linux-kernel - [PATCH] thermal: int340x_thermal: Add production mode attribute

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Message-Id: <20230117165029.2782484-1-srinivas.pandruvada@linux.intel.com>
Date:   Tue, 17 Jan 2023 08:50:29 -0800
From:   Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
To:     rafael@...nel.org, rui.zhang@...el.com, daniel.lezcano@...aro.org
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: [PATCH] thermal: int340x_thermal: Add production mode attribute

It is possible that system manufacturer locks further thermal tuning. In
this case user space calibration tools should not try to adjust thermal
configuration.

Add an attribute "production_mode". This attribute is only present when
the ACPI DCFG method is present under INT3400 device scope.

When DCFG evaluates to non 0, user space configuration tools should exit.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
---
 .../driver-api/thermal/intel_dptf.rst         |  4 ++
 .../intel/int340x_thermal/int3400_thermal.c   | 48 +++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/Documentation/driver-api/thermal/intel_dptf.rst b/Documentation/driver-api/thermal/intel_dptf.rst
index 372bdb4d04c6..9a7b651ba764 100644
--- a/Documentation/driver-api/thermal/intel_dptf.rst
+++ b/Documentation/driver-api/thermal/intel_dptf.rst
@@ -84,6 +84,10 @@ DPTF ACPI Drivers interface
 	https:/github.com/intel/thermal_daemon for decoding
 	thermal table.
 
+``production_mode`` (RO)
+	When non zero, manufacturer locked thermal configuration from
+	further changes.
+
 
 ACPI Thermal Relationship table interface
 ------------------------------------------
diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
index db8a6f63657d..ec5ec07ccf41 100644
--- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
+++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
@@ -60,6 +60,8 @@ struct int3400_thermal_priv {
 	int odvp_count;
 	int *odvp;
 	u32 os_uuid_mask;
+	int production_mode;
+	bool production_mode_support;
 	struct odvp_attr *odvp_attrs;
 };
 
@@ -315,6 +317,43 @@ static int int3400_thermal_get_uuids(struct int3400_thermal_priv *priv)
 	return result;
 }
 
+static ssize_t production_mode_show(struct device *dev, struct device_attribute *attr,
+				     char *buf)
+{
+	struct int3400_thermal_priv *priv = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", priv->production_mode);
+}
+
+static DEVICE_ATTR_RO(production_mode);
+
+static int production_mode_init(struct int3400_thermal_priv *priv)
+{
+	unsigned long long mode;
+	acpi_status status;
+	int ret;
+
+	status = acpi_evaluate_integer(priv->adev->handle, "DCFG", NULL, &mode);
+	/* If the method is not present, this is not an error */
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	ret = sysfs_create_file(&priv->pdev->dev.kobj, &dev_attr_production_mode.attr);
+	if (ret)
+		return ret;
+
+	priv->production_mode_support = true;
+	priv->production_mode = mode;
+
+	return 0;
+}
+
+void production_mode_exit(struct int3400_thermal_priv *priv)
+{
+	if (priv->production_mode_support)
+		sysfs_remove_file(&priv->pdev->dev.kobj, &dev_attr_production_mode.attr);
+}
+
 static ssize_t odvp_show(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
@@ -610,8 +649,15 @@ static int int3400_thermal_probe(struct platform_device *pdev)
 	if (result)
 		goto free_sysfs;
 
+	result = production_mode_init(priv);
+	if (result)
+		goto free_notify;
+
 	return 0;
 
+free_notify:
+	acpi_remove_notify_handler(priv->adev->handle, ACPI_DEVICE_NOTIFY,
+				   int3400_notify);
 free_sysfs:
 	cleanup_odvp(priv);
 	if (!ZERO_OR_NULL_PTR(priv->data_vault)) {
@@ -638,6 +684,8 @@ static int int3400_thermal_remove(struct platform_device *pdev)
 {
 	struct int3400_thermal_priv *priv = platform_get_drvdata(pdev);
 
+	production_mode_exit(priv);
+
 	acpi_remove_notify_handler(
 			priv->adev->handle, ACPI_DEVICE_NOTIFY,
 			int3400_notify);
-- 
2.31.1