drivers/gpu/drm/omapdrm/displays/connector-dvi.c

   1 /*
   2  * Generic DVI Connector driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
   5  * Author: Tomi Valkeinen <[email protected]>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/i2c.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/slab.h>
  17
  18 #include <drm/drm_edid.h>
  19
  20 #include "../dss/omapdss.h"
  21
  22 struct panel_drv_data {
  23         struct omap_dss_device dssdev;
  24
  25         struct i2c_adapter *i2c_adapter;
  26
  27         struct gpio_desc *hpd_gpio;
  28
  29         void (*hpd_cb)(void *cb_data, enum drm_connector_status status);
  30         void *hpd_cb_data;
  31         bool hpd_enabled;
  32         /* mutex for hpd fields above */
  33         struct mutex hpd_lock;
  34 };
  35
  36 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
  37
  38 static int dvic_connect(struct omap_dss_device *src,
  39                         struct omap_dss_device *dst)
  40 {
  41         return 0;
  42 }
  43
  44 static void dvic_disconnect(struct omap_dss_device *src,
  45                             struct omap_dss_device *dst)
  46 {
  47 }
  48
  49 static int dvic_enable(struct omap_dss_device *dssdev)
  50 {
  51         struct omap_dss_device *src = dssdev->src;
  52         int r;
  53
  54         if (!omapdss_device_is_connected(dssdev))
  55                 return -ENODEV;
  56
  57         if (omapdss_device_is_enabled(dssdev))
  58                 return 0;
  59
  60         r = src->ops->enable(src);
  61         if (r)
  62                 return r;
  63
  64         dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
  65
  66         return 0;
  67 }
  68
  69 static void dvic_disable(struct omap_dss_device *dssdev)
  70 {
  71         struct omap_dss_device *src = dssdev->src;
  72
  73         if (!omapdss_device_is_enabled(dssdev))
  74                 return;
  75
  76         src->ops->disable(src);
  77
  78         dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
  79 }
  80
  81 static int dvic_ddc_read(struct i2c_adapter *adapter,
  82                 unsigned char *buf, u16 count, u8 offset)
  83 {
  84         int r, retries;
  85
  86         for (retries = 3; retries > 0; retries--) {
  87                 struct i2c_msg msgs[] = {
  88                         {
  89                                 .addr   = DDC_ADDR,
  90                                 .flags  = 0,
  91                                 .len    = 1,
  92                                 .buf    = &offset,
  93                         }, {
  94                                 .addr   = DDC_ADDR,
  95                                 .flags  = I2C_M_RD,
  96                                 .len    = count,
  97                                 .buf    = buf,
  98                         }
  99                 };
 100
 101                 r = i2c_transfer(adapter, msgs, 2);
 102                 if (r == 2)
 103                         return 0;
 104
 105                 if (r != -EAGAIN)
 106                         break;
 107         }
 108
 109         return r < 0 ? r : -EIO;
 110 }
 111
 112 static int dvic_read_edid(struct omap_dss_device *dssdev,
 113                 u8 *edid, int len)
 114 {
 115         struct panel_drv_data *ddata = to_panel_data(dssdev);
 116         int r, l, bytes_read;
 117
 118         l = min(EDID_LENGTH, len);
 119         r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
 120         if (r)
 121                 return r;
 122
 123         bytes_read = l;
 124
 125         /* if there are extensions, read second block */
 126         if (len > EDID_LENGTH && edid[0x7e] > 0) {
 127                 l = min(EDID_LENGTH, len - EDID_LENGTH);
 128
 129                 r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
 130                                 l, EDID_LENGTH);
 131                 if (r)
 132                         return r;
 133
 134                 bytes_read += l;
 135         }
 136
 137         return bytes_read;
 138 }
 139
 140 static bool dvic_detect(struct omap_dss_device *dssdev)
 141 {
 142         struct panel_drv_data *ddata = to_panel_data(dssdev);
 143         unsigned char out;
 144         int r;
 145
 146         if (ddata->hpd_gpio)
 147                 return gpiod_get_value_cansleep(ddata->hpd_gpio);
 148
 149         if (!ddata->i2c_adapter)
 150                 return true;
 151
 152         r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
 153
 154         return r == 0;
 155 }
 156
 157 static void dvic_register_hpd_cb(struct omap_dss_device *dssdev,
 158                                  void (*cb)(void *cb_data,
 159                                             enum drm_connector_status status),
 160                                  void *cb_data)
 161 {
 162         struct panel_drv_data *ddata = to_panel_data(dssdev);
 163
 164         mutex_lock(&ddata->hpd_lock);
 165         ddata->hpd_cb = cb;
 166         ddata->hpd_cb_data = cb_data;
 167         mutex_unlock(&ddata->hpd_lock);
 168 }
 169
 170 static void dvic_unregister_hpd_cb(struct omap_dss_device *dssdev)
 171 {
 172         struct panel_drv_data *ddata = to_panel_data(dssdev);
 173
 174         mutex_lock(&ddata->hpd_lock);
 175         ddata->hpd_cb = NULL;
 176         ddata->hpd_cb_data = NULL;
 177         mutex_unlock(&ddata->hpd_lock);
 178 }
 179
 180 static const struct omap_dss_device_ops dvic_ops = {
 181         .connect        = dvic_connect,
 182         .disconnect     = dvic_disconnect,
 183
 184         .enable         = dvic_enable,
 185         .disable        = dvic_disable,
 186
 187         .read_edid      = dvic_read_edid,
 188         .detect         = dvic_detect,
 189
 190         .register_hpd_cb        = dvic_register_hpd_cb,
 191         .unregister_hpd_cb      = dvic_unregister_hpd_cb,
 192 };
 193
 194 static irqreturn_t dvic_hpd_isr(int irq, void *data)
 195 {
 196         struct panel_drv_data *ddata = data;
 197
 198         mutex_lock(&ddata->hpd_lock);
 199         if (ddata->hpd_enabled && ddata->hpd_cb) {
 200                 enum drm_connector_status status;
 201
 202                 if (dvic_detect(&ddata->dssdev))
 203                         status = connector_status_connected;
 204                 else
 205                         status = connector_status_disconnected;
 206
 207                 ddata->hpd_cb(ddata->hpd_cb_data, status);
 208         }
 209         mutex_unlock(&ddata->hpd_lock);
 210
 211         return IRQ_HANDLED;
 212 }
 213
 214 static int dvic_probe_of(struct platform_device *pdev)
 215 {
 216         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 217         struct device_node *node = pdev->dev.of_node;
 218         struct device_node *adapter_node;
 219         struct i2c_adapter *adapter;
 220         struct gpio_desc *gpio;
 221         int r;
 222
 223         gpio = devm_gpiod_get_optional(&pdev->dev, "hpd", GPIOD_IN);
 224         if (IS_ERR(gpio)) {
 225                 dev_err(&pdev->dev, "failed to parse HPD gpio\n");
 226                 return PTR_ERR(gpio);
 227         }
 228
 229         ddata->hpd_gpio = gpio;
 230
 231         mutex_init(&ddata->hpd_lock);
 232
 233         if (ddata->hpd_gpio) {
 234                 r = devm_request_threaded_irq(&pdev->dev,
 235                         gpiod_to_irq(ddata->hpd_gpio), NULL, dvic_hpd_isr,
 236                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 237                         "DVI HPD", ddata);
 238                 if (r)
 239                         return r;
 240         }
 241
 242         adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
 243         if (adapter_node) {
 244                 adapter = of_get_i2c_adapter_by_node(adapter_node);
 245                 of_node_put(adapter_node);
 246                 if (adapter == NULL) {
 247                         dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
 248                         return -EPROBE_DEFER;
 249                 }
 250
 251                 ddata->i2c_adapter = adapter;
 252         }
 253
 254         return 0;
 255 }
 256
 257 static int dvic_probe(struct platform_device *pdev)
 258 {
 259         struct panel_drv_data *ddata;
 260         struct omap_dss_device *dssdev;
 261         int r;
 262
 263         ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
 264         if (!ddata)
 265                 return -ENOMEM;
 266
 267         platform_set_drvdata(pdev, ddata);
 268
 269         r = dvic_probe_of(pdev);
 270         if (r)
 271                 return r;
 272
 273         dssdev = &ddata->dssdev;
 274         dssdev->ops = &dvic_ops;
 275         dssdev->dev = &pdev->dev;
 276         dssdev->type = OMAP_DISPLAY_TYPE_DVI;
 277         dssdev->owner = THIS_MODULE;
 278         dssdev->of_ports = BIT(0);
 279
 280         if (ddata->hpd_gpio)
 281                 dssdev->ops_flags |= OMAP_DSS_DEVICE_OP_DETECT
 282                                   |  OMAP_DSS_DEVICE_OP_HPD;
 283         if (ddata->i2c_adapter)
 284                 dssdev->ops_flags |= OMAP_DSS_DEVICE_OP_DETECT
 285                                   |  OMAP_DSS_DEVICE_OP_EDID;
 286
 287         omapdss_display_init(dssdev);
 288         omapdss_device_register(dssdev);
 289
 290         return 0;
 291 }
 292
 293 static int __exit dvic_remove(struct platform_device *pdev)
 294 {
 295         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 296         struct omap_dss_device *dssdev = &ddata->dssdev;
 297
 298         omapdss_device_unregister(&ddata->dssdev);
 299
 300         dvic_disable(dssdev);
 301
 302         i2c_put_adapter(ddata->i2c_adapter);
 303
 304         mutex_destroy(&ddata->hpd_lock);
 305
 306         return 0;
 307 }
 308
 309 static const struct of_device_id dvic_of_match[] = {
 310         { .compatible = "omapdss,dvi-connector", },
 311         {},
 312 };
 313
 314 MODULE_DEVICE_TABLE(of, dvic_of_match);
 315
 316 static struct platform_driver dvi_connector_driver = {
 317         .probe  = dvic_probe,
 318         .remove = __exit_p(dvic_remove),
 319         .driver = {
 320                 .name   = "connector-dvi",
 321                 .of_match_table = dvic_of_match,
 322                 .suppress_bind_attrs = true,
 323         },
 324 };
 325
 326 module_platform_driver(dvi_connector_driver);
 327
 328 MODULE_AUTHOR("Tomi Valkeinen <[email protected]>");
 329 MODULE_DESCRIPTION("Generic DVI Connector driver");
 330 MODULE_LICENSE("GPL");