAD(&dsi->bridge_chain);

  dsi->dsi_host.ops = &exynos_dsi_ops; dsi->dsi_host.dev = dev;

@@ -1708,6 +1708,10 @@ static int exynos_dsi_probe(struct platform_device *pdev)

pm_runtime_enable(dev);

• dsi->bridge.funcs = &exynos_dsi_bridge_funcs;
• dsi->bridge.of_node = dev->of_node;
• dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
• ret = component_add(dev, &exynos_dsi_component_ops); if (ret) goto err_disable_runtime;