[PATCH 2/2] hid: add PM support to PicoLCD device

["Bruno Prémont" <bonbons@linux-vserver.org>]

Add PM support in order to turn off backlight on suspend, restore
it on resume and especially restore complete state on reset-resume.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
---
 drivers/hid/hid-picolcd.c |   61 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 61 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index aa6f2e1..c652390 100644
--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -852,6 +852,20 @@ static inline int picolcd_resume_backlight(struct picolcd_data *data)
 	return picolcd_set_brightness(data->backlight);
 }
 
+#ifdef CONFIG_PM
+static void picolcd_suspend_backlight(struct picolcd_data *data)
+{
+	int bl_power = data->lcd_power;
+	if (!data->backlight)
+		return;
+
+	data->backlight->props.power = FB_BLANK_POWERDOWN;
+	picolcd_set_brightness(data->backlight);
+	data->lcd_power = data->backlight->props.power = bl_power;
+}
+#else
+#define picolcd_suspend_backlight(a)
+#endif /* CONFIG_PM */
 #else
 static inline int picolcd_init_backlight(struct picolcd_data *data,
 		struct hid_report *report)
@@ -865,6 +879,7 @@ static inline int picolcd_resume_backlight(struct picolcd_data *data)
 {
 	return 0;
 }
+#define picolcd_suspend_backlight(a)
 #endif /* CONFIG_HID_PICOLCD_BACKLIGHT */
 
 #ifdef CONFIG_HID_PICOLCD_LCD
@@ -2259,6 +2274,46 @@ static int picolcd_raw_event(struct hid_device *hdev,
 	return 1;
 }
 
+#ifdef CONFIG_PM
+static int picolcd_suspend(struct hid_device *hdev, pm_message_t message)
+{
+	if (message.event & PM_EVENT_AUTO)
+		return 0;
+
+	picolcd_suspend_backlight(hid_get_drvdata(hdev));
+	dbg_hid(PICOLCD_NAME " device ready for suspend\n");
+	return 0;
+}
+
+static int picolcd_resume(struct hid_device *hdev)
+{
+	int ret;
+	ret = picolcd_resume_backlight(hid_get_drvdata(hdev));
+	if (ret)
+		dbg_hid(PICOLCD_NAME " restoring backlight failed: %d\n", ret);
+	return 0;
+}
+
+static int picolcd_reset_resume(struct hid_device *hdev)
+{
+	int ret;
+	ret = picolcd_reset(hdev);
+	if (ret)
+		dbg_hid(PICOLCD_NAME " resetting our device failed: %d\n", ret);
+	ret = picolcd_fb_reset(hid_get_drvdata(hdev), 0);
+	if (ret)
+		dbg_hid(PICOLCD_NAME " restoring framebuffer content failed: %d\n", ret);
+	ret = picolcd_resume_lcd(hid_get_drvdata(hdev));
+	if (ret)
+		dbg_hid(PICOLCD_NAME " restoring lcd failed: %d\n", ret);
+	ret = picolcd_resume_backlight(hid_get_drvdata(hdev));
+	if (ret)
+		dbg_hid(PICOLCD_NAME " restoring backlight failed: %d\n", ret);
+	picolcd_leds_set(hid_get_drvdata(hdev));
+	return 0;
+}
+#endif
+
 /* initialize keypad input device */
 static int picolcd_init_keys(struct picolcd_data *data,
 		struct hid_report *report)
@@ -2544,6 +2599,11 @@ static struct hid_driver picolcd_driver = {
 	.probe =         picolcd_probe,
 	.remove =        picolcd_remove,
 	.raw_event =     picolcd_raw_event,
+#ifdef CONFIG_PM
+	.suspend =       picolcd_suspend,
+	.resume =        picolcd_resume,
+	.reset_resume =  picolcd_reset_resume,
+#endif
 };
 
 static int __init picolcd_init(void)
-- 
1.6.4.4