drivers/gpu/drm/bridge/ptn3460.c

   1 /*
   2  * NXP PTN3460 DP/LVDS bridge driver
   3  *
   4  * Copyright (C) 2013 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/gpio.h>
  18 #include <linux/gpio/consumer.h>
  19 #include <linux/i2c.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_gpio.h>
  23 #include <linux/of_graph.h>
  24
  25 #include <drm/drm_panel.h>
  26
  27 #include "drm_crtc.h"
  28 #include "drm_crtc_helper.h"
  29 #include "drm_edid.h"
  30 #include "drmP.h"
  31
  32 #define PTN3460_EDID_ADDR                       0x0
  33 #define PTN3460_EDID_EMULATION_ADDR             0x84
  34 #define PTN3460_EDID_ENABLE_EMULATION           0
  35 #define PTN3460_EDID_EMULATION_SELECTION        1
  36 #define PTN3460_EDID_SRAM_LOAD_ADDR             0x85
  37
  38 struct ptn3460_bridge {
  39         struct drm_connector connector;
  40         struct i2c_client *client;
  41         struct drm_bridge bridge;
  42         struct edid *edid;
  43         struct drm_panel *panel;
  44         struct gpio_desc *gpio_pd_n;
  45         struct gpio_desc *gpio_rst_n;
  46         u32 edid_emulation;
  47         bool enabled;
  48 };
  49
  50 static inline struct ptn3460_bridge *
  51                 bridge_to_ptn3460(struct drm_bridge *bridge)
  52 {
  53         return container_of(bridge, struct ptn3460_bridge, bridge);
  54 }
  55
  56 static inline struct ptn3460_bridge *
  57                 connector_to_ptn3460(struct drm_connector *connector)
  58 {
  59         return container_of(connector, struct ptn3460_bridge, connector);
  60 }
  61
  62 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
  63                 u8 *buf, int len)
  64 {
  65         int ret;
  66
  67         ret = i2c_master_send(ptn_bridge->client, &addr, 1);
  68         if (ret <= 0) {
  69                 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
  70                 return ret;
  71         }
  72
  73         ret = i2c_master_recv(ptn_bridge->client, buf, len);
  74         if (ret <= 0) {
  75                 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
  76                 return ret;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
  83                 char val)
  84 {
  85         int ret;
  86         char buf[2];
  87
  88         buf[0] = addr;
  89         buf[1] = val;
  90
  91         ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
  92         if (ret <= 0) {
  93                 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
  94                 return ret;
  95         }
  96
  97         return 0;
  98 }
  99
 100 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
 101 {
 102         int ret;
 103         char val;
 104
 105         /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
 106         ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
 107                         ptn_bridge->edid_emulation);
 108         if (ret) {
 109                 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
 110                 return ret;
 111         }
 112
 113         /* Enable EDID emulation and select the desired EDID */
 114         val = 1 << PTN3460_EDID_ENABLE_EMULATION |
 115                 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
 116
 117         ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
 118         if (ret) {
 119                 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
 120                 return ret;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static void ptn3460_pre_enable(struct drm_bridge *bridge)
 127 {
 128         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 129         int ret;
 130
 131         if (ptn_bridge->enabled)
 132                 return;
 133
 134         gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
 135
 136         gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
 137         usleep_range(10, 20);
 138         gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
 139
 140         if (drm_panel_prepare(ptn_bridge->panel)) {
 141                 DRM_ERROR("failed to prepare panel\n");
 142                 return;
 143         }
 144
 145         /*
 146          * There's a bug in the PTN chip where it falsely asserts hotplug before
 147          * it is fully functional. We're forced to wait for the maximum start up
 148          * time specified in the chip's datasheet to make sure we're really up.
 149          */
 150         msleep(90);
 151
 152         ret = ptn3460_select_edid(ptn_bridge);
 153         if (ret)
 154                 DRM_ERROR("Select EDID failed ret=%d\n", ret);
 155
 156         ptn_bridge->enabled = true;
 157 }
 158
 159 static void ptn3460_enable(struct drm_bridge *bridge)
 160 {
 161         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 162
 163         if (drm_panel_enable(ptn_bridge->panel)) {
 164                 DRM_ERROR("failed to enable panel\n");
 165                 return;
 166         }
 167 }
 168
 169 static void ptn3460_disable(struct drm_bridge *bridge)
 170 {
 171         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 172
 173         if (!ptn_bridge->enabled)
 174                 return;
 175
 176         ptn_bridge->enabled = false;
 177
 178         if (drm_panel_disable(ptn_bridge->panel)) {
 179                 DRM_ERROR("failed to disable panel\n");
 180                 return;
 181         }
 182
 183         gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
 184         gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
 185 }
 186
 187 static void ptn3460_post_disable(struct drm_bridge *bridge)
 188 {
 189         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 190
 191         if (drm_panel_unprepare(ptn_bridge->panel)) {
 192                 DRM_ERROR("failed to unprepare panel\n");
 193                 return;
 194         }
 195 }
 196
 197 static int ptn3460_get_modes(struct drm_connector *connector)
 198 {
 199         struct ptn3460_bridge *ptn_bridge;
 200         u8 *edid;
 201         int ret, num_modes = 0;
 202         bool power_off;
 203
 204         ptn_bridge = connector_to_ptn3460(connector);
 205
 206         if (ptn_bridge->edid)
 207                 return drm_add_edid_modes(connector, ptn_bridge->edid);
 208
 209         power_off = !ptn_bridge->enabled;
 210         ptn3460_pre_enable(&ptn_bridge->bridge);
 211
 212         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 213         if (!edid) {
 214                 DRM_ERROR("Failed to allocate EDID\n");
 215                 return 0;
 216         }
 217
 218         ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
 219                         EDID_LENGTH);
 220         if (ret) {
 221                 kfree(edid);
 222                 goto out;
 223         }
 224
 225         ptn_bridge->edid = (struct edid *)edid;
 226         drm_mode_connector_update_edid_property(connector, ptn_bridge->edid);
 227
 228         num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
 229
 230 out:
 231         if (power_off)
 232                 ptn3460_disable(&ptn_bridge->bridge);
 233
 234         return num_modes;
 235 }
 236
 237 static struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
 238 {
 239         struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);
 240
 241         return ptn_bridge->bridge.encoder;
 242 }
 243
 244 static struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
 245         .get_modes = ptn3460_get_modes,
 246         .best_encoder = ptn3460_best_encoder,
 247 };
 248
 249 static enum drm_connector_status ptn3460_detect(struct drm_connector *connector,
 250                 bool force)
 251 {
 252         return connector_status_connected;
 253 }
 254
 255 static void ptn3460_connector_destroy(struct drm_connector *connector)
 256 {
 257         drm_connector_cleanup(connector);
 258 }
 259
 260 static struct drm_connector_funcs ptn3460_connector_funcs = {
 261         .dpms = drm_helper_connector_dpms,
 262         .fill_modes = drm_helper_probe_single_connector_modes,
 263         .detect = ptn3460_detect,
 264         .destroy = ptn3460_connector_destroy,
 265 };
 266
 267 static int ptn3460_bridge_attach(struct drm_bridge *bridge)
 268 {
 269         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 270         int ret;
 271
 272         if (!bridge->encoder) {
 273                 DRM_ERROR("Parent encoder object not found");
 274                 return -ENODEV;
 275         }
 276
 277         ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
 278         ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
 279                         &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
 280         if (ret) {
 281                 DRM_ERROR("Failed to initialize connector with drm\n");
 282                 return ret;
 283         }
 284         drm_connector_helper_add(&ptn_bridge->connector,
 285                                         &ptn3460_connector_helper_funcs);
 286         drm_connector_register(&ptn_bridge->connector);
 287         drm_mode_connector_attach_encoder(&ptn_bridge->connector,
 288                                                         bridge->encoder);
 289
 290         if (ptn_bridge->panel)
 291                 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
 292
 293         drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
 294
 295         return ret;
 296 }
 297
 298 static struct drm_bridge_funcs ptn3460_bridge_funcs = {
 299         .pre_enable = ptn3460_pre_enable,
 300         .enable = ptn3460_enable,
 301         .disable = ptn3460_disable,
 302         .post_disable = ptn3460_post_disable,
 303         .attach = ptn3460_bridge_attach,
 304 };
 305
 306 static int ptn3460_probe(struct i2c_client *client,
 307                                 const struct i2c_device_id *id)
 308 {
 309         struct device *dev = &client->dev;
 310         struct ptn3460_bridge *ptn_bridge;
 311         struct device_node *endpoint, *panel_node;
 312         int ret;
 313
 314         ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
 315         if (!ptn_bridge) {
 316                 return -ENOMEM;
 317         }
 318
 319         endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 320         if (endpoint) {
 321                 panel_node = of_graph_get_remote_port_parent(endpoint);
 322                 if (panel_node) {
 323                         ptn_bridge->panel = of_drm_find_panel(panel_node);
 324                         of_node_put(panel_node);
 325                         if (!ptn_bridge->panel)
 326                                 return -EPROBE_DEFER;
 327                 }
 328         }
 329
 330         ptn_bridge->client = client;
 331
 332         ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
 333                                                GPIOD_OUT_HIGH);
 334         if (IS_ERR(ptn_bridge->gpio_pd_n)) {
 335                 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
 336                 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
 337                 return ret;
 338         }
 339
 340         /*
 341          * Request the reset pin low to avoid the bridge being
 342          * initialized prematurely
 343          */
 344         ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
 345                                                 GPIOD_OUT_LOW);
 346         if (IS_ERR(ptn_bridge->gpio_rst_n)) {
 347                 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
 348                 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
 349                 return ret;
 350         }
 351
 352         ret = of_property_read_u32(dev->of_node, "edid-emulation",
 353                         &ptn_bridge->edid_emulation);
 354         if (ret) {
 355                 dev_err(dev, "Can't read EDID emulation value\n");
 356                 return ret;
 357         }
 358
 359         ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
 360         ptn_bridge->bridge.of_node = dev->of_node;
 361         ret = drm_bridge_add(&ptn_bridge->bridge);
 362         if (ret) {
 363                 DRM_ERROR("Failed to add bridge\n");
 364                 return ret;
 365         }
 366
 367         i2c_set_clientdata(client, ptn_bridge);
 368
 369         return 0;
 370 }
 371
 372 static int ptn3460_remove(struct i2c_client *client)
 373 {
 374         struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
 375
 376         drm_bridge_remove(&ptn_bridge->bridge);
 377
 378         return 0;
 379 }
 380
 381 static const struct i2c_device_id ptn3460_i2c_table[] = {
 382         {"ptn3460", 0},
 383         {},
 384 };
 385 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
 386
 387 static const struct of_device_id ptn3460_match[] = {
 388         { .compatible = "nxp,ptn3460" },
 389         {},
 390 };
 391 MODULE_DEVICE_TABLE(of, ptn3460_match);
 392
 393 static struct i2c_driver ptn3460_driver = {
 394         .id_table       = ptn3460_i2c_table,
 395         .probe          = ptn3460_probe,
 396         .remove         = ptn3460_remove,
 397         .driver         = {
 398                 .name   = "nxp,ptn3460",
 399                 .owner  = THIS_MODULE,
 400                 .of_match_table = ptn3460_match,
 401         },
 402 };
 403 module_i2c_driver(ptn3460_driver);
 404
 405 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
 406 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
 407 MODULE_LICENSE("GPL v2");