vga_switcheroo: initial implementation (v15)

Many new laptops now come with 2 gpus, one to be used for low power
modes and one for gaming/on-ac applications. These GPUs are typically
wired to the laptop panel and VGA ports via a multiplexer unit which
is controlled via ACPI methods.

4 combinations of systems typically exist - with 2 ACPI methods.
Intel/ATI - Lenovo W500/T500 - use ATPX ACPI method
ATI/ATI - some ASUS - use ATPX ACPI Method
Intel/Nvidia - - use _DSM ACPI method
Nvidia/Nvidia - - use _DSM ACPI method.

TODO:
This patch adds support for the ATPX method and initial bits
for the _DSM methods that need to written by someone with
access to the hardware.
Add a proper non-debugfs interface - need to get some proper
testing first.

v2: add power up/down support for both devices
on W500 puts i915/radeon into D3 and cuts power to radeon.

v3: redo probing methods, no DMI list, drm devices call to
register with switcheroo, it tries to find an ATPX method on
any device and once there is two devices + ATPX it inits the
switcher.

v4: ATPX msg handling using buffers - should work on more machines

v5: rearchitect after more mjg59 discussion - move ATPX handling to
radeon driver.

v6: add file headers + initial nouveau bits (to be filled out).

v7: merge delayed switcher code.

v8: avoid suspend/resume of gpu that is off

v9: rearchitect - mjg59 is always right. - move all ATPX code to
radeon, should allow simpler DSM also proper ATRM handling

v10: add ATRM support for radeon BIOS, add mutex to lock vgasr_priv

v11: fix bug in resuming Intel for 2nd time.

v12: start fixing up nvidia code blindly.

v13: blindly guess at finishing nvidia code

v14: remove radeon audio hacks - fix up intel resume more like upstream

v15: clean up printks + remove unnecessary igd/dis pointers

mount debugfs

/sys/kernel/debug/vgaswitcheroo/switch - should exist if ATPX detected
+ 2 cards.

DIS - immediate change to discrete
IGD - immediate change to IGD
DDIS - delayed change to discrete
DIGD - delayed change to IGD
ON - turn on not in use
OFF - turn off not in use

Tested on W500 (Intel/ATI) and T500 (Intel/ATI)

Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/i915/i915_dma.c

···
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
 
 /* Really want an OS-independent resettable timer.  Would like to have
  * this loop run for (eg) 3 sec, but have the timer reset every time
···
 		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
 }
 
+static void i915_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
+	if (state == VGA_SWITCHEROO_ON) {
+		printk(KERN_INFO "i915: switched off\n");
+		/* i915 resume handler doesn't set to D0 */
+		pci_set_power_state(dev->pdev, PCI_D0);
+		i915_resume(dev);
+	} else {
+		printk(KERN_ERR "i915: switched off\n");
+		i915_suspend(dev, pmm);
+	}
+}
+
+static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	bool can_switch;
+
+	spin_lock(&dev->count_lock);
+	can_switch = (dev->open_count == 0);
+	spin_unlock(&dev->count_lock);
+	return can_switch;
+}
+
 static int i915_load_modeset_init(struct drm_device *dev,
 				  unsigned long prealloc_start,
 				  unsigned long prealloc_size,
···
 
 	/* if we have > 1 VGA cards, then disable the radeon VGA resources */
 	ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
+	if (ret)
+		goto destroy_ringbuffer;
+
+	ret = vga_switcheroo_register_client(dev->pdev,
+					     i915_switcheroo_set_state,
+					     i915_switcheroo_can_switch);
 	if (ret)
 		goto destroy_ringbuffer;
 
···
 			dev_priv->child_dev_num = 0;
 		}
 		drm_irq_uninstall(dev);
+		vga_switcheroo_unregister_client(dev->pdev);
 		vga_client_register(dev->pdev, NULL, NULL, NULL);
 	}
 
···
 
 	if (!dev_priv || drm_core_check_feature(dev, DRIVER_MODESET)) {
 		drm_fb_helper_restore();
+		vga_switcheroo_process_delayed_switch();
 		return;
 	}
 

drivers/gpu/drm/i915/i915_drv.c

···
 	return 0;
 }
 
-static int i915_suspend(struct drm_device *dev, pm_message_t state)
+int i915_suspend(struct drm_device *dev, pm_message_t state)
 {
 	int error;
 
···
 	return error;
 }
 
-static int i915_resume(struct drm_device *dev)
+int i915_resume(struct drm_device *dev)
 {
 	if (pci_enable_device(dev->pdev))
 		return -EIO;

drivers/gpu/drm/i915/i915_drv.h

···
 extern unsigned int i915_powersave;
 extern unsigned int i915_lvds_downclock;
 
+extern int i915_suspend(struct drm_device *dev, pm_message_t state);
+extern int i915_resume(struct drm_device *dev);
 extern void i915_save_display(struct drm_device *dev);
 extern void i915_restore_display(struct drm_device *dev);
 extern int i915_master_create(struct drm_device *dev, struct drm_master *master);

drivers/gpu/drm/i915/intel_fb.c

···
 #include <linux/delay.h>
 #include <linux/fb.h>
 #include <linux/init.h>
+#include <linux/vga_switcheroo.h>
 
 #include "drmP.h"
 #include "drm.h"
···
 			obj_priv->gtt_offset, fbo);
 
 	mutex_unlock(&dev->struct_mutex);
+	vga_switcheroo_client_fb_set(dev->pdev, info);
 	return 0;
 
 out_unpin:

drivers/gpu/drm/nouveau/nouveau_acpi.c

···
 #include "nouveau_drm.h"
 #include "nv50_display.h"
 
+#include <linux/vga_switcheroo.h>
+
 #define NOUVEAU_DSM_SUPPORTED 0x00
 #define NOUVEAU_DSM_SUPPORTED_FUNCTIONS 0x00
 
···
 #define NOUVEAU_DSM_POWER_SPEED 0x01
 #define NOUVEAU_DSM_POWER_STAMINA 0x02
 
-static int nouveau_dsm(struct drm_device *dev, int func, int arg, int *result)
-{
-	static char muid[] = {
-		0xA0, 0xA0, 0x95, 0x9D, 0x60, 0x00, 0x48, 0x4D,
-		0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4,
-	};
+static struct nouveau_dsm_priv {
+	bool dsm_detected;
+	acpi_handle dhandle;
+	acpi_handle dsm_handle;
+} nouveau_dsm_priv;
 
-	struct pci_dev *pdev = dev->pdev;
-	struct acpi_handle *handle;
+static const char nouveau_dsm_muid[] = {
+	0xA0, 0xA0, 0x95, 0x9D, 0x60, 0x00, 0x48, 0x4D,
+	0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4,
+};
+
+static int nouveau_dsm(acpi_handle handle, int func, int arg, int *result)
+{
 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
 	struct acpi_object_list input;
 	union acpi_object params[4];
 	union acpi_object *obj;
 	int err;
 
-	handle = DEVICE_ACPI_HANDLE(&pdev->dev);
-
-	if (!handle)
-		return -ENODEV;
-
 	input.count = 4;
 	input.pointer = params;
 	params[0].type = ACPI_TYPE_BUFFER;
-	params[0].buffer.length = sizeof(muid);
-	params[0].buffer.pointer = (char *)muid;
+	params[0].buffer.length = sizeof(nouveau_dsm_muid);
+	params[0].buffer.pointer = (char *)nouveau_dsm_muid;
 	params[1].type = ACPI_TYPE_INTEGER;
 	params[1].integer.value = 0x00000102;
 	params[2].type = ACPI_TYPE_INTEGER;
···
 
 	err = acpi_evaluate_object(handle, "_DSM", &input, &output);
 	if (err) {
-		NV_INFO(dev, "failed to evaluate _DSM: %d\n", err);
+		printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
 		return err;
 	}
 
···
 	return 0;
 }
 
-int nouveau_hybrid_setup(struct drm_device *dev)
+static int nouveau_dsm_switch_mux(acpi_handle handle, int mux_id)
 {
-	int result;
+	return nouveau_dsm(handle, NOUVEAU_DSM_LED, mux_id, NULL);
+}
 
-	if (nouveau_dsm(dev, NOUVEAU_DSM_POWER, NOUVEAU_DSM_POWER_STATE,
-								&result))
-		return -ENODEV;
-
-	NV_INFO(dev, "_DSM hardware status gave 0x%x\n", result);
-
-	if (result) { /* Ensure that the external GPU is enabled */
-		nouveau_dsm(dev, NOUVEAU_DSM_LED, NOUVEAU_DSM_LED_SPEED, NULL);
-		nouveau_dsm(dev, NOUVEAU_DSM_POWER, NOUVEAU_DSM_POWER_SPEED,
-									NULL);
-	} else { /* Stamina mode - disable the external GPU */
-		nouveau_dsm(dev, NOUVEAU_DSM_LED, NOUVEAU_DSM_LED_STAMINA,
-									NULL);
-		nouveau_dsm(dev, NOUVEAU_DSM_POWER, NOUVEAU_DSM_POWER_STAMINA,
-									NULL);
-	}
-
+static int nouveau_dsm_set_discrete_state(acpi_handle handle, enum vga_switcheroo_state state)
+{
+	int arg;
+	if (state == VGA_SWITCHEROO_ON)
+		arg = NOUVEAU_DSM_POWER_SPEED;
+	else
+		arg = NOUVEAU_DSM_POWER_STAMINA;
+	nouveau_dsm(handle, NOUVEAU_DSM_POWER, arg, NULL);
 	return 0;
 }
 
-bool nouveau_dsm_probe(struct drm_device *dev)
+static int nouveau_dsm_switchto(enum vga_switcheroo_client_id id)
 {
-	int support = 0;
+	if (id == VGA_SWITCHEROO_IGD)
+		return nouveau_dsm_switch_mux(nouveau_dsm_priv.dsm_handle, NOUVEAU_DSM_LED_STAMINA);
+	else
+		return nouveau_dsm_switch_mux(nouveau_dsm_priv.dsm_handle, NOUVEAU_DSM_LED_SPEED);
+}
 
-	if (nouveau_dsm(dev, NOUVEAU_DSM_SUPPORTED,
-				NOUVEAU_DSM_SUPPORTED_FUNCTIONS, &support))
+static int nouveau_dsm_power_state(enum vga_switcheroo_client_id id,
+				   enum vga_switcheroo_state state)
+{
+	if (id == VGA_SWITCHEROO_IGD)
+		return 0;
+
+	return nouveau_dsm_set_discrete_state(nouveau_dsm_priv.dsm_handle, state);
+}
+
+static int nouveau_dsm_init(void)
+{
+	return 0;
+}
+
+static int nouveau_dsm_get_client_id(struct pci_dev *pdev)
+{
+	if (nouveau_dsm_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
+		return VGA_SWITCHEROO_IGD;
+	else
+		return VGA_SWITCHEROO_DIS;
+}
+
+static struct vga_switcheroo_handler nouveau_dsm_handler = {
+	.switchto = nouveau_dsm_switchto,
+	.power_state = nouveau_dsm_power_state,
+	.init = nouveau_dsm_init,
+	.get_client_id = nouveau_dsm_get_client_id,
+};
+
+static bool nouveau_dsm_pci_probe(struct pci_dev *pdev)
+{
+	acpi_handle dhandle, nvidia_handle;
+	acpi_status status;
+	int ret;
+	uint32_t result;
+
+	dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
+	if (!dhandle)
+		return false;
+	status = acpi_get_handle(dhandle, "_DSM", &nvidia_handle);
+	if (ACPI_FAILURE(status)) {
+		return false;
+	}
+
+	ret= nouveau_dsm(nvidia_handle, NOUVEAU_DSM_SUPPORTED,
+			 NOUVEAU_DSM_SUPPORTED_FUNCTIONS, &result);
+	if (ret < 0)
 		return false;
 
-	if (!support)
-		return false;
-
+	nouveau_dsm_priv.dhandle = dhandle;
+	nouveau_dsm_priv.dsm_handle = nvidia_handle;
 	return true;
+}
+
+static bool nouveau_dsm_detect(void)
+{
+	char acpi_method_name[255] = { 0 };
+	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
+	struct pci_dev *pdev = NULL;
+	int has_dsm = 0;
+	int vga_count = 0;
+	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
+		vga_count++;
+
+		has_dsm |= (nouveau_dsm_pci_probe(pdev) == true);
+	}
+
+	if (vga_count == 2 && has_dsm) {
+		acpi_get_name(nouveau_dsm_priv.dsm_handle, ACPI_FULL_PATHNAME, &buffer);
+		printk(KERN_INFO "VGA switcheroo: detected DSM switching method %s handle\n",
+		       acpi_method_name);
+		nouveau_dsm_priv.dsm_detected = true;
+		return true;
+	}
+	return false;
+}
+
+void nouveau_register_dsm_handler(void)
+{
+	bool r;
+
+	r = nouveau_dsm_detect();
+	if (!r)
+		return;
+
+	vga_switcheroo_register_handler(&nouveau_dsm_handler);
+}
+
+void nouveau_unregister_dsm_handler(void)
+{
+	vga_switcheroo_unregister_handler();
 }

drivers/gpu/drm/nouveau/nouveau_drv.c

···
 	drm_put_dev(dev);
 }
 
-static int
+int
 nouveau_pci_suspend(struct pci_dev *pdev, pm_message_t pm_state)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
···
 	return ret;
 }
 
-static int
+int
 nouveau_pci_resume(struct pci_dev *pdev)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
···
 			nouveau_modeset = 1;
 	}
 
-	if (nouveau_modeset == 1)
+	if (nouveau_modeset == 1) {
 		driver.driver_features |= DRIVER_MODESET;
+		nouveau_register_dsm_handler();
+	}
 
 	return drm_init(&driver);
 }
···
 static void __exit nouveau_exit(void)
 {
 	drm_exit(&driver);
+	nouveau_unregister_dsm_handler();
 }
 
 module_init(nouveau_init);

drivers/gpu/drm/nouveau/nouveau_drv.h

···
 	} susres;
 
 	struct backlight_device *backlight;
-	bool acpi_dsm;
 
 	struct nouveau_channel *evo;
 
···
 extern int nouveau_ignorelid;
 extern int nouveau_nofbaccel;
 extern int nouveau_noaccel;
+
+extern int nouveau_pci_suspend(struct pci_dev *pdev, pm_message_t pm_state);
+extern int nouveau_pci_resume(struct pci_dev *pdev);
 
 /* nouveau_state.c */
 extern void nouveau_preclose(struct drm_device *dev, struct drm_file *);
···
 extern int  nouveau_dma_wait(struct nouveau_channel *, int size);
 
 /* nouveau_acpi.c */
-#ifdef CONFIG_ACPI
-extern int nouveau_hybrid_setup(struct drm_device *dev);
-extern bool nouveau_dsm_probe(struct drm_device *dev);
-#else
-static inline int nouveau_hybrid_setup(struct drm_device *dev)
-{
-	return 0;
-}
-static inline bool nouveau_dsm_probe(struct drm_device *dev)
-{
-	return false;
-}
-#endif
+void nouveau_register_dsm_handler(void);
+void nouveau_unregister_dsm_handler(void);
 
 /* nouveau_backlight.c */
 #ifdef CONFIG_DRM_NOUVEAU_BACKLIGHT

drivers/gpu/drm/nouveau/nouveau_fbcon.c

···
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/screen_info.h>
+#include <linux/vga_switcheroo.h>
 
 #include "drmP.h"
 #include "drm.h"
···
 						nvbo->bo.offset, nvbo);
 
 	mutex_unlock(&dev->struct_mutex);
+	vga_switcheroo_client_fb_set(dev->pdev, info);
 	return 0;
 
 out_unref:

drivers/gpu/drm/nouveau/nouveau_state.c

···
 #include "drm_sarea.h"
 #include "drm_crtc_helper.h"
 #include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
 
 #include "nouveau_drv.h"
 #include "nouveau_drm.h"
···
 	return ret;
 }
 
+static void nouveau_switcheroo_set_state(struct pci_dev *pdev,
+					 enum vga_switcheroo_state state)
+{
+	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
+	if (state == VGA_SWITCHEROO_ON) {
+		printk(KERN_ERR "VGA switcheroo: switched nouveau on\n");
+		nouveau_pci_resume(pdev);
+	} else {
+		printk(KERN_ERR "VGA switcheroo: switched nouveau off\n");
+		nouveau_pci_suspend(pdev, pmm);
+	}
+}
+
+static bool nouveau_switcheroo_can_switch(struct pci_dev *pdev)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	bool can_switch;
+
+	spin_lock(&dev->count_lock);
+	can_switch = (dev->open_count == 0);
+	spin_unlock(&dev->count_lock);
+	return can_switch;
+}
+
 int
 nouveau_card_init(struct drm_device *dev)
 {
···
 		return 0;
 
 	vga_client_register(dev->pdev, dev, NULL, nouveau_vga_set_decode);
+	vga_switcheroo_register_client(dev->pdev, nouveau_switcheroo_set_state,
+				       nouveau_switcheroo_can_switch);
 
 	/* Initialise internal driver API hooks */
 	ret = nouveau_init_engine_ptrs(dev);
···
 
 	NV_DEBUG(dev, "vendor: 0x%X device: 0x%X class: 0x%X\n",
 		 dev->pci_vendor, dev->pci_device, dev->pdev->class);
-
-	dev_priv->acpi_dsm = nouveau_dsm_probe(dev);
-
-	if (dev_priv->acpi_dsm)
-		nouveau_hybrid_setup(dev);
 
 	dev_priv->wq = create_workqueue("nouveau");
 	if (!dev_priv->wq)

drivers/gpu/drm/radeon/Makefile

···
 	radeon_cs.o radeon_bios.o radeon_benchmark.o r100.o r300.o r420.o \
 	rs400.o rs600.o rs690.o rv515.o r520.o r600.o rv770.o radeon_test.o \
 	r200.o radeon_legacy_tv.o r600_cs.o r600_blit.o r600_blit_shaders.o \
-	r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o
+	r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o \
+	radeon_atpx_handler.o
 
 radeon-$(CONFIG_COMPAT) += radeon_ioc32.o
 

drivers/gpu/drm/radeon/radeon.h

···
 /*
  * BIOS.
  */
+#define ATRM_BIOS_PAGE 4096
+
+bool radeon_atrm_supported(struct pci_dev *pdev);
+int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len);
 bool radeon_get_bios(struct radeon_device *rdev);
 
 
···
 	int			audio_bits_per_sample;
 	uint8_t			audio_status_bits;
 	uint8_t			audio_category_code;
+
+	bool powered_down;
 };
 
 int radeon_device_init(struct radeon_device *rdev,
···
 extern void radeon_atom_set_clock_gating(struct radeon_device *rdev, int enable);
 extern void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain);
 extern bool radeon_ttm_bo_is_radeon_bo(struct ttm_buffer_object *bo);
+extern int radeon_resume_kms(struct drm_device *dev);
+extern int radeon_suspend_kms(struct drm_device *dev, pm_message_t state);
 
 /* r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280 */
 struct r100_mc_save {

drivers/gpu/drm/radeon/radeon_atpx_handler.c

···
+/*
+ * Copyright (c) 2010 Red Hat Inc.
+ * Author : Dave Airlie <[e-mail]>
+ *
+ * Licensed under GPLv2
+ *
+ * ATPX support for both Intel/ATI
+ */
+
+#include <linux/vga_switcheroo.h>
+#include <acpi/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <linux/pci.h>
+
+#define ATPX_VERSION 0
+#define ATPX_GPU_PWR 2
+#define ATPX_MUX_SELECT 3
+
+#define ATPX_INTEGRATED 0
+#define ATPX_DISCRETE 1
+
+#define ATPX_MUX_IGD 0
+#define ATPX_MUX_DISCRETE 1
+
+static struct radeon_atpx_priv {
+	bool atpx_detected;
+	/* handle for device - and atpx */
+	acpi_handle dhandle;
+	acpi_handle atpx_handle;
+	acpi_handle atrm_handle;
+} radeon_atpx_priv;
+
+/* retrieve the ROM in 4k blocks */
+static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
+			    int offset, int len)
+{
+	acpi_status status;
+	union acpi_object atrm_arg_elements[2], *obj;
+	struct acpi_object_list atrm_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
+
+	atrm_arg.count = 2;
+	atrm_arg.pointer = &atrm_arg_elements[0];
+
+	atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	atrm_arg_elements[0].integer.value = offset;
+
+	atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
+	atrm_arg_elements[1].integer.value = len;
+
+	status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
+	if (ACPI_FAILURE(status)) {
+		printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
+		return -ENODEV;
+	}
+
+	obj = (union acpi_object *)buffer.pointer;
+	memcpy(bios+offset, obj->buffer.pointer, len);
+	kfree(buffer.pointer);
+	return len;
+}
+
+bool radeon_atrm_supported(struct pci_dev *pdev)
+{
+	/* get the discrete ROM only via ATRM */
+	if (!radeon_atpx_priv.atpx_detected)
+		return false;
+
+	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
+		return false;
+	return true;
+}
+
+
+int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len)
+{
+	return radeon_atrm_call(radeon_atpx_priv.atrm_handle, bios, offset, len);
+}
+
+static int radeon_atpx_get_version(acpi_handle handle)
+{
+	acpi_status status;
+	union acpi_object atpx_arg_elements[2], *obj;
+	struct acpi_object_list atpx_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	atpx_arg.count = 2;
+	atpx_arg.pointer = &atpx_arg_elements[0];
+
+	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	atpx_arg_elements[0].integer.value = ATPX_VERSION;
+
+	atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
+	atpx_arg_elements[1].integer.value = ATPX_VERSION;
+
+	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
+	if (ACPI_FAILURE(status)) {
+		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
+		return -ENOSYS;
+	}
+	obj = (union acpi_object *)buffer.pointer;
+	if (obj && (obj->type == ACPI_TYPE_BUFFER))
+		printk(KERN_INFO "radeon atpx: version is %d\n", *((u8 *)(obj->buffer.pointer) + 2));
+	kfree(buffer.pointer);
+	return 0;
+}
+
+static int radeon_atpx_execute(acpi_handle handle, int cmd_id, u16 value)
+{
+	acpi_status status;
+	union acpi_object atpx_arg_elements[2];
+	struct acpi_object_list atpx_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	uint8_t buf[4] = {0};
+
+	if (!handle)
+		return -EINVAL;
+
+	atpx_arg.count = 2;
+	atpx_arg.pointer = &atpx_arg_elements[0];
+
+	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	atpx_arg_elements[0].integer.value = cmd_id;
+
+	buf[2] = value & 0xff;
+	buf[3] = (value >> 8) & 0xff;
+
+	atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
+	atpx_arg_elements[1].buffer.length = 4;
+	atpx_arg_elements[1].buffer.pointer = buf;
+
+	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
+	if (ACPI_FAILURE(status)) {
+		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
+		return -ENOSYS;
+	}
+	kfree(buffer.pointer);
+
+	return 0;
+}
+
+static int radeon_atpx_set_discrete_state(acpi_handle handle, int state)
+{
+	return radeon_atpx_execute(handle, ATPX_GPU_PWR, state);
+}
+
+static int radeon_atpx_switch_mux(acpi_handle handle, int mux_id)
+{
+	return radeon_atpx_execute(handle, ATPX_MUX_SELECT, mux_id);
+}
+
+
+static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
+{
+	if (id == VGA_SWITCHEROO_IGD)
+		radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 0);
+	else
+		radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 1);
+	return 0;
+}
+
+static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
+				   enum vga_switcheroo_state state)
+{
+	/* on w500 ACPI can't change intel gpu state */
+	if (id == VGA_SWITCHEROO_IGD)
+		return 0;
+
+	radeon_atpx_set_discrete_state(radeon_atpx_priv.atpx_handle, state);
+	return 0;
+}
+
+static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
+{
+	acpi_handle dhandle, atpx_handle, atrm_handle;
+	acpi_status status;
+
+	dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
+	if (!dhandle)
+		return false;
+
+	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
+	if (ACPI_FAILURE(status))
+		return false;
+
+	status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
+	if (ACPI_FAILURE(status))
+		return false;
+
+	radeon_atpx_priv.dhandle = dhandle;
+	radeon_atpx_priv.atpx_handle = atpx_handle;
+	radeon_atpx_priv.atrm_handle = atrm_handle;
+	return true;
+}
+
+static int radeon_atpx_init(void)
+{
+	/* set up the ATPX handle */
+
+	radeon_atpx_get_version(radeon_atpx_priv.atpx_handle);
+	return 0;
+}
+
+static int radeon_atpx_get_client_id(struct pci_dev *pdev)
+{
+	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
+		return VGA_SWITCHEROO_IGD;
+	else
+		return VGA_SWITCHEROO_DIS;
+}
+
+static struct vga_switcheroo_handler radeon_atpx_handler = {
+	.switchto = radeon_atpx_switchto,
+	.power_state = radeon_atpx_power_state,
+	.init = radeon_atpx_init,
+	.get_client_id = radeon_atpx_get_client_id,
+};
+
+static bool radeon_atpx_detect(void)
+{
+	char acpi_method_name[255] = { 0 };
+	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
+	struct pci_dev *pdev = NULL;
+	bool has_atpx = false;
+	int vga_count = 0;
+
+	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
+		vga_count++;
+
+		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
+	}
+
+	if (has_atpx && vga_count == 2) {
+		acpi_get_name(radeon_atpx_priv.atpx_handle, ACPI_FULL_PATHNAME, &buffer);
+		printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
+		       acpi_method_name);
+		radeon_atpx_priv.atpx_detected = true;
+		return true;
+	}
+	return false;
+}
+
+void radeon_register_atpx_handler(void)
+{
+	bool r;
+
+	/* detect if we have any ATPX + 2 VGA in the system */
+	r = radeon_atpx_detect();
+	if (!r)
+		return;
+
+	vga_switcheroo_register_handler(&radeon_atpx_handler);
+}
+
+void radeon_unregister_atpx_handler(void)
+{
+	vga_switcheroo_unregister_handler();
+}

drivers/gpu/drm/radeon/radeon_bios.c

···
 #include "radeon.h"
 #include "atom.h"
 
+#include <linux/vga_switcheroo.h>
 /*
  * BIOS.
  */
···
 		iounmap(bios);
 		return false;
 	}
-	memcpy(rdev->bios, bios, size);
+	memcpy_fromio(rdev->bios, bios, size);
 	iounmap(bios);
 	return true;
 }
···
 	return true;
 }
 
+/* ATRM is used to get the BIOS on the discrete cards in
+ * dual-gpu systems.
+ */
+static bool radeon_atrm_get_bios(struct radeon_device *rdev)
+{
+	int ret;
+	int size = 64 * 1024;
+	int i;
+
+	if (!radeon_atrm_supported(rdev->pdev))
+		return false;
+
+	rdev->bios = kmalloc(size, GFP_KERNEL);
+	if (!rdev->bios) {
+		DRM_ERROR("Unable to allocate bios\n");
+		return false;
+	}
+
+	for (i = 0; i < size / ATRM_BIOS_PAGE; i++) {
+		ret = radeon_atrm_get_bios_chunk(rdev->bios,
+						 (i * ATRM_BIOS_PAGE),
+						 ATRM_BIOS_PAGE);
+		if (ret <= 0)
+			break;
+	}
+
+	if (i == 0 || rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
+		kfree(rdev->bios);
+		return false;
+	}
+	return true;
+}
 static bool r700_read_disabled_bios(struct radeon_device *rdev)
 {
 	uint32_t viph_control;
···
 		return legacy_read_disabled_bios(rdev);
 }
 
+
 bool radeon_get_bios(struct radeon_device *rdev)
 {
 	bool r;
 	uint16_t tmp;
 
-	if (rdev->flags & RADEON_IS_IGP) {
+	r = radeon_atrm_get_bios(rdev);
+	if (r == false)
 		r = igp_read_bios_from_vram(rdev);
-		if (r == false)
-			r = radeon_read_bios(rdev);
-	} else
+	if (r == false)
 		r = radeon_read_bios(rdev);
 	if (r == false) {
 		r = radeon_read_disabled_bios(rdev);
···
 		return false;
 	}
 	if (rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
+		printk("BIOS signature incorrect %x %x\n", rdev->bios[0], rdev->bios[1]);
 		goto free_bios;
 	}
 

drivers/gpu/drm/radeon/radeon_device.c

···
 #include <drm/drm_crtc_helper.h>
 #include <drm/radeon_drm.h>
 #include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
 #include "radeon_reg.h"
 #include "radeon.h"
 #include "radeon_asic.h"
···
 	}
 }
 
+static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	struct radeon_device *rdev = dev->dev_private;
+	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
+	if (state == VGA_SWITCHEROO_ON) {
+		printk(KERN_INFO "radeon: switched on\n");
+		/* don't suspend or resume card normally */
+		rdev->powered_down = false;
+		radeon_resume_kms(dev);
+	} else {
+		printk(KERN_INFO "radeon: switched off\n");
+		radeon_suspend_kms(dev, pmm);
+		/* don't suspend or resume card normally */
+		rdev->powered_down = true;
+	}
+}
+
+static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	bool can_switch;
+
+	spin_lock(&dev->count_lock);
+	can_switch = (dev->open_count == 0);
+	spin_unlock(&dev->count_lock);
+	return can_switch;
+}
+
+
 int radeon_device_init(struct radeon_device *rdev,
 		       struct drm_device *ddev,
 		       struct pci_dev *pdev,
···
 	/* this will fail for cards that aren't VGA class devices, just
 	 * ignore it */
 	vga_client_register(rdev->pdev, rdev, NULL, radeon_vga_set_decode);
+	vga_switcheroo_register_client(rdev->pdev,
+				       radeon_switcheroo_set_state,
+				       radeon_switcheroo_can_switch);
 
 	r = radeon_init(rdev);
 	if (r)
···
 	rdev->shutdown = true;
 	radeon_fini(rdev);
 	destroy_workqueue(rdev->wq);
+	vga_switcheroo_unregister_client(rdev->pdev);
 	vga_client_register(rdev->pdev, NULL, NULL, NULL);
 	iounmap(rdev->rmmio);
 	rdev->rmmio = NULL;
···
 	}
 	rdev = dev->dev_private;
 
+	if (rdev->powered_down)
+		return 0;
 	/* unpin the front buffers */
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct radeon_framebuffer *rfb = to_radeon_framebuffer(crtc->fb);
···
 int radeon_resume_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
+
+	if (rdev->powered_down)
+		return 0;
 
 	acquire_console_sem();
 	pci_set_power_state(dev->pdev, PCI_D0);

drivers/gpu/drm/radeon/radeon_drv.c

···
 		driver = &kms_driver;
 		driver->driver_features |= DRIVER_MODESET;
 		driver->num_ioctls = radeon_max_kms_ioctl;
+		radeon_register_atpx_handler();
 	}
 	/* if the vga console setting is enabled still
 	 * let modprobe override it */
···
 static void __exit radeon_exit(void)
 {
 	drm_exit(driver);
+	radeon_unregister_atpx_handler();
 }
 
 module_init(radeon_init);

drivers/gpu/drm/radeon/radeon_drv.h

···
 			   int sx, int sy, int dx, int dy,
 			   int w, int h, int src_pitch, int dst_pitch, int cpp);
 
+/* atpx handler */
+void radeon_register_atpx_handler(void);
+void radeon_unregister_atpx_handler(void);
 /* Flags for stats.boxes
  */
 #define RADEON_BOX_DMA_IDLE      0x1

drivers/gpu/drm/radeon/radeon_fb.c

···
 
 #include "drm_fb_helper.h"
 
+#include <linux/vga_switcheroo.h>
+
 struct radeon_fb_device {
 	struct drm_fb_helper helper;
 	struct radeon_framebuffer	*rfb;
···
 	rfbdev->rdev = rdev;
 
 	mutex_unlock(&rdev->ddev->struct_mutex);
+	vga_switcheroo_client_fb_set(rdev->ddev->pdev, info);
 	return 0;
 
 out_unref:

drivers/gpu/drm/radeon/radeon_kms.c

···
 #include "radeon.h"
 #include "radeon_drm.h"
 
+#include <linux/vga_switcheroo.h>
+
 int radeon_driver_unload_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
···
 
 void radeon_driver_lastclose_kms(struct drm_device *dev)
 {
+	vga_switcheroo_process_delayed_switch();
 }
 
 int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)

drivers/gpu/vga/Kconfig

···
 	  are accessed at same time they need some kind of coordination. Please
 	  see Documentation/vgaarbiter.txt for more details. Select this to
 	  enable VGA arbiter.
+
+config VGA_SWITCHEROO
+	bool "Laptop Hybrid Grapics - GPU switching support"
+	default y
+	depends on X86
+	depends on ACPI
+	help
+	  Many laptops released in 2008/9/10 have two gpus with a multiplxer
+	  to switch between them. This adds support for dynamic switching when
+          X isn't running and delayed switching until the next logoff. This
+	  features is called hybrid graphics, ATI PowerXpress, and Nvidia
+	  HybridPower.
+

drivers/gpu/vga/Makefile

···
 obj-$(CONFIG_VGA_ARB)  += vgaarb.o
+obj-$(CONFIG_VGA_SWITCHEROO) += vga_switcheroo.o

drivers/gpu/vga/vga_switcheroo.c

···
+/*
+ * Copyright (c) 2010 Red Hat Inc.
+ * Author : Dave Airlie <[e-mail]>
+ *
+ *
+ * Licensed under GPLv2
+ *
+ * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
+
+ Switcher interface - methods require for ATPX and DCM
+ - switchto - this throws the output MUX switch
+ - discrete_set_power - sets the power state for the discrete card
+
+ GPU driver interface
+ - set_gpu_state - this should do the equiv of s/r for the card
+		  - this should *not* set the discrete power state
+ - switch_check  - check if the device is in a position to switch now
+ */
+
+#include <linux/module.h>
+#include <linux/dmi.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/fb.h>
+
+#include <acpi/acpi.h>
+#include <acpi/acpi_bus.h>
+
+#include <linux/pci.h>
+#include <linux/vga_switcheroo.h>
+
+struct vga_switcheroo_client {
+	struct pci_dev *pdev;
+	struct fb_info *fb_info;
+	int pwr_state;
+	void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state);
+	bool (*can_switch)(struct pci_dev *pdev);
+	int id;
+	bool active;
+};
+
+static DEFINE_MUTEX(vgasr_mutex);
+
+struct vgasr_priv {
+
+	bool active;
+	bool delayed_switch_active;
+	enum vga_switcheroo_client_id delayed_client_id;
+
+	struct dentry *debugfs_root;
+	struct dentry *switch_file;
+
+	int registered_clients;
+	struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];
+
+	struct vga_switcheroo_handler *handler;
+};
+
+static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
+static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
+
+/* only one switcheroo per system */
+static struct vgasr_priv vgasr_priv;
+
+int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
+{
+	mutex_lock(&vgasr_mutex);
+	if (vgasr_priv.handler) {
+		mutex_unlock(&vgasr_mutex);
+		return -EINVAL;
+	}
+
+	vgasr_priv.handler = handler;
+	mutex_unlock(&vgasr_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(vga_switcheroo_register_handler);
+
+void vga_switcheroo_unregister_handler(void)
+{
+	mutex_lock(&vgasr_mutex);
+	vgasr_priv.handler = NULL;
+	mutex_unlock(&vgasr_mutex);
+}
+EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
+
+static void vga_switcheroo_enable(void)
+{
+	int i;
+	int ret;
+	/* call the handler to init */
+	vgasr_priv.handler->init();
+
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
+		if (ret < 0)
+			return;
+
+		vgasr_priv.clients[i].id = ret;
+	}
+	vga_switcheroo_debugfs_init(&vgasr_priv);
+	vgasr_priv.active = true;
+}
+
+int vga_switcheroo_register_client(struct pci_dev *pdev,
+				   void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state),
+				   bool (*can_switch)(struct pci_dev *pdev))
+{
+	int index;
+
+	mutex_lock(&vgasr_mutex);
+	/* don't do IGD vs DIS here */
+	if (vgasr_priv.registered_clients & 1)
+		index = 1;
+	else
+		index = 0;
+
+	vgasr_priv.clients[index].pwr_state = VGA_SWITCHEROO_ON;
+	vgasr_priv.clients[index].pdev = pdev;
+	vgasr_priv.clients[index].set_gpu_state = set_gpu_state;
+	vgasr_priv.clients[index].can_switch = can_switch;
+	vgasr_priv.clients[index].id = -1;
+	if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
+		vgasr_priv.clients[index].active = true;
+
+	vgasr_priv.registered_clients |= (1 << index);
+
+	/* if we get two clients + handler */
+	if (vgasr_priv.registered_clients == 0x3 && vgasr_priv.handler) {
+		printk(KERN_INFO "vga_switcheroo: enabled\n");
+		vga_switcheroo_enable();
+	}
+	mutex_unlock(&vgasr_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(vga_switcheroo_register_client);
+
+void vga_switcheroo_unregister_client(struct pci_dev *pdev)
+{
+	int i;
+
+	mutex_lock(&vgasr_mutex);
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		if (vgasr_priv.clients[i].pdev == pdev) {
+			vgasr_priv.registered_clients &= ~(1 << i);
+			break;
+		}
+	}
+
+	printk(KERN_INFO "vga_switcheroo: disabled\n");
+	vga_switcheroo_debugfs_fini(&vgasr_priv);
+	vgasr_priv.active = false;
+	mutex_unlock(&vgasr_mutex);
+}
+EXPORT_SYMBOL(vga_switcheroo_unregister_client);
+
+void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
+				 struct fb_info *info)
+{
+	int i;
+
+	mutex_lock(&vgasr_mutex);
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		if (vgasr_priv.clients[i].pdev == pdev) {
+			vgasr_priv.clients[i].fb_info = info;
+			break;
+		}
+	}
+	mutex_unlock(&vgasr_mutex);
+}
+EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
+
+static int vga_switcheroo_show(struct seq_file *m, void *v)
+{
+	int i;
+	mutex_lock(&vgasr_mutex);
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		seq_printf(m, "%d:%c:%s:%s\n", i,
+			   vgasr_priv.clients[i].active ? '+' : ' ',
+			   vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off",
+			   pci_name(vgasr_priv.clients[i].pdev));
+	}
+	mutex_unlock(&vgasr_mutex);
+	return 0;
+}
+
+static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, vga_switcheroo_show, NULL);
+}
+
+static int vga_switchon(struct vga_switcheroo_client *client)
+{
+	int ret;
+
+	ret = vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON);
+	/* call the driver callback to turn on device */
+	client->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON);
+	client->pwr_state = VGA_SWITCHEROO_ON;
+	return 0;
+}
+
+static int vga_switchoff(struct vga_switcheroo_client *client)
+{
+	/* call the driver callback to turn off device */
+	client->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
+	vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
+	client->pwr_state = VGA_SWITCHEROO_OFF;
+	return 0;
+}
+
+static int vga_switchto(struct vga_switcheroo_client *new_client)
+{
+	int ret;
+	int i;
+	struct vga_switcheroo_client *active = NULL;
+
+	if (new_client->active == true)
+		return 0;
+
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		if (vgasr_priv.clients[i].active == true) {
+			active = &vgasr_priv.clients[i];
+			break;
+		}
+	}
+	if (!active)
+		return 0;
+
+	/* power up the first device */
+	ret = pci_enable_device(new_client->pdev);
+	if (ret)
+		return ret;
+
+	if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
+		vga_switchon(new_client);
+
+	/* swap shadow resource to denote boot VGA device has changed so X starts on new device */
+	active->active = false;
+
+	active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
+	new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
+
+	if (new_client->fb_info) {
+		struct fb_event event;
+		event.info = new_client->fb_info;
+		fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
+	}
+
+	ret = vgasr_priv.handler->switchto(new_client->id);
+	if (ret)
+		return ret;
+
+	if (active->pwr_state == VGA_SWITCHEROO_ON)
+		vga_switchoff(active);
+
+	new_client->active = true;
+	return 0;
+}
+
+static ssize_t
+vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
+			     size_t cnt, loff_t *ppos)
+{
+	char usercmd[64];
+	const char *pdev_name;
+	int i, ret;
+	bool delay = false, can_switch;
+	int client_id = -1;
+	struct vga_switcheroo_client *client = NULL;
+
+	if (cnt > 63)
+		cnt = 63;
+
+	if (copy_from_user(usercmd, ubuf, cnt))
+		return -EFAULT;
+
+	mutex_lock(&vgasr_mutex);
+
+	if (!vgasr_priv.active)
+		return -EINVAL;
+
+	/* pwr off the device not in use */
+	if (strncmp(usercmd, "OFF", 3) == 0) {
+		for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+			if (vgasr_priv.clients[i].active)
+				continue;
+			if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
+				vga_switchoff(&vgasr_priv.clients[i]);
+		}
+		goto out;
+	}
+	/* pwr on the device not in use */
+	if (strncmp(usercmd, "ON", 2) == 0) {
+		for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+			if (vgasr_priv.clients[i].active)
+				continue;
+			if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
+				vga_switchon(&vgasr_priv.clients[i]);
+		}
+		goto out;
+	}
+
+	/* request a delayed switch - test can we switch now */
+	if (strncmp(usercmd, "DIGD", 4) == 0) {
+		client_id = VGA_SWITCHEROO_IGD;
+		delay = true;
+	}
+
+	if (strncmp(usercmd, "DDIS", 4) == 0) {
+		client_id = VGA_SWITCHEROO_DIS;
+		delay = true;
+	}
+
+	if (strncmp(usercmd, "IGD", 3) == 0)
+		client_id = VGA_SWITCHEROO_IGD;
+
+	if (strncmp(usercmd, "DIS", 3) == 0)
+		client_id = VGA_SWITCHEROO_DIS;
+
+	if (client_id == -1)
+		goto out;
+
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		if (vgasr_priv.clients[i].id == client_id) {
+			client = &vgasr_priv.clients[i];
+			break;
+		}
+	}
+
+	vgasr_priv.delayed_switch_active = false;
+	/* okay we want a switch - test if devices are willing to switch */
+	can_switch = true;
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
+		if (can_switch == false) {
+			printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
+			break;
+		}
+	}
+
+	if (can_switch == false && delay == false)
+		goto out;
+
+	if (can_switch == true) {
+		pdev_name = pci_name(client->pdev);
+		ret = vga_switchto(client);
+		if (ret)
+			printk(KERN_ERR "vga_switcheroo: switching failed %d\n", ret);
+	} else {
+		printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
+		vgasr_priv.delayed_switch_active = true;
+		vgasr_priv.delayed_client_id = client_id;
+
+		/* we should at least power up the card to
+		   make the switch faster */
+		if (client->pwr_state == VGA_SWITCHEROO_OFF)
+			vga_switchon(client);
+	}
+
+out:
+	mutex_unlock(&vgasr_mutex);
+	return cnt;
+}
+
+static const struct file_operations vga_switcheroo_debugfs_fops = {
+	.owner = THIS_MODULE,
+	.open = vga_switcheroo_debugfs_open,
+	.write = vga_switcheroo_debugfs_write,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
+{
+	if (priv->switch_file) {
+		debugfs_remove(priv->switch_file);
+		priv->switch_file = NULL;
+	}
+	if (priv->debugfs_root) {
+		debugfs_remove(priv->debugfs_root);
+		priv->debugfs_root = NULL;
+	}
+}
+
+static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
+{
+	/* already initialised */
+	if (priv->debugfs_root)
+		return 0;
+	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
+
+	if (!priv->debugfs_root) {
+		printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
+		goto fail;
+	}
+
+	priv->switch_file = debugfs_create_file("switch", 0644,
+						priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
+	if (!priv->switch_file) {
+		printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
+		goto fail;
+	}
+	return 0;
+fail:
+	vga_switcheroo_debugfs_fini(priv);
+	return -1;
+}
+
+int vga_switcheroo_process_delayed_switch(void)
+{
+	struct vga_switcheroo_client *client = NULL;
+	const char *pdev_name;
+	bool can_switch = true;
+	int i;
+	int ret;
+	int err = -EINVAL;
+
+	mutex_lock(&vgasr_mutex);
+	if (!vgasr_priv.delayed_switch_active)
+		goto err;
+
+	printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
+
+	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
+		if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
+			client = &vgasr_priv.clients[i];
+		can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
+		if (can_switch == false) {
+			printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
+			break;
+		}
+	}
+
+	if (can_switch == false || client == NULL)
+		goto err;
+
+	pdev_name = pci_name(client->pdev);
+	ret = vga_switchto(client);
+	if (ret)
+		printk(KERN_ERR "vga_switcheroo: delayed switching failed %d\n", ret);
+
+	vgasr_priv.delayed_switch_active = false;
+	err = 0;
+err:
+	mutex_unlock(&vgasr_mutex);
+	return err;
+}
+EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
+

drivers/video/console/fbcon.c

···
 	return 0;
 }
 
+static void fbcon_remap_all(int idx)
+{
+	int i;
+	for (i = first_fb_vc; i <= last_fb_vc; i++)
+		set_con2fb_map(i, idx, 0);
+
+	if (con_is_bound(&fb_con)) {
+		printk(KERN_INFO "fbcon: Remapping primary device, "
+		       "fb%i, to tty %i-%i\n", idx,
+		       first_fb_vc + 1, last_fb_vc + 1);
+		info_idx = idx;
+	}
+}
+
 #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
 static void fbcon_select_primary(struct fb_info *info)
 {
···
 	case FB_EVENT_GET_REQ:
 		caps = event->data;
 		fbcon_get_requirement(info, caps);
+		break;
+	case FB_EVENT_REMAP_ALL_CONSOLE:
+		idx = info->node;
+		fbcon_remap_all(idx);
 		break;
 	}
 done:

include/linux/fb.h

···
 #define FB_EVENT_GET_REQ                0x0D
 /*      Unbind from the console if possible */
 #define FB_EVENT_FB_UNBIND              0x0E
+/*      CONSOLE-SPECIFIC: remap all consoles to new fb - for vga switcheroo */
+#define FB_EVENT_REMAP_ALL_CONSOLE      0x0F
 
 struct fb_event {
 	struct fb_info *info;

include/linux/vga_switcheroo.h

···
+/*
+ * Copyright (c) 2010 Red Hat Inc.
+ * Author : Dave Airlie <[e-mail]>
+ *
+ * Licensed under GPLv2
+ *
+ * vga_switcheroo.h - Support for laptop with dual GPU using one set of outputs
+ */
+
+#include <acpi/acpi.h>
+#include <linux/fb.h>
+
+enum vga_switcheroo_state {
+	VGA_SWITCHEROO_OFF,
+	VGA_SWITCHEROO_ON,
+};
+
+enum vga_switcheroo_client_id {
+	VGA_SWITCHEROO_IGD,
+	VGA_SWITCHEROO_DIS,
+	VGA_SWITCHEROO_MAX_CLIENTS,
+};
+
+struct vga_switcheroo_handler {
+	int (*switchto)(enum vga_switcheroo_client_id id);
+	int (*power_state)(enum vga_switcheroo_client_id id,
+			   enum vga_switcheroo_state state);
+	int (*init)(void);
+	int (*get_client_id)(struct pci_dev *pdev);
+};
+
+
+#if defined(CONFIG_VGA_SWITCHEROO)
+void vga_switcheroo_unregister_client(struct pci_dev *dev);
+int vga_switcheroo_register_client(struct pci_dev *dev,
+				   void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state),
+				   bool (*can_switch)(struct pci_dev *dev));
+
+void vga_switcheroo_client_fb_set(struct pci_dev *dev,
+				  struct fb_info *info);
+
+int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler);
+void vga_switcheroo_unregister_handler(void);
+
+int vga_switcheroo_process_delayed_switch(void);
+
+#else
+
+static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
+static inline int vga_switcheroo_register_client(struct pci_dev *dev,
+					  void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state),
+					  bool (*can_switch)(struct pci_dev *dev)) { return 0; }
+static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {}
+static inline int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) { return 0; }
+static inline void vga_switcheroo_unregister_handler(void) {}
+static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
+
+#endif