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 static unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
45
46 struct da9062_thermal_config {
47 const char *name;
48 };
49
50 struct da9062_thermal {
51 struct da9062 *hw;
52 struct delayed_work work;
53 struct thermal_zone_device *zone;
54 struct mutex lock; /* protection for da9062_thermal temperature */
55 int temperature;
56 int irq;
57 const struct da9062_thermal_config *config;
58 struct device *dev;
59 };
60
da9062_thermal_poll_on(struct work_struct * work)61 static void da9062_thermal_poll_on(struct work_struct *work)
62 {
63 struct da9062_thermal *thermal = container_of(work,
64 struct da9062_thermal,
65 work.work);
66 unsigned long delay;
67 unsigned int val;
68 int ret;
69
70 /* clear E_TEMP */
71 ret = regmap_write(thermal->hw->regmap,
72 DA9062AA_EVENT_B,
73 DA9062AA_E_TEMP_MASK);
74 if (ret < 0) {
75 dev_err(thermal->dev,
76 "Cannot clear the TJUNC temperature status\n");
77 goto err_enable_irq;
78 }
79
80 /* Now read E_TEMP again: it is acting like a status bit.
81 * If over-temperature, then this status will be true.
82 * If not over-temperature, this status will be false.
83 */
84 ret = regmap_read(thermal->hw->regmap,
85 DA9062AA_EVENT_B,
86 &val);
87 if (ret < 0) {
88 dev_err(thermal->dev,
89 "Cannot check the TJUNC temperature status\n");
90 goto err_enable_irq;
91 }
92
93 if (val & DA9062AA_E_TEMP_MASK) {
94 mutex_lock(&thermal->lock);
95 thermal->temperature = DA9062_MILLI_CELSIUS(125);
96 mutex_unlock(&thermal->lock);
97 thermal_zone_device_update(thermal->zone,
98 THERMAL_EVENT_UNSPECIFIED);
99
100 /*
101 * pp_tmp is between 1s and 10s, so we can round the jiffies
102 */
103 delay = round_jiffies(msecs_to_jiffies(pp_tmp));
104 queue_delayed_work(system_freezable_wq, &thermal->work, delay);
105 return;
106 }
107
108 mutex_lock(&thermal->lock);
109 thermal->temperature = DA9062_MILLI_CELSIUS(0);
110 mutex_unlock(&thermal->lock);
111 thermal_zone_device_update(thermal->zone,
112 THERMAL_EVENT_UNSPECIFIED);
113
114 err_enable_irq:
115 enable_irq(thermal->irq);
116 }
117
da9062_thermal_irq_handler(int irq,void * data)118 static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
119 {
120 struct da9062_thermal *thermal = data;
121
122 disable_irq_nosync(thermal->irq);
123 queue_delayed_work(system_freezable_wq, &thermal->work, 0);
124
125 return IRQ_HANDLED;
126 }
127
da9062_thermal_get_temp(struct thermal_zone_device * z,int * temp)128 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
129 int *temp)
130 {
131 struct da9062_thermal *thermal = thermal_zone_device_priv(z);
132
133 mutex_lock(&thermal->lock);
134 *temp = thermal->temperature;
135 mutex_unlock(&thermal->lock);
136
137 return 0;
138 }
139
140 static struct thermal_zone_device_ops da9062_thermal_ops = {
141 .get_temp = da9062_thermal_get_temp,
142 };
143
144 static struct thermal_trip trips[] = {
145 { .temperature = DA9062_MILLI_CELSIUS(125), .type = THERMAL_TRIP_HOT },
146 };
147
148 static const struct da9062_thermal_config da9062_config = {
149 .name = "da9062-thermal",
150 };
151
152 static const struct of_device_id da9062_compatible_reg_id_table[] = {
153 { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
154 { },
155 };
156
157 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
158
da9062_thermal_probe(struct platform_device * pdev)159 static int da9062_thermal_probe(struct platform_device *pdev)
160 {
161 struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
162 struct da9062_thermal *thermal;
163 const struct of_device_id *match;
164 int ret = 0;
165
166 match = of_match_node(da9062_compatible_reg_id_table,
167 pdev->dev.of_node);
168 if (!match)
169 return -ENXIO;
170
171 if (pdev->dev.of_node) {
172 if (!of_property_read_u32(pdev->dev.of_node,
173 "polling-delay-passive",
174 &pp_tmp)) {
175 if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
176 pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
177 dev_warn(&pdev->dev,
178 "Out-of-range polling period %d ms\n",
179 pp_tmp);
180 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
181 }
182 }
183 }
184
185 thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
186 GFP_KERNEL);
187 if (!thermal) {
188 ret = -ENOMEM;
189 goto err;
190 }
191
192 thermal->config = match->data;
193 thermal->hw = chip;
194 thermal->dev = &pdev->dev;
195
196 INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
197 mutex_init(&thermal->lock);
198
199 thermal->zone = thermal_zone_device_register_with_trips(thermal->config->name,
200 trips, ARRAY_SIZE(trips), thermal,
201 &da9062_thermal_ops, NULL, pp_tmp,
202 0);
203 if (IS_ERR(thermal->zone)) {
204 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
205 ret = PTR_ERR(thermal->zone);
206 goto err;
207 }
208 ret = thermal_zone_device_enable(thermal->zone);
209 if (ret) {
210 dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
211 goto err_zone;
212 }
213
214 dev_dbg(&pdev->dev,
215 "TJUNC temperature polling period set at %d ms\n", pp_tmp);
216
217 ret = platform_get_irq_byname(pdev, "THERMAL");
218 if (ret < 0)
219 goto err_zone;
220
221 thermal->irq = ret;
222
223 ret = request_threaded_irq(thermal->irq, NULL,
224 da9062_thermal_irq_handler,
225 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
226 "THERMAL", thermal);
227 if (ret) {
228 dev_err(&pdev->dev,
229 "Failed to request thermal device IRQ.\n");
230 goto err_zone;
231 }
232
233 platform_set_drvdata(pdev, thermal);
234 return 0;
235
236 err_zone:
237 thermal_zone_device_unregister(thermal->zone);
238 err:
239 return ret;
240 }
241
da9062_thermal_remove(struct platform_device * pdev)242 static void da9062_thermal_remove(struct platform_device *pdev)
243 {
244 struct da9062_thermal *thermal = platform_get_drvdata(pdev);
245
246 free_irq(thermal->irq, thermal);
247 cancel_delayed_work_sync(&thermal->work);
248 thermal_zone_device_unregister(thermal->zone);
249 }
250
251 static struct platform_driver da9062_thermal_driver = {
252 .probe = da9062_thermal_probe,
253 .remove_new = da9062_thermal_remove,
254 .driver = {
255 .name = "da9062-thermal",
256 .of_match_table = da9062_compatible_reg_id_table,
257 },
258 };
259
260 module_platform_driver(da9062_thermal_driver);
261
262 MODULE_AUTHOR("Steve Twiss");
263 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
264 MODULE_LICENSE("GPL");
265 MODULE_ALIAS("platform:da9062-thermal");
266