From 87cc537a54fc017d998cf603f5fab9ca4a85d668 Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Tue, 30 Oct 2007 18:02:07 -0200 Subject: [PATCH] ACPI: thinkpad-acpi: add brightness_force parameter Add a "brightness_enable" module parameter that allows the local admin to force the backlight support to not be enabled. It can also be used to force the backlight support to be enabled, but that is currently a no-op as the backlight support is enabled by default when available. This will be changed by a different patch. Signed-off-by: Henrique de Moraes Holschuh Signed-off-by: Len Brown --- Documentation/thinkpad-acpi.txt | 4 ++++ drivers/misc/thinkpad_acpi.c | 9 +++++++++ drivers/misc/thinkpad_acpi.h | 1 + 3 files changed, 14 insertions(+) diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt index a743bfa62b95..f877c13c5ef8 100644 --- a/Documentation/thinkpad-acpi.txt +++ b/Documentation/thinkpad-acpi.txt @@ -944,6 +944,10 @@ When display backlight brightness controls are available through the standard ACPI interface, it is best to use it instead of this direct ThinkPad-specific interface. +The brightness_enable module parameter can be used to control whether +the LCD brightness control feature will be enabled when available. +brightness_enable=0 forces it to be disabled. + Procfs notes: The available commands are: diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index 322ba25b4798..56a21e6b80a9 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -3182,6 +3182,12 @@ static int __init brightness_init(struct ibm_init_struct *iibm) mutex_init(&brightness_mutex); + if (!brightness_enable) { + dbg_printk(TPACPI_DBG_INIT, + "brightness support disabled by module parameter\n"); + return 1; + } + if (!brightness_mode) { if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) brightness_mode = 2; @@ -4803,6 +4809,9 @@ module_param_named(fan_control, fan_control_allowed, bool, 0); static int brightness_mode; module_param_named(brightness_mode, brightness_mode, int, 0); +static unsigned int brightness_enable = 2; /* 2 = auto, 0 = no, 1 = yes */ +module_param(brightness_enable, uint, 0); + static unsigned int hotkey_report_mode; module_param(hotkey_report_mode, uint, 0); diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h index 8ca19c333727..8fba2bbe345e 100644 --- a/drivers/misc/thinkpad_acpi.h +++ b/drivers/misc/thinkpad_acpi.h @@ -339,6 +339,7 @@ static int bluetooth_write(char *buf); static struct backlight_device *ibm_backlight_device; static int brightness_offset = 0x31; static int brightness_mode; +static unsigned int brightness_enable; /* 0 = no, 1 = yes, 2 = auto */ static int brightness_init(struct ibm_init_struct *iibm); static void brightness_exit(void);