linux-kernel - [PATCH v3 4/5] platform/chrome: cros_ec

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Message-ID: <20240605063351.14836-5-ben@jubnut.com>
Date: Wed,  5 Jun 2024 07:33:50 +0100
From: Ben Walsh <ben@...nut.com>
To: Benson Leung <bleung@...omium.org>,
	Tzung-Bi Shih <tzungbi@...nel.org>,
	Guenter Roeck <groeck@...omium.org>,
	"Dustin L. Howett" <dustin@...ett.net>,
	Kieran Levin <ktl@...me.work>,
	Thomas Weißschuh <linux@...ssschuh.net>,
	Mario Limonciello <mario.limonciello@....com>,
	chrome-platform@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Cc: Ben Walsh <ben@...nut.com>
Subject: [PATCH v3 4/5] platform/chrome: cros_ec_lpc: Add a new quirk for AML mutex

Add a new quirk "CROS_EC_LPC_QUIRK_AML_MUTEX" which provides the name
of an AML mutex to protect MEC memory access.

Signed-off-by: Ben Walsh <ben@...nut.com>
---
 drivers/platform/chrome/cros_ec_lpc.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index fa6606da802a..5d9cc8df208b 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -44,6 +44,11 @@ static bool cros_ec_lpc_acpi_device_found;
  * the ACPI device.
  */
 #define CROS_EC_LPC_QUIRK_ACPI_ID                   BIT(1)
+/*
+ * Indicates that lpc_driver_data.quirk_aml_mutex_name should be used
+ * to find an AML mutex to protect access to Microchip EC.
+ */
+#define CROS_EC_LPC_QUIRK_AML_MUTEX                 BIT(2)
 
 /**
  * struct lpc_driver_data - driver data attached to a DMI device ID to indicate
@@ -52,11 +57,14 @@ static bool cros_ec_lpc_acpi_device_found;
  * @quirk_mmio_memory_base: The first I/O port addressing EC mapped memory (used
  *                          when quirk ...REMAP_MEMORY is set.)
  * @quirk_acpi_id: An ACPI HID to be used to find the ACPI device.
+ * @quirk_aml_mutex_name: The name of an AML mutex to be used to protect access
+ *                        to Microchip EC.
  */
 struct lpc_driver_data {
 	u32 quirks;
 	u16 quirk_mmio_memory_base;
 	const char *quirk_acpi_id;
+	const char *quirk_aml_mutex_name;
 };
 
 /**
@@ -482,6 +490,17 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
 			}
 			ACPI_COMPANION_SET(dev, adev);
 		}
+
+		if (quirks & CROS_EC_LPC_QUIRK_AML_MUTEX) {
+			const char *name
+				= driver_data->quirk_aml_mutex_name;
+			ret = cros_ec_lpc_mec_acpi_mutex(ACPI_COMPANION(dev), name);
+			if (ret) {
+				dev_err(dev, "failed to get AML mutex '%s'", name);
+				return ret;
+			}
+			dev_info(dev, "got AML mutex '%s'", name);
+		}
 	}
 
 	/*
-- 
2.45.1