linux/drivers/leds/leds-alix2.c
Daniel Mack 7f131cf3ed leds: leds-alix2c - take port address from MSR
This makes the LEDs driver for ALIX2.C boards work with Coreboot by
looking up the port address in the MSR rather than hard-coding it.

The BIOS scan also needed some tweaks as the string in Coreboot differs
from the one in the legacy BIOS.

Successfully tested with both the legacy tinyBIOS as well as Coreboot
v3.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-12-16 11:30:09 +00:00

239 lines
5.1 KiB
C

/*
* LEDs driver for PCEngines ALIX.2 and ALIX.3
*
* Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/pci.h>
static int force = 0;
module_param(force, bool, 0444);
MODULE_PARM_DESC(force, "Assume system has ALIX.2/ALIX.3 style LEDs");
#define MSR_LBAR_GPIO 0x5140000C
#define CS5535_GPIO_SIZE 256
static u32 gpio_base;
static struct pci_device_id divil_pci[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
{ } /* NULL entry */
};
MODULE_DEVICE_TABLE(pci, divil_pci);
struct alix_led {
struct led_classdev cdev;
unsigned short port;
unsigned int on_value;
unsigned int off_value;
};
static void alix_led_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct alix_led *led_dev =
container_of(led_cdev, struct alix_led, cdev);
if (brightness)
outl(led_dev->on_value, gpio_base + led_dev->port);
else
outl(led_dev->off_value, gpio_base + led_dev->port);
}
static struct alix_led alix_leds[] = {
{
.cdev = {
.name = "alix:1",
.brightness_set = alix_led_set,
},
.port = 0x00,
.on_value = 1 << 22,
.off_value = 1 << 6,
},
{
.cdev = {
.name = "alix:2",
.brightness_set = alix_led_set,
},
.port = 0x80,
.on_value = 1 << 25,
.off_value = 1 << 9,
},
{
.cdev = {
.name = "alix:3",
.brightness_set = alix_led_set,
},
.port = 0x80,
.on_value = 1 << 27,
.off_value = 1 << 11,
},
};
static int __init alix_led_probe(struct platform_device *pdev)
{
int i;
int ret;
for (i = 0; i < ARRAY_SIZE(alix_leds); i++) {
alix_leds[i].cdev.flags |= LED_CORE_SUSPENDRESUME;
ret = led_classdev_register(&pdev->dev, &alix_leds[i].cdev);
if (ret < 0)
goto fail;
}
return 0;
fail:
while (--i >= 0)
led_classdev_unregister(&alix_leds[i].cdev);
return ret;
}
static int alix_led_remove(struct platform_device *pdev)
{
int i;
for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
led_classdev_unregister(&alix_leds[i].cdev);
return 0;
}
static struct platform_driver alix_led_driver = {
.remove = alix_led_remove,
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
},
};
static int __init alix_present(unsigned long bios_phys,
const char *alix_sig,
size_t alix_sig_len)
{
const size_t bios_len = 0x00010000;
const char *bios_virt;
const char *scan_end;
const char *p;
char name[64];
if (force) {
printk(KERN_NOTICE "%s: forced to skip BIOS test, "
"assume system has ALIX.2 style LEDs\n",
KBUILD_MODNAME);
return 1;
}
bios_virt = phys_to_virt(bios_phys);
scan_end = bios_virt + bios_len - (alix_sig_len + 2);
for (p = bios_virt; p < scan_end; p++) {
const char *tail;
char *a;
if (memcmp(p, alix_sig, alix_sig_len) != 0)
continue;
memcpy(name, p, sizeof(name));
/* remove the first \0 character from string */
a = strchr(name, '\0');
if (a)
*a = ' ';
/* cut the string at a newline */
a = strchr(name, '\r');
if (a)
*a = '\0';
tail = p + alix_sig_len;
if ((tail[0] == '2' || tail[0] == '3')) {
printk(KERN_INFO
"%s: system is recognized as \"%s\"\n",
KBUILD_MODNAME, name);
return 1;
}
}
return 0;
}
static struct platform_device *pdev;
static int __init alix_pci_led_init(void)
{
u32 low, hi;
if (pci_dev_present(divil_pci) == 0) {
printk(KERN_WARNING KBUILD_MODNAME": DIVIL not found\n");
return -ENODEV;
}
/* Grab the GPIO I/O range */
rdmsr(MSR_LBAR_GPIO, low, hi);
/* Check the mask and whether GPIO is enabled (sanity check) */
if (hi != 0x0000f001) {
printk(KERN_WARNING KBUILD_MODNAME": GPIO not enabled\n");
return -ENODEV;
}
/* Mask off the IO base address */
gpio_base = low & 0x0000ff00;
if (!request_region(gpio_base, CS5535_GPIO_SIZE, KBUILD_MODNAME)) {
printk(KERN_ERR KBUILD_MODNAME": can't allocate I/O for GPIO\n");
return -ENODEV;
}
/* Set GPIO function to output */
outl(1 << 6, gpio_base + 0x04);
outl(1 << 9, gpio_base + 0x84);
outl(1 << 11, gpio_base + 0x84);
return 0;
}
static int __init alix_led_init(void)
{
int ret = -ENODEV;
const char tinybios_sig[] = "PC Engines ALIX.";
const char coreboot_sig[] = "PC Engines\0ALIX.";
if (alix_present(0xf0000, tinybios_sig, sizeof(tinybios_sig) - 1) ||
alix_present(0x500, coreboot_sig, sizeof(coreboot_sig) - 1))
ret = alix_pci_led_init();
if (ret < 0)
return ret;
pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
if (!IS_ERR(pdev)) {
ret = platform_driver_probe(&alix_led_driver, alix_led_probe);
if (ret)
platform_device_unregister(pdev);
} else
ret = PTR_ERR(pdev);
return ret;
}
static void __exit alix_led_exit(void)
{
platform_device_unregister(pdev);
platform_driver_unregister(&alix_led_driver);
release_region(gpio_base, CS5535_GPIO_SIZE);
}
module_init(alix_led_init);
module_exit(alix_led_exit);
MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
MODULE_LICENSE("GPL");