[PATCH] platform/x86: thinkpad_acpi: Fix incorrect use of platform profile on AMD platforms

[Mark Pearson <markpearson@lenovo.com>]

Lenovo AMD based platforms have been offering platform_profiles but they
are not working correctly. This is because the mode we are using on the
Intel platforms (MMC) is not available on the AMD platforms.

This commit adds checking of the functional capabilities returned by the
BIOS to confirm if MMC is supported or not. Profiles will not be
available if the platform is not MMC capable.

I'm investigating and working on an alternative for AMD platforms but
that is still work-in-progress.

Signed-off-by: Mark Pearson <markpearson@lenovo.com>
---
Changes in v2:
 - Rebased on review-hans branch to be in sync with latest
 - Return -ENODEV if funtion not available

 drivers/platform/x86/thinkpad_acpi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 33f611af6e51..5e4de74586cd 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -10119,6 +10119,9 @@ static struct ibm_struct proxsensor_driver_data = {
 #define DYTC_CMD_MMC_GET      8 /* To get current MMC function and mode */
 #define DYTC_CMD_RESET    0x1ff /* To reset back to default */
 
+#define DYTC_CMD_FUNC_CAP     3 /* To get DYTC capabilities */
+#define DYTC_FC_MMC           27 /* MMC Mode supported */
+
 #define DYTC_GET_FUNCTION_BIT 8  /* Bits  8-11 - function setting */
 #define DYTC_GET_MODE_BIT     12 /* Bits 12-15 - mode setting */
 
@@ -10331,6 +10334,15 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm)
 	if (dytc_version < 5)
 		return -ENODEV;
 
+	/* Check what capabilities are supported. Currently MMC is needed */
+	err = dytc_command(DYTC_CMD_FUNC_CAP, &output);
+	if (err)
+		return err;
+	if (!test_bit(DYTC_FC_MMC, (void *)&output)) {
+		dbg_printk(TPACPI_DBG_INIT, " DYTC MMC mode not supported\n");
+		return -ENODEV;
+	}
+
 	dbg_printk(TPACPI_DBG_INIT,
 			"DYTC version %d: thermal mode available\n", dytc_version);
 	/*
-- 
2.34.1