1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Thermal device driver for DA9062 and DA9061
  4 * Copyright (C) 2017  Dialog Semiconductor
  5 */
  6
  7/* When over-temperature is reached, an interrupt from the device will be
  8 * triggered. Following this event the interrupt will be disabled and
  9 * periodic transmission of uevents (HOT trip point) should define the
 10 * first level of temperature supervision. It is expected that any final
 11 * implementation of the thermal driver will include a .notify() function
 12 * to implement these uevents to userspace.
 13 *
 14 * These uevents are intended to indicate non-invasive temperature control
 15 * of the system, where the necessary measures for cooling are the
 16 * responsibility of the host software. Once the temperature falls again,
 17 * the IRQ is re-enabled so the start of a new over-temperature event can
 18 * be detected without constant software monitoring.
 19 */
 20
 21#include <linux/errno.h>
 22#include <linux/interrupt.h>
 23#include <linux/module.h>
 24#include <linux/of.h>
 25#include <linux/platform_device.h>
 26#include <linux/regmap.h>
 27#include <linux/thermal.h>
 28#include <linux/workqueue.h>
 29
 30#include <linux/mfd/da9062/core.h>
 31#include <linux/mfd/da9062/registers.h>
 32
 33/* Minimum, maximum and default polling millisecond periods are provided
 34 * here as an example. It is expected that any final implementation to also
 35 * include a modification of these settings to match the required
 36 * application.
 37 */
 38#define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
 39#define DA9062_MAX_POLLING_MS_PERIOD		10000
 40#define DA9062_MIN_POLLING_MS_PERIOD		1000
 41
 42#define DA9062_MILLI_CELSIUS(t)			((t) * 1000)
 43
 44static unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 45
 46struct da9062_thermal_config {
 47	const char *name;
 48};
 49
 50struct da9062_thermal {
 51	struct da9062 *hw;
 52	struct delayed_work work;
 53	struct thermal_zone_device *zone;
 54	struct mutex lock; /* protection for da9062_thermal temperature */
 55	int temperature;
 56	int irq;
 57	const struct da9062_thermal_config *config;
 58	struct device *dev;
 59};
 60
 61static void da9062_thermal_poll_on(struct work_struct *work)
 62{
 63	struct da9062_thermal *thermal = container_of(work,
 64						struct da9062_thermal,
 65						work.work);
 66	unsigned long delay;
 67	unsigned int val;
 68	int ret;
 69
 70	/* clear E_TEMP */
 71	ret = regmap_write(thermal->hw->regmap,
 72			   DA9062AA_EVENT_B,
 73			   DA9062AA_E_TEMP_MASK);
 74	if (ret < 0) {
 75		dev_err(thermal->dev,
 76			"Cannot clear the TJUNC temperature status\n");
 77		goto err_enable_irq;
 78	}
 79
 80	/* Now read E_TEMP again: it is acting like a status bit.
 81	 * If over-temperature, then this status will be true.
 82	 * If not over-temperature, this status will be false.
 83	 */
 84	ret = regmap_read(thermal->hw->regmap,
 85			  DA9062AA_EVENT_B,
 86			  &val);
 87	if (ret < 0) {
 88		dev_err(thermal->dev,
 89			"Cannot check the TJUNC temperature status\n");
 90		goto err_enable_irq;
 91	}
 92
 93	if (val & DA9062AA_E_TEMP_MASK) {
 94		mutex_lock(&thermal->lock);
 95		thermal->temperature = DA9062_MILLI_CELSIUS(125);
 96		mutex_unlock(&thermal->lock);
 97		thermal_zone_device_update(thermal->zone,
 98					   THERMAL_EVENT_UNSPECIFIED);
 99
100		/*
101		 * pp_tmp is between 1s and 10s, so we can round the jiffies
102		 */
103		delay = round_jiffies(msecs_to_jiffies(pp_tmp));
104		queue_delayed_work(system_freezable_wq, &thermal->work, delay);
105		return;
106	}
107
108	mutex_lock(&thermal->lock);
109	thermal->temperature = DA9062_MILLI_CELSIUS(0);
110	mutex_unlock(&thermal->lock);
111	thermal_zone_device_update(thermal->zone,
112				   THERMAL_EVENT_UNSPECIFIED);
113
114err_enable_irq:
115	enable_irq(thermal->irq);
116}
117
118static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
119{
120	struct da9062_thermal *thermal = data;
121
122	disable_irq_nosync(thermal->irq);
123	queue_delayed_work(system_freezable_wq, &thermal->work, 0);
124
125	return IRQ_HANDLED;
126}
127
128static int da9062_thermal_get_temp(struct thermal_zone_device *z,
129				   int *temp)
130{
131	struct da9062_thermal *thermal = thermal_zone_device_priv(z);
132
133	mutex_lock(&thermal->lock);
134	*temp = thermal->temperature;
135	mutex_unlock(&thermal->lock);
136
137	return 0;
138}
139
140static struct thermal_zone_device_ops da9062_thermal_ops = {
141	.get_temp	= da9062_thermal_get_temp,
142};
143
144static struct thermal_trip trips[] = {
145	{ .temperature = DA9062_MILLI_CELSIUS(125), .type = THERMAL_TRIP_HOT },
146};
147
148static const struct da9062_thermal_config da9062_config = {
149	.name = "da9062-thermal",
150};
151
152static const struct of_device_id da9062_compatible_reg_id_table[] = {
153	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
154	{ },
155};
156
157MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
158
159static int da9062_thermal_probe(struct platform_device *pdev)
160{
161	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
162	struct da9062_thermal *thermal;
163	const struct of_device_id *match;
164	int ret = 0;
165
166	match = of_match_node(da9062_compatible_reg_id_table,
167			      pdev->dev.of_node);
168	if (!match)
169		return -ENXIO;
170
171	if (pdev->dev.of_node) {
172		if (!of_property_read_u32(pdev->dev.of_node,
173					  "polling-delay-passive",
174					  &pp_tmp)) {
175			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
176			    pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
177				dev_warn(&pdev->dev,
178					 "Out-of-range polling period %d ms\n",
179					 pp_tmp);
180				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
181			}
182		}
183	}
184
185	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
186			       GFP_KERNEL);
187	if (!thermal) {
188		ret = -ENOMEM;
189		goto err;
190	}
191
192	thermal->config = match->data;
193	thermal->hw = chip;
194	thermal->dev = &pdev->dev;
195
196	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
197	mutex_init(&thermal->lock);
198
199	thermal->zone = thermal_zone_device_register_with_trips(thermal->config->name,
200								trips, ARRAY_SIZE(trips), 0, thermal,
201								&da9062_thermal_ops, NULL, pp_tmp,
202								0);
203	if (IS_ERR(thermal->zone)) {
204		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
205		ret = PTR_ERR(thermal->zone);
206		goto err;
207	}
208	ret = thermal_zone_device_enable(thermal->zone);
209	if (ret) {
210		dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
211		goto err_zone;
212	}
213
214	dev_dbg(&pdev->dev,
215		"TJUNC temperature polling period set at %d ms\n", pp_tmp);
216
217	ret = platform_get_irq_byname(pdev, "THERMAL");
218	if (ret < 0)
219		goto err_zone;
220
221	thermal->irq = ret;
222
223	ret = request_threaded_irq(thermal->irq, NULL,
224				   da9062_thermal_irq_handler,
225				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
226				   "THERMAL", thermal);
227	if (ret) {
228		dev_err(&pdev->dev,
229			"Failed to request thermal device IRQ.\n");
230		goto err_zone;
231	}
232
233	platform_set_drvdata(pdev, thermal);
234	return 0;
235
236err_zone:
237	thermal_zone_device_unregister(thermal->zone);
238err:
239	return ret;
240}
241
242static void da9062_thermal_remove(struct platform_device *pdev)
243{
244	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
245
246	free_irq(thermal->irq, thermal);
247	cancel_delayed_work_sync(&thermal->work);
248	thermal_zone_device_unregister(thermal->zone);
249}
250
251static struct platform_driver da9062_thermal_driver = {
252	.probe	= da9062_thermal_probe,
253	.remove_new = da9062_thermal_remove,
254	.driver	= {
255		.name	= "da9062-thermal",
256		.of_match_table = da9062_compatible_reg_id_table,
257	},
258};
259
260module_platform_driver(da9062_thermal_driver);
261
262MODULE_AUTHOR("Steve Twiss");
263MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
264MODULE_LICENSE("GPL");
265MODULE_ALIAS("platform:da9062-thermal");