kernel-fxtec-pro1x/drivers/media/IR/ir-sysfs.c
Maxim Levitsky 58b3dd449f [media] IR: make sure we register the input device when it is safe to do so
As soon as input device is registered, it might be accessed (and it is)
This can trigger a hardware interrupt that can access
not yet initialized ir->raw, (by sending a sample)

This can be reproduced by holding down a remote button and reloading the module.
And this always crashes the systems where hardware decides to send an interrupt
right at the moment it is enabled.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-10-21 07:54:13 -02:00

362 lines
9 KiB
C

/* ir-sysfs.c - sysfs interface for RC devices (/sys/class/rc)
*
* Copyright (C) 2009-2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
*
* 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 version 2 of the License.
*
* 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.
*/
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/device.h>
#include "ir-core-priv.h"
#define IRRCV_NUM_DEVICES 256
/* bit array to represent IR sysfs device number */
static unsigned long ir_core_dev_number;
/* class for /sys/class/rc */
static char *ir_devnode(struct device *dev, mode_t *mode)
{
return kasprintf(GFP_KERNEL, "rc/%s", dev_name(dev));
}
static struct class ir_input_class = {
.name = "rc",
.devnode = ir_devnode,
};
static struct {
u64 type;
char *name;
} proto_names[] = {
{ IR_TYPE_UNKNOWN, "unknown" },
{ IR_TYPE_RC5, "rc-5" },
{ IR_TYPE_NEC, "nec" },
{ IR_TYPE_RC6, "rc-6" },
{ IR_TYPE_JVC, "jvc" },
{ IR_TYPE_SONY, "sony" },
{ IR_TYPE_RC5_SZ, "rc-5-sz" },
{ IR_TYPE_LIRC, "lirc" },
};
#define PROTO_NONE "none"
/**
* show_protocols() - shows the current IR protocol(s)
* @d: the device descriptor
* @mattr: the device attribute struct (unused)
* @buf: a pointer to the output buffer
*
* This routine is a callback routine for input read the IR protocol type(s).
* it is trigged by reading /sys/class/rc/rc?/protocols.
* It returns the protocol names of supported protocols.
* Enabled protocols are printed in brackets.
*/
static ssize_t show_protocols(struct device *d,
struct device_attribute *mattr, char *buf)
{
struct ir_input_dev *ir_dev = dev_get_drvdata(d);
u64 allowed, enabled;
char *tmp = buf;
int i;
/* Device is being removed */
if (!ir_dev)
return -EINVAL;
if (ir_dev->props && ir_dev->props->driver_type == RC_DRIVER_SCANCODE) {
enabled = ir_dev->rc_tab.ir_type;
allowed = ir_dev->props->allowed_protos;
} else if (ir_dev->raw) {
enabled = ir_dev->raw->enabled_protocols;
allowed = ir_raw_get_allowed_protocols();
} else
return sprintf(tmp, "[builtin]\n");
IR_dprintk(1, "allowed - 0x%llx, enabled - 0x%llx\n",
(long long)allowed,
(long long)enabled);
for (i = 0; i < ARRAY_SIZE(proto_names); i++) {
if (allowed & enabled & proto_names[i].type)
tmp += sprintf(tmp, "[%s] ", proto_names[i].name);
else if (allowed & proto_names[i].type)
tmp += sprintf(tmp, "%s ", proto_names[i].name);
}
if (tmp != buf)
tmp--;
*tmp = '\n';
return tmp + 1 - buf;
}
/**
* store_protocols() - changes the current IR protocol(s)
* @d: the device descriptor
* @mattr: the device attribute struct (unused)
* @buf: a pointer to the input buffer
* @len: length of the input buffer
*
* This routine is a callback routine for changing the IR protocol type.
* It is trigged by writing to /sys/class/rc/rc?/protocols.
* Writing "+proto" will add a protocol to the list of enabled protocols.
* Writing "-proto" will remove a protocol from the list of enabled protocols.
* Writing "proto" will enable only "proto".
* Writing "none" will disable all protocols.
* Returns -EINVAL if an invalid protocol combination or unknown protocol name
* is used, otherwise @len.
*/
static ssize_t store_protocols(struct device *d,
struct device_attribute *mattr,
const char *data,
size_t len)
{
struct ir_input_dev *ir_dev = dev_get_drvdata(d);
bool enable, disable;
const char *tmp;
u64 type;
u64 mask;
int rc, i, count = 0;
unsigned long flags;
/* Device is being removed */
if (!ir_dev)
return -EINVAL;
if (ir_dev->props && ir_dev->props->driver_type == RC_DRIVER_SCANCODE)
type = ir_dev->rc_tab.ir_type;
else if (ir_dev->raw)
type = ir_dev->raw->enabled_protocols;
else {
IR_dprintk(1, "Protocol switching not supported\n");
return -EINVAL;
}
while ((tmp = strsep((char **) &data, " \n")) != NULL) {
if (!*tmp)
break;
if (*tmp == '+') {
enable = true;
disable = false;
tmp++;
} else if (*tmp == '-') {
enable = false;
disable = true;
tmp++;
} else {
enable = false;
disable = false;
}
if (!enable && !disable && !strncasecmp(tmp, PROTO_NONE, sizeof(PROTO_NONE))) {
tmp += sizeof(PROTO_NONE);
mask = 0;
count++;
} else {
for (i = 0; i < ARRAY_SIZE(proto_names); i++) {
if (!strncasecmp(tmp, proto_names[i].name, strlen(proto_names[i].name))) {
tmp += strlen(proto_names[i].name);
mask = proto_names[i].type;
break;
}
}
if (i == ARRAY_SIZE(proto_names)) {
IR_dprintk(1, "Unknown protocol: '%s'\n", tmp);
return -EINVAL;
}
count++;
}
if (enable)
type |= mask;
else if (disable)
type &= ~mask;
else
type = mask;
}
if (!count) {
IR_dprintk(1, "Protocol not specified\n");
return -EINVAL;
}
if (ir_dev->props && ir_dev->props->change_protocol) {
rc = ir_dev->props->change_protocol(ir_dev->props->priv,
type);
if (rc < 0) {
IR_dprintk(1, "Error setting protocols to 0x%llx\n",
(long long)type);
return -EINVAL;
}
}
if (ir_dev->props && ir_dev->props->driver_type == RC_DRIVER_SCANCODE) {
spin_lock_irqsave(&ir_dev->rc_tab.lock, flags);
ir_dev->rc_tab.ir_type = type;
spin_unlock_irqrestore(&ir_dev->rc_tab.lock, flags);
} else {
ir_dev->raw->enabled_protocols = type;
}
IR_dprintk(1, "Current protocol(s): 0x%llx\n",
(long long)type);
return len;
}
#define ADD_HOTPLUG_VAR(fmt, val...) \
do { \
int err = add_uevent_var(env, fmt, val); \
if (err) \
return err; \
} while (0)
static int rc_dev_uevent(struct device *device, struct kobj_uevent_env *env)
{
struct ir_input_dev *ir_dev = dev_get_drvdata(device);
if (ir_dev->rc_tab.name)
ADD_HOTPLUG_VAR("NAME=%s", ir_dev->rc_tab.name);
if (ir_dev->driver_name)
ADD_HOTPLUG_VAR("DRV_NAME=%s", ir_dev->driver_name);
return 0;
}
/*
* Static device attribute struct with the sysfs attributes for IR's
*/
static DEVICE_ATTR(protocols, S_IRUGO | S_IWUSR,
show_protocols, store_protocols);
static struct attribute *rc_dev_attrs[] = {
&dev_attr_protocols.attr,
NULL,
};
static struct attribute_group rc_dev_attr_grp = {
.attrs = rc_dev_attrs,
};
static const struct attribute_group *rc_dev_attr_groups[] = {
&rc_dev_attr_grp,
NULL
};
static struct device_type rc_dev_type = {
.groups = rc_dev_attr_groups,
.uevent = rc_dev_uevent,
};
/**
* ir_register_class() - creates the sysfs for /sys/class/rc/rc?
* @input_dev: the struct input_dev descriptor of the device
*
* This routine is used to register the syfs code for IR class
*/
int ir_register_class(struct input_dev *input_dev)
{
struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
int devno = find_first_zero_bit(&ir_core_dev_number,
IRRCV_NUM_DEVICES);
if (unlikely(devno < 0))
return devno;
ir_dev->dev.type = &rc_dev_type;
ir_dev->devno = devno;
ir_dev->dev.class = &ir_input_class;
ir_dev->dev.parent = input_dev->dev.parent;
input_dev->dev.parent = &ir_dev->dev;
dev_set_name(&ir_dev->dev, "rc%d", devno);
dev_set_drvdata(&ir_dev->dev, ir_dev);
return device_register(&ir_dev->dev);
};
/**
* ir_register_input - registers ir input device with input subsystem
* @input_dev: the struct input_dev descriptor of the device
*/
int ir_register_input(struct input_dev *input_dev)
{
struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
int rc;
const char *path;
rc = input_register_device(input_dev);
if (rc < 0) {
device_del(&ir_dev->dev);
return rc;
}
__module_get(THIS_MODULE);
path = kobject_get_path(&ir_dev->dev.kobj, GFP_KERNEL);
printk(KERN_INFO "%s: %s as %s\n",
dev_name(&ir_dev->dev),
input_dev->name ? input_dev->name : "Unspecified device",
path ? path : "N/A");
kfree(path);
set_bit(ir_dev->devno, &ir_core_dev_number);
return 0;
}
/**
* ir_unregister_class() - removes the sysfs for sysfs for
* /sys/class/rc/rc?
* @input_dev: the struct input_dev descriptor of the device
*
* This routine is used to unregister the syfs code for IR class
*/
void ir_unregister_class(struct input_dev *input_dev)
{
struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
input_set_drvdata(input_dev, NULL);
clear_bit(ir_dev->devno, &ir_core_dev_number);
input_unregister_device(input_dev);
device_del(&ir_dev->dev);
module_put(THIS_MODULE);
}
/*
* Init/exit code for the module. Basically, creates/removes /sys/class/rc
*/
static int __init ir_core_init(void)
{
int rc = class_register(&ir_input_class);
if (rc) {
printk(KERN_ERR "ir_core: unable to register rc class\n");
return rc;
}
/* Initialize/load the decoders/keymap code that will be used */
ir_raw_init();
ir_rcmap_init();
return 0;
}
static void __exit ir_core_exit(void)
{
class_unregister(&ir_input_class);
ir_rcmap_cleanup();
}
module_init(ir_core_init);
module_exit(ir_core_exit);