1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
new file mode 100644
index 000000000000..2776bec89c88
--- /dev/null
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -0,0 +1,200 @@
+/*
+ * Intel Core SoC Power Management Controller Driver
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Authors: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
+ *          Vishwanath Somayaji <vishwanath.somayaji@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/seq_file.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/pmc_core.h>
+
+#include "intel_pmc_core.h"
+
+static struct pmc_dev pmc;
+
+static const struct pci_device_id pmc_pci_ids[] = {
+	{ PCI_VDEVICE(INTEL, SPT_PMC_PCI_DEVICE_ID), (kernel_ulong_t)NULL },
+	{ 0, },
+};
+
+static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
+{
+	return readl(pmcdev->regbase + reg_offset);
+}
+
+static inline u32 pmc_core_adjust_slp_s0_step(u32 value)
+{
+	return value * SPT_PMC_SLP_S0_RES_COUNTER_STEP;
+}
+
+/**
+ * intel_pmc_slp_s0_counter_read() - Read SLP_S0 residency.
+ * @data: Out param that contains current SLP_S0 count.
+ *
+ * This API currently supports Intel Skylake SoC and Sunrise
+ * Point Platform Controller Hub. Future platform support
+ * should be added for platforms that support low power modes
+ * beyond Package C10 state.
+ *
+ * SLP_S0_RESIDENCY counter counts in 100 us granularity per
+ * step hence function populates the multiplied value in out
+ * parameter @data.
+ *
+ * Return: an error code or 0 on success.
+ */
+int intel_pmc_slp_s0_counter_read(u32 *data)
+{
+	struct pmc_dev *pmcdev = &pmc;
+	u32 value;
+
+	if (!pmcdev->has_slp_s0_res)
+		return -EACCES;
+
+	value = pmc_core_reg_read(pmcdev, SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
+	*data = pmc_core_adjust_slp_s0_step(value);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_pmc_slp_s0_counter_read);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int pmc_core_dev_state_show(struct seq_file *s, void *unused)
+{
+	struct pmc_dev *pmcdev = s->private;
+	u32 counter_val;
+
+	counter_val = pmc_core_reg_read(pmcdev,
+					SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
+	seq_printf(s, "%u\n", pmc_core_adjust_slp_s0_step(counter_val));
+
+	return 0;
+}
+
+static int pmc_core_dev_state_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pmc_core_dev_state_show, inode->i_private);
+}
+
+static const struct file_operations pmc_core_dev_state_ops = {
+	.open           = pmc_core_dev_state_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
+{
+	debugfs_remove_recursive(pmcdev->dbgfs_dir);
+}
+
+static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
+{
+	struct dentry *dir, *file;
+
+	dir = debugfs_create_dir("pmc_core", NULL);
+	if (!dir)
+		return -ENOMEM;
+
+	pmcdev->dbgfs_dir = dir;
+	file = debugfs_create_file("slp_s0_residency_usec", S_IFREG | S_IRUGO,
+				   dir, pmcdev, &pmc_core_dev_state_ops);
+
+	if (!file) {
+		pmc_core_dbgfs_unregister(pmcdev);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+#else
+static inline int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
+{
+	return 0;
+}
+
+static inline void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static const struct x86_cpu_id intel_pmc_core_ids[] = {
+	{ X86_VENDOR_INTEL, 6, 0x4e, X86_FEATURE_MWAIT,
+		(kernel_ulong_t)NULL}, /* Skylake CPUID Signature */
+	{ X86_VENDOR_INTEL, 6, 0x5e, X86_FEATURE_MWAIT,
+		(kernel_ulong_t)NULL}, /* Skylake CPUID Signature */
+	{}
+};
+
+static int pmc_core_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	struct device *ptr_dev = &dev->dev;
+	struct pmc_dev *pmcdev = &pmc;
+	const struct x86_cpu_id *cpu_id;
+	int err;
+
+	cpu_id = x86_match_cpu(intel_pmc_core_ids);
+	if (!cpu_id) {
+		dev_dbg(&dev->dev, "PMC Core: cpuid mismatch.\n");
+		return -EINVAL;
+	}
+
+	err = pcim_enable_device(dev);
+	if (err < 0) {
+		dev_dbg(&dev->dev, "PMC Core: failed to enable Power Management Controller.\n");
+		return err;
+	}
+
+	err = pci_read_config_dword(dev,
+				    SPT_PMC_BASE_ADDR_OFFSET,
+				    &pmcdev->base_addr);
+	if (err < 0) {
+		dev_dbg(&dev->dev, "PMC Core: failed to read PCI config space.\n");
+		return err;
+	}
+	dev_dbg(&dev->dev, "PMC Core: PWRMBASE is %#x\n", pmcdev->base_addr);
+
+	pmcdev->regbase = devm_ioremap_nocache(ptr_dev,
+					      pmcdev->base_addr,
+					      SPT_PMC_MMIO_REG_LEN);
+	if (!pmcdev->regbase) {
+		dev_dbg(&dev->dev, "PMC Core: ioremap failed.\n");
+		return -ENOMEM;
+	}
+
+	err = pmc_core_dbgfs_register(pmcdev);
+	if (err < 0) {
+		dev_err(&dev->dev, "PMC Core: debugfs register failed.\n");
+		return err;
+	}
+
+	pmc.has_slp_s0_res = true;
+	return 0;
+}
+
+static struct pci_driver intel_pmc_core_driver = {
+	.name = "intel_pmc_core",
+	.id_table = pmc_pci_ids,
+	.probe = pmc_core_probe,
+};
+
+builtin_pci_driver(intel_pmc_core_driver);