1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * NXP PTN3460 DP/LVDS bridge driver 4 * 5 * Copyright (C) 2013 Google, Inc. 6 */ 7 8 #include <linux/delay.h> 9 #include <linux/gpio/consumer.h> 10 #include <linux/i2c.h> 11 #include <linux/module.h> 12 #include <linux/of.h> 13 #include <drm/drm_atomic_helper.h> 14 #include <drm/drm_bridge.h> 15 #include <drm/drm_crtc.h> 16 #include <drm/drm_edid.h> 17 #include <drm/drm_of.h> 18 #include <drm/drm_panel.h> 19 #include <drm/drm_print.h> 20 #include <drm/drm_probe_helper.h> 21 22 #define PTN3460_EDID_ADDR 0x0 23 #define PTN3460_EDID_EMULATION_ADDR 0x84 24 #define PTN3460_EDID_ENABLE_EMULATION 0 25 #define PTN3460_EDID_EMULATION_SELECTION 1 26 #define PTN3460_EDID_SRAM_LOAD_ADDR 0x85 27 28 struct ptn3460_bridge { 29 struct drm_connector connector; 30 struct i2c_client *client; 31 struct drm_bridge bridge; 32 struct edid *edid; 33 struct drm_panel *panel; 34 struct gpio_desc *gpio_pd_n; 35 struct gpio_desc *gpio_rst_n; 36 u32 edid_emulation; 37 bool enabled; 38 }; 39 40 static inline struct ptn3460_bridge * 41 bridge_to_ptn3460(struct drm_bridge *bridge) 42 { 43 return container_of(bridge, struct ptn3460_bridge, bridge); 44 } 45 46 static inline struct ptn3460_bridge * 47 connector_to_ptn3460(struct drm_connector *connector) 48 { 49 return container_of(connector, struct ptn3460_bridge, connector); 50 } 51 52 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, 53 u8 *buf, int len) 54 { 55 int ret; 56 57 ret = i2c_master_send(ptn_bridge->client, &addr, 1); 58 if (ret <= 0) { 59 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 60 return ret; 61 } 62 63 ret = i2c_master_recv(ptn_bridge->client, buf, len); 64 if (ret <= 0) { 65 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); 66 return ret; 67 } 68 69 return 0; 70 } 71 72 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, 73 char val) 74 { 75 int ret; 76 char buf[2]; 77 78 buf[0] = addr; 79 buf[1] = val; 80 81 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); 82 if (ret <= 0) { 83 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 84 return ret; 85 } 86 87 return 0; 88 } 89 90 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge) 91 { 92 int ret; 93 char val; 94 95 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */ 96 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR, 97 ptn_bridge->edid_emulation); 98 if (ret) { 99 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret); 100 return ret; 101 } 102 103 /* Enable EDID emulation and select the desired EDID */ 104 val = 1 << PTN3460_EDID_ENABLE_EMULATION | 105 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION; 106 107 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val); 108 if (ret) { 109 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret); 110 return ret; 111 } 112 113 return 0; 114 } 115 116 static void ptn3460_pre_enable(struct drm_bridge *bridge) 117 { 118 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 119 int ret; 120 121 if (ptn_bridge->enabled) 122 return; 123 124 gpiod_set_value(ptn_bridge->gpio_pd_n, 1); 125 126 gpiod_set_value(ptn_bridge->gpio_rst_n, 0); 127 usleep_range(10, 20); 128 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 129 130 if (drm_panel_prepare(ptn_bridge->panel)) { 131 DRM_ERROR("failed to prepare panel\n"); 132 return; 133 } 134 135 /* 136 * There's a bug in the PTN chip where it falsely asserts hotplug before 137 * it is fully functional. We're forced to wait for the maximum start up 138 * time specified in the chip's datasheet to make sure we're really up. 139 */ 140 msleep(90); 141 142 ret = ptn3460_select_edid(ptn_bridge); 143 if (ret) 144 DRM_ERROR("Select EDID failed ret=%d\n", ret); 145 146 ptn_bridge->enabled = true; 147 } 148 149 static void ptn3460_enable(struct drm_bridge *bridge) 150 { 151 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 152 153 if (drm_panel_enable(ptn_bridge->panel)) { 154 DRM_ERROR("failed to enable panel\n"); 155 return; 156 } 157 } 158 159 static void ptn3460_disable(struct drm_bridge *bridge) 160 { 161 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 162 163 if (!ptn_bridge->enabled) 164 return; 165 166 ptn_bridge->enabled = false; 167 168 if (drm_panel_disable(ptn_bridge->panel)) { 169 DRM_ERROR("failed to disable panel\n"); 170 return; 171 } 172 173 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 174 gpiod_set_value(ptn_bridge->gpio_pd_n, 0); 175 } 176 177 static void ptn3460_post_disable(struct drm_bridge *bridge) 178 { 179 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 180 181 if (drm_panel_unprepare(ptn_bridge->panel)) { 182 DRM_ERROR("failed to unprepare panel\n"); 183 return; 184 } 185 } 186 187 static int ptn3460_get_modes(struct drm_connector *connector) 188 { 189 struct ptn3460_bridge *ptn_bridge; 190 u8 *edid; 191 int ret, num_modes = 0; 192 bool power_off; 193 194 ptn_bridge = connector_to_ptn3460(connector); 195 196 if (ptn_bridge->edid) 197 return drm_add_edid_modes(connector, ptn_bridge->edid); 198 199 power_off = !ptn_bridge->enabled; 200 ptn3460_pre_enable(&ptn_bridge->bridge); 201 202 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 203 if (!edid) { 204 DRM_ERROR("Failed to allocate EDID\n"); 205 return 0; 206 } 207 208 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, 209 EDID_LENGTH); 210 if (ret) { 211 kfree(edid); 212 goto out; 213 } 214 215 ptn_bridge->edid = (struct edid *)edid; 216 drm_connector_update_edid_property(connector, ptn_bridge->edid); 217 218 num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); 219 220 out: 221 if (power_off) 222 ptn3460_disable(&ptn_bridge->bridge); 223 224 return num_modes; 225 } 226 227 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 228 .get_modes = ptn3460_get_modes, 229 }; 230 231 static const struct drm_connector_funcs ptn3460_connector_funcs = { 232 .fill_modes = drm_helper_probe_single_connector_modes, 233 .destroy = drm_connector_cleanup, 234 .reset = drm_atomic_helper_connector_reset, 235 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 236 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 237 }; 238 239 static int ptn3460_bridge_attach(struct drm_bridge *bridge, 240 enum drm_bridge_attach_flags flags) 241 { 242 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 243 int ret; 244 245 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) { 246 DRM_ERROR("Fix bridge driver to make connector optional!"); 247 return -EINVAL; 248 } 249 250 if (!bridge->encoder) { 251 DRM_ERROR("Parent encoder object not found"); 252 return -ENODEV; 253 } 254 255 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 256 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 257 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 258 if (ret) { 259 DRM_ERROR("Failed to initialize connector with drm\n"); 260 return ret; 261 } 262 drm_connector_helper_add(&ptn_bridge->connector, 263 &ptn3460_connector_helper_funcs); 264 drm_connector_register(&ptn_bridge->connector); 265 drm_connector_attach_encoder(&ptn_bridge->connector, 266 bridge->encoder); 267 268 if (ptn_bridge->panel) 269 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector); 270 271 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 272 273 return ret; 274 } 275 276 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 277 .pre_enable = ptn3460_pre_enable, 278 .enable = ptn3460_enable, 279 .disable = ptn3460_disable, 280 .post_disable = ptn3460_post_disable, 281 .attach = ptn3460_bridge_attach, 282 }; 283 284 static int ptn3460_probe(struct i2c_client *client, 285 const struct i2c_device_id *id) 286 { 287 struct device *dev = &client->dev; 288 struct ptn3460_bridge *ptn_bridge; 289 int ret; 290 291 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 292 if (!ptn_bridge) { 293 return -ENOMEM; 294 } 295 296 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ptn_bridge->panel, NULL); 297 if (ret) 298 return ret; 299 300 ptn_bridge->client = client; 301 302 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 303 GPIOD_OUT_HIGH); 304 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 305 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 306 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 307 return ret; 308 } 309 310 /* 311 * Request the reset pin low to avoid the bridge being 312 * initialized prematurely 313 */ 314 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 315 GPIOD_OUT_LOW); 316 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 317 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 318 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 319 return ret; 320 } 321 322 ret = of_property_read_u32(dev->of_node, "edid-emulation", 323 &ptn_bridge->edid_emulation); 324 if (ret) { 325 dev_err(dev, "Can't read EDID emulation value\n"); 326 return ret; 327 } 328 329 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 330 ptn_bridge->bridge.of_node = dev->of_node; 331 drm_bridge_add(&ptn_bridge->bridge); 332 333 i2c_set_clientdata(client, ptn_bridge); 334 335 return 0; 336 } 337 338 static int ptn3460_remove(struct i2c_client *client) 339 { 340 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 341 342 drm_bridge_remove(&ptn_bridge->bridge); 343 344 return 0; 345 } 346 347 static const struct i2c_device_id ptn3460_i2c_table[] = { 348 {"ptn3460", 0}, 349 {}, 350 }; 351 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 352 353 static const struct of_device_id ptn3460_match[] = { 354 { .compatible = "nxp,ptn3460" }, 355 {}, 356 }; 357 MODULE_DEVICE_TABLE(of, ptn3460_match); 358 359 static struct i2c_driver ptn3460_driver = { 360 .id_table = ptn3460_i2c_table, 361 .probe = ptn3460_probe, 362 .remove = ptn3460_remove, 363 .driver = { 364 .name = "nxp,ptn3460", 365 .of_match_table = ptn3460_match, 366 }, 367 }; 368 module_i2c_driver(ptn3460_driver); 369 370 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 371 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 372 MODULE_LICENSE("GPL v2"); 373