Minimal support for viafb suspend/resume

This patch adds minimal support for suspend/resume of the
VIA framebuffer device. It requires a version of OFW
that restores the video mode.

This patch is OLPC-specific as the proper upstream solution
is to move the VIA video path to using the kernel modesetting
infrastructure and doing a proper save/restore in the kernel.

[jc: extensive changes for 2.6.34 merge]
Signed-off-by: Deepak Saxena <dsaxena@laptop.org>
[fts: viafb_driver moved from viafbdev.c to via-core.c]
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Cc: Joseph Chan <JosephChan@via.com.tw>

drivers/video/via/via-core.c

@@ -644,6 +644,10 @@ static struct pci_driver via_driver = {
 	.id_table	= via_pci_table,
 	.probe		= via_pci_probe,
 	.remove		= __devexit_p(via_pci_remove),
+#ifdef CONFIG_PM
+	.suspend	= viafb_suspend,
+	.resume		= viafb_resume,
+#endif
 };
 
 static int __init via_core_init(void)

drivers/video/via/viafbdev.c

@@ -1669,6 +1669,52 @@ static int parse_mode(const char *str, u32 *xres, u32 *yres)
 }
 
 
+#ifdef CONFIG_PM
+int viafb_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	if (state.event == PM_EVENT_SUSPEND) {
+		acquire_console_sem();
+
+		memcpy_fromio(viaparinfo->shared->saved_regs,
+			      viaparinfo->shared->vdev->engine_mmio + 0x100,
+			      0xff * sizeof(u32));
+
+		fb_set_suspend(viafbinfo, 1);
+
+		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)
+{
+	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);
+
+	memcpy_toio(viaparinfo->shared->vdev->engine_mmio + 0x100,
+		    viaparinfo->shared->saved_regs,
+		    0x100 * sizeof(u32));
+
+	fb_set_suspend(viafbinfo, 0);
+
+fail:
+	release_console_sem();
+	return 0;
+}
+
+#endif
+
+
 int __devinit via_fb_pci_probe(struct viafb_dev *vdev)
 {
 	u32 default_xres, default_yres;

drivers/video/via/viafbdev.h

@@ -62,6 +62,9 @@ struct viafb_shared {
 		u8 dst_bpp, u32 dst_addr, u32 dst_pitch, u32 dst_x, u32 dst_y,
 		u32 *src_mem, u32 src_addr, u32 src_pitch, u32 src_x, u32 src_y,
 		u32 fg_color, u32 bg_color, u8 fill_rop);
+
+	/* For suspend/resume */
+	u32 saved_regs[0x100];
 };
 
 struct viafb_par {
@@ -108,4 +111,6 @@ void via_fb_pci_remove(struct pci_dev *pdev);
 /* 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__ */