gpm940b0: Add suspend/resume support.

target/linux/xburst/files-2.6.31/drivers/video/backlight/gpm940b0.c

@@ -17,11 +17,13 @@
 #include <linux/spi/spi.h>
 #include <linux/lcd.h>
 #include <linux/backlight.h>
+#include <linux/delay.h>
 
 struct gpm940b0 {
 	struct spi_device *spi;
 	struct lcd_device *lcd;
 	struct backlight_device *bl;
+	unsigned enabled:1;
 };
 
 static int gpm940b0_write_reg(struct spi_device *spi, uint8_t reg,
@@ -34,16 +36,31 @@ static int gpm940b0_write_reg(struct spi_device *spi, uint8_t reg,
 	return spi_write(spi, buf, sizeof(buf));
 }
 
+static void gpm940b0_power_disable(struct gpm940b0 *gpm940b0)
+{
+	int ret = gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc6) ;
+	if (ret < 0)
+		printk("Failed to disable power: %d\n", ret);
+}
+
+static void gpm940b0_power_enable(struct gpm940b0 *gpm940b0)
+{
+	gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc7);
+}
+
+
 static int gpm940b0_set_power(struct lcd_device *lcd, int power)
 {
 	struct gpm940b0 *gpm940b0 = lcd_get_data(lcd);
 
 	switch (power) {
 	case FB_BLANK_UNBLANK:
-	    gpm940b0_write_reg(gpm940b0->spi, 0x05, 0x5f);
+		gpm940b0->enabled = 1;
+		gpm940b0_power_enable(gpm940b0);
 		break;
 	default:
-	    gpm940b0_write_reg(gpm940b0->spi, 0x05, 0x5e);
+		gpm940b0->enabled = 0;
+		gpm940b0_power_disable(gpm940b0);
 		break;
 	}
 	return 0;
@@ -64,17 +81,20 @@ static int gpm940b0_set_mode(struct lcd_device *lcd, struct fb_videomode *mode)
 	return 0;
 }
 
+/*
 int gpm940b0_bl_update_status(struct backlight_device *bl)
 {
 	struct gpm940b0 *gpm940b0 = bl_get_data(bl);
 
-    /* The datasheet suggest that this is not possible on the giantplus module 
+	gpm940b0->reg5 &= ~0x38;
-	gpm940b0_write_reg(gpm940b0->spi, 21, bl->props.brightness);*/
+	gpm940b0->reg5 |= ((bl->props.brightness << 3) & 0x38);
+
+	gpm940b0_write_reg(gpm940b0->spi, 0x5, gpm940b0->reg5);
 
 	return 0;
-}
+}*/
 
-static size_t reg_write(struct device *dev, struct device_attribute *attr,
+static ssize_t reg_write(struct device *dev, struct device_attribute *attr,
 						const char *buf, size_t count)
 {
 	char *buf2;
@@ -97,10 +117,12 @@ static struct lcd_ops gpm940b0_lcd_ops = {
 	.set_mode = gpm940b0_set_mode,
 };
 
+#if 0
 static struct backlight_ops gpm940b0_bl_ops = {
 /*	.get_brightness	= gpm940b0_bl_get_brightness,*/
 	.update_status	= gpm940b0_bl_update_status,
 };
+#endif
 
 static int __devinit gpm940b0_probe(struct spi_device *spi)
 {
@@ -130,6 +152,7 @@ static int __devinit gpm940b0_probe(struct spi_device *spi)
 
 	gpm940b0->lcd->props.max_contrast = 255;
 
+#if 0
 	gpm940b0->bl = backlight_device_register("gpm940b0-bl", &spi->dev, gpm940b0,
 						 &gpm940b0_bl_ops);
 
@@ -138,26 +161,36 @@ static int __devinit gpm940b0_probe(struct spi_device *spi)
 		dev_err(&spi->dev, "Failed to register backlight device: %d\n", ret);
 		gpm940b0->bl = NULL;
 	} else {
-		gpm940b0->bl->props.max_brightness = 15;
+		gpm940b0->bl->props.max_brightness = 8;
 		gpm940b0->bl->props.brightness = 0;
 		gpm940b0->bl->props.power = FB_BLANK_UNBLANK;
 	}
-	device_create_file(&spi->dev, &dev_attr_reg);
+#endif
 
+	ret = device_create_file(&spi->dev, &dev_attr_reg);
+	if (ret)
+		goto err_unregister_lcd;
+
+	gpm940b0->enabled = 1;
 	dev_set_drvdata(&spi->dev, gpm940b0);
 
 	gpm940b0_write_reg(spi, 0x13, 0x01);
-	gpm940b0_write_reg(spi, 0x05, 0x5f);
+	gpm940b0_write_reg(spi, 0x5, 0xc7);
 	return 0;
+err_unregister_lcd:
+	lcd_device_unregister(gpm940b0->lcd);
 err_free_gpm940b0:
+	kfree(gpm940b0);
 	return ret;
 }
 
 static int __devexit gpm940b0_remove(struct spi_device *spi)
 {
 	struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
+#if 0
 	if (gpm940b0->bl)
 		backlight_device_unregister(gpm940b0->bl);
+#endif
 
 	lcd_device_unregister(gpm940b0->lcd);
 
@@ -166,6 +199,31 @@ static int __devexit gpm940b0_remove(struct spi_device *spi)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+
+static int gpm940b0_suspend(struct spi_device *spi, pm_message_t state)
+{
+	struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
+	if (gpm940b0->enabled) {
+		gpm940b0_power_disable(gpm940b0);
+		mdelay(10);
+	}
+	return 0;
+}
+
+static int gpm940b0_resume(struct spi_device *spi)
+{
+	struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
+	if (gpm940b0->enabled)
+		gpm940b0_power_enable(gpm940b0);
+	return 0;
+}
+
+#else
+#define gpm940b0_suspend NULL
+#define gpm940b0_resume NULL
+#endif
+
 static struct spi_driver gpm940b0_driver = {
 	.driver = {
 		.name = "gpm940b0",
@@ -173,6 +231,8 @@ static struct spi_driver gpm940b0_driver = {
 	},
 	.probe = gpm940b0_probe,
 	.remove = __devexit_p(gpm940b0_remove),
+	.suspend = gpm940b0_suspend,
+	.resume = gpm940b0_resume,
 };
 
 static int __init gpm940b0_init(void)
@@ -190,4 +250,4 @@ module_exit(gpm940b0_exit)
 MODULE_AUTHOR("Lars-Peter Clausen");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("LCD and backlight controll for Giantplus GPM940B0");
-MODULE_ALIAS("i2c:gpm940b0");
+MODULE_ALIAS("spi:gpm940b0");