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 const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 239 .get_modes = ptn3460_get_modes, 240 }; 241 242 static enum drm_connector_status ptn3460_detect(struct drm_connector *connector, 243 bool force) 244 { 245 return connector_status_connected; 246 } 247 248 static const struct drm_connector_funcs ptn3460_connector_funcs = { 249 .dpms = drm_atomic_helper_connector_dpms, 250 .fill_modes = drm_helper_probe_single_connector_modes, 251 .detect = ptn3460_detect, 252 .destroy = drm_connector_cleanup, 253 .reset = drm_atomic_helper_connector_reset, 254 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 255 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 256 }; 257 258 static int ptn3460_bridge_attach(struct drm_bridge *bridge) 259 { 260 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 261 int ret; 262 263 if (!bridge->encoder) { 264 DRM_ERROR("Parent encoder object not found"); 265 return -ENODEV; 266 } 267 268 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 269 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 270 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 271 if (ret) { 272 DRM_ERROR("Failed to initialize connector with drm\n"); 273 return ret; 274 } 275 drm_connector_helper_add(&ptn_bridge->connector, 276 &ptn3460_connector_helper_funcs); 277 drm_connector_register(&ptn_bridge->connector); 278 drm_mode_connector_attach_encoder(&ptn_bridge->connector, 279 bridge->encoder); 280 281 if (ptn_bridge->panel) 282 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector); 283 284 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 285 286 return ret; 287 } 288 289 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 290 .pre_enable = ptn3460_pre_enable, 291 .enable = ptn3460_enable, 292 .disable = ptn3460_disable, 293 .post_disable = ptn3460_post_disable, 294 .attach = ptn3460_bridge_attach, 295 }; 296 297 static int ptn3460_probe(struct i2c_client *client, 298 const struct i2c_device_id *id) 299 { 300 struct device *dev = &client->dev; 301 struct ptn3460_bridge *ptn_bridge; 302 struct device_node *endpoint, *panel_node; 303 int ret; 304 305 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 306 if (!ptn_bridge) { 307 return -ENOMEM; 308 } 309 310 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); 311 if (endpoint) { 312 panel_node = of_graph_get_remote_port_parent(endpoint); 313 if (panel_node) { 314 ptn_bridge->panel = of_drm_find_panel(panel_node); 315 of_node_put(panel_node); 316 if (!ptn_bridge->panel) 317 return -EPROBE_DEFER; 318 } 319 } 320 321 ptn_bridge->client = client; 322 323 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 324 GPIOD_OUT_HIGH); 325 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 326 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 327 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 328 return ret; 329 } 330 331 /* 332 * Request the reset pin low to avoid the bridge being 333 * initialized prematurely 334 */ 335 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 336 GPIOD_OUT_LOW); 337 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 338 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 339 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 340 return ret; 341 } 342 343 ret = of_property_read_u32(dev->of_node, "edid-emulation", 344 &ptn_bridge->edid_emulation); 345 if (ret) { 346 dev_err(dev, "Can't read EDID emulation value\n"); 347 return ret; 348 } 349 350 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 351 ptn_bridge->bridge.of_node = dev->of_node; 352 ret = drm_bridge_add(&ptn_bridge->bridge); 353 if (ret) { 354 DRM_ERROR("Failed to add bridge\n"); 355 return ret; 356 } 357 358 i2c_set_clientdata(client, ptn_bridge); 359 360 return 0; 361 } 362 363 static int ptn3460_remove(struct i2c_client *client) 364 { 365 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 366 367 drm_bridge_remove(&ptn_bridge->bridge); 368 369 return 0; 370 } 371 372 static const struct i2c_device_id ptn3460_i2c_table[] = { 373 {"ptn3460", 0}, 374 {}, 375 }; 376 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 377 378 static const struct of_device_id ptn3460_match[] = { 379 { .compatible = "nxp,ptn3460" }, 380 {}, 381 }; 382 MODULE_DEVICE_TABLE(of, ptn3460_match); 383 384 static struct i2c_driver ptn3460_driver = { 385 .id_table = ptn3460_i2c_table, 386 .probe = ptn3460_probe, 387 .remove = ptn3460_remove, 388 .driver = { 389 .name = "nxp,ptn3460", 390 .of_match_table = ptn3460_match, 391 }, 392 }; 393 module_i2c_driver(ptn3460_driver); 394 395 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 396 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 397 MODULE_LICENSE("GPL v2"); 398