1 /* 2 * NXP PTN3460 DP/LVDS bridge driver 3 * 4 * Copyright (C) 2013 Google, Inc. 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/delay.h> 17 #include <linux/gpio.h> 18 #include <linux/gpio/consumer.h> 19 #include <linux/i2c.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/of_gpio.h> 23 #include <linux/of_graph.h> 24 25 #include <drm/drm_panel.h> 26 27 #include "drm_crtc.h" 28 #include "drm_crtc_helper.h" 29 #include "drm_atomic_helper.h" 30 #include "drm_edid.h" 31 #include "drmP.h" 32 33 #define PTN3460_EDID_ADDR 0x0 34 #define PTN3460_EDID_EMULATION_ADDR 0x84 35 #define PTN3460_EDID_ENABLE_EMULATION 0 36 #define PTN3460_EDID_EMULATION_SELECTION 1 37 #define PTN3460_EDID_SRAM_LOAD_ADDR 0x85 38 39 struct ptn3460_bridge { 40 struct drm_connector connector; 41 struct i2c_client *client; 42 struct drm_bridge bridge; 43 struct edid *edid; 44 struct drm_panel *panel; 45 struct gpio_desc *gpio_pd_n; 46 struct gpio_desc *gpio_rst_n; 47 u32 edid_emulation; 48 bool enabled; 49 }; 50 51 static inline struct ptn3460_bridge * 52 bridge_to_ptn3460(struct drm_bridge *bridge) 53 { 54 return container_of(bridge, struct ptn3460_bridge, bridge); 55 } 56 57 static inline struct ptn3460_bridge * 58 connector_to_ptn3460(struct drm_connector *connector) 59 { 60 return container_of(connector, struct ptn3460_bridge, connector); 61 } 62 63 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, 64 u8 *buf, int len) 65 { 66 int ret; 67 68 ret = i2c_master_send(ptn_bridge->client, &addr, 1); 69 if (ret <= 0) { 70 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 71 return ret; 72 } 73 74 ret = i2c_master_recv(ptn_bridge->client, buf, len); 75 if (ret <= 0) { 76 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); 77 return ret; 78 } 79 80 return 0; 81 } 82 83 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, 84 char val) 85 { 86 int ret; 87 char buf[2]; 88 89 buf[0] = addr; 90 buf[1] = val; 91 92 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); 93 if (ret <= 0) { 94 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 95 return ret; 96 } 97 98 return 0; 99 } 100 101 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge) 102 { 103 int ret; 104 char val; 105 106 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */ 107 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR, 108 ptn_bridge->edid_emulation); 109 if (ret) { 110 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret); 111 return ret; 112 } 113 114 /* Enable EDID emulation and select the desired EDID */ 115 val = 1 << PTN3460_EDID_ENABLE_EMULATION | 116 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION; 117 118 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val); 119 if (ret) { 120 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret); 121 return ret; 122 } 123 124 return 0; 125 } 126 127 static void ptn3460_pre_enable(struct drm_bridge *bridge) 128 { 129 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 130 int ret; 131 132 if (ptn_bridge->enabled) 133 return; 134 135 gpiod_set_value(ptn_bridge->gpio_pd_n, 1); 136 137 gpiod_set_value(ptn_bridge->gpio_rst_n, 0); 138 usleep_range(10, 20); 139 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 140 141 if (drm_panel_prepare(ptn_bridge->panel)) { 142 DRM_ERROR("failed to prepare panel\n"); 143 return; 144 } 145 146 /* 147 * There's a bug in the PTN chip where it falsely asserts hotplug before 148 * it is fully functional. We're forced to wait for the maximum start up 149 * time specified in the chip's datasheet to make sure we're really up. 150 */ 151 msleep(90); 152 153 ret = ptn3460_select_edid(ptn_bridge); 154 if (ret) 155 DRM_ERROR("Select EDID failed ret=%d\n", ret); 156 157 ptn_bridge->enabled = true; 158 } 159 160 static void ptn3460_enable(struct drm_bridge *bridge) 161 { 162 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 163 164 if (drm_panel_enable(ptn_bridge->panel)) { 165 DRM_ERROR("failed to enable panel\n"); 166 return; 167 } 168 } 169 170 static void ptn3460_disable(struct drm_bridge *bridge) 171 { 172 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 173 174 if (!ptn_bridge->enabled) 175 return; 176 177 ptn_bridge->enabled = false; 178 179 if (drm_panel_disable(ptn_bridge->panel)) { 180 DRM_ERROR("failed to disable panel\n"); 181 return; 182 } 183 184 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 185 gpiod_set_value(ptn_bridge->gpio_pd_n, 0); 186 } 187 188 static void ptn3460_post_disable(struct drm_bridge *bridge) 189 { 190 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 191 192 if (drm_panel_unprepare(ptn_bridge->panel)) { 193 DRM_ERROR("failed to unprepare panel\n"); 194 return; 195 } 196 } 197 198 static int ptn3460_get_modes(struct drm_connector *connector) 199 { 200 struct ptn3460_bridge *ptn_bridge; 201 u8 *edid; 202 int ret, num_modes = 0; 203 bool power_off; 204 205 ptn_bridge = connector_to_ptn3460(connector); 206 207 if (ptn_bridge->edid) 208 return drm_add_edid_modes(connector, ptn_bridge->edid); 209 210 power_off = !ptn_bridge->enabled; 211 ptn3460_pre_enable(&ptn_bridge->bridge); 212 213 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 214 if (!edid) { 215 DRM_ERROR("Failed to allocate EDID\n"); 216 return 0; 217 } 218 219 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, 220 EDID_LENGTH); 221 if (ret) { 222 kfree(edid); 223 goto out; 224 } 225 226 ptn_bridge->edid = (struct edid *)edid; 227 drm_mode_connector_update_edid_property(connector, ptn_bridge->edid); 228 229 num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); 230 231 out: 232 if (power_off) 233 ptn3460_disable(&ptn_bridge->bridge); 234 235 return num_modes; 236 } 237 238 static struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector) 239 { 240 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); 241 242 return ptn_bridge->bridge.encoder; 243 } 244 245 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 246 .get_modes = ptn3460_get_modes, 247 .best_encoder = ptn3460_best_encoder, 248 }; 249 250 static enum drm_connector_status ptn3460_detect(struct drm_connector *connector, 251 bool force) 252 { 253 return connector_status_connected; 254 } 255 256 static void ptn3460_connector_destroy(struct drm_connector *connector) 257 { 258 drm_connector_cleanup(connector); 259 } 260 261 static const struct drm_connector_funcs ptn3460_connector_funcs = { 262 .dpms = drm_atomic_helper_connector_dpms, 263 .fill_modes = drm_helper_probe_single_connector_modes, 264 .detect = ptn3460_detect, 265 .destroy = ptn3460_connector_destroy, 266 .reset = drm_atomic_helper_connector_reset, 267 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 268 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 269 }; 270 271 static int ptn3460_bridge_attach(struct drm_bridge *bridge) 272 { 273 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 274 int ret; 275 276 if (!bridge->encoder) { 277 DRM_ERROR("Parent encoder object not found"); 278 return -ENODEV; 279 } 280 281 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 282 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 283 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 284 if (ret) { 285 DRM_ERROR("Failed to initialize connector with drm\n"); 286 return ret; 287 } 288 drm_connector_helper_add(&ptn_bridge->connector, 289 &ptn3460_connector_helper_funcs); 290 drm_connector_register(&ptn_bridge->connector); 291 drm_mode_connector_attach_encoder(&ptn_bridge->connector, 292 bridge->encoder); 293 294 if (ptn_bridge->panel) 295 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector); 296 297 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 298 299 return ret; 300 } 301 302 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 303 .pre_enable = ptn3460_pre_enable, 304 .enable = ptn3460_enable, 305 .disable = ptn3460_disable, 306 .post_disable = ptn3460_post_disable, 307 .attach = ptn3460_bridge_attach, 308 }; 309 310 static int ptn3460_probe(struct i2c_client *client, 311 const struct i2c_device_id *id) 312 { 313 struct device *dev = &client->dev; 314 struct ptn3460_bridge *ptn_bridge; 315 struct device_node *endpoint, *panel_node; 316 int ret; 317 318 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 319 if (!ptn_bridge) { 320 return -ENOMEM; 321 } 322 323 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); 324 if (endpoint) { 325 panel_node = of_graph_get_remote_port_parent(endpoint); 326 if (panel_node) { 327 ptn_bridge->panel = of_drm_find_panel(panel_node); 328 of_node_put(panel_node); 329 if (!ptn_bridge->panel) 330 return -EPROBE_DEFER; 331 } 332 } 333 334 ptn_bridge->client = client; 335 336 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 337 GPIOD_OUT_HIGH); 338 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 339 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 340 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 341 return ret; 342 } 343 344 /* 345 * Request the reset pin low to avoid the bridge being 346 * initialized prematurely 347 */ 348 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 349 GPIOD_OUT_LOW); 350 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 351 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 352 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 353 return ret; 354 } 355 356 ret = of_property_read_u32(dev->of_node, "edid-emulation", 357 &ptn_bridge->edid_emulation); 358 if (ret) { 359 dev_err(dev, "Can't read EDID emulation value\n"); 360 return ret; 361 } 362 363 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 364 ptn_bridge->bridge.of_node = dev->of_node; 365 ret = drm_bridge_add(&ptn_bridge->bridge); 366 if (ret) { 367 DRM_ERROR("Failed to add bridge\n"); 368 return ret; 369 } 370 371 i2c_set_clientdata(client, ptn_bridge); 372 373 return 0; 374 } 375 376 static int ptn3460_remove(struct i2c_client *client) 377 { 378 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 379 380 drm_bridge_remove(&ptn_bridge->bridge); 381 382 return 0; 383 } 384 385 static const struct i2c_device_id ptn3460_i2c_table[] = { 386 {"ptn3460", 0}, 387 {}, 388 }; 389 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 390 391 static const struct of_device_id ptn3460_match[] = { 392 { .compatible = "nxp,ptn3460" }, 393 {}, 394 }; 395 MODULE_DEVICE_TABLE(of, ptn3460_match); 396 397 static struct i2c_driver ptn3460_driver = { 398 .id_table = ptn3460_i2c_table, 399 .probe = ptn3460_probe, 400 .remove = ptn3460_remove, 401 .driver = { 402 .name = "nxp,ptn3460", 403 .of_match_table = ptn3460_match, 404 }, 405 }; 406 module_i2c_driver(ptn3460_driver); 407 408 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 409 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 410 MODULE_LICENSE("GPL v2"); 411