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 <acpi/acpi_drivers.h>
10
11 #include <drm/drmP.h>
12 #include "i915_drv.h"
13
14 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
15
16 #define INTEL_DSM_FN_SUPPORTED_FUNCTIONS 0 /* No args */
17 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
18
19 static struct intel_dsm_priv {
20 acpi_handle dhandle;
21 } intel_dsm_priv;
22
23 static const u8 intel_dsm_guid[] = {
24 0xd3, 0x73, 0xd8, 0x7e,
25 0xd0, 0xc2,
26 0x4f, 0x4e,
27 0xa8, 0x54,
28 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
29 };
30
intel_dsm(acpi_handle handle,int func,int arg)31 static int intel_dsm(acpi_handle handle, int func, int arg)
32 {
33 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
34 struct acpi_object_list input;
35 union acpi_object params[4];
36 union acpi_object *obj;
37 u32 result;
38 int ret = 0;
39
40 input.count = 4;
41 input.pointer = params;
42 params[0].type = ACPI_TYPE_BUFFER;
43 params[0].buffer.length = sizeof(intel_dsm_guid);
44 params[0].buffer.pointer = (char *)intel_dsm_guid;
45 params[1].type = ACPI_TYPE_INTEGER;
46 params[1].integer.value = INTEL_DSM_REVISION_ID;
47 params[2].type = ACPI_TYPE_INTEGER;
48 params[2].integer.value = func;
49 params[3].type = ACPI_TYPE_INTEGER;
50 params[3].integer.value = arg;
51
52 ret = acpi_evaluate_object(handle, "_DSM", &input, &output);
53 if (ret) {
54 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
55 return ret;
56 }
57
58 obj = (union acpi_object *)output.pointer;
59
60 result = 0;
61 switch (obj->type) {
62 case ACPI_TYPE_INTEGER:
63 result = obj->integer.value;
64 break;
65
66 case ACPI_TYPE_BUFFER:
67 if (obj->buffer.length == 4) {
68 result = (obj->buffer.pointer[0] |
69 (obj->buffer.pointer[1] << 8) |
70 (obj->buffer.pointer[2] << 16) |
71 (obj->buffer.pointer[3] << 24));
72 break;
73 }
74 default:
75 ret = -EINVAL;
76 break;
77 }
78 if (result == 0x80000002)
79 ret = -ENODEV;
80
81 kfree(output.pointer);
82 return ret;
83 }
84
intel_dsm_port_name(u8 id)85 static char *intel_dsm_port_name(u8 id)
86 {
87 switch (id) {
88 case 0:
89 return "Reserved";
90 case 1:
91 return "Analog VGA";
92 case 2:
93 return "LVDS";
94 case 3:
95 return "Reserved";
96 case 4:
97 return "HDMI/DVI_B";
98 case 5:
99 return "HDMI/DVI_C";
100 case 6:
101 return "HDMI/DVI_D";
102 case 7:
103 return "DisplayPort_A";
104 case 8:
105 return "DisplayPort_B";
106 case 9:
107 return "DisplayPort_C";
108 case 0xa:
109 return "DisplayPort_D";
110 case 0xb:
111 case 0xc:
112 case 0xd:
113 return "Reserved";
114 case 0xe:
115 return "WiDi";
116 default:
117 return "bad type";
118 }
119 }
120
intel_dsm_mux_type(u8 type)121 static char *intel_dsm_mux_type(u8 type)
122 {
123 switch (type) {
124 case 0:
125 return "unknown";
126 case 1:
127 return "No MUX, iGPU only";
128 case 2:
129 return "No MUX, dGPU only";
130 case 3:
131 return "MUXed between iGPU and dGPU";
132 default:
133 return "bad type";
134 }
135 }
136
intel_dsm_platform_mux_info(void)137 static void intel_dsm_platform_mux_info(void)
138 {
139 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
140 struct acpi_object_list input;
141 union acpi_object params[4];
142 union acpi_object *pkg;
143 int i, ret;
144
145 input.count = 4;
146 input.pointer = params;
147 params[0].type = ACPI_TYPE_BUFFER;
148 params[0].buffer.length = sizeof(intel_dsm_guid);
149 params[0].buffer.pointer = (char *)intel_dsm_guid;
150 params[1].type = ACPI_TYPE_INTEGER;
151 params[1].integer.value = INTEL_DSM_REVISION_ID;
152 params[2].type = ACPI_TYPE_INTEGER;
153 params[2].integer.value = INTEL_DSM_FN_PLATFORM_MUX_INFO;
154 params[3].type = ACPI_TYPE_INTEGER;
155 params[3].integer.value = 0;
156
157 ret = acpi_evaluate_object(intel_dsm_priv.dhandle, "_DSM", &input,
158 &output);
159 if (ret) {
160 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
161 goto out;
162 }
163
164 pkg = (union acpi_object *)output.pointer;
165
166 if (pkg->type == ACPI_TYPE_PACKAGE) {
167 union acpi_object *connector_count = &pkg->package.elements[0];
168 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
169 (unsigned long long)connector_count->integer.value);
170 for (i = 1; i < pkg->package.count; i++) {
171 union acpi_object *obj = &pkg->package.elements[i];
172 union acpi_object *connector_id =
173 &obj->package.elements[0];
174 union acpi_object *info = &obj->package.elements[1];
175 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
176 (unsigned long long)connector_id->integer.value);
177 DRM_DEBUG_DRIVER(" port id: %s\n",
178 intel_dsm_port_name(info->buffer.pointer[0]));
179 DRM_DEBUG_DRIVER(" display mux info: %s\n",
180 intel_dsm_mux_type(info->buffer.pointer[1]));
181 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
182 intel_dsm_mux_type(info->buffer.pointer[2]));
183 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
184 intel_dsm_mux_type(info->buffer.pointer[3]));
185 }
186 }
187
188 out:
189 kfree(output.pointer);
190 }
191
intel_dsm_pci_probe(struct pci_dev * pdev)192 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
193 {
194 acpi_handle dhandle, intel_handle;
195 acpi_status status;
196 int ret;
197
198 dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
199 if (!dhandle)
200 return false;
201
202 status = acpi_get_handle(dhandle, "_DSM", &intel_handle);
203 if (ACPI_FAILURE(status)) {
204 DRM_DEBUG_KMS("no _DSM method for intel device\n");
205 return false;
206 }
207
208 ret = intel_dsm(dhandle, INTEL_DSM_FN_SUPPORTED_FUNCTIONS, 0);
209 if (ret < 0) {
210 DRM_DEBUG_KMS("failed to get supported _DSM functions\n");
211 return false;
212 }
213
214 intel_dsm_priv.dhandle = dhandle;
215
216 intel_dsm_platform_mux_info();
217 return true;
218 }
219
intel_dsm_detect(void)220 static bool intel_dsm_detect(void)
221 {
222 char acpi_method_name[255] = { 0 };
223 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
224 struct pci_dev *pdev = NULL;
225 bool has_dsm = false;
226 int vga_count = 0;
227
228 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
229 vga_count++;
230 has_dsm |= intel_dsm_pci_probe(pdev);
231 }
232
233 if (vga_count == 2 && has_dsm) {
234 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
235 DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
236 acpi_method_name);
237 return true;
238 }
239
240 return false;
241 }
242
intel_register_dsm_handler(void)243 void intel_register_dsm_handler(void)
244 {
245 if (!intel_dsm_detect())
246 return;
247 }
248
intel_unregister_dsm_handler(void)249 void intel_unregister_dsm_handler(void)
250 {
251 }
252