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 drm_bridge *panel_bridge; 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 /* 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 { 145 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 146 147 if (!ptn_bridge->enabled) 148 return; 149 150 ptn_bridge->enabled = false; 151 152 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 153 gpiod_set_value(ptn_bridge->gpio_pd_n, 0); 154 } 155 156 157 static struct edid *ptn3460_get_edid(struct drm_bridge *bridge, 158 struct drm_connector *connector) 159 { 160 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 161 bool power_off; 162 u8 *edid; 163 int ret; 164 165 power_off = !ptn_bridge->enabled; 166 ptn3460_pre_enable(&ptn_bridge->bridge); 167 168 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 169 if (!edid) { 170 DRM_ERROR("Failed to allocate EDID\n"); 171 goto out; 172 } 173 174 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, 175 EDID_LENGTH); 176 if (ret) { 177 kfree(edid); 178 edid = NULL; 179 goto out; 180 } 181 182 out: 183 if (power_off) 184 ptn3460_disable(&ptn_bridge->bridge); 185 186 return (struct edid *)edid; 187 } 188 189 static int ptn3460_connector_get_modes(struct drm_connector *connector) 190 { 191 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); 192 struct edid *edid; 193 int num_modes; 194 195 edid = ptn3460_get_edid(&ptn_bridge->bridge, connector); 196 drm_connector_update_edid_property(connector, edid); 197 num_modes = drm_add_edid_modes(connector, edid); 198 kfree(edid); 199 200 return num_modes; 201 } 202 203 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 204 .get_modes = ptn3460_connector_get_modes, 205 }; 206 207 static const struct drm_connector_funcs ptn3460_connector_funcs = { 208 .fill_modes = drm_helper_probe_single_connector_modes, 209 .destroy = drm_connector_cleanup, 210 .reset = drm_atomic_helper_connector_reset, 211 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 212 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 213 }; 214 215 static int ptn3460_bridge_attach(struct drm_bridge *bridge, 216 enum drm_bridge_attach_flags flags) 217 { 218 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 219 int ret; 220 221 /* Let this driver create connector if requested */ 222 ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge, 223 bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR); 224 if (ret < 0) 225 return ret; 226 227 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) 228 return 0; 229 230 if (!bridge->encoder) { 231 DRM_ERROR("Parent encoder object not found"); 232 return -ENODEV; 233 } 234 235 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 236 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 237 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 238 if (ret) { 239 DRM_ERROR("Failed to initialize connector with drm\n"); 240 return ret; 241 } 242 drm_connector_helper_add(&ptn_bridge->connector, 243 &ptn3460_connector_helper_funcs); 244 drm_connector_register(&ptn_bridge->connector); 245 drm_connector_attach_encoder(&ptn_bridge->connector, 246 bridge->encoder); 247 248 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 249 250 return ret; 251 } 252 253 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 254 .pre_enable = ptn3460_pre_enable, 255 .disable = ptn3460_disable, 256 .attach = ptn3460_bridge_attach, 257 .get_edid = ptn3460_get_edid, 258 }; 259 260 static int ptn3460_probe(struct i2c_client *client) 261 { 262 struct device *dev = &client->dev; 263 struct ptn3460_bridge *ptn_bridge; 264 struct drm_bridge *panel_bridge; 265 int ret; 266 267 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 268 if (!ptn_bridge) { 269 return -ENOMEM; 270 } 271 272 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 273 if (IS_ERR(panel_bridge)) 274 return PTR_ERR(panel_bridge); 275 276 ptn_bridge->panel_bridge = panel_bridge; 277 ptn_bridge->client = client; 278 279 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 280 GPIOD_OUT_HIGH); 281 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 282 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 283 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 284 return ret; 285 } 286 287 /* 288 * Request the reset pin low to avoid the bridge being 289 * initialized prematurely 290 */ 291 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 292 GPIOD_OUT_LOW); 293 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 294 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 295 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 296 return ret; 297 } 298 299 ret = of_property_read_u32(dev->of_node, "edid-emulation", 300 &ptn_bridge->edid_emulation); 301 if (ret) { 302 dev_err(dev, "Can't read EDID emulation value\n"); 303 return ret; 304 } 305 306 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 307 ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; 308 ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; 309 ptn_bridge->bridge.of_node = dev->of_node; 310 drm_bridge_add(&ptn_bridge->bridge); 311 312 i2c_set_clientdata(client, ptn_bridge); 313 314 return 0; 315 } 316 317 static void ptn3460_remove(struct i2c_client *client) 318 { 319 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 320 321 drm_bridge_remove(&ptn_bridge->bridge); 322 } 323 324 static const struct i2c_device_id ptn3460_i2c_table[] = { 325 {"ptn3460", 0}, 326 {}, 327 }; 328 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 329 330 static const struct of_device_id ptn3460_match[] = { 331 { .compatible = "nxp,ptn3460" }, 332 {}, 333 }; 334 MODULE_DEVICE_TABLE(of, ptn3460_match); 335 336 static struct i2c_driver ptn3460_driver = { 337 .id_table = ptn3460_i2c_table, 338 .probe = ptn3460_probe, 339 .remove = ptn3460_remove, 340 .driver = { 341 .name = "nxp,ptn3460", 342 .of_match_table = ptn3460_match, 343 }, 344 }; 345 module_i2c_driver(ptn3460_driver); 346 347 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 348 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 349 MODULE_LICENSE("GPL v2"); 350