On Monday, November 14, 2011 10:24:17 AM Nuno Santos wrote:
> Hi,
>
> I have defined my first attribute in the following way:
>
> static ssize_t usbtouchscreen_update_sensibility(struct device *dev,
> struct device_attribute *attr,
> const char *buf, size_t count)
> {
>
> printk(KERN_INFO "update sensibility called");
>
Updating sensibility is always a good thing but I gather you mean
sensitivity here...
BTW this should probably be a per-user setting and belong to the X driver,
not kernel driver. I.e. kernel streams all data and userspace (X) decides
what data do discard according to current user preferences.
> return 0;
> }
>
> static DEVICE_ATTR(sensibility, 0664, NULL,
> usbtouchscreen_update_sensibility);
>
> static struct attribute *usbtouchscreen_attrs[] = {
> &dev_attr_sensibility.attr,
> NULL
> };
>
> static const struct attribute_group usbtouchscreen_attr_group = {
> .attrs = usbtouchscreen_attrs,
> };
>
> In the probe function I have added:
>
> if (sysfs_create_group(&intf->dev.kobj, &usbtouchscreen_attr_group))
> goto out_unregister_input;
>
>
> Then I tried to write on the attribute in the following way:
>
> nsantos@NS-PC:~/workspaces/linux-kernel-driver$ echo 45 >
> /sys/class/input/input7/sensibility
> bash: /sys/class/input/input7/sensibility: No such file or directory
>
> After digging a bit under /sys/class/input/input7 i found that the sub
> directory device add sensibilty listed so I tried the following:
>
> nsantos@NS-PC:~/workspaces/workspace-mtt/linux-kernel-driver$ sudo echo
> 45 > /sys/class/input/input7/device/sensibility
> bash: /sys/class/input/input7/device/sensibility: Permission denied
>
> With no success again...
>
> Am I doing something terribly wrong?
You aren't doing this as root and don't have permission to access the
attribute.
--
Dmitry
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