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");