1 /*
2 * Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/iio/consumer.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/thermal.h>
24
25 #define QPNP_TM_REG_TYPE 0x04
26 #define QPNP_TM_REG_SUBTYPE 0x05
27 #define QPNP_TM_REG_STATUS 0x08
28 #define QPNP_TM_REG_SHUTDOWN_CTRL1 0x40
29 #define QPNP_TM_REG_ALARM_CTRL 0x46
30
31 #define QPNP_TM_TYPE 0x09
32 #define QPNP_TM_SUBTYPE 0x08
33
34 #define STATUS_STAGE_MASK 0x03
35
36 #define SHUTDOWN_CTRL1_THRESHOLD_MASK 0x03
37
38 #define ALARM_CTRL_FORCE_ENABLE 0x80
39
40 /*
41 * Trip point values based on threshold control
42 * 0 = {105 C, 125 C, 145 C}
43 * 1 = {110 C, 130 C, 150 C}
44 * 2 = {115 C, 135 C, 155 C}
45 * 3 = {120 C, 140 C, 160 C}
46 */
47 #define TEMP_STAGE_STEP 20000 /* Stage step: 20.000 C */
48 #define TEMP_STAGE_HYSTERESIS 2000
49
50 #define TEMP_THRESH_MIN 105000 /* Threshold Min: 105 C */
51 #define TEMP_THRESH_STEP 5000 /* Threshold step: 5 C */
52
53 #define THRESH_MIN 0
54
55 /* Temperature in Milli Celsius reported during stage 0 if no ADC is present */
56 #define DEFAULT_TEMP 37000
57
58 struct qpnp_tm_chip {
59 struct regmap *map;
60 struct thermal_zone_device *tz_dev;
61 long temp;
62 unsigned int thresh;
63 unsigned int stage;
64 unsigned int prev_stage;
65 unsigned int base;
66 struct iio_channel *adc;
67 };
68
qpnp_tm_read(struct qpnp_tm_chip * chip,u16 addr,u8 * data)69 static int qpnp_tm_read(struct qpnp_tm_chip *chip, u16 addr, u8 *data)
70 {
71 unsigned int val;
72 int ret;
73
74 ret = regmap_read(chip->map, chip->base + addr, &val);
75 if (ret < 0)
76 return ret;
77
78 *data = val;
79 return 0;
80 }
81
qpnp_tm_write(struct qpnp_tm_chip * chip,u16 addr,u8 data)82 static int qpnp_tm_write(struct qpnp_tm_chip *chip, u16 addr, u8 data)
83 {
84 return regmap_write(chip->map, chip->base + addr, data);
85 }
86
87 /*
88 * This function updates the internal temp value based on the
89 * current thermal stage and threshold as well as the previous stage
90 */
qpnp_tm_update_temp_no_adc(struct qpnp_tm_chip * chip)91 static int qpnp_tm_update_temp_no_adc(struct qpnp_tm_chip *chip)
92 {
93 unsigned int stage;
94 int ret;
95 u8 reg = 0;
96
97 ret = qpnp_tm_read(chip, QPNP_TM_REG_STATUS, ®);
98 if (ret < 0)
99 return ret;
100
101 stage = reg & STATUS_STAGE_MASK;
102
103 if (stage > chip->stage) {
104 /* increasing stage, use lower bound */
105 chip->temp = (stage - 1) * TEMP_STAGE_STEP +
106 chip->thresh * TEMP_THRESH_STEP +
107 TEMP_STAGE_HYSTERESIS + TEMP_THRESH_MIN;
108 } else if (stage < chip->stage) {
109 /* decreasing stage, use upper bound */
110 chip->temp = stage * TEMP_STAGE_STEP +
111 chip->thresh * TEMP_THRESH_STEP -
112 TEMP_STAGE_HYSTERESIS + TEMP_THRESH_MIN;
113 }
114
115 chip->stage = stage;
116
117 return 0;
118 }
119
qpnp_tm_get_temp(void * data,int * temp)120 static int qpnp_tm_get_temp(void *data, int *temp)
121 {
122 struct qpnp_tm_chip *chip = data;
123 int ret, mili_celsius;
124
125 if (!temp)
126 return -EINVAL;
127
128 if (IS_ERR(chip->adc)) {
129 ret = qpnp_tm_update_temp_no_adc(chip);
130 if (ret < 0)
131 return ret;
132 } else {
133 ret = iio_read_channel_processed(chip->adc, &mili_celsius);
134 if (ret < 0)
135 return ret;
136
137 chip->temp = mili_celsius;
138 }
139
140 *temp = chip->temp < 0 ? 0 : chip->temp;
141
142 return 0;
143 }
144
145 static const struct thermal_zone_of_device_ops qpnp_tm_sensor_ops = {
146 .get_temp = qpnp_tm_get_temp,
147 };
148
qpnp_tm_isr(int irq,void * data)149 static irqreturn_t qpnp_tm_isr(int irq, void *data)
150 {
151 struct qpnp_tm_chip *chip = data;
152
153 thermal_zone_device_update(chip->tz_dev);
154
155 return IRQ_HANDLED;
156 }
157
158 /*
159 * This function initializes the internal temp value based on only the
160 * current thermal stage and threshold. Setup threshold control and
161 * disable shutdown override.
162 */
qpnp_tm_init(struct qpnp_tm_chip * chip)163 static int qpnp_tm_init(struct qpnp_tm_chip *chip)
164 {
165 int ret;
166 u8 reg;
167
168 chip->thresh = THRESH_MIN;
169 chip->temp = DEFAULT_TEMP;
170
171 ret = qpnp_tm_read(chip, QPNP_TM_REG_STATUS, ®);
172 if (ret < 0)
173 return ret;
174
175 chip->stage = reg & STATUS_STAGE_MASK;
176
177 if (chip->stage)
178 chip->temp = chip->thresh * TEMP_THRESH_STEP +
179 (chip->stage - 1) * TEMP_STAGE_STEP +
180 TEMP_THRESH_MIN;
181
182 /*
183 * Set threshold and disable software override of stage 2 and 3
184 * shutdowns.
185 */
186 reg = chip->thresh & SHUTDOWN_CTRL1_THRESHOLD_MASK;
187 ret = qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg);
188 if (ret < 0)
189 return ret;
190
191 /* Enable the thermal alarm PMIC module in always-on mode. */
192 reg = ALARM_CTRL_FORCE_ENABLE;
193 ret = qpnp_tm_write(chip, QPNP_TM_REG_ALARM_CTRL, reg);
194
195 return ret;
196 }
197
qpnp_tm_probe(struct platform_device * pdev)198 static int qpnp_tm_probe(struct platform_device *pdev)
199 {
200 struct qpnp_tm_chip *chip;
201 struct device_node *node;
202 u8 type, subtype;
203 u32 res[2];
204 int ret, irq;
205
206 node = pdev->dev.of_node;
207
208 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
209 if (!chip)
210 return -ENOMEM;
211
212 dev_set_drvdata(&pdev->dev, chip);
213
214 chip->map = dev_get_regmap(pdev->dev.parent, NULL);
215 if (!chip->map)
216 return -ENXIO;
217
218 ret = of_property_read_u32_array(node, "reg", res, 2);
219 if (ret < 0)
220 return ret;
221
222 irq = platform_get_irq(pdev, 0);
223 if (irq < 0)
224 return irq;
225
226 /* ADC based measurements are optional */
227 chip->adc = iio_channel_get(&pdev->dev, "thermal");
228 if (PTR_ERR(chip->adc) == -EPROBE_DEFER)
229 return PTR_ERR(chip->adc);
230
231 chip->base = res[0];
232
233 ret = qpnp_tm_read(chip, QPNP_TM_REG_TYPE, &type);
234 if (ret < 0) {
235 dev_err(&pdev->dev, "could not read type\n");
236 goto fail;
237 }
238
239 ret = qpnp_tm_read(chip, QPNP_TM_REG_SUBTYPE, &subtype);
240 if (ret < 0) {
241 dev_err(&pdev->dev, "could not read subtype\n");
242 goto fail;
243 }
244
245 if (type != QPNP_TM_TYPE || subtype != QPNP_TM_SUBTYPE) {
246 dev_err(&pdev->dev, "invalid type 0x%02x or subtype 0x%02x\n",
247 type, subtype);
248 ret = -ENODEV;
249 goto fail;
250 }
251
252 ret = qpnp_tm_init(chip);
253 if (ret < 0) {
254 dev_err(&pdev->dev, "init failed\n");
255 goto fail;
256 }
257
258 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, qpnp_tm_isr,
259 IRQF_ONESHOT, node->name, chip);
260 if (ret < 0)
261 goto fail;
262
263 chip->tz_dev = thermal_zone_of_sensor_register(&pdev->dev, 0, chip,
264 &qpnp_tm_sensor_ops);
265 if (IS_ERR(chip->tz_dev)) {
266 dev_err(&pdev->dev, "failed to register sensor\n");
267 ret = PTR_ERR(chip->tz_dev);
268 goto fail;
269 }
270
271 return 0;
272
273 fail:
274 if (!IS_ERR(chip->adc))
275 iio_channel_release(chip->adc);
276
277 return ret;
278 }
279
qpnp_tm_remove(struct platform_device * pdev)280 static int qpnp_tm_remove(struct platform_device *pdev)
281 {
282 struct qpnp_tm_chip *chip = dev_get_drvdata(&pdev->dev);
283
284 thermal_zone_of_sensor_unregister(&pdev->dev, chip->tz_dev);
285 if (!IS_ERR(chip->adc))
286 iio_channel_release(chip->adc);
287
288 return 0;
289 }
290
291 static const struct of_device_id qpnp_tm_match_table[] = {
292 { .compatible = "qcom,spmi-temp-alarm" },
293 { }
294 };
295 MODULE_DEVICE_TABLE(of, qpnp_tm_match_table);
296
297 static struct platform_driver qpnp_tm_driver = {
298 .driver = {
299 .name = "spmi-temp-alarm",
300 .of_match_table = qpnp_tm_match_table,
301 },
302 .probe = qpnp_tm_probe,
303 .remove = qpnp_tm_remove,
304 };
305 module_platform_driver(qpnp_tm_driver);
306
307 MODULE_ALIAS("platform:spmi-temp-alarm");
308 MODULE_DESCRIPTION("QPNP PMIC Temperature Alarm driver");
309 MODULE_LICENSE("GPL v2");
310