--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Processor Thermal Device Interface for Reading and Writing
+ * SoC Power Slider Values from User Space.
+ *
+ * Operation:
+ * The SOC_EFFICIENCY_SLIDER_0_0_0_MCHBAR register is accessed
+ * using the MMIO (Memory-Mapped I/O) interface with an MMIO offset of 0x5B38.
+ * Although this register is 64 bits wide, only bits 7:0 are used,
+ * and the other bits remain unchanged.
+ *
+ * Bit definitions
+ *
+ * Bits 2:0 (Slider value):
+ * The SoC optimizer slider value indicates the system wide energy performance
+ * hint. The slider has no specific units and ranges from 0 (highest
+ * performance) to 6 (highest energy efficiency). Value of 7 is reserved.
+ * Bits 3 : Reserved
+ * Bits 6:4 (Offset)
+ * Offset allows the SoC to automatically switch slider position in range
+ * [slider value (bits 2:0) + offset] to improve power efficiency based on
+ * internal SoC algorithms.
+ * Bit 7 (Enable):
+ * If this bit is set, the SoC Optimization sliders will be processed by the
+ * SoC firmware.
+ *
+ * Copyright (c) 2025, Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/pci.h>
+#include <linux/platform_profile.h>
+#include "processor_thermal_device.h"
+
+#define SOC_POWER_SLIDER_OFFSET 0x5B38
+
+enum power_slider_preference {
+ SOC_POWER_SLIDER_PERFORMANCE,
+ SOC_POWER_SLIDER_BALANCE,
+ SOC_POWER_SLIDER_POWERSAVE,
+};
+
+#define SOC_SLIDER_VALUE_MINIMUM 0x00
+#define SOC_SLIDER_VALUE_BALANCE 0x03
+#define SOC_SLIDER_VALUE_MAXIMUM 0x06
+
+#define SLIDER_MASK GENMASK_ULL(2, 0)
+#define SLIDER_ENABLE_BIT 7
+
+static u8 slider_values[] = {
+ [SOC_POWER_SLIDER_PERFORMANCE] = SOC_SLIDER_VALUE_MINIMUM,
+ [SOC_POWER_SLIDER_BALANCE] = SOC_SLIDER_VALUE_BALANCE,
+ [SOC_POWER_SLIDER_POWERSAVE] = SOC_SLIDER_VALUE_MAXIMUM,
+};
+
+/* Convert from platform power profile option to SoC slider value */
+static int convert_profile_to_power_slider(enum platform_profile_option profile)
+{
+ switch (profile) {
+ case PLATFORM_PROFILE_LOW_POWER:
+ return slider_values[SOC_POWER_SLIDER_POWERSAVE];
+ case PLATFORM_PROFILE_BALANCED:
+ return slider_values[SOC_POWER_SLIDER_BALANCE];
+ case PLATFORM_PROFILE_PERFORMANCE:
+ return slider_values[SOC_POWER_SLIDER_PERFORMANCE];
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+/* Convert to platform power profile option from SoC slider values */
+static int convert_power_slider_to_profile(u8 slider)
+{
+ if (slider == slider_values[SOC_POWER_SLIDER_PERFORMANCE])
+ return PLATFORM_PROFILE_PERFORMANCE;
+ if (slider == slider_values[SOC_POWER_SLIDER_BALANCE])
+ return PLATFORM_PROFILE_BALANCED;
+ if (slider == slider_values[SOC_POWER_SLIDER_POWERSAVE])
+ return PLATFORM_PROFILE_LOW_POWER;
+
+ return -EOPNOTSUPP;
+}
+
+static inline u64 read_soc_slider(struct proc_thermal_device *proc_priv)
+{
+ return readq(proc_priv->mmio_base + SOC_POWER_SLIDER_OFFSET);
+}
+
+static inline void write_soc_slider(struct proc_thermal_device *proc_priv, u64 val)
+{
+ writeq(val, proc_priv->mmio_base + SOC_POWER_SLIDER_OFFSET);
+}
+
+static void set_soc_power_profile(struct proc_thermal_device *proc_priv, int slider)
+{
+ u64 val;
+
+ val = read_soc_slider(proc_priv);
+ val &= ~SLIDER_MASK;
+ val |= FIELD_PREP(SLIDER_MASK, slider) | BIT(SLIDER_ENABLE_BIT);
+ write_soc_slider(proc_priv, val);
+}
+
+/* profile get/set callbacks are called with a profile lock, so no need for local locks */
+
+static int power_slider_platform_profile_set(struct device *dev,
+ enum platform_profile_option profile)
+{
+ struct proc_thermal_device *proc_priv;
+ int slider;
+
+ proc_priv = dev_get_drvdata(dev);
+ if (!proc_priv)
+ return -EOPNOTSUPP;
+
+ slider = convert_profile_to_power_slider(profile);
+ if (slider < 0)
+ return slider;
+
+ set_soc_power_profile(proc_priv, slider);
+
+ return 0;
+}
+
+static int power_slider_platform_profile_get(struct device *dev,
+ enum platform_profile_option *profile)
+{
+ struct proc_thermal_device *proc_priv;
+ int slider, ret;
+ u64 val;
+
+ proc_priv = dev_get_drvdata(dev);
+ if (!proc_priv)
+ return -EOPNOTSUPP;
+
+ val = read_soc_slider(proc_priv);
+ slider = FIELD_GET(SLIDER_MASK, val);
+
+ ret = convert_power_slider_to_profile(slider);
+ if (ret < 0)
+ return ret;
+
+ *profile = ret;
+
+ return 0;
+}
+
+static int power_slider_platform_profile_probe(void *drvdata, unsigned long *choices)
+{
+ set_bit(PLATFORM_PROFILE_LOW_POWER, choices);
+ set_bit(PLATFORM_PROFILE_BALANCED, choices);
+ set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);
+
+ return 0;
+}
+
+static const struct platform_profile_ops power_slider_platform_profile_ops = {
+ .probe = power_slider_platform_profile_probe,
+ .profile_get = power_slider_platform_profile_get,
+ .profile_set = power_slider_platform_profile_set,
+};
+
+int proc_thermal_soc_power_slider_add(struct pci_dev *pdev, struct proc_thermal_device *proc_priv)
+{
+ struct device *ppdev;
+
+ set_soc_power_profile(proc_priv, slider_values[SOC_POWER_SLIDER_BALANCE]);
+
+ ppdev = devm_platform_profile_register(&pdev->dev, "SoC Power Slider", proc_priv,
+ &power_slider_platform_profile_ops);
+
+ return PTR_ERR_OR_ZERO(ppdev);
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_soc_power_slider_add, "INT340X_THERMAL");
+
+static u64 soc_slider_save;
+
+void proc_thermal_soc_power_slider_suspend(struct proc_thermal_device *proc_priv)
+{
+ soc_slider_save = read_soc_slider(proc_priv);
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_soc_power_slider_suspend, "INT340X_THERMAL");
+
+void proc_thermal_soc_power_slider_resume(struct proc_thermal_device *proc_priv)
+{
+ write_soc_slider(proc_priv, soc_slider_save);
+}
+EXPORT_SYMBOL_NS_GPL(proc_thermal_soc_power_slider_resume, "INT340X_THERMAL");
+
+MODULE_IMPORT_NS("INT340X_THERMAL");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Processor Thermal Power Slider Interface");
projects / thirdparty / linux.git / commitdiff
