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_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT, BYT_SOC_DTS_APIC_IRQ),
40	{}
41};
42MODULE_DEVICE_TABLE(x86cpu, soc_thermal_ids);
43
44static int __init intel_soc_thermal_init(void)
45{
46	int err = 0;
47	const struct x86_cpu_id *match_cpu;
48
49	match_cpu = x86_match_cpu(soc_thermal_ids);
50	if (!match_cpu)
51		return -ENODEV;
52
53	/* Create a zone with 2 trips with marked as read only */
54	soc_dts = intel_soc_dts_iosf_init(INTEL_SOC_DTS_INTERRUPT_APIC, 2, 1);
55	if (IS_ERR(soc_dts)) {
56		err = PTR_ERR(soc_dts);
57		return err;
58	}
59
60	soc_dts_thres_gsi = (int)match_cpu->driver_data;
61	if (soc_dts_thres_gsi) {
62		/*
63		 * Note the flags here MUST match the firmware defaults, rather
64		 * then the request_irq flags, otherwise we get an EBUSY error.
65		 */
66		soc_dts_thres_irq = acpi_register_gsi(NULL, soc_dts_thres_gsi,
67						      ACPI_LEVEL_SENSITIVE,
68						      ACPI_ACTIVE_LOW);
69		if (soc_dts_thres_irq < 0) {
70			pr_warn("intel_soc_dts: Could not get IRQ for GSI %d, err %d\n",
71				soc_dts_thres_gsi, soc_dts_thres_irq);
72			soc_dts_thres_irq = 0;
73		}
74	}
75
76	if (soc_dts_thres_irq) {
77		err = request_threaded_irq(soc_dts_thres_irq, NULL,
78					   soc_irq_thread_fn,
79					   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
80					   "soc_dts", soc_dts);
81		if (err) {
82			/*
83			 * Do not just error out because the user space thermal
84			 * daemon such as DPTF may use polling instead of being
85			 * interrupt driven.
86			 */
87			pr_warn("request_threaded_irq ret %d\n", err);
88		}
89	}
90
91	err = intel_soc_dts_iosf_add_read_only_critical_trip(soc_dts,
92							     crit_offset);
93	if (err)
94		goto error_trips;
95
96	return 0;
97
98error_trips:
99	if (soc_dts_thres_irq) {
100		free_irq(soc_dts_thres_irq, soc_dts);
101		acpi_unregister_gsi(soc_dts_thres_gsi);
102	}
103	intel_soc_dts_iosf_exit(soc_dts);
104
105	return err;
106}
107
108static void __exit intel_soc_thermal_exit(void)
109{
110	if (soc_dts_thres_irq) {
111		free_irq(soc_dts_thres_irq, soc_dts);
112		acpi_unregister_gsi(soc_dts_thres_gsi);
113	}
114	intel_soc_dts_iosf_exit(soc_dts);
115}
116
117module_init(intel_soc_thermal_init)
118module_exit(intel_soc_thermal_exit)
119
120MODULE_DESCRIPTION("Intel SoC DTS Thermal Driver");
121MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
122MODULE_LICENSE("GPL v2");
123