drivers/thermal/intel_soc_dts_thermal.c

   1 /*
   2  * intel_soc_dts_thermal.c
   3  * Copyright (c) 2014, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/acpi.h>
  19 #include <linux/module.h>
  20 #include <linux/interrupt.h>
  21 #include <asm/cpu_device_id.h>
  22 #include <asm/intel-family.h>
  23 #include "intel_soc_dts_iosf.h"
  24
  25 #define CRITICAL_OFFSET_FROM_TJ_MAX     5000
  26
  27 static int crit_offset = CRITICAL_OFFSET_FROM_TJ_MAX;
  28 module_param(crit_offset, int, 0644);
  29 MODULE_PARM_DESC(crit_offset,
  30         "Critical Temperature offset from tj max in millidegree Celsius.");
  31
  32 /* IRQ 86 is a fixed APIC interrupt for BYT DTS Aux threshold notifications */
  33 #define BYT_SOC_DTS_APIC_IRQ    86
  34
  35 static int soc_dts_thres_gsi;
  36 static int soc_dts_thres_irq;
  37 static struct intel_soc_dts_sensors *soc_dts;
  38
  39 static irqreturn_t soc_irq_thread_fn(int irq, void *dev_data)
  40 {
  41         pr_debug("proc_thermal_interrupt\n");
  42         intel_soc_dts_iosf_interrupt_handler(soc_dts);
  43
  44         return IRQ_HANDLED;
  45 }
  46
  47 static const struct x86_cpu_id soc_thermal_ids[] = {
  48         { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT, 0,
  49                 BYT_SOC_DTS_APIC_IRQ},
  50         {}
  51 };
  52 MODULE_DEVICE_TABLE(x86cpu, soc_thermal_ids);
  53
  54 static int __init intel_soc_thermal_init(void)
  55 {
  56         int err = 0;
  57         const struct x86_cpu_id *match_cpu;
  58
  59         match_cpu = x86_match_cpu(soc_thermal_ids);
  60         if (!match_cpu)
  61                 return -ENODEV;
  62
  63         /* Create a zone with 2 trips with marked as read only */
  64         soc_dts = intel_soc_dts_iosf_init(INTEL_SOC_DTS_INTERRUPT_APIC, 2, 1);
  65         if (IS_ERR(soc_dts)) {
  66                 err = PTR_ERR(soc_dts);
  67                 return err;
  68         }
  69
  70         soc_dts_thres_gsi = (int)match_cpu->driver_data;
  71         if (soc_dts_thres_gsi) {
  72                 /*
  73                  * Note the flags here MUST match the firmware defaults, rather
  74                  * then the request_irq flags, otherwise we get an EBUSY error.
  75                  */
  76                 soc_dts_thres_irq = acpi_register_gsi(NULL, soc_dts_thres_gsi,
  77                                                       ACPI_LEVEL_SENSITIVE,
  78                                                       ACPI_ACTIVE_LOW);
  79                 if (soc_dts_thres_irq < 0) {
  80                         pr_warn("intel_soc_dts: Could not get IRQ for GSI %d, err %d\n",
  81                                 soc_dts_thres_gsi, soc_dts_thres_irq);
  82                         soc_dts_thres_irq = 0;
  83                 }
  84         }
  85
  86         if (soc_dts_thres_irq) {
  87                 err = request_threaded_irq(soc_dts_thres_irq, NULL,
  88                                            soc_irq_thread_fn,
  89                                            IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  90                                            "soc_dts", soc_dts);
  91                 if (err) {
  92                         /*
  93                          * Do not just error out because the user space thermal
  94                          * daemon such as DPTF may use polling instead of being
  95                          * interrupt driven.
  96                          */
  97                         pr_warn("request_threaded_irq ret %d\n", err);
  98                 }
  99         }
 100
 101         err = intel_soc_dts_iosf_add_read_only_critical_trip(soc_dts,
 102                                                              crit_offset);
 103         if (err)
 104                 goto error_trips;
 105
 106         return 0;
 107
 108 error_trips:
 109         if (soc_dts_thres_irq) {
 110                 free_irq(soc_dts_thres_irq, soc_dts);
 111                 acpi_unregister_gsi(soc_dts_thres_gsi);
 112         }
 113         intel_soc_dts_iosf_exit(soc_dts);
 114
 115         return err;
 116 }
 117
 118 static void __exit intel_soc_thermal_exit(void)
 119 {
 120         if (soc_dts_thres_irq) {
 121                 free_irq(soc_dts_thres_irq, soc_dts);
 122                 acpi_unregister_gsi(soc_dts_thres_gsi);
 123         }
 124         intel_soc_dts_iosf_exit(soc_dts);
 125 }
 126
 127 module_init(intel_soc_thermal_init)
 128 module_exit(intel_soc_thermal_exit)
 129
 130 MODULE_DESCRIPTION("Intel SoC DTS Thermal Driver");
 131 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 132 MODULE_LICENSE("GPL v2");