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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2015-2016 Free Electrons4 * Copyright (C) 2015-2016 NextThing Co5 *6 * Maxime Ripard <maxime.ripard@free-electrons.com>7 */8 9#include <linux/gpio/consumer.h>10#include <linux/module.h>11#include <linux/of.h>12#include <linux/of_graph.h>13#include <linux/platform_device.h>14#include <linux/regulator/consumer.h>15 16#include <drm/drm_atomic_helper.h>17#include <drm/drm_bridge.h>18#include <drm/drm_crtc.h>19#include <drm/drm_edid.h>20#include <drm/drm_print.h>21#include <drm/drm_probe_helper.h>22 23struct simple_bridge_info {24 const struct drm_bridge_timings *timings;25 unsigned int connector_type;26};27 28struct simple_bridge {29 struct drm_bridge bridge;30 struct drm_connector connector;31 32 const struct simple_bridge_info *info;33 34 struct drm_bridge *next_bridge;35 struct regulator *vdd;36 struct gpio_desc *enable;37};38 39static inline struct simple_bridge *40drm_bridge_to_simple_bridge(struct drm_bridge *bridge)41{42 return container_of(bridge, struct simple_bridge, bridge);43}44 45static inline struct simple_bridge *46drm_connector_to_simple_bridge(struct drm_connector *connector)47{48 return container_of(connector, struct simple_bridge, connector);49}50 51static int simple_bridge_get_modes(struct drm_connector *connector)52{53 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);54 const struct drm_edid *drm_edid;55 int ret;56 57 if (sbridge->next_bridge->ops & DRM_BRIDGE_OP_EDID) {58 drm_edid = drm_bridge_edid_read(sbridge->next_bridge, connector);59 if (!drm_edid)60 DRM_INFO("EDID read failed. Fallback to standard modes\n");61 } else {62 drm_edid = NULL;63 }64 65 drm_edid_connector_update(connector, drm_edid);66 67 if (!drm_edid) {68 /*69 * In case we cannot retrieve the EDIDs (missing or broken DDC70 * bus from the next bridge), fallback on the XGA standards and71 * prefer a mode pretty much anyone can handle.72 */73 ret = drm_add_modes_noedid(connector, 1920, 1200);74 drm_set_preferred_mode(connector, 1024, 768);75 return ret;76 }77 78 ret = drm_edid_connector_add_modes(connector);79 drm_edid_free(drm_edid);80 81 return ret;82}83 84static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = {85 .get_modes = simple_bridge_get_modes,86};87 88static enum drm_connector_status89simple_bridge_connector_detect(struct drm_connector *connector, bool force)90{91 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);92 93 return drm_bridge_detect(sbridge->next_bridge);94}95 96static const struct drm_connector_funcs simple_bridge_con_funcs = {97 .detect = simple_bridge_connector_detect,98 .fill_modes = drm_helper_probe_single_connector_modes,99 .destroy = drm_connector_cleanup,100 .reset = drm_atomic_helper_connector_reset,101 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,102 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,103};104 105static int simple_bridge_attach(struct drm_bridge *bridge,106 enum drm_bridge_attach_flags flags)107{108 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);109 int ret;110 111 ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,112 DRM_BRIDGE_ATTACH_NO_CONNECTOR);113 if (ret < 0)114 return ret;115 116 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)117 return 0;118 119 drm_connector_helper_add(&sbridge->connector,120 &simple_bridge_con_helper_funcs);121 ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector,122 &simple_bridge_con_funcs,123 sbridge->info->connector_type,124 sbridge->next_bridge->ddc);125 if (ret) {126 DRM_ERROR("Failed to initialize connector\n");127 return ret;128 }129 130 drm_connector_attach_encoder(&sbridge->connector, bridge->encoder);131 132 return 0;133}134 135static void simple_bridge_enable(struct drm_bridge *bridge)136{137 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);138 int ret;139 140 if (sbridge->vdd) {141 ret = regulator_enable(sbridge->vdd);142 if (ret)143 DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);144 }145 146 gpiod_set_value_cansleep(sbridge->enable, 1);147}148 149static void simple_bridge_disable(struct drm_bridge *bridge)150{151 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);152 153 gpiod_set_value_cansleep(sbridge->enable, 0);154 155 if (sbridge->vdd)156 regulator_disable(sbridge->vdd);157}158 159static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {160 .attach = simple_bridge_attach,161 .enable = simple_bridge_enable,162 .disable = simple_bridge_disable,163};164 165static int simple_bridge_probe(struct platform_device *pdev)166{167 struct simple_bridge *sbridge;168 struct device_node *remote;169 170 sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);171 if (!sbridge)172 return -ENOMEM;173 174 sbridge->info = of_device_get_match_data(&pdev->dev);175 176 /* Get the next bridge in the pipeline. */177 remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);178 if (!remote)179 return -EINVAL;180 181 sbridge->next_bridge = of_drm_find_bridge(remote);182 of_node_put(remote);183 184 if (!sbridge->next_bridge) {185 dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");186 return -EPROBE_DEFER;187 }188 189 /* Get the regulator and GPIO resources. */190 sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");191 if (IS_ERR(sbridge->vdd)) {192 int ret = PTR_ERR(sbridge->vdd);193 if (ret == -EPROBE_DEFER)194 return -EPROBE_DEFER;195 sbridge->vdd = NULL;196 dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);197 }198 199 sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable",200 GPIOD_OUT_LOW);201 if (IS_ERR(sbridge->enable))202 return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->enable),203 "Unable to retrieve enable GPIO\n");204 205 /* Register the bridge. */206 sbridge->bridge.funcs = &simple_bridge_bridge_funcs;207 sbridge->bridge.of_node = pdev->dev.of_node;208 sbridge->bridge.timings = sbridge->info->timings;209 210 return devm_drm_bridge_add(&pdev->dev, &sbridge->bridge);211}212 213/*214 * We assume the ADV7123 DAC is the "default" for historical reasons215 * Information taken from the ADV7123 datasheet, revision D.216 * NOTE: the ADV7123EP seems to have other timings and need a new timings217 * set if used.218 */219static const struct drm_bridge_timings default_bridge_timings = {220 /* Timing specifications, datasheet page 7 */221 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,222 .setup_time_ps = 500,223 .hold_time_ps = 1500,224};225 226/*227 * Information taken from the THS8134, THS8134A, THS8134B datasheet named228 * "SLVS205D", dated May 1990, revised March 2000.229 */230static const struct drm_bridge_timings ti_ths8134_bridge_timings = {231 /* From timing diagram, datasheet page 9 */232 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,233 /* From datasheet, page 12 */234 .setup_time_ps = 3000,235 /* I guess this means latched input */236 .hold_time_ps = 0,237};238 239/*240 * Information taken from the THS8135 datasheet named "SLAS343B", dated241 * May 2001, revised April 2013.242 */243static const struct drm_bridge_timings ti_ths8135_bridge_timings = {244 /* From timing diagram, datasheet page 14 */245 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,246 /* From datasheet, page 16 */247 .setup_time_ps = 2000,248 .hold_time_ps = 500,249};250 251static const struct of_device_id simple_bridge_match[] = {252 {253 .compatible = "dumb-vga-dac",254 .data = &(const struct simple_bridge_info) {255 .connector_type = DRM_MODE_CONNECTOR_VGA,256 },257 }, {258 .compatible = "adi,adv7123",259 .data = &(const struct simple_bridge_info) {260 .timings = &default_bridge_timings,261 .connector_type = DRM_MODE_CONNECTOR_VGA,262 },263 }, {264 .compatible = "ti,opa362",265 .data = &(const struct simple_bridge_info) {266 .connector_type = DRM_MODE_CONNECTOR_Composite,267 },268 }, {269 .compatible = "ti,ths8135",270 .data = &(const struct simple_bridge_info) {271 .timings = &ti_ths8135_bridge_timings,272 .connector_type = DRM_MODE_CONNECTOR_VGA,273 },274 }, {275 .compatible = "ti,ths8134",276 .data = &(const struct simple_bridge_info) {277 .timings = &ti_ths8134_bridge_timings,278 .connector_type = DRM_MODE_CONNECTOR_VGA,279 },280 },281 {},282};283MODULE_DEVICE_TABLE(of, simple_bridge_match);284 285static struct platform_driver simple_bridge_driver = {286 .probe = simple_bridge_probe,287 .driver = {288 .name = "simple-bridge",289 .of_match_table = simple_bridge_match,290 },291};292module_platform_driver(simple_bridge_driver);293 294MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");295MODULE_DESCRIPTION("Simple DRM bridge driver");296MODULE_LICENSE("GPL");297