1 /*
2 * Broadcom STB AVS TMON thermal sensor driver
3 *
4 * Copyright (c) 2015-2017 Broadcom
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 */
16
17 #define DRV_NAME "brcmstb_thermal"
18
19 #define pr_fmt(fmt) DRV_NAME ": " fmt
20
21 #include <linux/bitops.h>
22 #include <linux/device.h>
23 #include <linux/err.h>
24 #include <linux/io.h>
25 #include <linux/irqreturn.h>
26 #include <linux/interrupt.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 #include <linux/of_device.h>
31 #include <linux/thermal.h>
32
33 #define AVS_TMON_STATUS 0x00
34 #define AVS_TMON_STATUS_valid_msk BIT(11)
35 #define AVS_TMON_STATUS_data_msk GENMASK(10, 1)
36 #define AVS_TMON_STATUS_data_shift 1
37
38 #define AVS_TMON_EN_OVERTEMP_RESET 0x04
39 #define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0)
40
41 #define AVS_TMON_RESET_THRESH 0x08
42 #define AVS_TMON_RESET_THRESH_msk GENMASK(10, 1)
43 #define AVS_TMON_RESET_THRESH_shift 1
44
45 #define AVS_TMON_INT_IDLE_TIME 0x10
46
47 #define AVS_TMON_EN_TEMP_INT_SRCS 0x14
48 #define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1)
49 #define AVS_TMON_EN_TEMP_INT_SRCS_low BIT(0)
50
51 #define AVS_TMON_INT_THRESH 0x18
52 #define AVS_TMON_INT_THRESH_high_msk GENMASK(26, 17)
53 #define AVS_TMON_INT_THRESH_high_shift 17
54 #define AVS_TMON_INT_THRESH_low_msk GENMASK(10, 1)
55 #define AVS_TMON_INT_THRESH_low_shift 1
56
57 #define AVS_TMON_TEMP_INT_CODE 0x1c
58 #define AVS_TMON_TP_TEST_ENABLE 0x20
59
60 /* Default coefficients */
61 #define AVS_TMON_TEMP_SLOPE 487
62 #define AVS_TMON_TEMP_OFFSET 410040
63
64 /* HW related temperature constants */
65 #define AVS_TMON_TEMP_MAX 0x3ff
66 #define AVS_TMON_TEMP_MIN -88161
67 #define AVS_TMON_TEMP_MASK AVS_TMON_TEMP_MAX
68
69 enum avs_tmon_trip_type {
70 TMON_TRIP_TYPE_LOW = 0,
71 TMON_TRIP_TYPE_HIGH,
72 TMON_TRIP_TYPE_RESET,
73 TMON_TRIP_TYPE_MAX,
74 };
75
76 struct avs_tmon_trip {
77 /* HW bit to enable the trip */
78 u32 enable_offs;
79 u32 enable_mask;
80
81 /* HW field to read the trip temperature */
82 u32 reg_offs;
83 u32 reg_msk;
84 int reg_shift;
85 };
86
87 static struct avs_tmon_trip avs_tmon_trips[] = {
88 /* Trips when temperature is below threshold */
89 [TMON_TRIP_TYPE_LOW] = {
90 .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
91 .enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_low,
92 .reg_offs = AVS_TMON_INT_THRESH,
93 .reg_msk = AVS_TMON_INT_THRESH_low_msk,
94 .reg_shift = AVS_TMON_INT_THRESH_low_shift,
95 },
96 /* Trips when temperature is above threshold */
97 [TMON_TRIP_TYPE_HIGH] = {
98 .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
99 .enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_high,
100 .reg_offs = AVS_TMON_INT_THRESH,
101 .reg_msk = AVS_TMON_INT_THRESH_high_msk,
102 .reg_shift = AVS_TMON_INT_THRESH_high_shift,
103 },
104 /* Automatically resets chip when above threshold */
105 [TMON_TRIP_TYPE_RESET] = {
106 .enable_offs = AVS_TMON_EN_OVERTEMP_RESET,
107 .enable_mask = AVS_TMON_EN_OVERTEMP_RESET_msk,
108 .reg_offs = AVS_TMON_RESET_THRESH,
109 .reg_msk = AVS_TMON_RESET_THRESH_msk,
110 .reg_shift = AVS_TMON_RESET_THRESH_shift,
111 },
112 };
113
114 struct brcmstb_thermal_priv {
115 void __iomem *tmon_base;
116 struct device *dev;
117 struct thermal_zone_device *thermal;
118 };
119
120 /* Convert a HW code to a temperature reading (millidegree celsius) */
avs_tmon_code_to_temp(struct thermal_zone_device * tz,u32 code)121 static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
122 u32 code)
123 {
124 return (AVS_TMON_TEMP_OFFSET -
125 (int)((code & AVS_TMON_TEMP_MAX) * AVS_TMON_TEMP_SLOPE));
126 }
127
128 /*
129 * Convert a temperature value (millidegree celsius) to a HW code
130 *
131 * @temp: temperature to convert
132 * @low: if true, round toward the low side
133 */
avs_tmon_temp_to_code(struct thermal_zone_device * tz,int temp,bool low)134 static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
135 int temp, bool low)
136 {
137 if (temp < AVS_TMON_TEMP_MIN)
138 return AVS_TMON_TEMP_MAX; /* Maximum code value */
139
140 if (temp >= AVS_TMON_TEMP_OFFSET)
141 return 0; /* Minimum code value */
142
143 if (low)
144 return (u32)(DIV_ROUND_UP(AVS_TMON_TEMP_OFFSET - temp,
145 AVS_TMON_TEMP_SLOPE));
146 else
147 return (u32)((AVS_TMON_TEMP_OFFSET - temp) /
148 AVS_TMON_TEMP_SLOPE);
149 }
150
brcmstb_get_temp(void * data,int * temp)151 static int brcmstb_get_temp(void *data, int *temp)
152 {
153 struct brcmstb_thermal_priv *priv = data;
154 u32 val;
155 long t;
156
157 val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
158
159 if (!(val & AVS_TMON_STATUS_valid_msk)) {
160 dev_err(priv->dev, "reading not valid\n");
161 return -EIO;
162 }
163
164 val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
165
166 t = avs_tmon_code_to_temp(priv->thermal, val);
167 if (t < 0)
168 *temp = 0;
169 else
170 *temp = t;
171
172 return 0;
173 }
174
avs_tmon_trip_enable(struct brcmstb_thermal_priv * priv,enum avs_tmon_trip_type type,int en)175 static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
176 enum avs_tmon_trip_type type, int en)
177 {
178 struct avs_tmon_trip *trip = &avs_tmon_trips[type];
179 u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
180
181 dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
182
183 if (en)
184 val |= trip->enable_mask;
185 else
186 val &= ~trip->enable_mask;
187
188 __raw_writel(val, priv->tmon_base + trip->enable_offs);
189 }
190
avs_tmon_get_trip_temp(struct brcmstb_thermal_priv * priv,enum avs_tmon_trip_type type)191 static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
192 enum avs_tmon_trip_type type)
193 {
194 struct avs_tmon_trip *trip = &avs_tmon_trips[type];
195 u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
196
197 val &= trip->reg_msk;
198 val >>= trip->reg_shift;
199
200 return avs_tmon_code_to_temp(priv->thermal, val);
201 }
202
avs_tmon_set_trip_temp(struct brcmstb_thermal_priv * priv,enum avs_tmon_trip_type type,int temp)203 static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
204 enum avs_tmon_trip_type type,
205 int temp)
206 {
207 struct avs_tmon_trip *trip = &avs_tmon_trips[type];
208 u32 val, orig;
209
210 dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
211
212 /* round toward low temp for the low interrupt */
213 val = avs_tmon_temp_to_code(priv->thermal, temp,
214 type == TMON_TRIP_TYPE_LOW);
215
216 val <<= trip->reg_shift;
217 val &= trip->reg_msk;
218
219 orig = __raw_readl(priv->tmon_base + trip->reg_offs);
220 orig &= ~trip->reg_msk;
221 orig |= val;
222 __raw_writel(orig, priv->tmon_base + trip->reg_offs);
223 }
224
avs_tmon_get_intr_temp(struct brcmstb_thermal_priv * priv)225 static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
226 {
227 u32 val;
228
229 val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
230 return avs_tmon_code_to_temp(priv->thermal, val);
231 }
232
brcmstb_tmon_irq_thread(int irq,void * data)233 static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
234 {
235 struct brcmstb_thermal_priv *priv = data;
236 int low, high, intr;
237
238 low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
239 high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
240 intr = avs_tmon_get_intr_temp(priv);
241
242 dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
243 low, intr, high);
244
245 /* Disable high-temp until next threshold shift */
246 if (intr >= high)
247 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
248 /* Disable low-temp until next threshold shift */
249 if (intr <= low)
250 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
251
252 /*
253 * Notify using the interrupt temperature, in case the temperature
254 * changes before it can next be read out
255 */
256 thermal_zone_device_update(priv->thermal, intr);
257
258 return IRQ_HANDLED;
259 }
260
brcmstb_set_trips(void * data,int low,int high)261 static int brcmstb_set_trips(void *data, int low, int high)
262 {
263 struct brcmstb_thermal_priv *priv = data;
264
265 dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
266
267 /*
268 * Disable low-temp if "low" is too small. As per thermal framework
269 * API, we use -INT_MAX rather than INT_MIN.
270 */
271 if (low <= -INT_MAX) {
272 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
273 } else {
274 avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
275 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
276 }
277
278 /* Disable high-temp if "high" is too big. */
279 if (high == INT_MAX) {
280 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
281 } else {
282 avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
283 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
284 }
285
286 return 0;
287 }
288
289 static struct thermal_zone_of_device_ops of_ops = {
290 .get_temp = brcmstb_get_temp,
291 .set_trips = brcmstb_set_trips,
292 };
293
294 static const struct of_device_id brcmstb_thermal_id_table[] = {
295 { .compatible = "brcm,avs-tmon" },
296 {},
297 };
298 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
299
brcmstb_thermal_probe(struct platform_device * pdev)300 static int brcmstb_thermal_probe(struct platform_device *pdev)
301 {
302 struct thermal_zone_device *thermal;
303 struct brcmstb_thermal_priv *priv;
304 struct resource *res;
305 int irq, ret;
306
307 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
308 if (!priv)
309 return -ENOMEM;
310
311 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
312 priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
313 if (IS_ERR(priv->tmon_base))
314 return PTR_ERR(priv->tmon_base);
315
316 priv->dev = &pdev->dev;
317 platform_set_drvdata(pdev, priv);
318
319 thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &of_ops);
320 if (IS_ERR(thermal)) {
321 ret = PTR_ERR(thermal);
322 dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
323 return ret;
324 }
325
326 priv->thermal = thermal;
327
328 irq = platform_get_irq(pdev, 0);
329 if (irq < 0) {
330 dev_err(&pdev->dev, "could not get IRQ\n");
331 ret = irq;
332 goto err;
333 }
334 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
335 brcmstb_tmon_irq_thread, IRQF_ONESHOT,
336 DRV_NAME, priv);
337 if (ret < 0) {
338 dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
339 goto err;
340 }
341
342 dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
343
344 return 0;
345
346 err:
347 thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
348 return ret;
349 }
350
brcmstb_thermal_exit(struct platform_device * pdev)351 static int brcmstb_thermal_exit(struct platform_device *pdev)
352 {
353 struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev);
354 struct thermal_zone_device *thermal = priv->thermal;
355
356 if (thermal)
357 thermal_zone_of_sensor_unregister(&pdev->dev, priv->thermal);
358
359 return 0;
360 }
361
362 static struct platform_driver brcmstb_thermal_driver = {
363 .probe = brcmstb_thermal_probe,
364 .remove = brcmstb_thermal_exit,
365 .driver = {
366 .name = DRV_NAME,
367 .of_match_table = brcmstb_thermal_id_table,
368 },
369 };
370 module_platform_driver(brcmstb_thermal_driver);
371
372 MODULE_LICENSE("GPL v2");
373 MODULE_AUTHOR("Brian Norris");
374 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
375