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>

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>
Daniel Drake · Florian Tobias Schandinat
1 parent 51f4332bb5
Showing 4 changed files with 107 additions and 23 deletions Side-by-side Diff
drivers/video/via/via-core.c
drivers/video/via/viafbdev.c
drivers/video/via/viafbdev.h
include/linux/via-core.h
@@ -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.
  
@@ -563,7 +565,79 @@
 		}
 }
  
+/*
+ * 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
 };
  
@@ -1672,31 +1672,19 @@
  
  
 #ifdef CONFIG_PM
-int viafb_suspend(struct pci_dev *pdev, pm_message_t state)
+static int viafb_suspend(void *unused)
 {
-	if (state.event == PM_EVENT_SUSPEND) {
-		acquire_console_sem();
-		fb_set_suspend(viafbinfo, 1);
+	acquire_console_sem();
+	fb_set_suspend(viafbinfo, 1);
+	viafb_sync(viafbinfo);
+	release_console_sem();
  
-		viafb_sync(viafbinfo);
-
-		pci_save_state(pdev);
-		pci_disable_device(pdev);
-		pci_set_power_state(pdev, pci_choose_state(pdev, state));
-		release_console_sem();
-	}
-
 	return 0;
 }
  
-int viafb_resume(struct pci_dev *pdev)
+static int viafb_resume(void *unused)
 {
 	acquire_console_sem();
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	if (pci_enable_device(pdev))
-		goto fail;
-	pci_set_master(pdev);
 	if (viaparinfo->shared->vdev->engine_mmio)
 		viafb_reset_engine(viaparinfo);
 	viafb_set_par(viafbinfo);
  
@@ -1704,11 +1692,15 @@
 		viafb_set_par(viafbinfo1);
 	fb_set_suspend(viafbinfo, 0);
  
-fail:
 	release_console_sem();
 	return 0;
 }
  
+static struct viafb_pm_hooks viafb_fb_pm_hooks = {
+	.suspend = viafb_suspend,
+	.resume = viafb_resume
+};
+
 #endif
  
  
@@ -1899,6 +1891,10 @@
  
 	viafb_init_proc(viaparinfo->shared);
 	viafb_init_dac(IGA2);
+
+#ifdef CONFIG_PM
+	viafb_pm_register(&viafb_fb_pm_hooks);
+#endif
 	return 0;
  
 out_fb_unreg:
@@ -108,7 +108,5 @@
 /* Temporary */
 int viafb_init(void);
 void viafb_exit(void);
-int viafb_suspend(struct pci_dev *pdev, pm_message_t state);
-int viafb_resume(struct pci_dev *pdev);
 #endif /* __VIAFBDEV_H__ */
@@ -60,6 +60,21 @@
 };
  
 /*
+ * Allow subdevs to register suspend/resume hooks.
+ */
+#ifdef CONFIG_PM
+struct viafb_pm_hooks {
+	struct list_head list;
+	int (*suspend)(void *private);
+	int (*resume)(void *private);
+	void *private;
+};
+
+void viafb_pm_register(struct viafb_pm_hooks *hooks);
+void viafb_pm_unregister(struct viafb_pm_hooks *hooks);
+#endif /* CONFIG_PM */
+
+/*
  * This is the global viafb "device" containing stuff needed by
  * all subdevs.
  */
...	...	@@ -15,6 +15,8 @@
15	15	#include <linux/module.h>
16	16	#include <linux/interrupt.h>
17	17	#include <linux/platform_device.h>
	18	+#include <linux/list.h>
	19	+#include <linux/pm.h>
18	20
19	21	/*
20	22	* The default port config.
21	23
...	...	@@ -563,7 +565,79 @@
563	565	}
564	566	}
565	567
	568	+/*
	569	+ * Power management functions
	570	+ */
	571	+#ifdef CONFIG_PM
	572	+static LIST_HEAD(viafb_pm_hooks);
	573	+static DEFINE_MUTEX(viafb_pm_hooks_lock);
566	574
	575	+void viafb_pm_register(struct viafb_pm_hooks *hooks)
	576	+{
	577	+ INIT_LIST_HEAD(&hooks->list);
	578	+
	579	+ mutex_lock(&viafb_pm_hooks_lock);
	580	+ list_add_tail(&hooks->list, &viafb_pm_hooks);
	581	+ mutex_unlock(&viafb_pm_hooks_lock);
	582	+}
	583	+EXPORT_SYMBOL_GPL(viafb_pm_register);
	584	+
	585	+void viafb_pm_unregister(struct viafb_pm_hooks *hooks)
	586	+{
	587	+ mutex_lock(&viafb_pm_hooks_lock);
	588	+ list_del(&hooks->list);
	589	+ mutex_unlock(&viafb_pm_hooks_lock);
	590	+}
	591	+EXPORT_SYMBOL_GPL(viafb_pm_unregister);
	592	+
	593	+static int via_suspend(struct pci_dev *pdev, pm_message_t state)
	594	+{
	595	+ struct viafb_pm_hooks *hooks;
	596	+
	597	+ if (state.event != PM_EVENT_SUSPEND)
	598	+ return 0;
	599	+ /*
	600	+ * "I've occasionally hit a few drivers that caused suspend
	601	+ * failures, and each and every time it was a driver bug, and
	602	+ * the right thing to do was to just ignore the error and suspend
	603	+ * anyway - returning an error code and trying to undo the suspend
	604	+ * is not what anybody ever really wants, even if our model
	605	+ *_allows_ for it."
	606	+ * -- Linus Torvalds, Dec. 7, 2009
	607	+ */
	608	+ mutex_lock(&viafb_pm_hooks_lock);
	609	+ list_for_each_entry_reverse(hooks, &viafb_pm_hooks, list)
	610	+ hooks->suspend(hooks->private);
	611	+ mutex_unlock(&viafb_pm_hooks_lock);
	612	+
	613	+ pci_save_state(pdev);
	614	+ pci_disable_device(pdev);
	615	+ pci_set_power_state(pdev, pci_choose_state(pdev, state));
	616	+ return 0;
	617	+}
	618	+
	619	+static int via_resume(struct pci_dev *pdev)
	620	+{
	621	+ struct viafb_pm_hooks *hooks;
	622	+
	623	+ /* Get the bus side powered up */
	624	+ pci_set_power_state(pdev, PCI_D0);
	625	+ pci_restore_state(pdev);
	626	+ if (pci_enable_device(pdev))
	627	+ return 0;
	628	+
	629	+ pci_set_master(pdev);
	630	+
	631	+ /* Now bring back any subdevs */
	632	+ mutex_lock(&viafb_pm_hooks_lock);
	633	+ list_for_each_entry(hooks, &viafb_pm_hooks, list)
	634	+ hooks->resume(hooks->private);
	635	+ mutex_unlock(&viafb_pm_hooks_lock);
	636	+
	637	+ return 0;
	638	+}
	639	+#endif /* CONFIG_PM */
	640	+
567	641	static int __devinit via_pci_probe(struct pci_dev *pdev,
568	642	const struct pci_device_id *ent)
569	643	{
...	...	@@ -572,6 +646,7 @@
572	646	ret = pci_enable_device(pdev);
573	647	if (ret)
574	648	return ret;
	649	+
575	650	/*
576	651	* Global device initialization.
577	652	*/
...	...	@@ -651,8 +726,8 @@
651	726	.probe = via_pci_probe,
652	727	.remove = __devexit_p(via_pci_remove),
653	728	#ifdef CONFIG_PM
654		- .suspend = viafb_suspend,
655		- .resume = viafb_resume,
	729	+ .suspend = via_suspend,
	730	+ .resume = via_resume,
656	731	#endif
657	732	};
658	733
...	...	@@ -1672,31 +1672,19 @@
1672	1672
1673	1673
1674	1674	#ifdef CONFIG_PM
1675		-int viafb_suspend(struct pci_dev *pdev, pm_message_t state)
	1675	+static int viafb_suspend(void *unused)
1676	1676	{
1677		- if (state.event == PM_EVENT_SUSPEND) {
1678		- acquire_console_sem();
1679		- fb_set_suspend(viafbinfo, 1);
	1677	+ acquire_console_sem();
	1678	+ fb_set_suspend(viafbinfo, 1);
	1679	+ viafb_sync(viafbinfo);
	1680	+ release_console_sem();
1680	1681
1681		- viafb_sync(viafbinfo);
1682		-
1683		- pci_save_state(pdev);
1684		- pci_disable_device(pdev);
1685		- pci_set_power_state(pdev, pci_choose_state(pdev, state));
1686		- release_console_sem();
1687		- }
1688		-
1689	1682	return 0;
1690	1683	}
1691	1684
1692		-int viafb_resume(struct pci_dev *pdev)
	1685	+static int viafb_resume(void *unused)
1693	1686	{
1694	1687	acquire_console_sem();
1695		- pci_set_power_state(pdev, PCI_D0);
1696		- pci_restore_state(pdev);
1697		- if (pci_enable_device(pdev))
1698		- goto fail;
1699		- pci_set_master(pdev);
1700	1688	if (viaparinfo->shared->vdev->engine_mmio)
1701	1689	viafb_reset_engine(viaparinfo);
1702	1690	viafb_set_par(viafbinfo);
1703	1691
...	...	@@ -1704,11 +1692,15 @@
1704	1692	viafb_set_par(viafbinfo1);
1705	1693	fb_set_suspend(viafbinfo, 0);
1706	1694
1707		-fail:
1708	1695	release_console_sem();
1709	1696	return 0;
1710	1697	}
1711	1698
	1699	+static struct viafb_pm_hooks viafb_fb_pm_hooks = {
	1700	+ .suspend = viafb_suspend,
	1701	+ .resume = viafb_resume
	1702	+};
	1703	+
1712	1704	#endif
1713	1705
1714	1706
...	...	@@ -1899,6 +1891,10 @@
1899	1891
1900	1892	viafb_init_proc(viaparinfo->shared);
1901	1893	viafb_init_dac(IGA2);
	1894	+
	1895	+#ifdef CONFIG_PM
	1896	+ viafb_pm_register(&viafb_fb_pm_hooks);
	1897	+#endif
1902	1898	return 0;
1903	1899
1904	1900	out_fb_unreg:
...	...	@@ -108,7 +108,5 @@
108	108	/* Temporary */
109	109	int viafb_init(void);
110	110	void viafb_exit(void);
111		-int viafb_suspend(struct pci_dev *pdev, pm_message_t state);
112		-int viafb_resume(struct pci_dev *pdev);
113	111	#endif /* __VIAFBDEV_H__ */
...	...	@@ -60,6 +60,21 @@
60	60	};
61	61
62	62	/*
	63	+ * Allow subdevs to register suspend/resume hooks.
	64	+ */
	65	+#ifdef CONFIG_PM
	66	+struct viafb_pm_hooks {
	67	+ struct list_head list;
	68	+ int (suspend)(void private);
	69	+ int (resume)(void private);
	70	+ void *private;
	71	+};
	72	+
	73	+void viafb_pm_register(struct viafb_pm_hooks *hooks);
	74	+void viafb_pm_unregister(struct viafb_pm_hooks *hooks);
	75	+#endif /* CONFIG_PM */
	76	+
	77	+/*
63	78	* This is the global viafb "device" containing stuff needed by
64	79	* all subdevs.
65	80	*/