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