// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2015-2016 Free Electrons * Copyright (C) 2015-2016 NextThing Co * * Maxime Ripard */ #include #include #include #include #include #include #include #include #include #include #include #include struct simple_bridge_info { const struct drm_bridge_timings *timings; unsigned int connector_type; }; struct simple_bridge { struct drm_bridge bridge; struct drm_connector connector; const struct simple_bridge_info *info; struct drm_bridge *next_bridge; struct regulator *vdd; struct gpio_desc *enable; }; static inline struct simple_bridge * drm_bridge_to_simple_bridge(struct drm_bridge *bridge) { return container_of(bridge, struct simple_bridge, bridge); } static inline struct simple_bridge * drm_connector_to_simple_bridge(struct drm_connector *connector) { return container_of(connector, struct simple_bridge, connector); } static int simple_bridge_get_modes(struct drm_connector *connector) { struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector); const struct drm_edid *drm_edid; int ret; if (sbridge->next_bridge->ops & DRM_BRIDGE_OP_EDID) { drm_edid = drm_bridge_edid_read(sbridge->next_bridge, connector); if (!drm_edid) DRM_INFO("EDID read failed. Fallback to standard modes\n"); } else { drm_edid = NULL; } drm_edid_connector_update(connector, drm_edid); if (!drm_edid) { /* * In case we cannot retrieve the EDIDs (missing or broken DDC * bus from the next bridge), fallback on the XGA standards and * prefer a mode pretty much anyone can handle. */ ret = drm_add_modes_noedid(connector, 1920, 1200); drm_set_preferred_mode(connector, 1024, 768); return ret; } ret = drm_edid_connector_add_modes(connector); drm_edid_free(drm_edid); return ret; } static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = { .get_modes = simple_bridge_get_modes, }; static enum drm_connector_status simple_bridge_connector_detect(struct drm_connector *connector, bool force) { struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector); return drm_bridge_detect(sbridge->next_bridge); } static const struct drm_connector_funcs simple_bridge_con_funcs = { .detect = simple_bridge_connector_detect, .fill_modes = drm_helper_probe_single_connector_modes, .destroy = drm_connector_cleanup, .reset = drm_atomic_helper_connector_reset, .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, }; static int simple_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge); int ret; ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge, DRM_BRIDGE_ATTACH_NO_CONNECTOR); if (ret < 0) return ret; if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) return 0; drm_connector_helper_add(&sbridge->connector, &simple_bridge_con_helper_funcs); ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector, &simple_bridge_con_funcs, sbridge->info->connector_type, sbridge->next_bridge->ddc); if (ret) { DRM_ERROR("Failed to initialize connector\n"); return ret; } drm_connector_attach_encoder(&sbridge->connector, bridge->encoder); return 0; } static void simple_bridge_enable(struct drm_bridge *bridge) { struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge); int ret; if (sbridge->vdd) { ret = regulator_enable(sbridge->vdd); if (ret) DRM_ERROR("Failed to enable vdd regulator: %d\n", ret); } gpiod_set_value_cansleep(sbridge->enable, 1); } static void simple_bridge_disable(struct drm_bridge *bridge) { struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge); gpiod_set_value_cansleep(sbridge->enable, 0); if (sbridge->vdd) regulator_disable(sbridge->vdd); } static const struct drm_bridge_funcs simple_bridge_bridge_funcs = { .attach = simple_bridge_attach, .enable = simple_bridge_enable, .disable = simple_bridge_disable, }; static int simple_bridge_probe(struct platform_device *pdev) { struct simple_bridge *sbridge; struct device_node *remote; sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL); if (!sbridge) return -ENOMEM; sbridge->info = of_device_get_match_data(&pdev->dev); /* Get the next bridge in the pipeline. */ remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1); if (!remote) return -EINVAL; sbridge->next_bridge = of_drm_find_bridge(remote); of_node_put(remote); if (!sbridge->next_bridge) { dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n"); return -EPROBE_DEFER; } /* Get the regulator and GPIO resources. */ sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd"); if (IS_ERR(sbridge->vdd)) { int ret = PTR_ERR(sbridge->vdd); if (ret == -EPROBE_DEFER) return -EPROBE_DEFER; sbridge->vdd = NULL; dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret); } sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable", GPIOD_OUT_LOW); if (IS_ERR(sbridge->enable)) return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->enable), "Unable to retrieve enable GPIO\n"); /* Register the bridge. */ sbridge->bridge.funcs = &simple_bridge_bridge_funcs; sbridge->bridge.of_node = pdev->dev.of_node; sbridge->bridge.timings = sbridge->info->timings; return devm_drm_bridge_add(&pdev->dev, &sbridge->bridge); } /* * We assume the ADV7123 DAC is the "default" for historical reasons * Information taken from the ADV7123 datasheet, revision D. * NOTE: the ADV7123EP seems to have other timings and need a new timings * set if used. */ static const struct drm_bridge_timings default_bridge_timings = { /* Timing specifications, datasheet page 7 */ .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, .setup_time_ps = 500, .hold_time_ps = 1500, }; /* * Information taken from the THS8134, THS8134A, THS8134B datasheet named * "SLVS205D", dated May 1990, revised March 2000. */ static const struct drm_bridge_timings ti_ths8134_bridge_timings = { /* From timing diagram, datasheet page 9 */ .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, /* From datasheet, page 12 */ .setup_time_ps = 3000, /* I guess this means latched input */ .hold_time_ps = 0, }; /* * Information taken from the THS8135 datasheet named "SLAS343B", dated * May 2001, revised April 2013. */ static const struct drm_bridge_timings ti_ths8135_bridge_timings = { /* From timing diagram, datasheet page 14 */ .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, /* From datasheet, page 16 */ .setup_time_ps = 2000, .hold_time_ps = 500, }; static const struct of_device_id simple_bridge_match[] = { { .compatible = "dumb-vga-dac", .data = &(const struct simple_bridge_info) { .connector_type = DRM_MODE_CONNECTOR_VGA, }, }, { .compatible = "adi,adv7123", .data = &(const struct simple_bridge_info) { .timings = &default_bridge_timings, .connector_type = DRM_MODE_CONNECTOR_VGA, }, }, { .compatible = "ti,opa362", .data = &(const struct simple_bridge_info) { .connector_type = DRM_MODE_CONNECTOR_Composite, }, }, { .compatible = "ti,ths8135", .data = &(const struct simple_bridge_info) { .timings = &ti_ths8135_bridge_timings, .connector_type = DRM_MODE_CONNECTOR_VGA, }, }, { .compatible = "ti,ths8134", .data = &(const struct simple_bridge_info) { .timings = &ti_ths8134_bridge_timings, .connector_type = DRM_MODE_CONNECTOR_VGA, }, }, {}, }; MODULE_DEVICE_TABLE(of, simple_bridge_match); static struct platform_driver simple_bridge_driver = { .probe = simple_bridge_probe, .driver = { .name = "simple-bridge", .of_match_table = simple_bridge_match, }, }; module_platform_driver(simple_bridge_driver); MODULE_AUTHOR("Maxime Ripard "); MODULE_DESCRIPTION("Simple DRM bridge driver"); MODULE_LICENSE("GPL");