linux/drivers/acpi/toshiba_acpi.c
Andrey Borzenkov 1299342bac Fix Oops in toshiba_acpi error return path
When backlight_device_register() fails, return after undo initialization, do
not try to use pointer that just was reset to NULL

This fixes this oops:

[ 1595.177672]  [<c010480a>] show_trace_log_lvl+0x1a/0x30
[ 1595.177706]  [<c01052a2>] show_trace+0x12/0x20
[ 1595.177718]  [<c0105305>] dump_stack+0x15/0x20
[ 1595.177728]  [<c01c9375>] kobject_shadow_add+0x125/0x1c0
[ 1595.177754]  [<c01c941a>] kobject_add+0xa/0x10
[ 1595.177764]  [<c0239a37>] device_add+0x97/0x5d0
[ 1595.177776]  [<c0239f82>] device_register+0x12/0x20
[ 1595.177786]  [<dfd912df>] backlight_device_register+0x9f/0x110 [backlight]
[ 1595.177814]  [<df861117>] toshiba_acpi_init+0x117/0x15e [toshiba_acpi]
[ 1595.177834]  [<c013e28d>] sys_init_module+0xfd/0x14e0
[ 1595.177871]  [<c0104112>] sysenter_past_esp+0x5f/0x99
[ 1595.177883]  =======================
[ 1595.177890] Could not register toshiba backlight device
[ 1595.177985] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000004
...
[ 1595.394097] EIP:    0060:[<df861143>]    Not tainted VLI
[ 1595.394101] EFLAGS: 00010282   (2.6.23-rc9-1avb #24)
[ 1595.480081] EIP is at toshiba_acpi_init+0x143/0x15e [toshiba_acpi]

Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: John Belmonte <toshiba_acpi@memebeam.org>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:36 -08:00

608 lines
14 KiB
C

/*
* toshiba_acpi.c - Toshiba Laptop ACPI Extras
*
*
* Copyright (C) 2002-2004 John Belmonte
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* The devolpment page for this driver is located at
* http://memebeam.org/toys/ToshibaAcpiDriver.
*
* Credits:
* Jonathan A. Buzzard - Toshiba HCI info, and critical tips on reverse
* engineering the Windows drivers
* Yasushi Nagato - changes for linux kernel 2.4 -> 2.5
* Rob Miller - TV out and hotkeys help
*
*
* TODO
*
*/
#define TOSHIBA_ACPI_VERSION "0.18"
#define PROC_INTERFACE_VERSION 1
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <asm/uaccess.h>
#include <acpi/acpi_drivers.h>
MODULE_AUTHOR("John Belmonte");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Extras Driver");
MODULE_LICENSE("GPL");
#define MY_LOGPREFIX "toshiba_acpi: "
#define MY_ERR KERN_ERR MY_LOGPREFIX
#define MY_NOTICE KERN_NOTICE MY_LOGPREFIX
#define MY_INFO KERN_INFO MY_LOGPREFIX
/* Toshiba ACPI method paths */
#define METHOD_LCD_BRIGHTNESS "\\_SB_.PCI0.VGA_.LCD_._BCM"
#define METHOD_HCI_1 "\\_SB_.VALD.GHCI"
#define METHOD_HCI_2 "\\_SB_.VALZ.GHCI"
#define METHOD_VIDEO_OUT "\\_SB_.VALX.DSSX"
/* Toshiba HCI interface definitions
*
* HCI is Toshiba's "Hardware Control Interface" which is supposed to
* be uniform across all their models. Ideally we would just call
* dedicated ACPI methods instead of using this primitive interface.
* However the ACPI methods seem to be incomplete in some areas (for
* example they allow setting, but not reading, the LCD brightness value),
* so this is still useful.
*/
#define HCI_WORDS 6
/* operations */
#define HCI_SET 0xff00
#define HCI_GET 0xfe00
/* return codes */
#define HCI_SUCCESS 0x0000
#define HCI_FAILURE 0x1000
#define HCI_NOT_SUPPORTED 0x8000
#define HCI_EMPTY 0x8c00
/* registers */
#define HCI_FAN 0x0004
#define HCI_SYSTEM_EVENT 0x0016
#define HCI_VIDEO_OUT 0x001c
#define HCI_HOTKEY_EVENT 0x001e
#define HCI_LCD_BRIGHTNESS 0x002a
/* field definitions */
#define HCI_LCD_BRIGHTNESS_BITS 3
#define HCI_LCD_BRIGHTNESS_SHIFT (16-HCI_LCD_BRIGHTNESS_BITS)
#define HCI_LCD_BRIGHTNESS_LEVELS (1 << HCI_LCD_BRIGHTNESS_BITS)
#define HCI_VIDEO_OUT_LCD 0x1
#define HCI_VIDEO_OUT_CRT 0x2
#define HCI_VIDEO_OUT_TV 0x4
/* utility
*/
static __inline__ void _set_bit(u32 * word, u32 mask, int value)
{
*word = (*word & ~mask) | (mask * value);
}
/* acpi interface wrappers
*/
static int is_valid_acpi_path(const char *methodName)
{
acpi_handle handle;
acpi_status status;
status = acpi_get_handle(NULL, (char *)methodName, &handle);
return !ACPI_FAILURE(status);
}
static int write_acpi_int(const char *methodName, int val)
{
struct acpi_object_list params;
union acpi_object in_objs[1];
acpi_status status;
params.count = ARRAY_SIZE(in_objs);
params.pointer = in_objs;
in_objs[0].type = ACPI_TYPE_INTEGER;
in_objs[0].integer.value = val;
status = acpi_evaluate_object(NULL, (char *)methodName, &params, NULL);
return (status == AE_OK);
}
#if 0
static int read_acpi_int(const char *methodName, int *pVal)
{
struct acpi_buffer results;
union acpi_object out_objs[1];
acpi_status status;
results.length = sizeof(out_objs);
results.pointer = out_objs;
status = acpi_evaluate_object(0, (char *)methodName, 0, &results);
*pVal = out_objs[0].integer.value;
return (status == AE_OK) && (out_objs[0].type == ACPI_TYPE_INTEGER);
}
#endif
static const char *method_hci /*= 0*/ ;
/* Perform a raw HCI call. Here we don't care about input or output buffer
* format.
*/
static acpi_status hci_raw(const u32 in[HCI_WORDS], u32 out[HCI_WORDS])
{
struct acpi_object_list params;
union acpi_object in_objs[HCI_WORDS];
struct acpi_buffer results;
union acpi_object out_objs[HCI_WORDS + 1];
acpi_status status;
int i;
params.count = HCI_WORDS;
params.pointer = in_objs;
for (i = 0; i < HCI_WORDS; ++i) {
in_objs[i].type = ACPI_TYPE_INTEGER;
in_objs[i].integer.value = in[i];
}
results.length = sizeof(out_objs);
results.pointer = out_objs;
status = acpi_evaluate_object(NULL, (char *)method_hci, &params,
&results);
if ((status == AE_OK) && (out_objs->package.count <= HCI_WORDS)) {
for (i = 0; i < out_objs->package.count; ++i) {
out[i] = out_objs->package.elements[i].integer.value;
}
}
return status;
}
/* common hci tasks (get or set one value)
*
* In addition to the ACPI status, the HCI system returns a result which
* may be useful (such as "not supported").
*/
static acpi_status hci_write1(u32 reg, u32 in1, u32 * result)
{
u32 in[HCI_WORDS] = { HCI_SET, reg, in1, 0, 0, 0 };
u32 out[HCI_WORDS];
acpi_status status = hci_raw(in, out);
*result = (status == AE_OK) ? out[0] : HCI_FAILURE;
return status;
}
static acpi_status hci_read1(u32 reg, u32 * out1, u32 * result)
{
u32 in[HCI_WORDS] = { HCI_GET, reg, 0, 0, 0, 0 };
u32 out[HCI_WORDS];
acpi_status status = hci_raw(in, out);
*out1 = out[2];
*result = (status == AE_OK) ? out[0] : HCI_FAILURE;
return status;
}
static struct proc_dir_entry *toshiba_proc_dir /*= 0*/ ;
static struct backlight_device *toshiba_backlight_device;
static int force_fan;
static int last_key_event;
static int key_event_valid;
typedef struct _ProcItem {
const char *name;
char *(*read_func) (char *);
unsigned long (*write_func) (const char *, unsigned long);
} ProcItem;
/* proc file handlers
*/
static int
dispatch_read(char *page, char **start, off_t off, int count, int *eof,
ProcItem * item)
{
char *p = page;
int len;
if (off == 0)
p = item->read_func(p);
/* ISSUE: I don't understand this code */
len = (p - page);
if (len <= off + count)
*eof = 1;
*start = page + off;
len -= off;
if (len > count)
len = count;
if (len < 0)
len = 0;
return len;
}
static int
dispatch_write(struct file *file, const char __user * buffer,
unsigned long count, ProcItem * item)
{
int result;
char *tmp_buffer;
/* Arg buffer points to userspace memory, which can't be accessed
* directly. Since we're making a copy, zero-terminate the
* destination so that sscanf can be used on it safely.
*/
tmp_buffer = kmalloc(count + 1, GFP_KERNEL);
if (!tmp_buffer)
return -ENOMEM;
if (copy_from_user(tmp_buffer, buffer, count)) {
result = -EFAULT;
} else {
tmp_buffer[count] = 0;
result = item->write_func(tmp_buffer, count);
}
kfree(tmp_buffer);
return result;
}
static int get_lcd(struct backlight_device *bd)
{
u32 hci_result;
u32 value;
hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
if (hci_result == HCI_SUCCESS) {
return (value >> HCI_LCD_BRIGHTNESS_SHIFT);
} else
return -EFAULT;
}
static char *read_lcd(char *p)
{
int value = get_lcd(NULL);
if (value >= 0) {
p += sprintf(p, "brightness: %d\n", value);
p += sprintf(p, "brightness_levels: %d\n",
HCI_LCD_BRIGHTNESS_LEVELS);
} else {
printk(MY_ERR "Error reading LCD brightness\n");
}
return p;
}
static int set_lcd(int value)
{
u32 hci_result;
value = value << HCI_LCD_BRIGHTNESS_SHIFT;
hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
if (hci_result != HCI_SUCCESS)
return -EFAULT;
return 0;
}
static int set_lcd_status(struct backlight_device *bd)
{
return set_lcd(bd->props.brightness);
}
static unsigned long write_lcd(const char *buffer, unsigned long count)
{
int value;
int ret;
if (sscanf(buffer, " brightness : %i", &value) == 1 &&
value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS) {
ret = set_lcd(value);
if (ret == 0)
ret = count;
} else {
ret = -EINVAL;
}
return ret;
}
static char *read_video(char *p)
{
u32 hci_result;
u32 value;
hci_read1(HCI_VIDEO_OUT, &value, &hci_result);
if (hci_result == HCI_SUCCESS) {
int is_lcd = (value & HCI_VIDEO_OUT_LCD) ? 1 : 0;
int is_crt = (value & HCI_VIDEO_OUT_CRT) ? 1 : 0;
int is_tv = (value & HCI_VIDEO_OUT_TV) ? 1 : 0;
p += sprintf(p, "lcd_out: %d\n", is_lcd);
p += sprintf(p, "crt_out: %d\n", is_crt);
p += sprintf(p, "tv_out: %d\n", is_tv);
} else {
printk(MY_ERR "Error reading video out status\n");
}
return p;
}
static unsigned long write_video(const char *buffer, unsigned long count)
{
int value;
int remain = count;
int lcd_out = -1;
int crt_out = -1;
int tv_out = -1;
u32 hci_result;
u32 video_out;
/* scan expression. Multiple expressions may be delimited with ;
*
* NOTE: to keep scanning simple, invalid fields are ignored
*/
while (remain) {
if (sscanf(buffer, " lcd_out : %i", &value) == 1)
lcd_out = value & 1;
else if (sscanf(buffer, " crt_out : %i", &value) == 1)
crt_out = value & 1;
else if (sscanf(buffer, " tv_out : %i", &value) == 1)
tv_out = value & 1;
/* advance to one character past the next ; */
do {
++buffer;
--remain;
}
while (remain && *(buffer - 1) != ';');
}
hci_read1(HCI_VIDEO_OUT, &video_out, &hci_result);
if (hci_result == HCI_SUCCESS) {
int new_video_out = video_out;
if (lcd_out != -1)
_set_bit(&new_video_out, HCI_VIDEO_OUT_LCD, lcd_out);
if (crt_out != -1)
_set_bit(&new_video_out, HCI_VIDEO_OUT_CRT, crt_out);
if (tv_out != -1)
_set_bit(&new_video_out, HCI_VIDEO_OUT_TV, tv_out);
/* To avoid unnecessary video disruption, only write the new
* video setting if something changed. */
if (new_video_out != video_out)
write_acpi_int(METHOD_VIDEO_OUT, new_video_out);
} else {
return -EFAULT;
}
return count;
}
static char *read_fan(char *p)
{
u32 hci_result;
u32 value;
hci_read1(HCI_FAN, &value, &hci_result);
if (hci_result == HCI_SUCCESS) {
p += sprintf(p, "running: %d\n", (value > 0));
p += sprintf(p, "force_on: %d\n", force_fan);
} else {
printk(MY_ERR "Error reading fan status\n");
}
return p;
}
static unsigned long write_fan(const char *buffer, unsigned long count)
{
int value;
u32 hci_result;
if (sscanf(buffer, " force_on : %i", &value) == 1 &&
value >= 0 && value <= 1) {
hci_write1(HCI_FAN, value, &hci_result);
if (hci_result != HCI_SUCCESS)
return -EFAULT;
else
force_fan = value;
} else {
return -EINVAL;
}
return count;
}
static char *read_keys(char *p)
{
u32 hci_result;
u32 value;
if (!key_event_valid) {
hci_read1(HCI_SYSTEM_EVENT, &value, &hci_result);
if (hci_result == HCI_SUCCESS) {
key_event_valid = 1;
last_key_event = value;
} else if (hci_result == HCI_EMPTY) {
/* better luck next time */
} else if (hci_result == HCI_NOT_SUPPORTED) {
/* This is a workaround for an unresolved issue on
* some machines where system events sporadically
* become disabled. */
hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);
printk(MY_NOTICE "Re-enabled hotkeys\n");
} else {
printk(MY_ERR "Error reading hotkey status\n");
goto end;
}
}
p += sprintf(p, "hotkey_ready: %d\n", key_event_valid);
p += sprintf(p, "hotkey: 0x%04x\n", last_key_event);
end:
return p;
}
static unsigned long write_keys(const char *buffer, unsigned long count)
{
int value;
if (sscanf(buffer, " hotkey_ready : %i", &value) == 1 && value == 0) {
key_event_valid = 0;
} else {
return -EINVAL;
}
return count;
}
static char *read_version(char *p)
{
p += sprintf(p, "driver: %s\n", TOSHIBA_ACPI_VERSION);
p += sprintf(p, "proc_interface: %d\n",
PROC_INTERFACE_VERSION);
return p;
}
/* proc and module init
*/
#define PROC_TOSHIBA "toshiba"
static ProcItem proc_items[] = {
{"lcd", read_lcd, write_lcd},
{"video", read_video, write_video},
{"fan", read_fan, write_fan},
{"keys", read_keys, write_keys},
{"version", read_version, NULL},
{NULL}
};
static acpi_status __init add_device(void)
{
struct proc_dir_entry *proc;
ProcItem *item;
for (item = proc_items; item->name; ++item) {
proc = create_proc_read_entry(item->name,
S_IFREG | S_IRUGO | S_IWUSR,
toshiba_proc_dir,
(read_proc_t *) dispatch_read,
item);
if (proc)
proc->owner = THIS_MODULE;
if (proc && item->write_func)
proc->write_proc = (write_proc_t *) dispatch_write;
}
return AE_OK;
}
static acpi_status remove_device(void)
{
ProcItem *item;
for (item = proc_items; item->name; ++item)
remove_proc_entry(item->name, toshiba_proc_dir);
return AE_OK;
}
static struct backlight_ops toshiba_backlight_data = {
.get_brightness = get_lcd,
.update_status = set_lcd_status,
};
static void toshiba_acpi_exit(void)
{
if (toshiba_backlight_device)
backlight_device_unregister(toshiba_backlight_device);
remove_device();
if (toshiba_proc_dir)
remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
return;
}
static int __init toshiba_acpi_init(void)
{
acpi_status status = AE_OK;
u32 hci_result;
if (acpi_disabled)
return -ENODEV;
/* simple device detection: look for HCI method */
if (is_valid_acpi_path(METHOD_HCI_1))
method_hci = METHOD_HCI_1;
else if (is_valid_acpi_path(METHOD_HCI_2))
method_hci = METHOD_HCI_2;
else
return -ENODEV;
printk(MY_INFO "Toshiba Laptop ACPI Extras version %s\n",
TOSHIBA_ACPI_VERSION);
printk(MY_INFO " HCI method: %s\n", method_hci);
force_fan = 0;
key_event_valid = 0;
/* enable event fifo */
hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);
toshiba_proc_dir = proc_mkdir(PROC_TOSHIBA, acpi_root_dir);
if (!toshiba_proc_dir) {
status = AE_ERROR;
} else {
toshiba_proc_dir->owner = THIS_MODULE;
status = add_device();
if (ACPI_FAILURE(status))
remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
}
toshiba_backlight_device = backlight_device_register("toshiba",NULL,
NULL,
&toshiba_backlight_data);
if (IS_ERR(toshiba_backlight_device)) {
int ret = PTR_ERR(toshiba_backlight_device);
printk(KERN_ERR "Could not register toshiba backlight device\n");
toshiba_backlight_device = NULL;
toshiba_acpi_exit();
return ret;
}
toshiba_backlight_device->props.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1;
return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
}
module_init(toshiba_acpi_init);
module_exit(toshiba_acpi_exit);