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 	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 
59 static 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 = thermal->zone->passive_delay_jiffies;
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 
109 err_enable_irq:
110 	enable_irq(thermal->irq);
111 }
112 
113 static 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 
123 static 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 
142 static 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 
161 static 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 
173 static 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 
179 static const struct da9062_thermal_config da9062_config = {
180 	.name = "da9062-thermal",
181 };
182 
183 static const struct of_device_id da9062_compatible_reg_id_table[] = {
184 	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
185 	{ },
186 };
187 
188 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
189 
190 static 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 		jiffies_to_msecs(thermal->zone->passive_delay_jiffies));
249 
250 	ret = platform_get_irq_byname(pdev, "THERMAL");
251 	if (ret < 0)
252 		goto err_zone;
253 
254 	thermal->irq = ret;
255 
256 	ret = request_threaded_irq(thermal->irq, NULL,
257 				   da9062_thermal_irq_handler,
258 				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
259 				   "THERMAL", thermal);
260 	if (ret) {
261 		dev_err(&pdev->dev,
262 			"Failed to request thermal device IRQ.\n");
263 		goto err_zone;
264 	}
265 
266 	platform_set_drvdata(pdev, thermal);
267 	return 0;
268 
269 err_zone:
270 	thermal_zone_device_unregister(thermal->zone);
271 err:
272 	return ret;
273 }
274 
275 static int da9062_thermal_remove(struct platform_device *pdev)
276 {
277 	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
278 
279 	free_irq(thermal->irq, thermal);
280 	cancel_delayed_work_sync(&thermal->work);
281 	thermal_zone_device_unregister(thermal->zone);
282 	return 0;
283 }
284 
285 static struct platform_driver da9062_thermal_driver = {
286 	.probe	= da9062_thermal_probe,
287 	.remove	= da9062_thermal_remove,
288 	.driver	= {
289 		.name	= "da9062-thermal",
290 		.of_match_table = da9062_compatible_reg_id_table,
291 	},
292 };
293 
294 module_platform_driver(da9062_thermal_driver);
295 
296 MODULE_AUTHOR("Steve Twiss");
297 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
298 MODULE_LICENSE("GPL");
299 MODULE_ALIAS("platform:da9062-thermal");
300