forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
3.1 KiB
132 lines
3.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Driver for the Cirrus EP93xx lcd backlight |
|
* |
|
* Copyright (c) 2010 H Hartley Sweeten <[email protected]> |
|
* |
|
* This driver controls the pulse width modulated brightness control output, |
|
* BRIGHT, on the Cirrus EP9307, EP9312, and EP9315 processors. |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/io.h> |
|
#include <linux/fb.h> |
|
#include <linux/backlight.h> |
|
|
|
#define EP93XX_MAX_COUNT 255 |
|
#define EP93XX_MAX_BRIGHT 255 |
|
#define EP93XX_DEF_BRIGHT 128 |
|
|
|
struct ep93xxbl { |
|
void __iomem *mmio; |
|
int brightness; |
|
}; |
|
|
|
static int ep93xxbl_set(struct backlight_device *bl, int brightness) |
|
{ |
|
struct ep93xxbl *ep93xxbl = bl_get_data(bl); |
|
|
|
writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio); |
|
|
|
ep93xxbl->brightness = brightness; |
|
|
|
return 0; |
|
} |
|
|
|
static int ep93xxbl_update_status(struct backlight_device *bl) |
|
{ |
|
return ep93xxbl_set(bl, backlight_get_brightness(bl)); |
|
} |
|
|
|
static int ep93xxbl_get_brightness(struct backlight_device *bl) |
|
{ |
|
struct ep93xxbl *ep93xxbl = bl_get_data(bl); |
|
|
|
return ep93xxbl->brightness; |
|
} |
|
|
|
static const struct backlight_ops ep93xxbl_ops = { |
|
.update_status = ep93xxbl_update_status, |
|
.get_brightness = ep93xxbl_get_brightness, |
|
}; |
|
|
|
static int ep93xxbl_probe(struct platform_device *dev) |
|
{ |
|
struct ep93xxbl *ep93xxbl; |
|
struct backlight_device *bl; |
|
struct backlight_properties props; |
|
struct resource *res; |
|
|
|
ep93xxbl = devm_kzalloc(&dev->dev, sizeof(*ep93xxbl), GFP_KERNEL); |
|
if (!ep93xxbl) |
|
return -ENOMEM; |
|
|
|
res = platform_get_resource(dev, IORESOURCE_MEM, 0); |
|
if (!res) |
|
return -ENXIO; |
|
|
|
/* |
|
* FIXME - We don't do a request_mem_region here because we are |
|
* sharing the register space with the framebuffer driver (see |
|
* drivers/video/ep93xx-fb.c) and doing so will cause the second |
|
* loaded driver to return -EBUSY. |
|
* |
|
* NOTE: No locking is required; the framebuffer does not touch |
|
* this register. |
|
*/ |
|
ep93xxbl->mmio = devm_ioremap(&dev->dev, res->start, |
|
resource_size(res)); |
|
if (!ep93xxbl->mmio) |
|
return -ENXIO; |
|
|
|
memset(&props, 0, sizeof(struct backlight_properties)); |
|
props.type = BACKLIGHT_RAW; |
|
props.max_brightness = EP93XX_MAX_BRIGHT; |
|
bl = devm_backlight_device_register(&dev->dev, dev->name, &dev->dev, |
|
ep93xxbl, &ep93xxbl_ops, &props); |
|
if (IS_ERR(bl)) |
|
return PTR_ERR(bl); |
|
|
|
bl->props.brightness = EP93XX_DEF_BRIGHT; |
|
|
|
platform_set_drvdata(dev, bl); |
|
|
|
ep93xxbl_update_status(bl); |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_PM_SLEEP |
|
static int ep93xxbl_suspend(struct device *dev) |
|
{ |
|
struct backlight_device *bl = dev_get_drvdata(dev); |
|
|
|
return ep93xxbl_set(bl, 0); |
|
} |
|
|
|
static int ep93xxbl_resume(struct device *dev) |
|
{ |
|
struct backlight_device *bl = dev_get_drvdata(dev); |
|
|
|
backlight_update_status(bl); |
|
return 0; |
|
} |
|
#endif |
|
|
|
static SIMPLE_DEV_PM_OPS(ep93xxbl_pm_ops, ep93xxbl_suspend, ep93xxbl_resume); |
|
|
|
static struct platform_driver ep93xxbl_driver = { |
|
.driver = { |
|
.name = "ep93xx-bl", |
|
.pm = &ep93xxbl_pm_ops, |
|
}, |
|
.probe = ep93xxbl_probe, |
|
}; |
|
|
|
module_platform_driver(ep93xxbl_driver); |
|
|
|
MODULE_DESCRIPTION("EP93xx Backlight Driver"); |
|
MODULE_AUTHOR("H Hartley Sweeten <[email protected]>"); |
|
MODULE_LICENSE("GPL"); |
|
MODULE_ALIAS("platform:ep93xx-bl");
|
|
|