From: Pali Rohár Date: Sat, 6 Jun 2015 08:23:30 +0000 (+0200) Subject: dell-laptop: Use dell-rbtn instead i8042 filter when possible X-Git-Tag: firefly_0821_release~176^2~1458^2~7 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f8358578e2f23bd82d0454c17676bdb28a40664a;p=firefly-linux-kernel-4.4.55.git dell-laptop: Use dell-rbtn instead i8042 filter when possible 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 Tested-by: Gabriele Mazzotta Signed-off-by: Darren Hart --- diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index d688d806a8a5..83e3d7f9d923 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -32,6 +32,7 @@ #include #include #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 ");