viafb: General power management infrastructure
Multiple devices need S/R hooks (framebuffer, GPIO, camera).
Add infrastructure and convert existing framebuffer code to the new
model.
This patch should create no functional change.
Based on earlier work by Jonathan Corbet.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/via/via-core.c b/drivers/video/via/via-core.c
index 31e3033..42be3d9 100644
--- a/drivers/video/via/via-core.c
+++ b/drivers/video/via/via-core.c
@@ -15,6 +15,8 @@
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/pm.h>
/*
* The default port config.
@@ -563,6 +565,78 @@
}
}
+/*
+ * Power management functions
+ */
+#ifdef CONFIG_PM
+static LIST_HEAD(viafb_pm_hooks);
+static DEFINE_MUTEX(viafb_pm_hooks_lock);
+
+void viafb_pm_register(struct viafb_pm_hooks *hooks)
+{
+ INIT_LIST_HEAD(&hooks->list);
+
+ mutex_lock(&viafb_pm_hooks_lock);
+ list_add_tail(&hooks->list, &viafb_pm_hooks);
+ mutex_unlock(&viafb_pm_hooks_lock);
+}
+EXPORT_SYMBOL_GPL(viafb_pm_register);
+
+void viafb_pm_unregister(struct viafb_pm_hooks *hooks)
+{
+ mutex_lock(&viafb_pm_hooks_lock);
+ list_del(&hooks->list);
+ mutex_unlock(&viafb_pm_hooks_lock);
+}
+EXPORT_SYMBOL_GPL(viafb_pm_unregister);
+
+static int via_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+ struct viafb_pm_hooks *hooks;
+
+ if (state.event != PM_EVENT_SUSPEND)
+ return 0;
+ /*
+ * "I've occasionally hit a few drivers that caused suspend
+ * failures, and each and every time it was a driver bug, and
+ * the right thing to do was to just ignore the error and suspend
+ * anyway - returning an error code and trying to undo the suspend
+ * is not what anybody ever really wants, even if our model
+ *_allows_ for it."
+ * -- Linus Torvalds, Dec. 7, 2009
+ */
+ mutex_lock(&viafb_pm_hooks_lock);
+ list_for_each_entry_reverse(hooks, &viafb_pm_hooks, list)
+ hooks->suspend(hooks->private);
+ mutex_unlock(&viafb_pm_hooks_lock);
+
+ pci_save_state(pdev);
+ pci_disable_device(pdev);
+ pci_set_power_state(pdev, pci_choose_state(pdev, state));
+ return 0;
+}
+
+static int via_resume(struct pci_dev *pdev)
+{
+ struct viafb_pm_hooks *hooks;
+
+ /* Get the bus side powered up */
+ pci_set_power_state(pdev, PCI_D0);
+ pci_restore_state(pdev);
+ if (pci_enable_device(pdev))
+ return 0;
+
+ pci_set_master(pdev);
+
+ /* Now bring back any subdevs */
+ mutex_lock(&viafb_pm_hooks_lock);
+ list_for_each_entry(hooks, &viafb_pm_hooks, list)
+ hooks->resume(hooks->private);
+ mutex_unlock(&viafb_pm_hooks_lock);
+
+ return 0;
+}
+#endif /* CONFIG_PM */
static int __devinit via_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
@@ -572,6 +646,7 @@
ret = pci_enable_device(pdev);
if (ret)
return ret;
+
/*
* Global device initialization.
*/
@@ -651,8 +726,8 @@
.probe = via_pci_probe,
.remove = __devexit_p(via_pci_remove),
#ifdef CONFIG_PM
- .suspend = viafb_suspend,
- .resume = viafb_resume,
+ .suspend = via_suspend,
+ .resume = via_resume,
#endif
};
