linux/arch/x86/platform/atom/punit_atom_debug.c
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   1/*
   2 * Intel SOC Punit device state debug driver
   3 * Punit controls power management for North Complex devices (Graphics
   4 * blocks, Image Signal Processing, video processing, display, DSP etc.)
   5 *
   6 * Copyright (c) 2015, Intel Corporation.
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms and conditions of the GNU General Public License,
  10 * version 2, as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope it will be useful, but WITHOUT
  13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15 * more details.
  16 *
  17 */
  18
  19#include <linux/module.h>
  20#include <linux/init.h>
  21#include <linux/device.h>
  22#include <linux/debugfs.h>
  23#include <linux/seq_file.h>
  24#include <linux/io.h>
  25#include <asm/cpu_device_id.h>
  26#include <asm/intel-family.h>
  27#include <asm/iosf_mbi.h>
  28
  29/* Subsystem config/status Video processor */
  30#define VED_SS_PM0              0x32
  31/* Subsystem config/status ISP (Image Signal Processor) */
  32#define ISP_SS_PM0              0x39
  33/* Subsystem config/status Input/output controller */
  34#define MIO_SS_PM               0x3B
  35/* Shift bits for getting status for video, isp and i/o */
  36#define SSS_SHIFT               24
  37
  38/* Power gate status reg */
  39#define PWRGT_STATUS            0x61
  40/* Shift bits for getting status for graphics rendering */
  41#define RENDER_POS              0
  42/* Shift bits for getting status for media control */
  43#define MEDIA_POS               2
  44/* Shift bits for getting status for Valley View/Baytrail display */
  45#define VLV_DISPLAY_POS         6
  46
  47/* Subsystem config/status display for Cherry Trail SOC */
  48#define CHT_DSP_SSS             0x36
  49/* Shift bits for getting status for display */
  50#define CHT_DSP_SSS_POS         16
  51
  52struct punit_device {
  53        char *name;
  54        int reg;
  55        int sss_pos;
  56};
  57
  58static const struct punit_device punit_device_tng[] = {
  59        { "DISPLAY",    CHT_DSP_SSS,    SSS_SHIFT },
  60        { "VED",        VED_SS_PM0,     SSS_SHIFT },
  61        { "ISP",        ISP_SS_PM0,     SSS_SHIFT },
  62        { "MIO",        MIO_SS_PM,      SSS_SHIFT },
  63        { NULL }
  64};
  65
  66static const struct punit_device punit_device_byt[] = {
  67        { "GFX RENDER", PWRGT_STATUS,   RENDER_POS },
  68        { "GFX MEDIA",  PWRGT_STATUS,   MEDIA_POS },
  69        { "DISPLAY",    PWRGT_STATUS,   VLV_DISPLAY_POS },
  70        { "VED",        VED_SS_PM0,     SSS_SHIFT },
  71        { "ISP",        ISP_SS_PM0,     SSS_SHIFT },
  72        { "MIO",        MIO_SS_PM,      SSS_SHIFT },
  73        { NULL }
  74};
  75
  76static const struct punit_device punit_device_cht[] = {
  77        { "GFX RENDER", PWRGT_STATUS,   RENDER_POS },
  78        { "GFX MEDIA",  PWRGT_STATUS,   MEDIA_POS },
  79        { "DISPLAY",    CHT_DSP_SSS,    CHT_DSP_SSS_POS },
  80        { "VED",        VED_SS_PM0,     SSS_SHIFT },
  81        { "ISP",        ISP_SS_PM0,     SSS_SHIFT },
  82        { "MIO",        MIO_SS_PM,      SSS_SHIFT },
  83        { NULL }
  84};
  85
  86static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
  87
  88static int punit_dev_state_show(struct seq_file *seq_file, void *unused)
  89{
  90        u32 punit_pwr_status;
  91        struct punit_device *punit_devp = seq_file->private;
  92        int index;
  93        int status;
  94
  95        seq_puts(seq_file, "\n\nPUNIT NORTH COMPLEX DEVICES :\n");
  96        while (punit_devp->name) {
  97                status = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
  98                                       punit_devp->reg, &punit_pwr_status);
  99                if (status) {
 100                        seq_printf(seq_file, "%9s : Read Failed\n",
 101                                   punit_devp->name);
 102                } else  {
 103                        index = (punit_pwr_status >> punit_devp->sss_pos) & 3;
 104                        seq_printf(seq_file, "%9s : %s\n", punit_devp->name,
 105                                   dstates[index]);
 106                }
 107                punit_devp++;
 108        }
 109
 110        return 0;
 111}
 112DEFINE_SHOW_ATTRIBUTE(punit_dev_state);
 113
 114static struct dentry *punit_dbg_file;
 115
 116static int punit_dbgfs_register(struct punit_device *punit_device)
 117{
 118        struct dentry *dev_state;
 119
 120        punit_dbg_file = debugfs_create_dir("punit_atom", NULL);
 121        if (!punit_dbg_file)
 122                return -ENXIO;
 123
 124        dev_state = debugfs_create_file("dev_power_state", 0444,
 125                                        punit_dbg_file, punit_device,
 126                                        &punit_dev_state_fops);
 127        if (!dev_state) {
 128                pr_err("punit_dev_state register failed\n");
 129                debugfs_remove(punit_dbg_file);
 130                return -ENXIO;
 131        }
 132
 133        return 0;
 134}
 135
 136static void punit_dbgfs_unregister(void)
 137{
 138        debugfs_remove_recursive(punit_dbg_file);
 139}
 140
 141#define ICPU(model, drv_data) \
 142        { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT,\
 143          (kernel_ulong_t)&drv_data }
 144
 145static const struct x86_cpu_id intel_punit_cpu_ids[] = {
 146        ICPU(INTEL_FAM6_ATOM_SILVERMONT, punit_device_byt),
 147        ICPU(INTEL_FAM6_ATOM_SILVERMONT_MID,  punit_device_tng),
 148        ICPU(INTEL_FAM6_ATOM_AIRMONT,     punit_device_cht),
 149        {}
 150};
 151
 152MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
 153
 154static int __init punit_atom_debug_init(void)
 155{
 156        const struct x86_cpu_id *id;
 157        int ret;
 158
 159        id = x86_match_cpu(intel_punit_cpu_ids);
 160        if (!id)
 161                return -ENODEV;
 162
 163        ret = punit_dbgfs_register((struct punit_device *)id->driver_data);
 164        if (ret < 0)
 165                return ret;
 166
 167        return 0;
 168}
 169
 170static void __exit punit_atom_debug_exit(void)
 171{
 172        punit_dbgfs_unregister();
 173}
 174
 175module_init(punit_atom_debug_init);
 176module_exit(punit_atom_debug_exit);
 177
 178MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
 179MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 180MODULE_DESCRIPTION("Driver for Punit devices states debugging");
 181MODULE_LICENSE("GPL v2");
 182