6 files changed, 299 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 1c32f8a3d6c4..32a57926cd04 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5879,6 +5879,14 @@ S:	Maintained
 F:      arch/x86/include/asm/intel_telemetry.h
 F:      drivers/platform/x86/intel_telemetry*
 
+INTEL PMC CORE DRIVER
+M:      Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
+M:      Vishwanath Somayaji <vishwanath.somayaji@intel.com>
+L:      platform-driver-x86@vger.kernel.org
+S:      Maintained
+F:      arch/x86/include/asm/pmc_core.h
+F:      drivers/platform/x86/intel_pmc_core*
+
 IOC3 ETHERNET DRIVER
 M:      Ralf Baechle <ralf@linux-mips.org>
 L:      linux-mips@linux-mips.org
diff --git a/arch/x86/include/asm/pmc_core.h b/arch/x86/include/asm/pmc_core.h
new file mode 100644
index 000000000000..d4855f11136d
--- /dev/null
+++ b/arch/x86/include/asm/pmc_core.h
@@ -0,0 +1,27 @@
+/*
+ * Intel Core SoC Power Management Controller Header File
+ *
+ * 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.
+ *
+ */
+
+#ifndef _ASM_PMC_CORE_H
+#define _ASM_PMC_CORE_H
+
+/* API to read SLP_S0_RESIDENCY counter */
+int intel_pmc_slp_s0_counter_read(u32 *data);
+
+#endif /* _ASM_PMC_CORE_H */
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index ed2004be13cf..c06bb85c2839 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -846,6 +846,18 @@ config INTEL_IMR
 
           If you are running on a Galileo/Quark say Y here.
 
+config INTEL_PMC_CORE
+        bool "Intel PMC Core driver"
+        depends on X86 && PCI
+        ---help---
+          The Intel Platform Controller Hub for Intel Core SoCs provides access
+          to Power Management Controller registers via a PCI interface. This
+          driver can utilize debugging capabilities and supported features as
+          exposed by the Power Management Controller.
+
+          Supported features:
+                - SLP_S0_RESIDENCY counter.
+
 config IBM_RTL
         tristate "Device driver to enable PRTL support"
         depends on X86 && PCI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 448443c3baba..9b11b4073e03 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -69,3 +69,4 @@ obj-$(CONFIG_INTEL_PUNIT_IPC)  += intel_punit_ipc.o
 obj-$(CONFIG_INTEL_TELEMETRY)   += intel_telemetry_core.o \
                                    intel_telemetry_pltdrv.o \
                                    intel_telemetry_debugfs.o
+obj-$(CONFIG_INTEL_PMC_CORE)    += intel_pmc_core.o
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);
diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
new file mode 100644
index 000000000000..a9dadaf787c1
--- /dev/null
+++ b/drivers/platform/x86/intel_pmc_core.h
@@ -0,0 +1,51 @@
+/*
+ * Intel Core SoC Power Management Controller Header File
+ *
+ * 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.
+ *
+ */
+
+#ifndef PMC_CORE_H
+#define PMC_CORE_H
+
+/* Sunrise Point Power Management Controller PCI Device ID */
+#define SPT_PMC_PCI_DEVICE_ID                   0x9d21
+#define SPT_PMC_BASE_ADDR_OFFSET                0x48
+#define SPT_PMC_SLP_S0_RES_COUNTER_OFFSET       0x13c
+#define SPT_PMC_MMIO_REG_LEN                    0x100
+#define SPT_PMC_SLP_S0_RES_COUNTER_STEP         0x64
+
+/**
+ * struct pmc_dev - pmc device structure
+ * @base_addr:          comtains pmc base address
+ * @regbase:            pointer to io-remapped memory location
+ * @dbgfs_dir:          path to debug fs interface
+ * @feature_available:  flag to indicate whether
+ *                      the feature is available
+ *                      on a particular platform or not.
+ *
+ * pmc_dev contains info about power management controller device.
+ */
+struct pmc_dev {
+        u32 base_addr;
+        void __iomem *regbase;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+        struct dentry *dbgfs_dir;
+#endif /* CONFIG_DEBUG_FS */
+        bool has_slp_s0_res;
+};
+
+#endif /* PMC_CORE_H */