eeepc-laptop: clean up coding style

Correct the white space and brace usage to comply with
Documentation/CodingStyle.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: change sysfs functions to API expectations

The eeepc-laptop driver follows the function naming convention
<action>_<attrname>(), while the sysfs macros are built around the
convention <attrname>_<action>(). Rename the sysfs functions to the
convention used by sysfs. This makes it easier to use the available API
later on.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: use DEVICE_ATTR* to instantiate device_attributes

Device attributes are instantiated manually, while we have DEVICE_ATTR*
macros available to do much of the work for us. Let's use them.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: pull out ACPI_STORE_FUNC and ACPI_SHOW_FUNC macros

Pull out macros EEEPC_ACPI_STORE_FUNC and EEEPC_ACPI_SHOW_FUNC. These
macros define functions that call store_sys_acpi() and show_sys_acpi()
respectively. This helps prevent duplication later on.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: make disp attribute really write-only

The disp attribute is write-only, but sysfs doesn't know this. Currently
show_sys_acpi() is mimicking sysfs behavior, if the underlying acpi call
should fail. This is not ideal; behaving like sysfs is better left to
sysfs.

Introduce EEEPC_CREATE_DEVICE_ATTR_WO() to instantiate a write-only
attribute, and declare the disp attribute with it. Sysfs makes sure
userspace can only write to disp at all times. This also means we can
back to propagating any errors from get_acpi().

This also causes EEEPC_CREATE_DEVICE_ATTR() to be used only for R/W
attributes. This enables us to drop the _mode argument from the macro
and use DEVICE_ATTR_RW() internally while we're at it. Append _RW to the
name for readability.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: pull out SENSOR_STORE_FUNC and SENSOR_SHOW_FUNC macros

Pull out EEEPC_SENSOR_STORE_FUNC and EEEPC_SENSOR_SHOW_FUNC. These
macros define functions that call store_sys_hwmon() and show_sys_hwmon()
respectively. This helps prevent duplication later on.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: make fan1_input really read-only

In the instantiation of the fan1_input device attribute, NULL is passed
as set function to store_sys_hwmon. The function pointer is never
checked before dereferencing it. This is fine if we can guarantee that
it will never be called with an invalid pointer, but we can't. If
someone from user space decides to change the permissions on this
attribute and write to it, kernel will crash.

Introduce EEEPC_CREATE_SENSOR_ATTR_RO() to instantiate a read-only
attribute, and declare fan1_input with it. This ensures store_sys_hwmon
is never called with NULL parameters. If someone tries to write the
attribute, the system will at least keep its sanity.

This also causes EEEPC_CREATE_SENSOR_ATTR() to be only used for R/W
attributes.This enables us to drop the _mode argument from the macro
and use DEVICE_ATTR_RW() internally while we're at it. Append _RW to the
name for readability.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: compare proper return values in get_cpufv

In get_cpufv the return value of get_acpi is stored in the cpufv struct.
Right before this value is checked for errors, it is and'ed with 0xff.
This means c->cur can never be less than zero. Besides that, the actual
error value is ignored.

c->num is also and'ed with 0xff, which means we can ignore values below
zero.

Check the result of get_acpi() right away. While at it, propagate the
error if we got one.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: propagate errors from get_cpufv

In available_cpufv_show, cpufv_show, and cpufv_store, errors from
get_cpufv are mapped to -ENODEV. To paint a clear picture to callers,
propagate the errors instead.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: store_cpufv: return error if set_acpi fails

The result of set_acpi is left unchecked, but it may return errors. If
one occurs, send the error to the caller.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
eeepc-laptop: return -ENXIO if acpi getter or setter fails

get_acpi() and set_acpi() return -ENODEV on error.  However, of the
available options, ENXIO seems more appropriate, since we're dealing
with both devices and addresses here:

	#define EIO              5      /* I/O error */
	#define ENXIO            6      /* No such device or address */
	#define ENODEV          19      /* No such device */

One could expect the same applies to acpi_setter_handle(), as this
follows a similar setup. Changing the return values here triggers the
error "Error removing rfkill notify handler" during boot, so we'll leave
that as is.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>