Date:	Tue, 5 Feb 2008 19:53:31 +0100
From:	Kristoffer Ericson <kristoffer.ericson@...il.com>
To:	Russell King <linux@....linux.org.uk>, rpurdie@...nedhand.com
Cc:	Linux-arm <linux-arm-kernel@...ts.arm.linux.org.uk>,
	linux-main <linux-kernel@...r.kernel.org>
Subject: [PATCH/HP7XX] - Add combined LCD / BL driver for platform HP
 Jornada 7xx handhelds

Greetings,

Richard I've cleaned up the driver by checking with checkpatch.pl as Russell suggested. I would appreciate it if you could
look through the patch again and give comments since the patch looks somewhat different.

I can add patch for Kconfig/Makefile later on but suspect there will be some changes required before that.

Oh and to answer your question regarding MAX/MIN values of the backlight, 0 = max and 255 = min. So we simply turn it around
by returning 255 - value. Same thing when we need to set value.

Best wishes
Kristoffer Ericson

diff --git a/drivers/video/backlight/jornada720_bllcd.c b/drivers/video/backlight/jornada720_bllcd.c
new file mode 100644
index 0000000..4967b86
--- /dev/null
+++ b/drivers/video/backlight/jornada720_bllcd.c
@@ -0,0 +1,284 @@
+/*
+ * drivers/video/backlight/jornada720_bllcd.c
+ *
+ * Backlight and LCD Driver for HP Jornada 720
+ * Copyright (C) 2007 Kristoffer Ericson <Kristoffer.Ericson@...il.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * or any later version as published by the Free Software Foundation.
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/backlight.h>
+#include <linux/lcd.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/device.h>
+#include <asm/hardware.h>
+#include <asm/arch/jornada720.h>
+#include <video/s1d13xxxfb.h>
+
+MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@...il.com>");
+MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight/LCD Driver");
+MODULE_LICENSE("GPL");
+
+#define JORNADA_LCD_MAX_CONTRAST	0xff
+#define JORNADA_LCD_DEFAULT_CONTRAST	0x80
+#define JORNADA_BL_MAX_BRIGHTNESS	0xff
+#define JORNADA_BL_DEFAULT_BRIGHTNESS	0x19
+
+struct jornada_bllcd_device {
+	struct backlight_device *jorn_backlight_device;
+	struct lcd_device *jorn_lcd_device;
+};
+
+/*
+ * BACKLIGHT HANDLING ROUTINES
+ */
+static int jornada_bl_get_brightness(struct backlight_device *dev)
+{
+	int ret;
+
+	/* check if backlight is on */
+	if (!(PPSR & PPC_LDD1))
+		return 255;
+
+	jornada_ssp_start();
+	if (jornada_ssp_inout(GETBRIGHTNESS) == -ETIMEDOUT) {
+		printk(KERN_ERR "jornada720_bl: GetBrightness failed\n");
+		ret = 256;
+	} else
+		ret = jornada_ssp_inout(TXDUMMY);
+
+	jornada_ssp_end();
+
+	/* 0 is max brightness */
+	return (255 - ret);
+}
+
+static int jornada_bl_update_status(struct backlight_device *dev)
+{
+	int ret = 0;
+
+	jornada_ssp_start();
+
+	if (dev->props.power != FB_BLANK_UNBLANK ||
+		dev->props.fb_blank != FB_BLANK_UNBLANK) {
+		ret = jornada_ssp_inout(BRIGHTNESSOFF);
+		if (ret == -ETIMEDOUT)
+			printk(KERN_ERR "jornada720_bl:
+				BrightnessOff timeout\n");
+		else {
+		/* backlight off */
+			PPSR &= ~PPC_LDD1;
+			PPDR |= PPC_LDD1;
+		}
+	} else {/* backlight on */
+			PPSR |= PPC_LDD1;
+
+	if ((jornada_ssp_inout(SETBRIGHTNESS)) == TXDUMMY) {
+		/* send brightness value (0 is max, 255 lowest) */
+		if (jornada_ssp_byte(255 - dev->props.brightness) != -ETIMEDOUT)
+			ret = (255 - dev->props.brightness);
+	} else
+		printk(KERN_ERR "jornada720_bl: SetBrightness timeout\n");
+	}
+
+	jornada_ssp_end();
+
+	return ret;
+}
+
+/* LCD HANDLING FUNCTIONS
+   ====================== */
+static int jornada_lcd_set_contrast(struct lcd_device *pdev, int contrast)
+{
+	int ret = 0;
+
+	jornada_ssp_start();
+
+	ret = jornada_ssp_inout(SETCONTRAST);
+
+	if (ret == -ETIMEDOUT)
+		printk(KERN_INFO "jornada_lcd: failure to set contrast\n");
+	 else
+		ret = jornada_ssp_byte(contrast);
+
+	jornada_ssp_end();
+
+	return ret;
+}
+
+static int jornada_lcd_set_power(struct lcd_device  *pdev, int power)
+{
+	if (power != FB_BLANK_UNBLANK) {
+		/* turn off LCD */
+		PPSR &= ~PPC_LDD2;
+		PPDR |= PPC_LDD2;
+	} else
+	/* turn on LCD */
+	PPSR |= PPC_LDD2;
+
+	return 0;
+}
+
+static int jornada_lcd_get_power(struct lcd_device *pdev)
+{
+	if (PPSR & PPC_LDD2)
+		return FB_BLANK_UNBLANK;
+	else
+		return FB_BLANK_POWERDOWN;
+}
+
+static int jornada_lcd_get_contrast(struct lcd_device *pdev)
+{
+	int ret;
+
+	/* Don't set contrast on off powerd LCD */
+	if (jornada_lcd_get_power(pdev) != FB_BLANK_UNBLANK)
+		return 0;
+
+	jornada_ssp_start();
+
+	ret = jornada_ssp_inout(GETCONTRAST);
+	if (ret != -ETIMEDOUT)
+		ret = jornada_ssp_inout(TXDUMMY);
+	else {
+		printk(KERN_INFO "jornada_lcd: getcontrast failed!\n");
+		ret = 256;
+	}
+
+	jornada_ssp_end();
+
+	return ret;
+}
+
+static struct backlight_ops jornada_bl_ops = {
+	.get_brightness = jornada_bl_get_brightness,
+	.update_status = jornada_bl_update_status,
+};
+
+static struct lcd_ops jornada_lcd_ops = {
+	.get_contrast = jornada_lcd_get_contrast,
+	.set_contrast = jornada_lcd_set_contrast,
+	.get_power = jornada_lcd_get_power,
+	.set_power = jornada_lcd_set_power,
+};
+
+static int jornada_bl_probe(struct platform_device *pdev)
+{
+	struct jornada_bllcd_device *bllcd;
+
+	bllcd = kzalloc(sizeof(*bllcd), GFP_KERNEL);
+	if (bllcd == NULL)
+		return -ENOMEM;
+
+	/* bl driver - name must match fb driver name */
+	bllcd->jorn_backlight_device = backlight_device_register(S1D_DEVICENAME,
+				&pdev->dev, NULL, &jornada_bl_ops);
+
+	if (IS_ERR(bllcd->jorn_backlight_device)) {
+		kfree(bllcd);
+		return PTR_ERR(bllcd->jorn_backlight_device);
+	}
+
+	/* lcd driver */
+	bllcd->jorn_lcd_device = lcd_device_register(S1D_DEVICENAME,
+				&pdev->dev, NULL, &jornada_lcd_ops);
+	if (IS_ERR(bllcd->jorn_lcd_device)) {
+		kfree(bllcd);
+		return PTR_ERR(bllcd->jorn_lcd_device);
+	}
+
+	jornada_lcd_set_contrast(bllcd->jorn_lcd_device,
+			JORNADA_LCD_DEFAULT_CONTRAST);
+	jornada_lcd_set_power(bllcd->jorn_lcd_device,
+			FB_BLANK_UNBLANK);
+
+	msleep(100);
+
+	bllcd->jorn_backlight_device->props.power
+		= FB_BLANK_UNBLANK;
+	bllcd->jorn_backlight_device->props.brightness
+		= JORNADA_BL_DEFAULT_BRIGHTNESS;
+	jornada_bl_update_status(bllcd->jorn_backlight_device);
+
+	platform_set_drvdata(pdev, bllcd);
+	printk(KERN_INFO "HP Jornada 7xx Backlight/LCD driver activated\n");
+
+	return 0;
+}
+
+static int jornada_bl_remove(struct platform_device *pdev)
+{
+	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
+
+	bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
+	bllcd->jorn_backlight_device->props.brightness = 0;
+	bllcd->jorn_backlight_device->props.max_brightness = 0;
+
+	backlight_device_unregister(bllcd->jorn_backlight_device);
+	lcd_device_unregister(bllcd->jorn_lcd_device);
+
+	return 0;
+}
+
+static int jornada_bl_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
+
+	bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
+	bllcd->jorn_backlight_device->props.brightness = 0;
+	bllcd->jorn_backlight_device->props.max_brightness = 0;
+	jornada_bl_update_status(bllcd->jorn_backlight_device);
+
+	jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_POWERDOWN);
+
+	return 0;
+}
+
+static int jornada_bl_resume(struct platform_device *pdev)
+{
+	struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
+
+	bllcd->jorn_backlight_device->props.power
+		= FB_BLANK_UNBLANK;
+	bllcd->jorn_backlight_device->props.brightness
+		= JORNADA_BL_DEFAULT_BRIGHTNESS;
+	bllcd->jorn_backlight_device->props.max_brightness
+		= JORNADA_BL_MAX_BRIGHTNESS;
+	jornada_bl_update_status(bllcd->jorn_backlight_device);
+
+	jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_UNBLANK);
+
+	return 0;
+}
+
+static struct platform_driver jornada_bl_driver = {
+	.probe	= jornada_bl_probe,
+	.remove	= jornada_bl_remove,
+#ifdef CONFIG_PM
+	.suspend = jornada_bl_suspend,
+	.resume = jornada_bl_resume,
+#endif
+	.driver = {
+	    .name = "jornada_bl",
+	},
+};
+
+static int __init jornada_bl_init(void)
+{
+	return platform_driver_register(&jornada_bl_driver);
+}
+
+static void __exit jornada_bl_exit(void)
+{
+	platform_driver_unregister(&jornada_bl_driver);
+}
+
+module_init(jornada_bl_init);
+module_exit(jornada_bl_exit);

Download attachment "jornada720_bllcd.patch" of type "application/octet-stream" (7499 bytes)

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