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
da9062_thermal_poll_on(struct work_struct * work)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
da9062_thermal_irq_handler(int irq,void * data)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
da9062_thermal_get_mode(struct thermal_zone_device * z,enum thermal_device_mode * mode)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
da9062_thermal_get_trip_type(struct thermal_zone_device * z,int trip,enum thermal_trip_type * type)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
da9062_thermal_get_trip_temp(struct thermal_zone_device * z,int trip,int * temp)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
da9062_thermal_get_temp(struct thermal_zone_device * z,int * temp)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
da9062_thermal_probe(struct platform_device * pdev)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
da9062_thermal_remove(struct platform_device * pdev)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