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6#include <linux/pci.h>
7#include <linux/acpi.h>
8#include <linux/vga_switcheroo.h>
9#include <acpi/acpi_drivers.h>
10
11#include "drmP.h"
12
13#define INTEL_DSM_REVISION_ID 1
14
15#define INTEL_DSM_FN_SUPPORTED_FUNCTIONS 0
16#define INTEL_DSM_FN_PLATFORM_MUX_INFO 1
17
18static struct intel_dsm_priv {
19 acpi_handle dhandle;
20} intel_dsm_priv;
21
22static const u8 intel_dsm_guid[] = {
23 0xd3, 0x73, 0xd8, 0x7e,
24 0xd0, 0xc2,
25 0x4f, 0x4e,
26 0xa8, 0x54,
27 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
28};
29
30static int intel_dsm(acpi_handle handle, int func, int arg)
31{
32 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
33 struct acpi_object_list input;
34 union acpi_object params[4];
35 union acpi_object *obj;
36 u32 result;
37 int ret = 0;
38
39 input.count = 4;
40 input.pointer = params;
41 params[0].type = ACPI_TYPE_BUFFER;
42 params[0].buffer.length = sizeof(intel_dsm_guid);
43 params[0].buffer.pointer = (char *)intel_dsm_guid;
44 params[1].type = ACPI_TYPE_INTEGER;
45 params[1].integer.value = INTEL_DSM_REVISION_ID;
46 params[2].type = ACPI_TYPE_INTEGER;
47 params[2].integer.value = func;
48 params[3].type = ACPI_TYPE_INTEGER;
49 params[3].integer.value = arg;
50
51 ret = acpi_evaluate_object(handle, "_DSM", &input, &output);
52 if (ret) {
53 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
54 return ret;
55 }
56
57 obj = (union acpi_object *)output.pointer;
58
59 result = 0;
60 switch (obj->type) {
61 case ACPI_TYPE_INTEGER:
62 result = obj->integer.value;
63 break;
64
65 case ACPI_TYPE_BUFFER:
66 if (obj->buffer.length == 4) {
67 result =(obj->buffer.pointer[0] |
68 (obj->buffer.pointer[1] << 8) |
69 (obj->buffer.pointer[2] << 16) |
70 (obj->buffer.pointer[3] << 24));
71 break;
72 }
73 default:
74 ret = -EINVAL;
75 break;
76 }
77 if (result == 0x80000002)
78 ret = -ENODEV;
79
80 kfree(output.pointer);
81 return ret;
82}
83
84static char *intel_dsm_port_name(u8 id)
85{
86 switch (id) {
87 case 0:
88 return "Reserved";
89 case 1:
90 return "Analog VGA";
91 case 2:
92 return "LVDS";
93 case 3:
94 return "Reserved";
95 case 4:
96 return "HDMI/DVI_B";
97 case 5:
98 return "HDMI/DVI_C";
99 case 6:
100 return "HDMI/DVI_D";
101 case 7:
102 return "DisplayPort_A";
103 case 8:
104 return "DisplayPort_B";
105 case 9:
106 return "DisplayPort_C";
107 case 0xa:
108 return "DisplayPort_D";
109 case 0xb:
110 case 0xc:
111 case 0xd:
112 return "Reserved";
113 case 0xe:
114 return "WiDi";
115 default:
116 return "bad type";
117 }
118}
119
120static char *intel_dsm_mux_type(u8 type)
121{
122 switch (type) {
123 case 0:
124 return "unknown";
125 case 1:
126 return "No MUX, iGPU only";
127 case 2:
128 return "No MUX, dGPU only";
129 case 3:
130 return "MUXed between iGPU and dGPU";
131 default:
132 return "bad type";
133 }
134}
135
136static void intel_dsm_platform_mux_info(void)
137{
138 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
139 struct acpi_object_list input;
140 union acpi_object params[4];
141 union acpi_object *pkg;
142 int i, ret;
143
144 input.count = 4;
145 input.pointer = params;
146 params[0].type = ACPI_TYPE_BUFFER;
147 params[0].buffer.length = sizeof(intel_dsm_guid);
148 params[0].buffer.pointer = (char *)intel_dsm_guid;
149 params[1].type = ACPI_TYPE_INTEGER;
150 params[1].integer.value = INTEL_DSM_REVISION_ID;
151 params[2].type = ACPI_TYPE_INTEGER;
152 params[2].integer.value = INTEL_DSM_FN_PLATFORM_MUX_INFO;
153 params[3].type = ACPI_TYPE_INTEGER;
154 params[3].integer.value = 0;
155
156 ret = acpi_evaluate_object(intel_dsm_priv.dhandle, "_DSM", &input,
157 &output);
158 if (ret) {
159 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
160 goto out;
161 }
162
163 pkg = (union acpi_object *)output.pointer;
164
165 if (pkg->type == ACPI_TYPE_PACKAGE) {
166 union acpi_object *connector_count = &pkg->package.elements[0];
167 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
168 (unsigned long long)connector_count->integer.value);
169 for (i = 1; i < pkg->package.count; i++) {
170 union acpi_object *obj = &pkg->package.elements[i];
171 union acpi_object *connector_id =
172 &obj->package.elements[0];
173 union acpi_object *info = &obj->package.elements[1];
174 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
175 (unsigned long long)connector_id->integer.value);
176 DRM_DEBUG_DRIVER(" port id: %s\n",
177 intel_dsm_port_name(info->buffer.pointer[0]));
178 DRM_DEBUG_DRIVER(" display mux info: %s\n",
179 intel_dsm_mux_type(info->buffer.pointer[1]));
180 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
181 intel_dsm_mux_type(info->buffer.pointer[2]));
182 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
183 intel_dsm_mux_type(info->buffer.pointer[3]));
184 }
185 } else {
186 DRM_ERROR("MUX INFO call failed\n");
187 }
188
189out:
190 kfree(output.pointer);
191}
192
193static bool intel_dsm_pci_probe(struct pci_dev *pdev)
194{
195 acpi_handle dhandle, intel_handle;
196 acpi_status status;
197 int ret;
198
199 dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
200 if (!dhandle)
201 return false;
202
203 status = acpi_get_handle(dhandle, "_DSM", &intel_handle);
204 if (ACPI_FAILURE(status)) {
205 DRM_DEBUG_KMS("no _DSM method for intel device\n");
206 return false;
207 }
208
209 ret = intel_dsm(dhandle, INTEL_DSM_FN_SUPPORTED_FUNCTIONS, 0);
210 if (ret < 0) {
211 DRM_ERROR("failed to get supported _DSM functions\n");
212 return false;
213 }
214
215 intel_dsm_priv.dhandle = dhandle;
216
217 intel_dsm_platform_mux_info();
218 return true;
219}
220
221static bool intel_dsm_detect(void)
222{
223 char acpi_method_name[255] = { 0 };
224 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
225 struct pci_dev *pdev = NULL;
226 bool has_dsm = false;
227 int vga_count = 0;
228
229 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
230 vga_count++;
231 has_dsm |= intel_dsm_pci_probe(pdev);
232 }
233
234 if (vga_count == 2 && has_dsm) {
235 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
236 DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
237 acpi_method_name);
238 return true;
239 }
240
241 return false;
242}
243
244void intel_register_dsm_handler(void)
245{
246 if (!intel_dsm_detect())
247 return;
248}
249
250void intel_unregister_dsm_handler(void)
251{
252}
253
