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 
44 struct da9062_thermal_config {
45 	const char *name;
46 };
47 
48 struct da9062_thermal {
49 	struct da9062 *hw;
50 	struct delayed_work work;
51 	struct thermal_zone_device *zone;
52 	enum thermal_device_mode mode;
53 	struct mutex lock; /* protection for da9062_thermal temperature */
54 	int temperature;
55 	int irq;
56 	const struct da9062_thermal_config *config;
57 	struct device *dev;
58 };
59 
60 static void da9062_thermal_poll_on(struct work_struct *work)
61 {
62 	struct da9062_thermal *thermal = container_of(work,
63 						struct da9062_thermal,
64 						work.work);
65 	unsigned long delay;
66 	unsigned int val;
67 	int ret;
68 
69 	/* clear E_TEMP */
70 	ret = regmap_write(thermal->hw->regmap,
71 			   DA9062AA_EVENT_B,
72 			   DA9062AA_E_TEMP_MASK);
73 	if (ret < 0) {
74 		dev_err(thermal->dev,
75 			"Cannot clear the TJUNC temperature status\n");
76 		goto err_enable_irq;
77 	}
78 
79 	/* Now read E_TEMP again: it is acting like a status bit.
80 	 * If over-temperature, then this status will be true.
81 	 * If not over-temperature, this status will be false.
82 	 */
83 	ret = regmap_read(thermal->hw->regmap,
84 			  DA9062AA_EVENT_B,
85 			  &val);
86 	if (ret < 0) {
87 		dev_err(thermal->dev,
88 			"Cannot check the TJUNC temperature status\n");
89 		goto err_enable_irq;
90 	}
91 
92 	if (val & DA9062AA_E_TEMP_MASK) {
93 		mutex_lock(&thermal->lock);
94 		thermal->temperature = DA9062_MILLI_CELSIUS(125);
95 		mutex_unlock(&thermal->lock);
96 		thermal_zone_device_update(thermal->zone,
97 					   THERMAL_EVENT_UNSPECIFIED);
98 
99 		delay = msecs_to_jiffies(thermal->zone->passive_delay);
100 		queue_delayed_work(system_freezable_wq, &thermal->work, delay);
101 		return;
102 	}
103 
104 	mutex_lock(&thermal->lock);
105 	thermal->temperature = DA9062_MILLI_CELSIUS(0);
106 	mutex_unlock(&thermal->lock);
107 	thermal_zone_device_update(thermal->zone,
108 				   THERMAL_EVENT_UNSPECIFIED);
109 
110 err_enable_irq:
111 	enable_irq(thermal->irq);
112 }
113 
114 static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
115 {
116 	struct da9062_thermal *thermal = data;
117 
118 	disable_irq_nosync(thermal->irq);
119 	queue_delayed_work(system_freezable_wq, &thermal->work, 0);
120 
121 	return IRQ_HANDLED;
122 }
123 
124 static int da9062_thermal_get_mode(struct thermal_zone_device *z,
125 				   enum thermal_device_mode *mode)
126 {
127 	struct da9062_thermal *thermal = z->devdata;
128 	*mode = thermal->mode;
129 	return 0;
130 }
131 
132 static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
133 					int trip,
134 					enum thermal_trip_type *type)
135 {
136 	struct da9062_thermal *thermal = z->devdata;
137 
138 	switch (trip) {
139 	case 0:
140 		*type = THERMAL_TRIP_HOT;
141 		break;
142 	default:
143 		dev_err(thermal->dev,
144 			"Driver does not support more than 1 trip-wire\n");
145 		return -EINVAL;
146 	}
147 
148 	return 0;
149 }
150 
151 static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
152 					int trip,
153 					int *temp)
154 {
155 	struct da9062_thermal *thermal = z->devdata;
156 
157 	switch (trip) {
158 	case 0:
159 		*temp = DA9062_MILLI_CELSIUS(125);
160 		break;
161 	default:
162 		dev_err(thermal->dev,
163 			"Driver does not support more than 1 trip-wire\n");
164 		return -EINVAL;
165 	}
166 
167 	return 0;
168 }
169 
170 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
171 				   int *temp)
172 {
173 	struct da9062_thermal *thermal = z->devdata;
174 
175 	mutex_lock(&thermal->lock);
176 	*temp = thermal->temperature;
177 	mutex_unlock(&thermal->lock);
178 
179 	return 0;
180 }
181 
182 static struct thermal_zone_device_ops da9062_thermal_ops = {
183 	.get_temp	= da9062_thermal_get_temp,
184 	.get_mode	= da9062_thermal_get_mode,
185 	.get_trip_type	= da9062_thermal_get_trip_type,
186 	.get_trip_temp	= da9062_thermal_get_trip_temp,
187 };
188 
189 static const struct da9062_thermal_config da9062_config = {
190 	.name = "da9062-thermal",
191 };
192 
193 static const struct of_device_id da9062_compatible_reg_id_table[] = {
194 	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
195 	{ },
196 };
197 
198 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
199 
200 static int da9062_thermal_probe(struct platform_device *pdev)
201 {
202 	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
203 	struct da9062_thermal *thermal;
204 	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
205 	const struct of_device_id *match;
206 	int ret = 0;
207 
208 	match = of_match_node(da9062_compatible_reg_id_table,
209 			      pdev->dev.of_node);
210 	if (!match)
211 		return -ENXIO;
212 
213 	if (pdev->dev.of_node) {
214 		if (!of_property_read_u32(pdev->dev.of_node,
215 					  "polling-delay-passive",
216 					  &pp_tmp)) {
217 			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
218 			    pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
219 				dev_warn(&pdev->dev,
220 					 "Out-of-range polling period %d ms\n",
221 					 pp_tmp);
222 				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
223 			}
224 		}
225 	}
226 
227 	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
228 			       GFP_KERNEL);
229 	if (!thermal) {
230 		ret = -ENOMEM;
231 		goto err;
232 	}
233 
234 	thermal->config = match->data;
235 	thermal->hw = chip;
236 	thermal->mode = THERMAL_DEVICE_ENABLED;
237 	thermal->dev = &pdev->dev;
238 
239 	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
240 	mutex_init(&thermal->lock);
241 
242 	thermal->zone = thermal_zone_device_register(thermal->config->name,
243 					1, 0, thermal,
244 					&da9062_thermal_ops, NULL, pp_tmp,
245 					0);
246 	if (IS_ERR(thermal->zone)) {
247 		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
248 		ret = PTR_ERR(thermal->zone);
249 		goto err;
250 	}
251 
252 	dev_dbg(&pdev->dev,
253 		"TJUNC temperature polling period set at %d ms\n",
254 		thermal->zone->passive_delay);
255 
256 	ret = platform_get_irq_byname(pdev, "THERMAL");
257 	if (ret < 0) {
258 		dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
259 		goto err_zone;
260 	}
261 	thermal->irq = ret;
262 
263 	ret = request_threaded_irq(thermal->irq, NULL,
264 				   da9062_thermal_irq_handler,
265 				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
266 				   "THERMAL", thermal);
267 	if (ret) {
268 		dev_err(&pdev->dev,
269 			"Failed to request thermal device IRQ.\n");
270 		goto err_zone;
271 	}
272 
273 	platform_set_drvdata(pdev, thermal);
274 	return 0;
275 
276 err_zone:
277 	thermal_zone_device_unregister(thermal->zone);
278 err:
279 	return ret;
280 }
281 
282 static int da9062_thermal_remove(struct platform_device *pdev)
283 {
284 	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
285 
286 	free_irq(thermal->irq, thermal);
287 	cancel_delayed_work_sync(&thermal->work);
288 	thermal_zone_device_unregister(thermal->zone);
289 	return 0;
290 }
291 
292 static struct platform_driver da9062_thermal_driver = {
293 	.probe	= da9062_thermal_probe,
294 	.remove	= da9062_thermal_remove,
295 	.driver	= {
296 		.name	= "da9062-thermal",
297 		.of_match_table = da9062_compatible_reg_id_table,
298 	},
299 };
300 
301 module_platform_driver(da9062_thermal_driver);
302 
303 MODULE_AUTHOR("Steve Twiss");
304 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
305 MODULE_LICENSE("GPL");
306 MODULE_ALIAS("platform:da9062-thermal");
307