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