lcd: add platform_lcd driver

Add a platform_lcd driver to allow boards with simple lcd power controls
to register themselves easily.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/video/backlight/platform_lcd.c b/drivers/video/backlight/platform_lcd.c
new file mode 100644
index 00000000000..72d44dbfce8
--- /dev/null
+++ b/drivers/video/backlight/platform_lcd.c
@@ -0,0 +1,172 @@
+/* drivers/video/backlight/platform_lcd.c
+ *
+ * Copyright 2008 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * Generic platform-device LCD power control interface.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+*/
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/lcd.h>
+
+#include <video/platform_lcd.h>
+
+struct platform_lcd {
+	struct device		*us;
+	struct lcd_device	*lcd;
+	struct plat_lcd_data	*pdata;
+
+	unsigned int		 power;
+	unsigned int		 suspended : 1;
+};
+
+static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
+{
+	return lcd_get_data(lcd);
+}
+
+static int platform_lcd_get_power(struct lcd_device *lcd)
+{
+	struct platform_lcd *plcd = to_our_lcd(lcd);
+
+	return plcd->power;
+}
+
+static int platform_lcd_set_power(struct lcd_device *lcd, int power)
+{
+	struct platform_lcd *plcd = to_our_lcd(lcd);
+	int lcd_power = 1;
+
+	if (power == FB_BLANK_POWERDOWN || plcd->suspended)
+		lcd_power = 0;
+
+	plcd->pdata->set_power(plcd->pdata, lcd_power);
+	plcd->power = power;
+
+	return 0;
+}
+
+static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
+{
+	struct platform_lcd *plcd = to_our_lcd(lcd);
+	struct plat_lcd_data *pdata = plcd->pdata;
+
+	if (pdata->match_fb)
+		return pdata->match_fb(pdata, info);
+
+	return plcd->us->parent == info->device;
+}
+
+static struct lcd_ops platform_lcd_ops = {
+	.get_power	= platform_lcd_get_power,
+	.set_power	= platform_lcd_set_power,
+	.check_fb	= platform_lcd_match,
+};
+
+static int __devinit platform_lcd_probe(struct platform_device *pdev)
+{
+	struct plat_lcd_data *pdata;
+	struct platform_lcd *plcd;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(dev, "no platform data supplied\n");
+		return -EINVAL;
+	}
+
+	plcd = kzalloc(sizeof(struct platform_lcd), GFP_KERNEL);
+	if (!plcd) {
+		dev_err(dev, "no memory for state\n");
+		return -ENOMEM;
+	}
+
+	plcd->us = dev;
+	plcd->pdata = pdata;
+	plcd->lcd = lcd_device_register("platform-lcd", dev,
+					plcd, &platform_lcd_ops);
+	if (IS_ERR(plcd->lcd)) {
+		dev_err(dev, "cannot register lcd device\n");
+		err = PTR_ERR(plcd->lcd);
+		goto err_mem;
+	}
+
+	platform_set_drvdata(pdev, plcd);
+	return 0;
+
+ err_mem:
+	kfree(plcd);
+	return err;
+}
+
+static int __devexit platform_lcd_remove(struct platform_device *pdev)
+{
+	struct platform_lcd *plcd = platform_get_drvdata(pdev);
+
+	lcd_device_unregister(plcd->lcd);
+	kfree(plcd);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st)
+{
+	struct platform_lcd *plcd = platform_get_drvdata(pdev);
+
+	plcd->suspended = 1;
+	platform_lcd_set_power(plcd->lcd, plcd->power);
+
+	return 0;
+}
+
+static int platform_lcd_resume(struct platform_device *pdev)
+{
+	struct platform_lcd *plcd = platform_get_drvdata(pdev);
+
+	plcd->suspended = 0;
+	platform_lcd_set_power(plcd->lcd, plcd->power);
+
+	return 0;
+}
+#else
+#define platform_lcd_suspend NULL
+#define platform_lcd_resume NULL
+#endif
+
+static struct platform_driver platform_lcd_driver = {
+	.driver		= {
+		.name	= "platform-lcd",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= platform_lcd_probe,
+	.remove		= __devexit_p(platform_lcd_remove),
+	.suspend        = platform_lcd_suspend,
+	.resume         = platform_lcd_resume,
+};
+
+static int __init platform_lcd_init(void)
+{
+	return platform_driver_register(&platform_lcd_driver);
+}
+
+static void __exit platform_lcd_cleanup(void)
+{
+	platform_driver_unregister(&platform_lcd_driver);
+}
+
+module_init(platform_lcd_init);
+module_exit(platform_lcd_cleanup);
+
+MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:platform-lcd");