drivers/gpu/drm/bridge/nxp-ptn3460.c

   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_panel *panel;
  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         if (drm_panel_prepare(ptn_bridge->panel)) {
 130                 DRM_ERROR("failed to prepare panel\n");
 131                 return;
 132         }
 133
 134         /*
 135          * There's a bug in the PTN chip where it falsely asserts hotplug before
 136          * it is fully functional. We're forced to wait for the maximum start up
 137          * time specified in the chip's datasheet to make sure we're really up.
 138          */
 139         msleep(90);
 140
 141         ret = ptn3460_select_edid(ptn_bridge);
 142         if (ret)
 143                 DRM_ERROR("Select EDID failed ret=%d\n", ret);
 144
 145         ptn_bridge->enabled = true;
 146 }
 147
 148 static void ptn3460_enable(struct drm_bridge *bridge)
 149 {
 150         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 151
 152         if (drm_panel_enable(ptn_bridge->panel)) {
 153                 DRM_ERROR("failed to enable panel\n");
 154                 return;
 155         }
 156 }
 157
 158 static void ptn3460_disable(struct drm_bridge *bridge)
 159 {
 160         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 161
 162         if (!ptn_bridge->enabled)
 163                 return;
 164
 165         ptn_bridge->enabled = false;
 166
 167         if (drm_panel_disable(ptn_bridge->panel)) {
 168                 DRM_ERROR("failed to disable panel\n");
 169                 return;
 170         }
 171
 172         gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
 173         gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
 174 }
 175
 176 static void ptn3460_post_disable(struct drm_bridge *bridge)
 177 {
 178         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 179
 180         if (drm_panel_unprepare(ptn_bridge->panel)) {
 181                 DRM_ERROR("failed to unprepare panel\n");
 182                 return;
 183         }
 184 }
 185
 186 static struct edid *ptn3460_get_edid(struct drm_bridge *bridge,
 187                                      struct drm_connector *connector)
 188 {
 189         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 190         bool power_off;
 191         u8 *edid;
 192         int ret;
 193
 194         power_off = !ptn_bridge->enabled;
 195         ptn3460_pre_enable(&ptn_bridge->bridge);
 196
 197         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 198         if (!edid) {
 199                 DRM_ERROR("Failed to allocate EDID\n");
 200                 goto out;
 201         }
 202
 203         ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
 204                                  EDID_LENGTH);
 205         if (ret) {
 206                 kfree(edid);
 207                 edid = NULL;
 208                 goto out;
 209         }
 210
 211 out:
 212         if (power_off)
 213                 ptn3460_disable(&ptn_bridge->bridge);
 214
 215         return (struct edid *)edid;
 216 }
 217
 218 static int ptn3460_connector_get_modes(struct drm_connector *connector)
 219 {
 220         struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);
 221         struct edid *edid;
 222         int num_modes;
 223
 224         edid = ptn3460_get_edid(&ptn_bridge->bridge, connector);
 225         drm_connector_update_edid_property(connector, edid);
 226         num_modes = drm_add_edid_modes(connector, edid);
 227         kfree(edid);
 228
 229         return num_modes;
 230 }
 231
 232 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
 233         .get_modes = ptn3460_connector_get_modes,
 234 };
 235
 236 static const struct drm_connector_funcs ptn3460_connector_funcs = {
 237         .fill_modes = drm_helper_probe_single_connector_modes,
 238         .destroy = drm_connector_cleanup,
 239         .reset = drm_atomic_helper_connector_reset,
 240         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 241         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 242 };
 243
 244 static int ptn3460_bridge_attach(struct drm_bridge *bridge,
 245                                  enum drm_bridge_attach_flags flags)
 246 {
 247         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 248         int ret;
 249
 250         if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
 251                 DRM_ERROR("Fix bridge driver to make connector optional!");
 252                 return -EINVAL;
 253         }
 254
 255         if (!bridge->encoder) {
 256                 DRM_ERROR("Parent encoder object not found");
 257                 return -ENODEV;
 258         }
 259
 260         ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
 261         ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
 262                         &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
 263         if (ret) {
 264                 DRM_ERROR("Failed to initialize connector with drm\n");
 265                 return ret;
 266         }
 267         drm_connector_helper_add(&ptn_bridge->connector,
 268                                         &ptn3460_connector_helper_funcs);
 269         drm_connector_register(&ptn_bridge->connector);
 270         drm_connector_attach_encoder(&ptn_bridge->connector,
 271                                                         bridge->encoder);
 272
 273         if (ptn_bridge->panel)
 274                 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
 275
 276         drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
 277
 278         return ret;
 279 }
 280
 281 static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
 282         .pre_enable = ptn3460_pre_enable,
 283         .enable = ptn3460_enable,
 284         .disable = ptn3460_disable,
 285         .post_disable = ptn3460_post_disable,
 286         .attach = ptn3460_bridge_attach,
 287         .get_edid = ptn3460_get_edid,
 288 };
 289
 290 static int ptn3460_probe(struct i2c_client *client,
 291                                 const struct i2c_device_id *id)
 292 {
 293         struct device *dev = &client->dev;
 294         struct ptn3460_bridge *ptn_bridge;
 295         int ret;
 296
 297         ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
 298         if (!ptn_bridge) {
 299                 return -ENOMEM;
 300         }
 301
 302         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ptn_bridge->panel, NULL);
 303         if (ret)
 304                 return ret;
 305
 306         ptn_bridge->client = client;
 307
 308         ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
 309                                                GPIOD_OUT_HIGH);
 310         if (IS_ERR(ptn_bridge->gpio_pd_n)) {
 311                 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
 312                 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
 313                 return ret;
 314         }
 315
 316         /*
 317          * Request the reset pin low to avoid the bridge being
 318          * initialized prematurely
 319          */
 320         ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
 321                                                 GPIOD_OUT_LOW);
 322         if (IS_ERR(ptn_bridge->gpio_rst_n)) {
 323                 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
 324                 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
 325                 return ret;
 326         }
 327
 328         ret = of_property_read_u32(dev->of_node, "edid-emulation",
 329                         &ptn_bridge->edid_emulation);
 330         if (ret) {
 331                 dev_err(dev, "Can't read EDID emulation value\n");
 332                 return ret;
 333         }
 334
 335         ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
 336         ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
 337         ptn_bridge->bridge.of_node = dev->of_node;
 338         drm_bridge_add(&ptn_bridge->bridge);
 339
 340         i2c_set_clientdata(client, ptn_bridge);
 341
 342         return 0;
 343 }
 344
 345 static int ptn3460_remove(struct i2c_client *client)
 346 {
 347         struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
 348
 349         drm_bridge_remove(&ptn_bridge->bridge);
 350
 351         return 0;
 352 }
 353
 354 static const struct i2c_device_id ptn3460_i2c_table[] = {
 355         {"ptn3460", 0},
 356         {},
 357 };
 358 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
 359
 360 static const struct of_device_id ptn3460_match[] = {
 361         { .compatible = "nxp,ptn3460" },
 362         {},
 363 };
 364 MODULE_DEVICE_TABLE(of, ptn3460_match);
 365
 366 static struct i2c_driver ptn3460_driver = {
 367         .id_table       = ptn3460_i2c_table,
 368         .probe          = ptn3460_probe,
 369         .remove         = ptn3460_remove,
 370         .driver         = {
 371                 .name   = "nxp,ptn3460",
 372                 .of_match_table = ptn3460_match,
 373         },
 374 };
 375 module_i2c_driver(ptn3460_driver);
 376
 377 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
 378 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
 379 MODULE_LICENSE("GPL v2");