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dell-laptop: Use dell-rbtn instead i8042 filter when possible

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Until now module dell-laptop registered rfkill device which used i8042
filter function for receiving HW switch rfkill events (handling special
keycode).

But for some dell laptops there is native ACPI driver dell-rbtn which can
receive rfkill events (without i8042 hooks).

So this patch will combine best from both sides. It will use native ACPI
driver dell-rbtn for receiving events and dell-laptop SMBIOS interface for
enabling or disabling radio devices. If ACPI driver or device will not be
available fallback to i8042 filter function will be used.

Patch also changes module_init() to late_initcall() to ensure that init
function will be called after initializing dell-rbtn.c driver.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
This commit is contained in:
Pali Rohár 2015-06-06 10:23:30 +02:00 committed by Darren Hart
parent b05ffc95f9
commit f8358578e2
1 changed files with 86 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

94
drivers/platform/x86/dell-laptop.c
View File

@ -32,6 +32,7 @@
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include "../../firmware/dcdbas.h"
#include "dell-rbtn.h"
#define BRIGHTNESS_TOKEN 0x7d
#define KBD_LED_OFF_TOKEN 0x01E1
@ -642,6 +643,20 @@ static bool dell_laptop_i8042_filter(unsigned char data, unsigned char str,
return false;
}
static int (*dell_rbtn_notifier_register_func)(struct notifier_block *);
static int (*dell_rbtn_notifier_unregister_func)(struct notifier_block *);
static int dell_laptop_rbtn_notifier_call(struct notifier_block *nb,
unsigned long action, void *data)
{
schedule_delayed_work(&dell_rfkill_work, 0);
return NOTIFY_OK;
}
static struct notifier_block dell_laptop_rbtn_notifier = {
.notifier_call = dell_laptop_rbtn_notifier_call,
};
static int __init dell_setup_rfkill(void)
{
int status, ret, whitelisted;
@ -718,10 +733,62 @@ static int __init dell_setup_rfkill(void)
goto err_wwan;
}
ret = i8042_install_filter(dell_laptop_i8042_filter);
if (ret) {
pr_warn("Unable to install key filter\n");
/*
* Dell Airplane Mode Switch driver (dell-rbtn) supports ACPI devices
* which can receive events from HW slider switch.
*
* Dell SMBIOS on whitelisted models supports controlling radio devices
* but does not support receiving HW button switch events. We can use
* i8042 filter hook function to receive keyboard data and handle
* keycode for HW button.
*
* So if it is possible we will use Dell Airplane Mode Switch ACPI
* driver for receiving HW events and Dell SMBIOS for setting rfkill
* states. If ACPI driver or device is not available we will fallback to
* i8042 filter hook function.
*
* To prevent duplicate rfkill devices which control and do same thing,
* dell-rbtn driver will automatically remove its own rfkill devices
* once function dell_rbtn_notifier_register() is called.
*/
dell_rbtn_notifier_register_func =
symbol_request(dell_rbtn_notifier_register);
if (dell_rbtn_notifier_register_func) {
dell_rbtn_notifier_unregister_func =
symbol_request(dell_rbtn_notifier_unregister);
if (!dell_rbtn_notifier_unregister_func) {
symbol_put(dell_rbtn_notifier_register);
dell_rbtn_notifier_register_func = NULL;
}
}
if (dell_rbtn_notifier_register_func) {
ret = dell_rbtn_notifier_register_func(
&dell_laptop_rbtn_notifier);
symbol_put(dell_rbtn_notifier_register);
dell_rbtn_notifier_register_func = NULL;
if (ret != 0) {
symbol_put(dell_rbtn_notifier_unregister);
dell_rbtn_notifier_unregister_func = NULL;
}
} else {
pr_info("Symbols from dell-rbtn acpi driver are not available\n");
ret = -ENODEV;
}
if (ret == 0) {
pr_info("Using dell-rbtn acpi driver for receiving events\n");
} else if (ret != -ENODEV) {
pr_warn("Unable to register dell rbtn notifier\n");
goto err_filter;
} else {
ret = i8042_install_filter(dell_laptop_i8042_filter);
if (ret) {
pr_warn("Unable to install key filter\n");
goto err_filter;
}
pr_info("Using i8042 filter function for receiving events\n");
}
return 0;
@ -744,6 +811,14 @@ err_wifi:
static void dell_cleanup_rfkill(void)
{
if (dell_rbtn_notifier_unregister_func) {
dell_rbtn_notifier_unregister_func(&dell_laptop_rbtn_notifier);
symbol_put(dell_rbtn_notifier_unregister);
dell_rbtn_notifier_unregister_func = NULL;
} else {
i8042_remove_filter(dell_laptop_i8042_filter);
}
cancel_delayed_work_sync(&dell_rfkill_work);
if (wifi_rfkill) {
rfkill_unregister(wifi_rfkill);
rfkill_destroy(wifi_rfkill);
@ -1961,8 +2036,6 @@ static int __init dell_init(void)
return 0;
fail_backlight:
i8042_remove_filter(dell_laptop_i8042_filter);
cancel_delayed_work_sync(&dell_rfkill_work);
dell_cleanup_rfkill();
fail_rfkill:
free_page((unsigned long)bufferpage);
@ -1983,8 +2056,6 @@ static void __exit dell_exit(void)
if (quirks && quirks->touchpad_led)
touchpad_led_exit();
kbd_led_exit();
i8042_remove_filter(dell_laptop_i8042_filter);
cancel_delayed_work_sync(&dell_rfkill_work);
backlight_device_unregister(dell_backlight_device);
dell_cleanup_rfkill();
if (platform_device) {
@ -1995,7 +2066,14 @@ static void __exit dell_exit(void)
free_page((unsigned long)buffer);
}
module_init(dell_init);
/* dell-rbtn.c driver export functions which will not work correctly (and could
* cause kernel crash) if they are called before dell-rbtn.c init code. This is
* not problem when dell-rbtn.c is compiled as external module. When both files
* (dell-rbtn.c and dell-laptop.c) are compiled statically into kernel, then we
* need to ensure that dell_init() will be called after initializing dell-rbtn.
* This can be achieved by late_initcall() instead module_init().
*/
late_initcall(dell_init);
module_exit(dell_exit);
MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");