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 const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge, 158 struct drm_connector *connector) 159 { 160 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 161 const struct drm_edid *drm_edid = NULL; 162 bool power_off; 163 u8 *edid; 164 int ret; 165 166 power_off = !ptn_bridge->enabled; 167 ptn3460_pre_enable(&ptn_bridge->bridge); 168 169 edid = kmalloc(EDID_LENGTH, GFP_KERNEL); 170 if (!edid) { 171 DRM_ERROR("Failed to allocate EDID\n"); 172 goto out; 173 } 174 175 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, 176 EDID_LENGTH); 177 if (ret) { 178 kfree(edid); 179 goto out; 180 } 181 182 drm_edid = drm_edid_alloc(edid, EDID_LENGTH); 183 184 out: 185 if (power_off) 186 ptn3460_disable(&ptn_bridge->bridge); 187 188 return drm_edid; 189 } 190 191 static int ptn3460_connector_get_modes(struct drm_connector *connector) 192 { 193 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); 194 const struct drm_edid *drm_edid; 195 int num_modes; 196 197 drm_edid = ptn3460_edid_read(&ptn_bridge->bridge, connector); 198 drm_edid_connector_update(connector, drm_edid); 199 num_modes = drm_edid_connector_add_modes(connector); 200 drm_edid_free(drm_edid); 201 202 return num_modes; 203 } 204 205 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 206 .get_modes = ptn3460_connector_get_modes, 207 }; 208 209 static const struct drm_connector_funcs ptn3460_connector_funcs = { 210 .fill_modes = drm_helper_probe_single_connector_modes, 211 .destroy = drm_connector_cleanup, 212 .reset = drm_atomic_helper_connector_reset, 213 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 214 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 215 }; 216 217 static int ptn3460_bridge_attach(struct drm_bridge *bridge, 218 enum drm_bridge_attach_flags flags) 219 { 220 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 221 int ret; 222 223 /* Let this driver create connector if requested */ 224 ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge, 225 bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR); 226 if (ret < 0) 227 return ret; 228 229 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) 230 return 0; 231 232 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 233 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 234 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 235 if (ret) { 236 DRM_ERROR("Failed to initialize connector with drm\n"); 237 return ret; 238 } 239 drm_connector_helper_add(&ptn_bridge->connector, 240 &ptn3460_connector_helper_funcs); 241 drm_connector_register(&ptn_bridge->connector); 242 drm_connector_attach_encoder(&ptn_bridge->connector, 243 bridge->encoder); 244 245 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 246 247 return ret; 248 } 249 250 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 251 .pre_enable = ptn3460_pre_enable, 252 .disable = ptn3460_disable, 253 .attach = ptn3460_bridge_attach, 254 .edid_read = ptn3460_edid_read, 255 }; 256 257 static int ptn3460_probe(struct i2c_client *client) 258 { 259 struct device *dev = &client->dev; 260 struct ptn3460_bridge *ptn_bridge; 261 struct drm_bridge *panel_bridge; 262 int ret; 263 264 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 265 if (!ptn_bridge) { 266 return -ENOMEM; 267 } 268 269 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 270 if (IS_ERR(panel_bridge)) 271 return PTR_ERR(panel_bridge); 272 273 ptn_bridge->panel_bridge = panel_bridge; 274 ptn_bridge->client = client; 275 276 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 277 GPIOD_OUT_HIGH); 278 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 279 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 280 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 281 return ret; 282 } 283 284 /* 285 * Request the reset pin low to avoid the bridge being 286 * initialized prematurely 287 */ 288 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 289 GPIOD_OUT_LOW); 290 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 291 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 292 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 293 return ret; 294 } 295 296 ret = of_property_read_u32(dev->of_node, "edid-emulation", 297 &ptn_bridge->edid_emulation); 298 if (ret) { 299 dev_err(dev, "Can't read EDID emulation value\n"); 300 return ret; 301 } 302 303 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 304 ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; 305 ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; 306 ptn_bridge->bridge.of_node = dev->of_node; 307 drm_bridge_add(&ptn_bridge->bridge); 308 309 i2c_set_clientdata(client, ptn_bridge); 310 311 return 0; 312 } 313 314 static void ptn3460_remove(struct i2c_client *client) 315 { 316 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 317 318 drm_bridge_remove(&ptn_bridge->bridge); 319 } 320 321 static const struct i2c_device_id ptn3460_i2c_table[] = { 322 {"ptn3460", 0}, 323 {}, 324 }; 325 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 326 327 static const struct of_device_id ptn3460_match[] = { 328 { .compatible = "nxp,ptn3460" }, 329 {}, 330 }; 331 MODULE_DEVICE_TABLE(of, ptn3460_match); 332 333 static struct i2c_driver ptn3460_driver = { 334 .id_table = ptn3460_i2c_table, 335 .probe = ptn3460_probe, 336 .remove = ptn3460_remove, 337 .driver = { 338 .name = "nxp,ptn3460", 339 .of_match_table = ptn3460_match, 340 }, 341 }; 342 module_i2c_driver(ptn3460_driver); 343 344 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 345 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 346 MODULE_LICENSE("GPL v2"); 347