drivers/gpu/drm/gma500/psb_intel_modes.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2007 Intel Corporation
   4  *
   5  * Authers: Jesse Barnes <[email protected]>
   6  */
   7
   8 #include <linux/i2c.h>
   9
  10 #include <drm/drm_edid.h>
  11
  12 #include "psb_intel_drv.h"
  13
  14 /**
  15  * psb_intel_ddc_probe
  16  * @adapter:   Associated I2C adaptor
  17  */
  18 bool psb_intel_ddc_probe(struct i2c_adapter *adapter)
  19 {
  20         u8 out_buf[] = { 0x0, 0x0 };
  21         u8 buf[2];
  22         int ret;
  23         struct i2c_msg msgs[] = {
  24                 {
  25                  .addr = 0x50,
  26                  .flags = 0,
  27                  .len = 1,
  28                  .buf = out_buf,
  29                  },
  30                 {
  31                  .addr = 0x50,
  32                  .flags = I2C_M_RD,
  33                  .len = 1,
  34                  .buf = buf,
  35                  }
  36         };
  37
  38         ret = i2c_transfer(adapter, msgs, 2);
  39         if (ret == 2)
  40                 return true;
  41
  42         return false;
  43 }
  44
  45 /**
  46  * psb_intel_ddc_get_modes - get modelist from monitor
  47  * @connector: DRM connector device to use
  48  * @adapter:   Associated I2C adaptor
  49  *
  50  * Fetch the EDID information from @connector using the DDC bus.
  51  */
  52 int psb_intel_ddc_get_modes(struct drm_connector *connector,
  53                             struct i2c_adapter *adapter)
  54 {
  55         struct edid *edid;
  56         int ret = 0;
  57
  58         edid = drm_get_edid(connector, adapter);
  59         if (edid) {
  60                 drm_connector_update_edid_property(connector, edid);
  61                 ret = drm_add_edid_modes(connector, edid);
  62                 kfree(edid);
  63         }
  64         return ret;
  65 }