[PATCH] platform/x86: lg-laptop: Add support for the HDAP opregion field

[Armin Wolf <W_Armin@gmx.de>]

Various LG notebooks have a special field called "HDAP" inside
the ACPI operation region handled by the lg-laptop driver:

	Field (XIN1, AnyAcc, Lock, Preserve)
	{
		DMSG,   8,
		HDAP,   8,
		Offset (0x10),
		P80B,   8,
		P81B,   8,
		P82B,   8,
		P83B,   8,
		P84B,   8,
		P85B,   8,
		P86B,   8,
		P87B,   8,
		Offset (0x3E8),
		PMSG,   1600
	}

This field is set to 1/0 when the HD audio device is enabled/disabled
using the _PS0/_PS3 ACPI control methods. Add support for this field
to avoid printing warning messages when AML bytecode writes data
into it.

Reported-by: Peter Chubb <peter@chubb.wattle.id.au>
Tested-by: Peter Chubb <peter@chubb.wattle.id.au>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/lg-laptop.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c
index 4b57102c7f62..9996bb43e9a0 100644
--- a/drivers/platform/x86/lg-laptop.c
+++ b/drivers/platform/x86/lg-laptop.c
@@ -18,6 +18,7 @@
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/string_choices.h>
 #include <linux/types.h>
 
 #include <acpi/battery.h>
@@ -41,6 +42,7 @@ MODULE_PARM_DESC(fw_debug, "Enable printing of firmware debug messages");
 #define LG_ADDRESS_SPACE_ID			0x8F
 
 #define LG_ADDRESS_SPACE_DEBUG_FLAG_ADR		0x00
+#define LG_ADDRESS_SPACE_HD_AUDIO_POWER_ADDR	0x01
 #define LG_ADDRESS_SPACE_FAN_MODE_ADR		0x03
 
 #define LG_ADDRESS_SPACE_DTTM_FLAG_ADR		0x20
@@ -674,6 +676,15 @@ static acpi_status lg_laptop_address_space_write(struct device *dev, acpi_physic
 	byte = value & 0xFF;
 
 	switch (address) {
+	case LG_ADDRESS_SPACE_HD_AUDIO_POWER_ADDR:
+		/*
+		 * The HD audio power field is not affected by the DTTM flag,
+		 * so we have to manually check fw_debug.
+		 */
+		if (fw_debug)
+			dev_dbg(dev, "HD audio power %s\n", str_enabled_disabled(byte));
+
+		return AE_OK;
 	case LG_ADDRESS_SPACE_FAN_MODE_ADR:
 		/*
 		 * The fan mode field is not affected by the DTTM flag, so we
-- 
2.39.5