Re: [PATCH 2/2] platform/x86: dell-*: Add interface for switchable graphics status query

From: Kai Heng Feng
Date: Thu Mar 08 2018 - 03:20:14 EST




On Mar 8, 2018, at 3:34 PM, Mario.Limonciello@xxxxxxxx wrote:

-----Original Message-----
From: Kai-Heng Feng [mailto:kai.heng.feng@xxxxxxxxxxxxx]
Sent: Thursday, March 8, 2018 3:12 PM
To: mjg59@xxxxxxxxxxxxx; pali.rohar@xxxxxxxxx; dvhart@xxxxxxxxxxxxx;
andy@xxxxxxxxxxxxx; Limonciello, Mario <Mario_Limonciello@xxxxxxxx>;
tiwai@xxxxxxxx
Cc: platform-driver-x86@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; alsa-
devel@xxxxxxxxxxxxxxxx; Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Subject: [PATCH 2/2] platform/x86: dell-*: Add interface for switchable graphics
status query

On some Dell platforms, there's a BIOS option "Enable Switchable
Graphics". This information is useful if we want to do different things
based on this value, e.g. disable unused audio controller that comes
with the discrete graphics.

I was expecting the follow on patch that uses this interface too as part of the
series. This patch itself however looks like.

I thought it should be easier to separate patch series for different subsystems.
But of course I can make them the as one series.

I'll resend a v2 for this.

Kai-Heng


Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
drivers/platform/x86/dell-laptop.c | 23 +++++++++++++++++++++++
drivers/platform/x86/dell-smbios.c | 2 ++
drivers/platform/x86/dell-smbios.h | 2 ++
3 files changed, 27 insertions(+)

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 8ba820e6c3d0..3f6fc07b8cf2 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -2116,6 +2116,29 @@ int dell_micmute_led_set(int state)
}
EXPORT_SYMBOL_GPL(dell_micmute_led_set);

+int dell_switchable_gfx_enabled(bool *enabled)
+{
+ struct calling_interface_buffer buffer;
+ struct calling_interface_token *token;
+ int ret;
+
+ *enabled = false;
+
+ token = dell_smbios_find_token(SWITCHABLE_GRAPHICS_ENABLE);
+ if (!token)
+ return -ENODEV;
+
+ dell_fill_request(&buffer, token->location, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_TOKEN_READ,
SELECT_TOKEN_STD);
+ if (ret)
+ return ret;
+
+ *enabled = !!buffer.output[1];
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dell_switchable_gfx_enabled);
+
static int __init dell_init(void)
{
struct calling_interface_token *token;
diff --git a/drivers/platform/x86/dell-smbios.c b/drivers/platform/x86/dell-smbios.c
index 8541cde4cb7d..ca38b9d9dcf4 100644
--- a/drivers/platform/x86/dell-smbios.c
+++ b/drivers/platform/x86/dell-smbios.c
@@ -86,6 +86,8 @@ struct token_range {
static struct token_range token_whitelist[] = {
/* used by userspace: fwupdate */
{CAP_SYS_ADMIN, CAPSULE_EN_TOKEN, CAPSULE_DIS_TOKEN},
+ /* can indicate to userspace Switchable Graphics enable status */
+ {CAP_SYS_ADMIN, SWITCHABLE_GRAPHICS_ENABLE,
SWITCHABLE_GRAPHICS_DISABLE},
/* can indicate to userspace that WMI is needed */
{0x0000, WSMT_EN_TOKEN, WSMT_DIS_TOKEN}
};
diff --git a/drivers/platform/x86/dell-smbios.h b/drivers/platform/x86/dell-smbios.h
index 138d478d9adc..b012d4abd239 100644
--- a/drivers/platform/x86/dell-smbios.h
+++ b/drivers/platform/x86/dell-smbios.h
@@ -37,6 +37,8 @@
#define KBD_LED_AUTO_100_TOKEN 0x02F6
#define GLOBAL_MIC_MUTE_ENABLE 0x0364
#define GLOBAL_MIC_MUTE_DISABLE 0x0365
+#define SWITCHABLE_GRAPHICS_ENABLE 0x037A
+#define SWITCHABLE_GRAPHICS_DISABLE 0x037B

struct notifier_block;

--
2.15.1