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