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 <drm/drm_edid.h>
11
12 #include "psb_intel_drv.h"
13
14 /**
15 * psb_intel_ddc_probe
16 * @adapter: Associated I2C adaptor
17 */
psb_intel_ddc_probe(struct i2c_adapter * adapter)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 */
psb_intel_ddc_get_modes(struct drm_connector * connector,struct i2c_adapter * adapter)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 }
66