hp680_bl.c

  1/*
  2 *  Backlight Driver for HP Jornada 680
  3 *
  4 *  Copyright (c) 2005 Andriy Skulysh
  5 *
  6 *  Based on Sharp's Corgi Backlight Driver
  7 *
  8 * This file is subject to the terms and conditions of the GNU General Public
  9 * License.  See the file "COPYING" in the main directory of this archive
 10 * for more details.
 11 */
 12
 13#include <linux/module.h>
 14#include <linux/kernel.h>
 15#include <linux/init.h>
 16#include <linux/platform_device.h>
 17#include <linux/spinlock.h>
 18#include <linux/backlight.h>
 19
 20#include <cpu/dac.h>
 21#include <mach/hp6xx.h>
 22#include <asm/hd64461.h>
 23
 24#define HP680_MAX_INTENSITY 255
 25#define HP680_DEFAULT_INTENSITY 10
 26
 27static int hp680bl_suspended;
 28static int current_intensity;
 29static DEFINE_SPINLOCK(bl_lock);
 30
 31static void hp680bl_send_intensity(struct backlight_device *bd)
 32{
 33	unsigned long flags;
 34	u16 v;
 35	int intensity = backlight_get_brightness(bd);
 36
 37	if (hp680bl_suspended)
 38		intensity = 0;
 39
 40	spin_lock_irqsave(&bl_lock, flags);
 41	if (intensity && current_intensity == 0) {
 42		sh_dac_enable(DAC_LCD_BRIGHTNESS);
 43		v = inw(HD64461_GPBDR);
 44		v &= ~HD64461_GPBDR_LCDOFF;
 45		outw(v, HD64461_GPBDR);
 46		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
 47	} else if (intensity == 0 && current_intensity != 0) {
 48		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
 49		sh_dac_disable(DAC_LCD_BRIGHTNESS);
 50		v = inw(HD64461_GPBDR);
 51		v |= HD64461_GPBDR_LCDOFF;
 52		outw(v, HD64461_GPBDR);
 53	} else if (intensity) {
 54		sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
 55	}
 56	spin_unlock_irqrestore(&bl_lock, flags);
 57
 58	current_intensity = intensity;
 59}
 60
 61
 62#ifdef CONFIG_PM_SLEEP
 63static int hp680bl_suspend(struct device *dev)
 64{
 65	struct backlight_device *bd = dev_get_drvdata(dev);
 66
 67	hp680bl_suspended = 1;
 68	hp680bl_send_intensity(bd);
 69	return 0;
 70}
 71
 72static int hp680bl_resume(struct device *dev)
 73{
 74	struct backlight_device *bd = dev_get_drvdata(dev);
 75
 76	hp680bl_suspended = 0;
 77	hp680bl_send_intensity(bd);
 78	return 0;
 79}
 80#endif
 81
 82static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
 83
 84static int hp680bl_set_intensity(struct backlight_device *bd)
 85{
 86	hp680bl_send_intensity(bd);
 87	return 0;
 88}
 89
 90static int hp680bl_get_intensity(struct backlight_device *bd)
 91{
 92	return current_intensity;
 93}
 94
 95static const struct backlight_ops hp680bl_ops = {
 96	.get_brightness = hp680bl_get_intensity,
 97	.update_status  = hp680bl_set_intensity,
 98};
 99
100static int hp680bl_probe(struct platform_device *pdev)
101{
102	struct backlight_properties props;
103	struct backlight_device *bd;
104
105	memset(&props, 0, sizeof(struct backlight_properties));
106	props.type = BACKLIGHT_RAW;
107	props.max_brightness = HP680_MAX_INTENSITY;
108	bd = devm_backlight_device_register(&pdev->dev, "hp680-bl", &pdev->dev,
109					NULL, &hp680bl_ops, &props);
110	if (IS_ERR(bd))
111		return PTR_ERR(bd);
112
113	platform_set_drvdata(pdev, bd);
114
115	bd->props.brightness = HP680_DEFAULT_INTENSITY;
116	hp680bl_send_intensity(bd);
117
118	return 0;
119}
120
121static void hp680bl_remove(struct platform_device *pdev)
122{
123	struct backlight_device *bd = platform_get_drvdata(pdev);
124
125	bd->props.brightness = 0;
126	bd->props.power = 0;
127	hp680bl_send_intensity(bd);
128}
129
130static struct platform_driver hp680bl_driver = {
131	.probe		= hp680bl_probe,
132	.remove		= hp680bl_remove,
133	.driver		= {
134		.name	= "hp680-bl",
135		.pm	= &hp680bl_pm_ops,
136	},
137};
138
139static struct platform_device *hp680bl_device;
140
141static int __init hp680bl_init(void)
142{
143	int ret;
144
145	ret = platform_driver_register(&hp680bl_driver);
146	if (ret)
147		return ret;
148	hp680bl_device = platform_device_register_simple("hp680-bl", -1,
149							NULL, 0);
150	if (IS_ERR(hp680bl_device)) {
151		platform_driver_unregister(&hp680bl_driver);
152		return PTR_ERR(hp680bl_device);
153	}
154	return 0;
155}
156
157static void __exit hp680bl_exit(void)
158{
159	platform_device_unregister(hp680bl_device);
160	platform_driver_unregister(&hp680bl_driver);
161}
162
163module_init(hp680bl_init);
164module_exit(hp680bl_exit);
165
166MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
167MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
168MODULE_LICENSE("GPL");