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