kb3886_bl.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  Backlight Driver for the KB3886 Backlight
  4 *
  5 *  Copyright (c) 2007-2008 Claudio Nieder
  6 *
  7 *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
  8 */
  9
 10#include <linux/module.h>
 11#include <linux/kernel.h>
 12#include <linux/init.h>
 13#include <linux/io.h>
 14#include <linux/platform_device.h>
 15#include <linux/mutex.h>
 16#include <linux/backlight.h>
 17#include <linux/delay.h>
 18#include <linux/dmi.h>
 19
 20#define KB3886_PARENT 0x64
 21#define KB3886_IO 0x60
 22#define KB3886_ADC_DAC_PWM 0xC4
 23#define KB3886_PWM0_WRITE 0x81
 24#define KB3886_PWM0_READ 0x41
 25
 26static DEFINE_MUTEX(bl_mutex);
 27
 28static void kb3886_bl_set_intensity(int intensity)
 29{
 30	mutex_lock(&bl_mutex);
 31	intensity = intensity&0xff;
 32	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
 33	usleep_range(10000, 11000);
 34	outb(KB3886_PWM0_WRITE, KB3886_IO);
 35	usleep_range(10000, 11000);
 36	outb(intensity, KB3886_IO);
 37	mutex_unlock(&bl_mutex);
 38}
 39
 40struct kb3886bl_machinfo {
 41	int max_intensity;
 42	int default_intensity;
 43	int limit_mask;
 44	void (*set_bl_intensity)(int intensity);
 45};
 46
 47static struct kb3886bl_machinfo kb3886_bl_machinfo = {
 48	.max_intensity = 0xff,
 49	.default_intensity = 0xa0,
 50	.limit_mask = 0x7f,
 51	.set_bl_intensity = kb3886_bl_set_intensity,
 52};
 53
 54static struct platform_device kb3886bl_device = {
 55	.name		= "kb3886-bl",
 56	.dev		= {
 57		.platform_data	= &kb3886_bl_machinfo,
 58	},
 59	.id		= -1,
 60};
 61
 62static struct platform_device *devices[] __initdata = {
 63	&kb3886bl_device,
 64};
 65
 66/*
 67 * Back to driver
 68 */
 69
 70static int kb3886bl_intensity;
 71static struct backlight_device *kb3886_backlight_device;
 72static struct kb3886bl_machinfo *bl_machinfo;
 73
 74static unsigned long kb3886bl_flags;
 75#define KB3886BL_SUSPENDED     0x01
 76
 77static const struct dmi_system_id kb3886bl_device_table[] __initconst = {
 78	{
 79		.ident = "Sahara Touch-iT",
 80		.matches = {
 81			DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
 82			DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
 83		},
 84	},
 85	{ }
 86};
 87
 88static int kb3886bl_send_intensity(struct backlight_device *bd)
 89{
 90	int intensity = backlight_get_brightness(bd);
 91
 92	if (kb3886bl_flags & KB3886BL_SUSPENDED)
 93		intensity = 0;
 94
 95	bl_machinfo->set_bl_intensity(intensity);
 96
 97	kb3886bl_intensity = intensity;
 98	return 0;
 99}
100
101#ifdef CONFIG_PM_SLEEP
102static int kb3886bl_suspend(struct device *dev)
103{
104	struct backlight_device *bd = dev_get_drvdata(dev);
105
106	kb3886bl_flags |= KB3886BL_SUSPENDED;
107	backlight_update_status(bd);
108	return 0;
109}
110
111static int kb3886bl_resume(struct device *dev)
112{
113	struct backlight_device *bd = dev_get_drvdata(dev);
114
115	kb3886bl_flags &= ~KB3886BL_SUSPENDED;
116	backlight_update_status(bd);
117	return 0;
118}
119#endif
120
121static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
122
123static int kb3886bl_get_intensity(struct backlight_device *bd)
124{
125	return kb3886bl_intensity;
126}
127
128static const struct backlight_ops kb3886bl_ops = {
129	.get_brightness = kb3886bl_get_intensity,
130	.update_status  = kb3886bl_send_intensity,
131};
132
133static int kb3886bl_probe(struct platform_device *pdev)
134{
135	struct backlight_properties props;
136	struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev);
137
138	bl_machinfo = machinfo;
139	if (!machinfo->limit_mask)
140		machinfo->limit_mask = -1;
141
142	memset(&props, 0, sizeof(struct backlight_properties));
143	props.type = BACKLIGHT_RAW;
144	props.max_brightness = machinfo->max_intensity;
145	kb3886_backlight_device = devm_backlight_device_register(&pdev->dev,
146							"kb3886-bl", &pdev->dev,
147							NULL, &kb3886bl_ops,
148							&props);
149	if (IS_ERR(kb3886_backlight_device))
150		return PTR_ERR(kb3886_backlight_device);
151
152	platform_set_drvdata(pdev, kb3886_backlight_device);
153
154	kb3886_backlight_device->props.power = BACKLIGHT_POWER_ON;
155	kb3886_backlight_device->props.brightness = machinfo->default_intensity;
156	backlight_update_status(kb3886_backlight_device);
157
158	return 0;
159}
160
161static struct platform_driver kb3886bl_driver = {
162	.probe		= kb3886bl_probe,
163	.driver		= {
164		.name	= "kb3886-bl",
165		.pm	= &kb3886bl_pm_ops,
166	},
167};
168
169static int __init kb3886_init(void)
170{
171	if (!dmi_check_system(kb3886bl_device_table))
172		return -ENODEV;
173
174	platform_add_devices(devices, ARRAY_SIZE(devices));
175	return platform_driver_register(&kb3886bl_driver);
176}
177
178static void __exit kb3886_exit(void)
179{
180	platform_driver_unregister(&kb3886bl_driver);
181}
182
183module_init(kb3886_init);
184module_exit(kb3886_exit);
185
186MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
187MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
188MODULE_LICENSE("GPL");
189MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");