| Message ID | 20211021140552.v2.2.I3ed2a84c58d9e81965f497d587f735eea56c1684@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] drm/bridge: parade-ps8640: Enable runtime power management | expand |
Quoting Philip Chen (2021-10-21 14:06:00) > diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c > index 220ca3b03d24..f99a2e0808b7 100644 > --- a/drivers/gpu/drm/bridge/parade-ps8640.c > +++ b/drivers/gpu/drm/bridge/parade-ps8640.c > @@ -149,6 +150,23 @@ static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux) > return container_of(aux, struct ps8640, aux); > } > > +static bool ps8640_of_panel_on_aux_bus(struct device *dev) > +{ > + struct device_node *bus, *panel; > + > + bus = of_get_child_by_name(dev->of_node, "aux-bus"); > + if (!bus) > + return false; > + of_node_put(bus); This should come after the next line... > + > + panel = of_get_child_by_name(bus, "panel"); here, so that 'bus' can't go away before getting children nodes. It doesn't actually matter in this case because 'device' holds the aux-bus, but we shouldn't add anti-patterns to the code lest someone copies it where it actually matters. > + if (!panel) > + return false; > + of_node_put(panel); > + > + return true; > +} > + > static void ps8640_ensure_hpd(struct ps8640 *ps_bridge) > { > struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL]; Otherwise Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Hi, On Mon, Oct 25, 2021 at 1:10 PM Stephen Boyd <swboyd@chromium.org> wrote: > > Quoting Philip Chen (2021-10-21 14:06:00) > > diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c > > index 220ca3b03d24..f99a2e0808b7 100644 > > --- a/drivers/gpu/drm/bridge/parade-ps8640.c > > +++ b/drivers/gpu/drm/bridge/parade-ps8640.c > > @@ -149,6 +150,23 @@ static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux) > > return container_of(aux, struct ps8640, aux); > > } > > > > +static bool ps8640_of_panel_on_aux_bus(struct device *dev) > > +{ > > + struct device_node *bus, *panel; > > + > > + bus = of_get_child_by_name(dev->of_node, "aux-bus"); > > + if (!bus) > > + return false; > > + of_node_put(bus); > > This should come after the next line... > > > + > > + panel = of_get_child_by_name(bus, "panel"); > > here, so that 'bus' can't go away before getting children nodes. It > doesn't actually matter in this case because 'device' holds the aux-bus, > but we shouldn't add anti-patterns to the code lest someone copies it > where it actually matters. Thanks for pointing it out. I will fix it in v3. > > > + if (!panel) > > + return false; > > + of_node_put(panel); > > + > > + return true; > > +} > > + > > static void ps8640_ensure_hpd(struct ps8640 *ps_bridge) > > { > > struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL]; > > Otherwise > > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index 431b6e12a81f..61db5a66b493 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -182,6 +182,7 @@ config DRM_PARADE_PS8622 config DRM_PARADE_PS8640 tristate "Parade PS8640 MIPI DSI to eDP Converter" depends on OF + select DRM_DP_AUX_BUS select DRM_KMS_HELPER select DRM_MIPI_DSI select DRM_PANEL diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c index 220ca3b03d24..f99a2e0808b7 100644 --- a/drivers/gpu/drm/bridge/parade-ps8640.c +++ b/drivers/gpu/drm/bridge/parade-ps8640.c @@ -14,6 +14,7 @@ #include <linux/regulator/consumer.h> #include <drm/drm_bridge.h> +#include <drm/drm_dp_aux_bus.h> #include <drm/drm_dp_helper.h> #include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> @@ -149,6 +150,23 @@ static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux) return container_of(aux, struct ps8640, aux); } +static bool ps8640_of_panel_on_aux_bus(struct device *dev) +{ + struct device_node *bus, *panel; + + bus = of_get_child_by_name(dev->of_node, "aux-bus"); + if (!bus) + return false; + of_node_put(bus); + + panel = of_get_child_by_name(bus, "panel"); + if (!panel) + return false; + of_node_put(panel); + + return true; +} + static void ps8640_ensure_hpd(struct ps8640 *ps_bridge) { struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL]; @@ -411,7 +429,7 @@ static void ps8640_post_disable(struct drm_bridge *bridge) ps_bridge->pre_enabled = false; ps8640_bridge_vdo_control(ps_bridge, DISABLE); - pm_runtime_put_sync(&ps_bridge->page[PAGE0_DP_CNTL]->dev); + pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev); } static int ps8640_bridge_attach(struct drm_bridge *bridge, @@ -549,17 +567,6 @@ static int ps8640_probe(struct i2c_client *client) if (!ps_bridge) return -ENOMEM; - /* port@1 is ps8640 output port */ - ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL); - if (ret < 0) - return ret; - if (!panel) - return -ENODEV; - - ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel); - if (IS_ERR(ps_bridge->panel_bridge)) - return PTR_ERR(ps_bridge->panel_bridge); - ps_bridge->supplies[0].supply = "vdd33"; ps_bridge->supplies[1].supply = "vdd12"; ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies), @@ -582,9 +589,16 @@ static int ps8640_probe(struct i2c_client *client) ps_bridge->bridge.funcs = &ps8640_bridge_funcs; ps_bridge->bridge.of_node = dev->of_node; - ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP; + /* + * In the device tree, if panel is listed under aux-bus of the bridge + * node, panel driver should be able to retrieve EDID by itself using + * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here. + */ + if (!ps8640_of_panel_on_aux_bus(&client->dev)) + ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; + ps_bridge->page[PAGE0_DP_CNTL] = client; ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config); @@ -618,6 +632,19 @@ static int ps8640_probe(struct i2c_client *client) if (ret) return ret; + devm_of_dp_aux_populate_ep_devices(&ps_bridge->aux); + + /* port@1 is ps8640 output port */ + ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL); + if (ret < 0) + return ret; + if (!panel) + return -ENODEV; + + ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel); + if (IS_ERR(ps_bridge->panel_bridge)) + return PTR_ERR(ps_bridge->panel_bridge); + drm_bridge_add(&ps_bridge->bridge); return 0;
Conventionally, panel is listed under the root of the device tree. When userland asks for display mode, ps8640 bridge is responsible for returning EDID when ps8640_bridge_get_edid() is called. Now enable a new option of listing panel under "aux-bus" of ps8640 bridge node in the device tree. In this case, panel driver can retrieve EDID by triggering AUX transactions, without ps8640_bridge_get_edid() calls at all. To prevent the "old" and "new" options from interfering with each other's logic flow, disable DRM_BRIDGE_OP_EDID when the new option is taken. Signed-off-by: Philip Chen <philipchen@chromium.org> --- Changes in v2: - Add of_node_put() calls in ps8640_of_panel_on_aux_bus() - Select DRM_DP_AUX_BUS for PS8640 driver in Kconfig - Replace _put_sync() with _put_sync_suspend() in ps8640_post_disable() drivers/gpu/drm/bridge/Kconfig | 1 + drivers/gpu/drm/bridge/parade-ps8640.c | 53 +++++++++++++++++++------- 2 files changed, 41 insertions(+), 13 deletions(-)