1/*
2 * Intel ACPI functions
3 *
4 * _DSM related code stolen from nouveau_acpi.c.
5 */
6#include <linux/pci.h>
7#include <linux/acpi.h>
8#include <linux/vga_switcheroo.h>
9#include <drm/drmP.h>
10#include "i915_drv.h"
11
12#define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
13#define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
14
15static struct intel_dsm_priv {
16	acpi_handle dhandle;
17} intel_dsm_priv;
18
19static const u8 intel_dsm_guid[] = {
20	0xd3, 0x73, 0xd8, 0x7e,
21	0xd0, 0xc2,
22	0x4f, 0x4e,
23	0xa8, 0x54,
24	0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
25};
26
27static char *intel_dsm_port_name(u8 id)
28{
29	switch (id) {
30	case 0:
31		return "Reserved";
32	case 1:
33		return "Analog VGA";
34	case 2:
35		return "LVDS";
36	case 3:
37		return "Reserved";
38	case 4:
39		return "HDMI/DVI_B";
40	case 5:
41		return "HDMI/DVI_C";
42	case 6:
43		return "HDMI/DVI_D";
44	case 7:
45		return "DisplayPort_A";
46	case 8:
47		return "DisplayPort_B";
48	case 9:
49		return "DisplayPort_C";
50	case 0xa:
51		return "DisplayPort_D";
52	case 0xb:
53	case 0xc:
54	case 0xd:
55		return "Reserved";
56	case 0xe:
57		return "WiDi";
58	default:
59		return "bad type";
60	}
61}
62
63static char *intel_dsm_mux_type(u8 type)
64{
65	switch (type) {
66	case 0:
67		return "unknown";
68	case 1:
69		return "No MUX, iGPU only";
70	case 2:
71		return "No MUX, dGPU only";
72	case 3:
73		return "MUXed between iGPU and dGPU";
74	default:
75		return "bad type";
76	}
77}
78
79static void intel_dsm_platform_mux_info(void)
80{
81	int i;
82	union acpi_object *pkg, *connector_count;
83
84	pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, intel_dsm_guid,
85			INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
86			NULL, ACPI_TYPE_PACKAGE);
87	if (!pkg) {
88		DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
89		return;
90	}
91
92	connector_count = &pkg->package.elements[0];
93	DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
94		  (unsigned long long)connector_count->integer.value);
95	for (i = 1; i < pkg->package.count; i++) {
96		union acpi_object *obj = &pkg->package.elements[i];
97		union acpi_object *connector_id = &obj->package.elements[0];
98		union acpi_object *info = &obj->package.elements[1];
99		DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
100			  (unsigned long long)connector_id->integer.value);
101		DRM_DEBUG_DRIVER("  port id: %s\n",
102		       intel_dsm_port_name(info->buffer.pointer[0]));
103		DRM_DEBUG_DRIVER("  display mux info: %s\n",
104		       intel_dsm_mux_type(info->buffer.pointer[1]));
105		DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
106		       intel_dsm_mux_type(info->buffer.pointer[2]));
107		DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
108		       intel_dsm_mux_type(info->buffer.pointer[3]));
109	}
110
111	ACPI_FREE(pkg);
112}
113
114static bool intel_dsm_pci_probe(struct pci_dev *pdev)
115{
116	acpi_handle dhandle;
117
118	dhandle = ACPI_HANDLE(&pdev->dev);
119	if (!dhandle)
120		return false;
121
122	if (!acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
123			    1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
124		DRM_DEBUG_KMS("no _DSM method for intel device\n");
125		return false;
126	}
127
128	intel_dsm_priv.dhandle = dhandle;
129	intel_dsm_platform_mux_info();
130
131	return true;
132}
133
134static bool intel_dsm_detect(void)
135{
136	char acpi_method_name[255] = { 0 };
137	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
138	struct pci_dev *pdev = NULL;
139	bool has_dsm = false;
140	int vga_count = 0;
141
142	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
143		vga_count++;
144		has_dsm |= intel_dsm_pci_probe(pdev);
145	}
146
147	if (vga_count == 2 && has_dsm) {
148		acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
149		DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
150				 acpi_method_name);
151		return true;
152	}
153
154	return false;
155}
156
157void intel_register_dsm_handler(void)
158{
159	if (!intel_dsm_detect())
160		return;
161}
162
163void intel_unregister_dsm_handler(void)
164{
165}
166