xref: /linux/drivers/gpu/drm/gma500/psb_intel_modes.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
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 }
64