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 <airlied@redhat.com>
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
new file mode 100644
index 0000000..a3f587a
--- /dev/null
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -0,0 +1,453 @@
+/*
+ * Copyright (c) 2010 Red Hat Inc.
+ * Author : Dave Airlie <airlied@redhat.com>
+ *
+ *
+ * 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);
+