drivers/platform/x86/intel_pmc_core.c

   1 /*
   2  * Intel Core SoC Power Management Controller Driver
   3  *
   4  * Copyright (c) 2016, Intel Corporation.
   5  * All Rights Reserved.
   6  *
   7  * Authors: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
   8  *          Vishwanath Somayaji <vishwanath.somayaji@intel.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms and conditions of the GNU General Public License,
  12  * version 2, as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17  * more details.
  18  *
  19  */
  20
  21 #include <linux/debugfs.h>
  22 #include <linux/device.h>
  23 #include <linux/init.h>
  24 #include <linux/io.h>
  25 #include <linux/pci.h>
  26
  27 #include <asm/cpu_device_id.h>
  28 #include <asm/intel-family.h>
  29 #include <asm/pmc_core.h>
  30
  31 #include "intel_pmc_core.h"
  32
  33 static struct pmc_dev pmc;
  34
  35 static const struct pci_device_id pmc_pci_ids[] = {
  36         { PCI_VDEVICE(INTEL, SPT_PMC_PCI_DEVICE_ID), (kernel_ulong_t)NULL },
  37         { 0, },
  38 };
  39
  40 static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
  41 {
  42         return readl(pmcdev->regbase + reg_offset);
  43 }
  44
  45 static inline u32 pmc_core_adjust_slp_s0_step(u32 value)
  46 {
  47         return value * SPT_PMC_SLP_S0_RES_COUNTER_STEP;
  48 }
  49
  50 /**
  51  * intel_pmc_slp_s0_counter_read() - Read SLP_S0 residency.
  52  * @data: Out param that contains current SLP_S0 count.
  53  *
  54  * This API currently supports Intel Skylake SoC and Sunrise
  55  * Point Platform Controller Hub. Future platform support
  56  * should be added for platforms that support low power modes
  57  * beyond Package C10 state.
  58  *
  59  * SLP_S0_RESIDENCY counter counts in 100 us granularity per
  60  * step hence function populates the multiplied value in out
  61  * parameter @data.
  62  *
  63  * Return: an error code or 0 on success.
  64  */
  65 int intel_pmc_slp_s0_counter_read(u32 *data)
  66 {
  67         struct pmc_dev *pmcdev = &pmc;
  68         u32 value;
  69
  70         if (!pmcdev->has_slp_s0_res)
  71                 return -EACCES;
  72
  73         value = pmc_core_reg_read(pmcdev, SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
  74         *data = pmc_core_adjust_slp_s0_step(value);
  75
  76         return 0;
  77 }
  78 EXPORT_SYMBOL_GPL(intel_pmc_slp_s0_counter_read);
  79
  80 static int pmc_core_dev_state_get(void *data, u64 *val)
  81 {
  82         struct pmc_dev *pmcdev = data;
  83         u32 value;
  84
  85         value = pmc_core_reg_read(pmcdev, SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
  86         *val = pmc_core_adjust_slp_s0_step(value);
  87
  88         return 0;
  89 }
  90
  91 DEFINE_DEBUGFS_ATTRIBUTE(pmc_core_dev_state, pmc_core_dev_state_get, NULL, "%llu\n");
  92
  93 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
  94 {
  95         debugfs_remove_recursive(pmcdev->dbgfs_dir);
  96 }
  97
  98 static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
  99 {
 100         struct dentry *dir, *file;
 101
 102         dir = debugfs_create_dir("pmc_core", NULL);
 103         if (!dir)
 104                 return -ENOMEM;
 105
 106         pmcdev->dbgfs_dir = dir;
 107         file = debugfs_create_file("slp_s0_residency_usec", S_IFREG | S_IRUGO,
 108                                    dir, pmcdev, &pmc_core_dev_state);
 109
 110         if (!file) {
 111                 pmc_core_dbgfs_unregister(pmcdev);
 112                 return -ENODEV;
 113         }
 114
 115         return 0;
 116 }
 117
 118 static const struct x86_cpu_id intel_pmc_core_ids[] = {
 119         { X86_VENDOR_INTEL, 6, INTEL_FAM6_SKYLAKE_MOBILE, X86_FEATURE_MWAIT,
 120                 (kernel_ulong_t)NULL},
 121         { X86_VENDOR_INTEL, 6, INTEL_FAM6_SKYLAKE_DESKTOP, X86_FEATURE_MWAIT,
 122                 (kernel_ulong_t)NULL},
 123         {}
 124 };
 125
 126 static int pmc_core_probe(struct pci_dev *dev, const struct pci_device_id *id)
 127 {
 128         struct device *ptr_dev = &dev->dev;
 129         struct pmc_dev *pmcdev = &pmc;
 130         const struct x86_cpu_id *cpu_id;
 131         int err;
 132
 133         cpu_id = x86_match_cpu(intel_pmc_core_ids);
 134         if (!cpu_id) {
 135                 dev_dbg(&dev->dev, "PMC Core: cpuid mismatch.\n");
 136                 return -EINVAL;
 137         }
 138
 139         err = pcim_enable_device(dev);
 140         if (err < 0) {
 141                 dev_dbg(&dev->dev, "PMC Core: failed to enable Power Management Controller.\n");
 142                 return err;
 143         }
 144
 145         err = pci_read_config_dword(dev,
 146                                     SPT_PMC_BASE_ADDR_OFFSET,
 147                                     &pmcdev->base_addr);
 148         if (err < 0) {
 149                 dev_dbg(&dev->dev, "PMC Core: failed to read PCI config space.\n");
 150                 return err;
 151         }
 152         dev_dbg(&dev->dev, "PMC Core: PWRMBASE is %#x\n", pmcdev->base_addr);
 153
 154         pmcdev->regbase = devm_ioremap_nocache(ptr_dev,
 155                                               pmcdev->base_addr,
 156                                               SPT_PMC_MMIO_REG_LEN);
 157         if (!pmcdev->regbase) {
 158                 dev_dbg(&dev->dev, "PMC Core: ioremap failed.\n");
 159                 return -ENOMEM;
 160         }
 161
 162         err = pmc_core_dbgfs_register(pmcdev);
 163         if (err < 0)
 164                 dev_warn(&dev->dev, "PMC Core: debugfs register failed.\n");
 165
 166         pmc.has_slp_s0_res = true;
 167         return 0;
 168 }
 169
 170 static struct pci_driver intel_pmc_core_driver = {
 171         .name = "intel_pmc_core",
 172         .id_table = pmc_pci_ids,
 173         .probe = pmc_core_probe,
 174 };
 175
 176 builtin_pci_driver(intel_pmc_core_driver);