245 lines
6.6 KiB
C
245 lines
6.6 KiB
C
![]() |
/*
|
||
|
* Gmux driver for Apple laptops
|
||
|
*
|
||
|
* Copyright (C) Canonical Ltd. <seth.forshee@canonical.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 as
|
||
|
* published by the Free Software Foundation.
|
||
|
*/
|
||
|
|
||
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
||
|
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/backlight.h>
|
||
|
#include <linux/acpi.h>
|
||
|
#include <linux/pnp.h>
|
||
|
#include <linux/apple_bl.h>
|
||
|
#include <linux/slab.h>
|
||
|
#include <acpi/video.h>
|
||
|
#include <asm/io.h>
|
||
|
|
||
|
struct apple_gmux_data {
|
||
|
unsigned long iostart;
|
||
|
unsigned long iolen;
|
||
|
|
||
|
struct backlight_device *bdev;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* gmux port offsets. Many of these are not yet used, but may be in the
|
||
|
* future, and it's useful to have them documented here anyhow.
|
||
|
*/
|
||
|
#define GMUX_PORT_VERSION_MAJOR 0x04
|
||
|
#define GMUX_PORT_VERSION_MINOR 0x05
|
||
|
#define GMUX_PORT_VERSION_RELEASE 0x06
|
||
|
#define GMUX_PORT_SWITCH_DISPLAY 0x10
|
||
|
#define GMUX_PORT_SWITCH_GET_DISPLAY 0x11
|
||
|
#define GMUX_PORT_INTERRUPT_ENABLE 0x14
|
||
|
#define GMUX_PORT_INTERRUPT_STATUS 0x16
|
||
|
#define GMUX_PORT_SWITCH_DDC 0x28
|
||
|
#define GMUX_PORT_SWITCH_EXTERNAL 0x40
|
||
|
#define GMUX_PORT_SWITCH_GET_EXTERNAL 0x41
|
||
|
#define GMUX_PORT_DISCRETE_POWER 0x50
|
||
|
#define GMUX_PORT_MAX_BRIGHTNESS 0x70
|
||
|
#define GMUX_PORT_BRIGHTNESS 0x74
|
||
|
|
||
|
#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)
|
||
|
|
||
|
#define GMUX_INTERRUPT_ENABLE 0xff
|
||
|
#define GMUX_INTERRUPT_DISABLE 0x00
|
||
|
|
||
|
#define GMUX_INTERRUPT_STATUS_ACTIVE 0
|
||
|
#define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0)
|
||
|
#define GMUX_INTERRUPT_STATUS_POWER (1 << 2)
|
||
|
#define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3)
|
||
|
|
||
|
#define GMUX_BRIGHTNESS_MASK 0x00ffffff
|
||
|
#define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK
|
||
|
|
||
|
static inline u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
|
||
|
{
|
||
|
return inb(gmux_data->iostart + port);
|
||
|
}
|
||
|
|
||
|
static inline void gmux_write8(struct apple_gmux_data *gmux_data, int port,
|
||
|
u8 val)
|
||
|
{
|
||
|
outb(val, gmux_data->iostart + port);
|
||
|
}
|
||
|
|
||
|
static inline u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
|
||
|
{
|
||
|
return inl(gmux_data->iostart + port);
|
||
|
}
|
||
|
|
||
|
static int gmux_get_brightness(struct backlight_device *bd)
|
||
|
{
|
||
|
struct apple_gmux_data *gmux_data = bl_get_data(bd);
|
||
|
return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
|
||
|
GMUX_BRIGHTNESS_MASK;
|
||
|
}
|
||
|
|
||
|
static int gmux_update_status(struct backlight_device *bd)
|
||
|
{
|
||
|
struct apple_gmux_data *gmux_data = bl_get_data(bd);
|
||
|
u32 brightness = bd->props.brightness;
|
||
|
|
||
|
/*
|
||
|
* Older gmux versions require writing out lower bytes first then
|
||
|
* setting the upper byte to 0 to flush the values. Newer versions
|
||
|
* accept a single u32 write, but the old method also works, so we
|
||
|
* just use the old method for all gmux versions.
|
||
|
*/
|
||
|
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
|
||
|
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 1, brightness >> 8);
|
||
|
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 2, brightness >> 16);
|
||
|
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 3, 0);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static const struct backlight_ops gmux_bl_ops = {
|
||
|
.get_brightness = gmux_get_brightness,
|
||
|
.update_status = gmux_update_status,
|
||
|
};
|
||
|
|
||
|
static int __devinit gmux_probe(struct pnp_dev *pnp,
|
||
|
const struct pnp_device_id *id)
|
||
|
{
|
||
|
struct apple_gmux_data *gmux_data;
|
||
|
struct resource *res;
|
||
|
struct backlight_properties props;
|
||
|
struct backlight_device *bdev;
|
||
|
u8 ver_major, ver_minor, ver_release;
|
||
|
int ret = -ENXIO;
|
||
|
|
||
|
gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
|
||
|
if (!gmux_data)
|
||
|
return -ENOMEM;
|
||
|
pnp_set_drvdata(pnp, gmux_data);
|
||
|
|
||
|
res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
|
||
|
if (!res) {
|
||
|
pr_err("Failed to find gmux I/O resource\n");
|
||
|
goto err_free;
|
||
|
}
|
||
|
|
||
|
gmux_data->iostart = res->start;
|
||
|
gmux_data->iolen = res->end - res->start;
|
||
|
|
||
|
if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
|
||
|
pr_err("gmux I/O region too small (%lu < %u)\n",
|
||
|
gmux_data->iolen, GMUX_MIN_IO_LEN);
|
||
|
goto err_free;
|
||
|
}
|
||
|
|
||
|
if (!request_region(gmux_data->iostart, gmux_data->iolen,
|
||
|
"Apple gmux")) {
|
||
|
pr_err("gmux I/O already in use\n");
|
||
|
goto err_free;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* On some machines the gmux is in ACPI even thought the machine
|
||
|
* doesn't really have a gmux. Check for invalid version information
|
||
|
* to detect this.
|
||
|
*/
|
||
|
ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
|
||
|
ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
|
||
|
ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
|
||
|
if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
|
||
|
pr_info("gmux device not present\n");
|
||
|
ret = -ENODEV;
|
||
|
goto err_release;
|
||
|
}
|
||
|
|
||
|
pr_info("Found gmux version %d.%d.%d\n", ver_major, ver_minor,
|
||
|
ver_release);
|
||
|
|
||
|
memset(&props, 0, sizeof(props));
|
||
|
props.type = BACKLIGHT_PLATFORM;
|
||
|
props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
|
||
|
|
||
|
/*
|
||
|
* Currently it's assumed that the maximum brightness is less than
|
||
|
* 2^24 for compatibility with old gmux versions. Cap the max
|
||
|
* brightness at this value, but print a warning if the hardware
|
||
|
* reports something higher so that it can be fixed.
|
||
|
*/
|
||
|
if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
|
||
|
props.max_brightness = GMUX_MAX_BRIGHTNESS;
|
||
|
|
||
|
bdev = backlight_device_register("gmux_backlight", &pnp->dev,
|
||
|
gmux_data, &gmux_bl_ops, &props);
|
||
|
if (IS_ERR(bdev)) {
|
||
|
ret = PTR_ERR(bdev);
|
||
|
goto err_release;
|
||
|
}
|
||
|
|
||
|
gmux_data->bdev = bdev;
|
||
|
bdev->props.brightness = gmux_get_brightness(bdev);
|
||
|
backlight_update_status(bdev);
|
||
|
|
||
|
/*
|
||
|
* The backlight situation on Macs is complicated. If the gmux is
|
||
|
* present it's the best choice, because it always works for
|
||
|
* backlight control and supports more levels than other options.
|
||
|
* Disable the other backlight choices.
|
||
|
*/
|
||
|
acpi_video_unregister();
|
||
|
apple_bl_unregister();
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
err_release:
|
||
|
release_region(gmux_data->iostart, gmux_data->iolen);
|
||
|
err_free:
|
||
|
kfree(gmux_data);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static void __devexit gmux_remove(struct pnp_dev *pnp)
|
||
|
{
|
||
|
struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
|
||
|
|
||
|
backlight_device_unregister(gmux_data->bdev);
|
||
|
release_region(gmux_data->iostart, gmux_data->iolen);
|
||
|
kfree(gmux_data);
|
||
|
|
||
|
acpi_video_register();
|
||
|
apple_bl_register();
|
||
|
}
|
||
|
|
||
|
static const struct pnp_device_id gmux_device_ids[] = {
|
||
|
{"APP000B", 0},
|
||
|
{"", 0}
|
||
|
};
|
||
|
|
||
|
static struct pnp_driver gmux_pnp_driver = {
|
||
|
.name = "apple-gmux",
|
||
|
.probe = gmux_probe,
|
||
|
.remove = __devexit_p(gmux_remove),
|
||
|
.id_table = gmux_device_ids,
|
||
|
};
|
||
|
|
||
|
static int __init apple_gmux_init(void)
|
||
|
{
|
||
|
return pnp_register_driver(&gmux_pnp_driver);
|
||
|
}
|
||
|
|
||
|
static void __exit apple_gmux_exit(void)
|
||
|
{
|
||
|
pnp_unregister_driver(&gmux_pnp_driver);
|
||
|
}
|
||
|
|
||
|
module_init(apple_gmux_init);
|
||
|
module_exit(apple_gmux_exit);
|
||
|
|
||
|
MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
|
||
|
MODULE_DESCRIPTION("Apple Gmux Driver");
|
||
|
MODULE_LICENSE("GPL");
|
||
|
MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
|