1 files changed, 126 insertions, 0 deletions
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c
new file mode 100644
index 000000000000..a1a108407f0f
--- /dev/null
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Processor thermal device module for registering and processing
+ * power floor. When the hardware reduces the power to the minimum
+ * possible, the power floor is notified via an interrupt.
+ *
+ * Operation:
+ * When user space enables power floor reporting:
+ * - Use mailbox to:
+ *	Enable processor thermal device interrupt
+ *
+ * - Current status of power floor is read from offset 0x5B18
+ *   bit 39.
+ *
+ * Two interface functions are provided to call when there is a
+ * thermal device interrupt:
+ * - proc_thermal_power_floor_intr():
+ *	Check if the interrupt is for change in power floor.
+ *	Called from interrupt context.
+ *
+ * - proc_thermal_power_floor_intr_callback():
+ *	Callback for interrupt processing in thread context. This involves
+ *	sending notification to user space that there is a change in the
+ *	power floor status.
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/pci.h>
+#include "processor_thermal_device.h"
+
+#define SOC_POWER_FLOOR_STATUS		BIT(39)
+#define SOC_POWER_FLOOR_SHIFT		39
+
+#define SOC_POWER_FLOOR_INT_ENABLE_BIT	31
+#define SOC_POWER_FLOOR_INT_ACTIVE	BIT(3)
+
+int proc_thermal_read_power_floor_status(struct proc_thermal_device *proc_priv)
+{
+	u64 status = 0;
+
+	status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET);
+	return (status & SOC_POWER_FLOOR_STATUS) >> SOC_POWER_FLOOR_SHIFT;
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_read_power_floor_status, INT340X_THERMAL);
+
+static bool enable_state;
+static DEFINE_MUTEX(pf_lock);
+
+int proc_thermal_power_floor_set_state(struct proc_thermal_device *proc_priv, bool enable)
+{
+	int ret = 0;
+
+	mutex_lock(&pf_lock);
+	if (enable_state == enable)
+		goto pf_unlock;
+
+	/*
+	 * Time window parameter is not applicable to power floor interrupt configuration.
+	 * Hence use -1 for time window.
+	 */
+	ret = processor_thermal_mbox_interrupt_config(to_pci_dev(proc_priv->dev), enable,
+						      SOC_POWER_FLOOR_INT_ENABLE_BIT, -1);
+	if (!ret)
+		enable_state = enable;
+
+pf_unlock:
+	mutex_unlock(&pf_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_set_state, INT340X_THERMAL);
+
+bool proc_thermal_power_floor_get_state(struct proc_thermal_device *proc_priv)
+{
+	return enable_state;
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_get_state, INT340X_THERMAL);
+
+/**
+ * proc_thermal_check_power_floor_intr() - Check power floor interrupt.
+ * @proc_priv: Processor thermal device instance.
+ *
+ * Callback to check if the interrupt for power floor is active.
+ *
+ * Context: Called from interrupt context.
+ *
+ * Return: true if power floor is active, false when not active.
+ */
+bool proc_thermal_check_power_floor_intr(struct proc_thermal_device *proc_priv)
+{
+	u64 int_status;
+
+	int_status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET);
+	return !!(int_status & SOC_POWER_FLOOR_INT_ACTIVE);
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_check_power_floor_intr, INT340X_THERMAL);
+
+/**
+ * proc_thermal_power_floor_intr_callback() - Process power floor notification
+ * @pdev:	PCI device instance
+ * @proc_priv: Processor thermal device instance.
+ *
+ * Check if the power floor interrupt is active, if active send notification to
+ * user space for the attribute "power_limits", so that user can read the attribute
+ * and take action.
+ *
+ * Context: Called from interrupt thread context.
+ *
+ * Return: None.
+ */
+void proc_thermal_power_floor_intr_callback(struct pci_dev *pdev,
+					    struct proc_thermal_device *proc_priv)
+{
+	u64 status;
+
+	status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET);
+	if (!(status & SOC_POWER_FLOOR_INT_ACTIVE))
+		return;
+
+	sysfs_notify(&pdev->dev.kobj, "power_limits", "power_floor_status");
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_intr_callback, INT340X_THERMAL);
+
+MODULE_IMPORT_NS(INT340X_THERMAL);
+MODULE_LICENSE("GPL");