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_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 drm_bridge *panel_bridge; 32 struct gpio_desc *gpio_pd_n; 33 struct gpio_desc *gpio_rst_n; 34 u32 edid_emulation; 35 bool enabled; 36 }; 37 38 static inline struct ptn3460_bridge * 39 bridge_to_ptn3460(struct drm_bridge *bridge) 40 { 41 return container_of(bridge, struct ptn3460_bridge, bridge); 42 } 43 44 static inline struct ptn3460_bridge * 45 connector_to_ptn3460(struct drm_connector *connector) 46 { 47 return container_of(connector, struct ptn3460_bridge, connector); 48 } 49 50 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, 51 u8 *buf, int len) 52 { 53 int ret; 54 55 ret = i2c_master_send(ptn_bridge->client, &addr, 1); 56 if (ret < 0) { 57 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 58 return ret; 59 } 60 61 ret = i2c_master_recv(ptn_bridge->client, buf, len); 62 if (ret < 0) { 63 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); 64 return ret; 65 } 66 67 return 0; 68 } 69 70 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, 71 char val) 72 { 73 int ret; 74 char buf[2]; 75 76 buf[0] = addr; 77 buf[1] = val; 78 79 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); 80 if (ret < 0) { 81 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); 82 return ret; 83 } 84 85 return 0; 86 } 87 88 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge) 89 { 90 int ret; 91 char val; 92 93 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */ 94 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR, 95 ptn_bridge->edid_emulation); 96 if (ret) { 97 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret); 98 return ret; 99 } 100 101 /* Enable EDID emulation and select the desired EDID */ 102 val = 1 << PTN3460_EDID_ENABLE_EMULATION | 103 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION; 104 105 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val); 106 if (ret) { 107 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret); 108 return ret; 109 } 110 111 return 0; 112 } 113 114 static void ptn3460_pre_enable(struct drm_bridge *bridge, 115 struct drm_atomic_commit *commit) 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 /* 130 * There's a bug in the PTN chip where it falsely asserts hotplug before 131 * it is fully functional. We're forced to wait for the maximum start up 132 * time specified in the chip's datasheet to make sure we're really up. 133 */ 134 msleep(90); 135 136 ret = ptn3460_select_edid(ptn_bridge); 137 if (ret) 138 DRM_ERROR("Select EDID failed ret=%d\n", ret); 139 140 ptn_bridge->enabled = true; 141 } 142 143 static void ptn3460_disable(struct drm_bridge *bridge, 144 struct drm_atomic_commit *commit) 145 { 146 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 147 148 if (!ptn_bridge->enabled) 149 return; 150 151 ptn_bridge->enabled = false; 152 153 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 154 gpiod_set_value(ptn_bridge->gpio_pd_n, 0); 155 } 156 157 158 static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge, 159 struct drm_connector *connector) 160 { 161 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 162 const struct drm_edid *drm_edid = NULL; 163 bool power_off; 164 u8 *edid; 165 int ret; 166 167 power_off = !ptn_bridge->enabled; 168 ptn3460_pre_enable(&ptn_bridge->bridge, NULL); 169 170 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 171 if (!edid) { 172 DRM_ERROR("Failed to allocate EDID\n"); 173 goto out; 174 } 175 176 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, 177 EDID_LENGTH); 178 if (ret) { 179 kfree(edid); 180 goto out; 181 } 182 183 drm_edid = drm_edid_alloc(edid, EDID_LENGTH); 184 185 out: 186 if (power_off) 187 ptn3460_disable(&ptn_bridge->bridge, NULL); 188 189 return drm_edid; 190 } 191 192 static int ptn3460_connector_get_modes(struct drm_connector *connector) 193 { 194 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); 195 const struct drm_edid *drm_edid; 196 int num_modes; 197 198 drm_edid = ptn3460_edid_read(&ptn_bridge->bridge, connector); 199 drm_edid_connector_update(connector, drm_edid); 200 num_modes = drm_edid_connector_add_modes(connector); 201 drm_edid_free(drm_edid); 202 203 return num_modes; 204 } 205 206 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 207 .get_modes = ptn3460_connector_get_modes, 208 }; 209 210 static const struct drm_connector_funcs ptn3460_connector_funcs = { 211 .fill_modes = drm_helper_probe_single_connector_modes, 212 .destroy = drm_connector_cleanup, 213 .reset = drm_atomic_helper_connector_reset, 214 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 215 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 216 }; 217 218 static int ptn3460_bridge_attach(struct drm_bridge *bridge, 219 struct drm_encoder *encoder, 220 enum drm_bridge_attach_flags flags) 221 { 222 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 223 int ret; 224 225 /* Let this driver create connector if requested */ 226 ret = drm_bridge_attach(encoder, ptn_bridge->panel_bridge, 227 bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR); 228 if (ret < 0) 229 return ret; 230 231 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) 232 return 0; 233 234 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 235 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 236 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 237 if (ret) { 238 DRM_ERROR("Failed to initialize connector with drm\n"); 239 return ret; 240 } 241 drm_connector_helper_add(&ptn_bridge->connector, 242 &ptn3460_connector_helper_funcs); 243 drm_connector_register(&ptn_bridge->connector); 244 drm_connector_attach_encoder(&ptn_bridge->connector, 245 encoder); 246 247 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 248 249 return ret; 250 } 251 252 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 253 .atomic_create_state = drm_atomic_helper_bridge_create_state, 254 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, 255 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, 256 .atomic_pre_enable = ptn3460_pre_enable, 257 .atomic_disable = ptn3460_disable, 258 .attach = ptn3460_bridge_attach, 259 .edid_read = ptn3460_edid_read, 260 }; 261 262 static int ptn3460_probe(struct i2c_client *client) 263 { 264 struct device *dev = &client->dev; 265 struct ptn3460_bridge *ptn_bridge; 266 struct drm_bridge *panel_bridge; 267 int ret; 268 269 ptn_bridge = devm_drm_bridge_alloc(dev, struct ptn3460_bridge, bridge, 270 &ptn3460_bridge_funcs); 271 if (IS_ERR(ptn_bridge)) 272 return PTR_ERR(ptn_bridge); 273 274 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 275 if (IS_ERR(panel_bridge)) 276 return PTR_ERR(panel_bridge); 277 278 ptn_bridge->panel_bridge = panel_bridge; 279 ptn_bridge->client = client; 280 281 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 282 GPIOD_OUT_HIGH); 283 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 284 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 285 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 286 return ret; 287 } 288 289 /* 290 * Request the reset pin low to avoid the bridge being 291 * initialized prematurely 292 */ 293 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 294 GPIOD_OUT_LOW); 295 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 296 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 297 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 298 return ret; 299 } 300 301 ret = of_property_read_u32(dev->of_node, "edid-emulation", 302 &ptn_bridge->edid_emulation); 303 if (ret) { 304 dev_err(dev, "Can't read EDID emulation value\n"); 305 return ret; 306 } 307 308 ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; 309 ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; 310 ptn_bridge->bridge.of_node = dev->of_node; 311 drm_bridge_add(&ptn_bridge->bridge); 312 313 i2c_set_clientdata(client, ptn_bridge); 314 315 return 0; 316 } 317 318 static void ptn3460_remove(struct i2c_client *client) 319 { 320 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 321 322 drm_bridge_remove(&ptn_bridge->bridge); 323 } 324 325 static const struct i2c_device_id ptn3460_i2c_table[] = { 326 { .name = "ptn3460" }, 327 { } 328 }; 329 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 330 331 static const struct of_device_id ptn3460_match[] = { 332 { .compatible = "nxp,ptn3460" }, 333 {}, 334 }; 335 MODULE_DEVICE_TABLE(of, ptn3460_match); 336 337 static struct i2c_driver ptn3460_driver = { 338 .id_table = ptn3460_i2c_table, 339 .probe = ptn3460_probe, 340 .remove = ptn3460_remove, 341 .driver = { 342 .name = "nxp,ptn3460", 343 .of_match_table = ptn3460_match, 344 }, 345 }; 346 module_i2c_driver(ptn3460_driver); 347 348 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 349 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 350 MODULE_LICENSE("GPL v2"); 351