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_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");