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
da9062_thermal_poll_on(struct work_struct * work)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
da9062_thermal_irq_handler(int irq,void * data)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
da9062_thermal_get_temp(struct thermal_zone_device * z,int * temp)123 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
124 int *temp)
125 {
126 struct da9062_thermal *thermal = z->devdata;
127
128 mutex_lock(&thermal->lock);
129 *temp = thermal->temperature;
130 mutex_unlock(&thermal->lock);
131
132 return 0;
133 }
134
135 static struct thermal_zone_device_ops da9062_thermal_ops = {
136 .get_temp = da9062_thermal_get_temp,
137 };
138
139 static struct thermal_trip trips[] = {
140 { .temperature = DA9062_MILLI_CELSIUS(125), .type = THERMAL_TRIP_HOT },
141 };
142
143 static const struct da9062_thermal_config da9062_config = {
144 .name = "da9062-thermal",
145 };
146
147 static const struct of_device_id da9062_compatible_reg_id_table[] = {
148 { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
149 { },
150 };
151
152 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
153
da9062_thermal_probe(struct platform_device * pdev)154 static int da9062_thermal_probe(struct platform_device *pdev)
155 {
156 struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
157 struct da9062_thermal *thermal;
158 unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
159 const struct of_device_id *match;
160 int ret = 0;
161
162 match = of_match_node(da9062_compatible_reg_id_table,
163 pdev->dev.of_node);
164 if (!match)
165 return -ENXIO;
166
167 if (pdev->dev.of_node) {
168 if (!of_property_read_u32(pdev->dev.of_node,
169 "polling-delay-passive",
170 &pp_tmp)) {
171 if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
172 pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
173 dev_warn(&pdev->dev,
174 "Out-of-range polling period %d ms\n",
175 pp_tmp);
176 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
177 }
178 }
179 }
180
181 thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
182 GFP_KERNEL);
183 if (!thermal) {
184 ret = -ENOMEM;
185 goto err;
186 }
187
188 thermal->config = match->data;
189 thermal->hw = chip;
190 thermal->dev = &pdev->dev;
191
192 INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
193 mutex_init(&thermal->lock);
194
195 thermal->zone = thermal_zone_device_register_with_trips(thermal->config->name,
196 trips, ARRAY_SIZE(trips), 0, thermal,
197 &da9062_thermal_ops, NULL, pp_tmp,
198 0);
199 if (IS_ERR(thermal->zone)) {
200 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
201 ret = PTR_ERR(thermal->zone);
202 goto err;
203 }
204 ret = thermal_zone_device_enable(thermal->zone);
205 if (ret) {
206 dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
207 goto err_zone;
208 }
209
210 dev_dbg(&pdev->dev,
211 "TJUNC temperature polling period set at %d ms\n",
212 jiffies_to_msecs(thermal->zone->passive_delay_jiffies));
213
214 ret = platform_get_irq_byname(pdev, "THERMAL");
215 if (ret < 0)
216 goto err_zone;
217
218 thermal->irq = ret;
219
220 ret = request_threaded_irq(thermal->irq, NULL,
221 da9062_thermal_irq_handler,
222 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
223 "THERMAL", thermal);
224 if (ret) {
225 dev_err(&pdev->dev,
226 "Failed to request thermal device IRQ.\n");
227 goto err_zone;
228 }
229
230 platform_set_drvdata(pdev, thermal);
231 return 0;
232
233 err_zone:
234 thermal_zone_device_unregister(thermal->zone);
235 err:
236 return ret;
237 }
238
da9062_thermal_remove(struct platform_device * pdev)239 static int da9062_thermal_remove(struct platform_device *pdev)
240 {
241 struct da9062_thermal *thermal = platform_get_drvdata(pdev);
242
243 free_irq(thermal->irq, thermal);
244 cancel_delayed_work_sync(&thermal->work);
245 thermal_zone_device_unregister(thermal->zone);
246 return 0;
247 }
248
249 static struct platform_driver da9062_thermal_driver = {
250 .probe = da9062_thermal_probe,
251 .remove = da9062_thermal_remove,
252 .driver = {
253 .name = "da9062-thermal",
254 .of_match_table = da9062_compatible_reg_id_table,
255 },
256 };
257
258 module_platform_driver(da9062_thermal_driver);
259
260 MODULE_AUTHOR("Steve Twiss");
261 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
262 MODULE_LICENSE("GPL");
263 MODULE_ALIAS("platform:da9062-thermal");
264