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