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 
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 
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 
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 
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), 0, 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 
242 static int 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 	return 0;
250 }
251 
252 static struct platform_driver da9062_thermal_driver = {
253 	.probe	= da9062_thermal_probe,
254 	.remove	= da9062_thermal_remove,
255 	.driver	= {
256 		.name	= "da9062-thermal",
257 		.of_match_table = da9062_compatible_reg_id_table,
258 	},
259 };
260 
261 module_platform_driver(da9062_thermal_driver);
262 
263 MODULE_AUTHOR("Steve Twiss");
264 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
265 MODULE_LICENSE("GPL");
266 MODULE_ALIAS("platform:da9062-thermal");
267