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
 44struct da9062_thermal_config {
 45	const char *name;
 46};
 47
 48struct da9062_thermal {
 49	struct da9062 *hw;
 50	struct delayed_work work;
 51	struct thermal_zone_device *zone;
 52	struct mutex lock; /* protection for da9062_thermal temperature */
 53	int temperature;
 54	int irq;
 55	const struct da9062_thermal_config *config;
 56	struct device *dev;
 57};
 58
 59static void da9062_thermal_poll_on(struct work_struct *work)
 60{
 61	struct da9062_thermal *thermal = container_of(work,
 62						struct da9062_thermal,
 63						work.work);
 64	unsigned long delay;
 65	unsigned int val;
 66	int ret;
 67
 68	/* clear E_TEMP */
 69	ret = regmap_write(thermal->hw->regmap,
 70			   DA9062AA_EVENT_B,
 71			   DA9062AA_E_TEMP_MASK);
 72	if (ret < 0) {
 73		dev_err(thermal->dev,
 74			"Cannot clear the TJUNC temperature status\n");
 75		goto err_enable_irq;
 76	}
 77
 78	/* Now read E_TEMP again: it is acting like a status bit.
 79	 * If over-temperature, then this status will be true.
 80	 * If not over-temperature, this status will be false.
 81	 */
 82	ret = regmap_read(thermal->hw->regmap,
 83			  DA9062AA_EVENT_B,
 84			  &val);
 85	if (ret < 0) {
 86		dev_err(thermal->dev,
 87			"Cannot check the TJUNC temperature status\n");
 88		goto err_enable_irq;
 89	}
 90
 91	if (val & DA9062AA_E_TEMP_MASK) {
 92		mutex_lock(&thermal->lock);
 93		thermal->temperature = DA9062_MILLI_CELSIUS(125);
 94		mutex_unlock(&thermal->lock);
 95		thermal_zone_device_update(thermal->zone,
 96					   THERMAL_EVENT_UNSPECIFIED);
 97
 98		delay = msecs_to_jiffies(thermal->zone->passive_delay);
 99		queue_delayed_work(system_freezable_wq, &thermal->work, delay);
100		return;
101	}
102
103	mutex_lock(&thermal->lock);
104	thermal->temperature = DA9062_MILLI_CELSIUS(0);
105	mutex_unlock(&thermal->lock);
106	thermal_zone_device_update(thermal->zone,
107				   THERMAL_EVENT_UNSPECIFIED);
108
109err_enable_irq:
110	enable_irq(thermal->irq);
111}
112
113static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
114{
115	struct da9062_thermal *thermal = data;
116
117	disable_irq_nosync(thermal->irq);
118	queue_delayed_work(system_freezable_wq, &thermal->work, 0);
119
120	return IRQ_HANDLED;
121}
122
123static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
124					int trip,
125					enum thermal_trip_type *type)
126{
127	struct da9062_thermal *thermal = z->devdata;
128
129	switch (trip) {
130	case 0:
131		*type = THERMAL_TRIP_HOT;
132		break;
133	default:
134		dev_err(thermal->dev,
135			"Driver does not support more than 1 trip-wire\n");
136		return -EINVAL;
137	}
138
139	return 0;
140}
141
142static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
143					int trip,
144					int *temp)
145{
146	struct da9062_thermal *thermal = z->devdata;
147
148	switch (trip) {
149	case 0:
150		*temp = DA9062_MILLI_CELSIUS(125);
151		break;
152	default:
153		dev_err(thermal->dev,
154			"Driver does not support more than 1 trip-wire\n");
155		return -EINVAL;
156	}
157
158	return 0;
159}
160
161static int da9062_thermal_get_temp(struct thermal_zone_device *z,
162				   int *temp)
163{
164	struct da9062_thermal *thermal = z->devdata;
165
166	mutex_lock(&thermal->lock);
167	*temp = thermal->temperature;
168	mutex_unlock(&thermal->lock);
169
170	return 0;
171}
172
173static struct thermal_zone_device_ops da9062_thermal_ops = {
174	.get_temp	= da9062_thermal_get_temp,
175	.get_trip_type	= da9062_thermal_get_trip_type,
176	.get_trip_temp	= da9062_thermal_get_trip_temp,
177};
178
179static const struct da9062_thermal_config da9062_config = {
180	.name = "da9062-thermal",
181};
182
183static const struct of_device_id da9062_compatible_reg_id_table[] = {
184	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
185	{ },
186};
187
188MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
189
190static int da9062_thermal_probe(struct platform_device *pdev)
191{
192	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
193	struct da9062_thermal *thermal;
194	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
195	const struct of_device_id *match;
196	int ret = 0;
197
198	match = of_match_node(da9062_compatible_reg_id_table,
199			      pdev->dev.of_node);
200	if (!match)
201		return -ENXIO;
202
203	if (pdev->dev.of_node) {
204		if (!of_property_read_u32(pdev->dev.of_node,
205					  "polling-delay-passive",
206					  &pp_tmp)) {
207			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
208			    pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
209				dev_warn(&pdev->dev,
210					 "Out-of-range polling period %d ms\n",
211					 pp_tmp);
212				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
213			}
214		}
215	}
216
217	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
218			       GFP_KERNEL);
219	if (!thermal) {
220		ret = -ENOMEM;
221		goto err;
222	}
223
224	thermal->config = match->data;
225	thermal->hw = chip;
226	thermal->dev = &pdev->dev;
227
228	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
229	mutex_init(&thermal->lock);
230
231	thermal->zone = thermal_zone_device_register(thermal->config->name,
232					1, 0, thermal,
233					&da9062_thermal_ops, NULL, pp_tmp,
234					0);
235	if (IS_ERR(thermal->zone)) {
236		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
237		ret = PTR_ERR(thermal->zone);
238		goto err;
239	}
240	ret = thermal_zone_device_enable(thermal->zone);
241	if (ret) {
242		dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
243		goto err_zone;
244	}
245
246	dev_dbg(&pdev->dev,
247		"TJUNC temperature polling period set at %d ms\n",
248		thermal->zone->passive_delay);
249
250	ret = platform_get_irq_byname(pdev, "THERMAL");
251	if (ret < 0) {
252		dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
253		goto err_zone;
254	}
255	thermal->irq = ret;
256
257	ret = request_threaded_irq(thermal->irq, NULL,
258				   da9062_thermal_irq_handler,
259				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
260				   "THERMAL", thermal);
261	if (ret) {
262		dev_err(&pdev->dev,
263			"Failed to request thermal device IRQ.\n");
264		goto err_zone;
265	}
266
267	platform_set_drvdata(pdev, thermal);
268	return 0;
269
270err_zone:
271	thermal_zone_device_unregister(thermal->zone);
272err:
273	return ret;
274}
275
276static int da9062_thermal_remove(struct platform_device *pdev)
277{
278	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
279
280	free_irq(thermal->irq, thermal);
281	cancel_delayed_work_sync(&thermal->work);
282	thermal_zone_device_unregister(thermal->zone);
283	return 0;
284}
285
286static struct platform_driver da9062_thermal_driver = {
287	.probe	= da9062_thermal_probe,
288	.remove	= da9062_thermal_remove,
289	.driver	= {
290		.name	= "da9062-thermal",
291		.of_match_table = da9062_compatible_reg_id_table,
292	},
293};
294
295module_platform_driver(da9062_thermal_driver);
296
297MODULE_AUTHOR("Steve Twiss");
298MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
299MODULE_LICENSE("GPL");
300MODULE_ALIAS("platform:da9062-thermal");