[PATCH 4/6] platform/chrome: cros_ec_lpc: Add a new quirk for AML mutex

From: Ben Walsh
Date: Wed May 15 2024 - 01:57:07 EST


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@xxxxxxxxxx>
---
drivers/platform/chrome/cros_ec_lpc.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index b27519fbdf58..ab7779b57a13 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -39,6 +39,11 @@ static bool cros_ec_lpc_acpi_device_found;
* be used as the base port for EC mapped memory.
*/
#define CROS_EC_LPC_QUIRK_REMAP_MEMORY BIT(0)
+/*
+ * Indicates that an AML mutex should be used to protect access to
+ * Microchip EC.
+ */
+#define CROS_EC_LPC_QUIRK_AML_MUTEX BIT(1)

/**
* struct lpc_driver_data - driver data attached to a DMI device ID to indicate
@@ -46,10 +51,13 @@ static bool cros_ec_lpc_acpi_device_found;
* @quirks: a bitfield composed of quirks from CROS_EC_LPC_QUIRK_*
* @quirk_mmio_memory_base: The first I/O port addressing EC mapped memory (used
* when quirk ...REMAP_MEMORY is set.)
+ * @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_aml_mutex_name;
};

/**
@@ -447,6 +455,8 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)

ec_lpc->mmio_memory_base = EC_LPC_ADDR_MEMMAP;

+ adev = ACPI_COMPANION(dev);
+
if (cros_ec_lpc_driver_data) {
quirks = cros_ec_lpc_driver_data->quirks;

@@ -456,6 +466,18 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
if (quirks & CROS_EC_LPC_QUIRK_REMAP_MEMORY)
ec_lpc->mmio_memory_base
= cros_ec_lpc_driver_data->quirk_mmio_memory_base;
+
+ if (quirks & CROS_EC_LPC_QUIRK_AML_MUTEX) {
+ const char *name
+ = cros_ec_lpc_driver_data->quirk_aml_mutex_name;
+ ret = cros_ec_lpc_mec_acpi_mutex(adev, name);
+ if (ret) {
+ dev_err(dev, "failed to get AML mutex '%s'", name);
+ return ret;
+ }
+
+ dev_info(dev, "got AML mutex '%s'", name);
+ }
}

/*
@@ -549,7 +571,6 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
* Connect a notify handler to process MKBP messages if we have a
* companion ACPI device.
*/
- adev = ACPI_COMPANION(dev);
if (adev) {
status = acpi_install_notify_handler(adev->handle,
ACPI_ALL_NOTIFY,
--
2.45.0