1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2015-2016 Free Electrons 4 * Copyright (C) 2015-2016 NextThing Co 5 * 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 23 struct simple_bridge_info { 24 const struct drm_bridge_timings *timings; 25 unsigned int connector_type; 26 }; 27 28 struct simple_bridge { 29 struct drm_bridge bridge; 30 struct drm_connector connector; 31 32 const struct simple_bridge_info *info; 33 34 struct regulator *vdd; 35 struct gpio_desc *enable; 36 }; 37 38 static inline struct simple_bridge * 39 drm_bridge_to_simple_bridge(struct drm_bridge *bridge) 40 { 41 return container_of(bridge, struct simple_bridge, bridge); 42 } 43 44 static inline struct simple_bridge * 45 drm_connector_to_simple_bridge(struct drm_connector *connector) 46 { 47 return container_of(connector, struct simple_bridge, connector); 48 } 49 50 static int simple_bridge_get_modes(struct drm_connector *connector) 51 { 52 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector); 53 const struct drm_edid *drm_edid; 54 int ret; 55 56 if (sbridge->bridge.next_bridge->ops & DRM_BRIDGE_OP_EDID) { 57 drm_edid = drm_bridge_edid_read(sbridge->bridge.next_bridge, connector); 58 if (!drm_edid) 59 DRM_INFO("EDID read failed. Fallback to standard modes\n"); 60 } else { 61 drm_edid = NULL; 62 } 63 64 drm_edid_connector_update(connector, drm_edid); 65 66 if (!drm_edid) { 67 /* 68 * In case we cannot retrieve the EDIDs (missing or broken DDC 69 * bus from the next bridge), fallback on the XGA standards and 70 * prefer a mode pretty much anyone can handle. 71 */ 72 ret = drm_add_modes_noedid(connector, 1920, 1200); 73 drm_set_preferred_mode(connector, 1024, 768); 74 return ret; 75 } 76 77 ret = drm_edid_connector_add_modes(connector); 78 drm_edid_free(drm_edid); 79 80 return ret; 81 } 82 83 static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = { 84 .get_modes = simple_bridge_get_modes, 85 }; 86 87 static enum drm_connector_status 88 simple_bridge_connector_detect(struct drm_connector *connector, bool force) 89 { 90 struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector); 91 92 return drm_bridge_detect(sbridge->bridge.next_bridge, connector); 93 } 94 95 static const struct drm_connector_funcs simple_bridge_con_funcs = { 96 .detect = simple_bridge_connector_detect, 97 .fill_modes = drm_helper_probe_single_connector_modes, 98 .destroy = drm_connector_cleanup, 99 .reset = drm_atomic_helper_connector_reset, 100 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 101 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 102 }; 103 104 static int simple_bridge_attach(struct drm_bridge *bridge, 105 struct drm_encoder *encoder, 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(encoder, sbridge->bridge.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->bridge.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, encoder); 131 132 return 0; 133 } 134 135 static void simple_bridge_enable(struct drm_bridge *bridge, 136 struct drm_atomic_commit *commit) 137 { 138 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge); 139 int ret; 140 141 if (sbridge->vdd) { 142 ret = regulator_enable(sbridge->vdd); 143 if (ret) 144 DRM_ERROR("Failed to enable vdd regulator: %d\n", ret); 145 } 146 147 gpiod_set_value_cansleep(sbridge->enable, 1); 148 } 149 150 static void simple_bridge_disable(struct drm_bridge *bridge, 151 struct drm_atomic_commit *commit) 152 { 153 struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge); 154 155 gpiod_set_value_cansleep(sbridge->enable, 0); 156 157 if (sbridge->vdd) 158 regulator_disable(sbridge->vdd); 159 } 160 161 static const struct drm_bridge_funcs simple_bridge_bridge_funcs = { 162 .atomic_create_state = drm_atomic_helper_bridge_create_state, 163 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, 164 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, 165 .attach = simple_bridge_attach, 166 .atomic_enable = simple_bridge_enable, 167 .atomic_disable = simple_bridge_disable, 168 }; 169 170 static int simple_bridge_probe(struct platform_device *pdev) 171 { 172 struct simple_bridge *sbridge; 173 struct device_node *remote; 174 175 sbridge = devm_drm_bridge_alloc(&pdev->dev, struct simple_bridge, 176 bridge, &simple_bridge_bridge_funcs); 177 if (IS_ERR(sbridge)) 178 return PTR_ERR(sbridge); 179 180 sbridge->info = of_device_get_match_data(&pdev->dev); 181 182 /* Get the next bridge in the pipeline. */ 183 remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1); 184 if (!remote) 185 return -EINVAL; 186 187 sbridge->bridge.next_bridge = of_drm_find_and_get_bridge(remote); 188 of_node_put(remote); 189 190 if (!sbridge->bridge.next_bridge) { 191 dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n"); 192 return -EPROBE_DEFER; 193 } 194 195 /* Get the regulator and GPIO resources. */ 196 sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd"); 197 if (IS_ERR(sbridge->vdd)) { 198 int ret = PTR_ERR(sbridge->vdd); 199 if (ret == -EPROBE_DEFER) 200 return -EPROBE_DEFER; 201 sbridge->vdd = NULL; 202 dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret); 203 } 204 205 sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable", 206 GPIOD_OUT_LOW); 207 if (IS_ERR(sbridge->enable)) 208 return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->enable), 209 "Unable to retrieve enable GPIO\n"); 210 211 /* Register the bridge. */ 212 sbridge->bridge.of_node = pdev->dev.of_node; 213 sbridge->bridge.timings = sbridge->info->timings; 214 215 return devm_drm_bridge_add(&pdev->dev, &sbridge->bridge); 216 } 217 218 /* 219 * We assume the ADV7123 DAC is the "default" for historical reasons 220 * Information taken from the ADV7123 datasheet, revision D. 221 * NOTE: the ADV7123EP seems to have other timings and need a new timings 222 * set if used. 223 */ 224 static const struct drm_bridge_timings default_bridge_timings = { 225 /* Timing specifications, datasheet page 7 */ 226 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, 227 .setup_time_ps = 500, 228 .hold_time_ps = 1500, 229 }; 230 231 /* 232 * Information taken from the THS8134, THS8134A, THS8134B datasheet named 233 * "SLVS205D", dated May 1990, revised March 2000. 234 */ 235 static const struct drm_bridge_timings ti_ths8134_bridge_timings = { 236 /* From timing diagram, datasheet page 9 */ 237 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, 238 /* From datasheet, page 12 */ 239 .setup_time_ps = 3000, 240 /* I guess this means latched input */ 241 .hold_time_ps = 0, 242 }; 243 244 /* 245 * Information taken from the THS8135 datasheet named "SLAS343B", dated 246 * May 2001, revised April 2013. 247 */ 248 static const struct drm_bridge_timings ti_ths8135_bridge_timings = { 249 /* From timing diagram, datasheet page 14 */ 250 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, 251 /* From datasheet, page 16 */ 252 .setup_time_ps = 2000, 253 .hold_time_ps = 500, 254 }; 255 256 static const struct of_device_id simple_bridge_match[] = { 257 { 258 .compatible = "dumb-vga-dac", 259 .data = &(const struct simple_bridge_info) { 260 .connector_type = DRM_MODE_CONNECTOR_VGA, 261 }, 262 }, { 263 .compatible = "adi,adv7123", 264 .data = &(const struct simple_bridge_info) { 265 .timings = &default_bridge_timings, 266 .connector_type = DRM_MODE_CONNECTOR_VGA, 267 }, 268 }, { 269 .compatible = "algoltek,ag6311", 270 .data = &(const struct simple_bridge_info) { 271 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 272 }, 273 }, { 274 .compatible = "asl-tek,cs5263", 275 .data = &(const struct simple_bridge_info) { 276 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 277 }, 278 }, { 279 .compatible = "mstar,tsumu88adt3-lf-1", 280 .data = &(const struct simple_bridge_info) { 281 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 282 }, 283 }, { 284 .compatible = "parade,ps185hdm", 285 .data = &(const struct simple_bridge_info) { 286 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 287 }, 288 }, { 289 .compatible = "radxa,ra620", 290 .data = &(const struct simple_bridge_info) { 291 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 292 }, 293 }, { 294 .compatible = "realtek,rtd2171", 295 .data = &(const struct simple_bridge_info) { 296 .connector_type = DRM_MODE_CONNECTOR_HDMIA, 297 }, 298 }, { 299 .compatible = "ti,opa362", 300 .data = &(const struct simple_bridge_info) { 301 .connector_type = DRM_MODE_CONNECTOR_Composite, 302 }, 303 }, { 304 .compatible = "ti,ths8135", 305 .data = &(const struct simple_bridge_info) { 306 .timings = &ti_ths8135_bridge_timings, 307 .connector_type = DRM_MODE_CONNECTOR_VGA, 308 }, 309 }, { 310 .compatible = "ti,ths8134", 311 .data = &(const struct simple_bridge_info) { 312 .timings = &ti_ths8134_bridge_timings, 313 .connector_type = DRM_MODE_CONNECTOR_VGA, 314 }, 315 }, 316 {}, 317 }; 318 MODULE_DEVICE_TABLE(of, simple_bridge_match); 319 320 static struct platform_driver simple_bridge_driver = { 321 .probe = simple_bridge_probe, 322 .driver = { 323 .name = "simple-bridge", 324 .of_match_table = simple_bridge_match, 325 }, 326 }; 327 module_platform_driver(simple_bridge_driver); 328 329 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); 330 MODULE_DESCRIPTION("Simple DRM bridge driver"); 331 MODULE_LICENSE("GPL"); 332