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/module.h>
  19 #include <linux/interrupt.h>
  20 #include <asm/cpu_device_id.h>
  21 #include <asm/intel-family.h>
  22 #include "intel_soc_dts_iosf.h"
  23
  24 #define CRITICAL_OFFSET_FROM_TJ_MAX     5000
  25
  26 static int crit_offset = CRITICAL_OFFSET_FROM_TJ_MAX;
  27 module_param(crit_offset, int, 0644);
  28 MODULE_PARM_DESC(crit_offset,
  29         "Critical Temperature offset from tj max in millidegree Celsius.");
  30
  31 /* IRQ 86 is a fixed APIC interrupt for BYT DTS Aux threshold notifications */
  32 #define BYT_SOC_DTS_APIC_IRQ    86
  33
  34 static int soc_dts_thres_irq;
  35 static struct intel_soc_dts_sensors *soc_dts;
  36
  37 static irqreturn_t soc_irq_thread_fn(int irq, void *dev_data)
  38 {
  39         pr_debug("proc_thermal_interrupt\n");
  40         intel_soc_dts_iosf_interrupt_handler(soc_dts);
  41
  42         return IRQ_HANDLED;
  43 }
  44
  45 static const struct x86_cpu_id soc_thermal_ids[] = {
  46         { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT, 0,
  47                 BYT_SOC_DTS_APIC_IRQ},
  48         {}
  49 };
  50 MODULE_DEVICE_TABLE(x86cpu, soc_thermal_ids);
  51
  52 static int __init intel_soc_thermal_init(void)
  53 {
  54         int err = 0;
  55         const struct x86_cpu_id *match_cpu;
  56
  57         match_cpu = x86_match_cpu(soc_thermal_ids);
  58         if (!match_cpu)
  59                 return -ENODEV;
  60
  61         /* Create a zone with 2 trips with marked as read only */
  62         soc_dts = intel_soc_dts_iosf_init(INTEL_SOC_DTS_INTERRUPT_APIC, 2, 1);
  63         if (IS_ERR(soc_dts)) {
  64                 err = PTR_ERR(soc_dts);
  65                 return err;
  66         }
  67
  68         soc_dts_thres_irq = (int)match_cpu->driver_data;
  69
  70         if (soc_dts_thres_irq) {
  71                 err = request_threaded_irq(soc_dts_thres_irq, NULL,
  72                                            soc_irq_thread_fn,
  73                                            IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  74                                            "soc_dts", soc_dts);
  75                 if (err) {
  76                         /*
  77                          * Do not just error out because the user space thermal
  78                          * daemon such as DPTF may use polling instead of being
  79                          * interrupt driven.
  80                          */
  81                         pr_warn("request_threaded_irq ret %d\n", err);
  82                 }
  83         }
  84
  85         err = intel_soc_dts_iosf_add_read_only_critical_trip(soc_dts,
  86                                                              crit_offset);
  87         if (err)
  88                 goto error_trips;
  89
  90         return 0;
  91
  92 error_trips:
  93         if (soc_dts_thres_irq)
  94                 free_irq(soc_dts_thres_irq, soc_dts);
  95         intel_soc_dts_iosf_exit(soc_dts);
  96
  97         return err;
  98 }
  99
 100 static void __exit intel_soc_thermal_exit(void)
 101 {
 102         if (soc_dts_thres_irq)
 103                 free_irq(soc_dts_thres_irq, soc_dts);
 104         intel_soc_dts_iosf_exit(soc_dts);
 105 }
 106
 107 module_init(intel_soc_thermal_init)
 108 module_exit(intel_soc_thermal_exit)
 109
 110 MODULE_DESCRIPTION("Intel SoC DTS Thermal Driver");
 111 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 112 MODULE_LICENSE("GPL v2");