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 { 116 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 117 int ret; 118 119 if (ptn_bridge->enabled) 120 return; 121 122 gpiod_set_value(ptn_bridge->gpio_pd_n, 1); 123 124 gpiod_set_value(ptn_bridge->gpio_rst_n, 0); 125 usleep_range(10, 20); 126 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 127 128 /* 129 * There's a bug in the PTN chip where it falsely asserts hotplug before 130 * it is fully functional. We're forced to wait for the maximum start up 131 * time specified in the chip's datasheet to make sure we're really up. 132 */ 133 msleep(90); 134 135 ret = ptn3460_select_edid(ptn_bridge); 136 if (ret) 137 DRM_ERROR("Select EDID failed ret=%d\n", ret); 138 139 ptn_bridge->enabled = true; 140 } 141 142 static void ptn3460_disable(struct drm_bridge *bridge) 143 { 144 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 145 146 if (!ptn_bridge->enabled) 147 return; 148 149 ptn_bridge->enabled = false; 150 151 gpiod_set_value(ptn_bridge->gpio_rst_n, 1); 152 gpiod_set_value(ptn_bridge->gpio_pd_n, 0); 153 } 154 155 156 static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge, 157 struct drm_connector *connector) 158 { 159 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 160 const struct drm_edid *drm_edid = NULL; 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 goto out; 179 } 180 181 drm_edid = drm_edid_alloc(edid, EDID_LENGTH); 182 183 out: 184 if (power_off) 185 ptn3460_disable(&ptn_bridge->bridge); 186 187 return drm_edid; 188 } 189 190 static int ptn3460_connector_get_modes(struct drm_connector *connector) 191 { 192 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); 193 const struct drm_edid *drm_edid; 194 int num_modes; 195 196 drm_edid = ptn3460_edid_read(&ptn_bridge->bridge, connector); 197 drm_edid_connector_update(connector, drm_edid); 198 num_modes = drm_edid_connector_add_modes(connector); 199 drm_edid_free(drm_edid); 200 201 return num_modes; 202 } 203 204 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { 205 .get_modes = ptn3460_connector_get_modes, 206 }; 207 208 static const struct drm_connector_funcs ptn3460_connector_funcs = { 209 .fill_modes = drm_helper_probe_single_connector_modes, 210 .destroy = drm_connector_cleanup, 211 .reset = drm_atomic_helper_connector_reset, 212 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 213 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 214 }; 215 216 static int ptn3460_bridge_attach(struct drm_bridge *bridge, 217 enum drm_bridge_attach_flags flags) 218 { 219 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); 220 int ret; 221 222 /* Let this driver create connector if requested */ 223 ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge, 224 bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR); 225 if (ret < 0) 226 return ret; 227 228 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) 229 return 0; 230 231 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD; 232 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector, 233 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 234 if (ret) { 235 DRM_ERROR("Failed to initialize connector with drm\n"); 236 return ret; 237 } 238 drm_connector_helper_add(&ptn_bridge->connector, 239 &ptn3460_connector_helper_funcs); 240 drm_connector_register(&ptn_bridge->connector); 241 drm_connector_attach_encoder(&ptn_bridge->connector, 242 bridge->encoder); 243 244 drm_helper_hpd_irq_event(ptn_bridge->connector.dev); 245 246 return ret; 247 } 248 249 static const struct drm_bridge_funcs ptn3460_bridge_funcs = { 250 .pre_enable = ptn3460_pre_enable, 251 .disable = ptn3460_disable, 252 .attach = ptn3460_bridge_attach, 253 .edid_read = ptn3460_edid_read, 254 }; 255 256 static int ptn3460_probe(struct i2c_client *client) 257 { 258 struct device *dev = &client->dev; 259 struct ptn3460_bridge *ptn_bridge; 260 struct drm_bridge *panel_bridge; 261 int ret; 262 263 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); 264 if (!ptn_bridge) { 265 return -ENOMEM; 266 } 267 268 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 269 if (IS_ERR(panel_bridge)) 270 return PTR_ERR(panel_bridge); 271 272 ptn_bridge->panel_bridge = panel_bridge; 273 ptn_bridge->client = client; 274 275 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown", 276 GPIOD_OUT_HIGH); 277 if (IS_ERR(ptn_bridge->gpio_pd_n)) { 278 ret = PTR_ERR(ptn_bridge->gpio_pd_n); 279 dev_err(dev, "cannot get gpio_pd_n %d\n", ret); 280 return ret; 281 } 282 283 /* 284 * Request the reset pin low to avoid the bridge being 285 * initialized prematurely 286 */ 287 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", 288 GPIOD_OUT_LOW); 289 if (IS_ERR(ptn_bridge->gpio_rst_n)) { 290 ret = PTR_ERR(ptn_bridge->gpio_rst_n); 291 DRM_ERROR("cannot get gpio_rst_n %d\n", ret); 292 return ret; 293 } 294 295 ret = of_property_read_u32(dev->of_node, "edid-emulation", 296 &ptn_bridge->edid_emulation); 297 if (ret) { 298 dev_err(dev, "Can't read EDID emulation value\n"); 299 return ret; 300 } 301 302 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs; 303 ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID; 304 ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS; 305 ptn_bridge->bridge.of_node = dev->of_node; 306 drm_bridge_add(&ptn_bridge->bridge); 307 308 i2c_set_clientdata(client, ptn_bridge); 309 310 return 0; 311 } 312 313 static void ptn3460_remove(struct i2c_client *client) 314 { 315 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); 316 317 drm_bridge_remove(&ptn_bridge->bridge); 318 } 319 320 static const struct i2c_device_id ptn3460_i2c_table[] = { 321 { "ptn3460" }, 322 {} 323 }; 324 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table); 325 326 static const struct of_device_id ptn3460_match[] = { 327 { .compatible = "nxp,ptn3460" }, 328 {}, 329 }; 330 MODULE_DEVICE_TABLE(of, ptn3460_match); 331 332 static struct i2c_driver ptn3460_driver = { 333 .id_table = ptn3460_i2c_table, 334 .probe = ptn3460_probe, 335 .remove = ptn3460_remove, 336 .driver = { 337 .name = "nxp,ptn3460", 338 .of_match_table = ptn3460_match, 339 }, 340 }; 341 module_i2c_driver(ptn3460_driver); 342 343 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>"); 344 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver"); 345 MODULE_LICENSE("GPL v2"); 346