linux/drivers/thermal/intel/intel_soc_dts_thermal.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * intel_soc_dts_thermal.c
   4 * Copyright (c) 2014, Intel Corporation.
   5 */
   6
   7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9#include <linux/acpi.h>
  10#include <linux/module.h>
  11#include <linux/interrupt.h>
  12#include <asm/cpu_device_id.h>
  13#include <asm/intel-family.h>
  14#include "intel_soc_dts_iosf.h"
  15
  16#define CRITICAL_OFFSET_FROM_TJ_MAX     5000
  17
  18static int crit_offset = CRITICAL_OFFSET_FROM_TJ_MAX;
  19module_param(crit_offset, int, 0644);
  20MODULE_PARM_DESC(crit_offset,
  21        "Critical Temperature offset from tj max in millidegree Celsius.");
  22
  23/* IRQ 86 is a fixed APIC interrupt for BYT DTS Aux threshold notifications */
  24#define BYT_SOC_DTS_APIC_IRQ    86
  25
  26static int soc_dts_thres_gsi;
  27static int soc_dts_thres_irq;
  28static struct intel_soc_dts_sensors *soc_dts;
  29
  30static irqreturn_t soc_irq_thread_fn(int irq, void *dev_data)
  31{
  32        pr_debug("proc_thermal_interrupt\n");
  33        intel_soc_dts_iosf_interrupt_handler(soc_dts);
  34
  35        return IRQ_HANDLED;
  36}
  37
  38static const struct x86_cpu_id soc_thermal_ids[] = {
  39        { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT, 0,
  40                BYT_SOC_DTS_APIC_IRQ},
  41        {}
  42};
  43MODULE_DEVICE_TABLE(x86cpu, soc_thermal_ids);
  44
  45static int __init intel_soc_thermal_init(void)
  46{
  47        int err = 0;
  48        const struct x86_cpu_id *match_cpu;
  49
  50        match_cpu = x86_match_cpu(soc_thermal_ids);
  51        if (!match_cpu)
  52                return -ENODEV;
  53
  54        /* Create a zone with 2 trips with marked as read only */
  55        soc_dts = intel_soc_dts_iosf_init(INTEL_SOC_DTS_INTERRUPT_APIC, 2, 1);
  56        if (IS_ERR(soc_dts)) {
  57                err = PTR_ERR(soc_dts);
  58                return err;
  59        }
  60
  61        soc_dts_thres_gsi = (int)match_cpu->driver_data;
  62        if (soc_dts_thres_gsi) {
  63                /*
  64                 * Note the flags here MUST match the firmware defaults, rather
  65                 * then the request_irq flags, otherwise we get an EBUSY error.
  66                 */
  67                soc_dts_thres_irq = acpi_register_gsi(NULL, soc_dts_thres_gsi,
  68                                                      ACPI_LEVEL_SENSITIVE,
  69                                                      ACPI_ACTIVE_LOW);
  70                if (soc_dts_thres_irq < 0) {
  71                        pr_warn("intel_soc_dts: Could not get IRQ for GSI %d, err %d\n",
  72                                soc_dts_thres_gsi, soc_dts_thres_irq);
  73                        soc_dts_thres_irq = 0;
  74                }
  75        }
  76
  77        if (soc_dts_thres_irq) {
  78                err = request_threaded_irq(soc_dts_thres_irq, NULL,
  79                                           soc_irq_thread_fn,
  80                                           IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  81                                           "soc_dts", soc_dts);
  82                if (err) {
  83                        /*
  84                         * Do not just error out because the user space thermal
  85                         * daemon such as DPTF may use polling instead of being
  86                         * interrupt driven.
  87                         */
  88                        pr_warn("request_threaded_irq ret %d\n", err);
  89                }
  90        }
  91
  92        err = intel_soc_dts_iosf_add_read_only_critical_trip(soc_dts,
  93                                                             crit_offset);
  94        if (err)
  95                goto error_trips;
  96
  97        return 0;
  98
  99error_trips:
 100        if (soc_dts_thres_irq) {
 101                free_irq(soc_dts_thres_irq, soc_dts);
 102                acpi_unregister_gsi(soc_dts_thres_gsi);
 103        }
 104        intel_soc_dts_iosf_exit(soc_dts);
 105
 106        return err;
 107}
 108
 109static void __exit intel_soc_thermal_exit(void)
 110{
 111        if (soc_dts_thres_irq) {
 112                free_irq(soc_dts_thres_irq, soc_dts);
 113                acpi_unregister_gsi(soc_dts_thres_gsi);
 114        }
 115        intel_soc_dts_iosf_exit(soc_dts);
 116}
 117
 118module_init(intel_soc_thermal_init)
 119module_exit(intel_soc_thermal_exit)
 120
 121MODULE_DESCRIPTION("Intel SoC DTS Thermal Driver");
 122MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 123MODULE_LICENSE("GPL v2");
 124