GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / thermal / da9062-thermal.c
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                 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
270 err_zone:
271         thermal_zone_device_unregister(thermal->zone);
272 err:
273         return ret;
274 }
275
276 static 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
286 static 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
295 module_platform_driver(da9062_thermal_driver);
296
297 MODULE_AUTHOR("Steve Twiss");
298 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
299 MODULE_LICENSE("GPL");
300 MODULE_ALIAS("platform:da9062-thermal");