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 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 <[email protected]>");
 345 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
 346 MODULE_LICENSE("GPL v2");