xref: /openbmc/linux/drivers/thermal/broadcom/brcmstb_thermal.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1) 
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 static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
121 				int *offset)
122 {
123 	*slope = thermal_zone_get_slope(tz);
124 	*offset = thermal_zone_get_offset(tz);
125 }
126 
127 /* Convert a HW code to a temperature reading (millidegree celsius) */
128 static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
129 					u32 code)
130 {
131 	const int val = code & AVS_TMON_TEMP_MASK;
132 	int slope, offset;
133 
134 	avs_tmon_get_coeffs(tz, &slope, &offset);
135 
136 	return slope * val + offset;
137 }
138 
139 /*
140  * Convert a temperature value (millidegree celsius) to a HW code
141  *
142  * @temp: temperature to convert
143  * @low: if true, round toward the low side
144  */
145 static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
146 					int temp, bool low)
147 {
148 	int slope, offset;
149 
150 	if (temp < AVS_TMON_TEMP_MIN)
151 		return AVS_TMON_TEMP_MAX; /* Maximum code value */
152 
153 	avs_tmon_get_coeffs(tz, &slope, &offset);
154 
155 	if (temp >= offset)
156 		return 0;	/* Minimum code value */
157 
158 	if (low)
159 		return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
160 	else
161 		return (u32)((offset - temp) / abs(slope));
162 }
163 
164 static int brcmstb_get_temp(void *data, int *temp)
165 {
166 	struct brcmstb_thermal_priv *priv = data;
167 	u32 val;
168 	long t;
169 
170 	val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
171 
172 	if (!(val & AVS_TMON_STATUS_valid_msk)) {
173 		dev_err(priv->dev, "reading not valid\n");
174 		return -EIO;
175 	}
176 
177 	val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
178 
179 	t = avs_tmon_code_to_temp(priv->thermal, val);
180 	if (t < 0)
181 		*temp = 0;
182 	else
183 		*temp = t;
184 
185 	return 0;
186 }
187 
188 static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
189 				 enum avs_tmon_trip_type type, int en)
190 {
191 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
192 	u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
193 
194 	dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
195 
196 	if (en)
197 		val |= trip->enable_mask;
198 	else
199 		val &= ~trip->enable_mask;
200 
201 	__raw_writel(val, priv->tmon_base + trip->enable_offs);
202 }
203 
204 static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
205 				  enum avs_tmon_trip_type type)
206 {
207 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
208 	u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
209 
210 	val &= trip->reg_msk;
211 	val >>= trip->reg_shift;
212 
213 	return avs_tmon_code_to_temp(priv->thermal, val);
214 }
215 
216 static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
217 				   enum avs_tmon_trip_type type,
218 				   int temp)
219 {
220 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
221 	u32 val, orig;
222 
223 	dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
224 
225 	/* round toward low temp for the low interrupt */
226 	val = avs_tmon_temp_to_code(priv->thermal, temp,
227 				    type == TMON_TRIP_TYPE_LOW);
228 
229 	val <<= trip->reg_shift;
230 	val &= trip->reg_msk;
231 
232 	orig = __raw_readl(priv->tmon_base + trip->reg_offs);
233 	orig &= ~trip->reg_msk;
234 	orig |= val;
235 	__raw_writel(orig, priv->tmon_base + trip->reg_offs);
236 }
237 
238 static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
239 {
240 	u32 val;
241 
242 	val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
243 	return avs_tmon_code_to_temp(priv->thermal, val);
244 }
245 
246 static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
247 {
248 	struct brcmstb_thermal_priv *priv = data;
249 	int low, high, intr;
250 
251 	low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
252 	high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
253 	intr = avs_tmon_get_intr_temp(priv);
254 
255 	dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
256 			low, intr, high);
257 
258 	/* Disable high-temp until next threshold shift */
259 	if (intr >= high)
260 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
261 	/* Disable low-temp until next threshold shift */
262 	if (intr <= low)
263 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
264 
265 	/*
266 	 * Notify using the interrupt temperature, in case the temperature
267 	 * changes before it can next be read out
268 	 */
269 	thermal_zone_device_update(priv->thermal, intr);
270 
271 	return IRQ_HANDLED;
272 }
273 
274 static int brcmstb_set_trips(void *data, int low, int high)
275 {
276 	struct brcmstb_thermal_priv *priv = data;
277 
278 	dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
279 
280 	/*
281 	 * Disable low-temp if "low" is too small. As per thermal framework
282 	 * API, we use -INT_MAX rather than INT_MIN.
283 	 */
284 	if (low <= -INT_MAX) {
285 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
286 	} else {
287 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
288 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
289 	}
290 
291 	/* Disable high-temp if "high" is too big. */
292 	if (high == INT_MAX) {
293 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
294 	} else {
295 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
296 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
297 	}
298 
299 	return 0;
300 }
301 
302 static const struct thermal_zone_of_device_ops of_ops = {
303 	.get_temp	= brcmstb_get_temp,
304 	.set_trips	= brcmstb_set_trips,
305 };
306 
307 static const struct of_device_id brcmstb_thermal_id_table[] = {
308 	{ .compatible = "brcm,avs-tmon" },
309 	{},
310 };
311 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
312 
313 static int brcmstb_thermal_probe(struct platform_device *pdev)
314 {
315 	struct thermal_zone_device *thermal;
316 	struct brcmstb_thermal_priv *priv;
317 	struct resource *res;
318 	int irq, ret;
319 
320 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
321 	if (!priv)
322 		return -ENOMEM;
323 
324 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
325 	priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
326 	if (IS_ERR(priv->tmon_base))
327 		return PTR_ERR(priv->tmon_base);
328 
329 	priv->dev = &pdev->dev;
330 	platform_set_drvdata(pdev, priv);
331 
332 	thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &of_ops);
333 	if (IS_ERR(thermal)) {
334 		ret = PTR_ERR(thermal);
335 		dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
336 		return ret;
337 	}
338 
339 	priv->thermal = thermal;
340 
341 	irq = platform_get_irq(pdev, 0);
342 	if (irq < 0) {
343 		dev_err(&pdev->dev, "could not get IRQ\n");
344 		ret = irq;
345 		goto err;
346 	}
347 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
348 					brcmstb_tmon_irq_thread, IRQF_ONESHOT,
349 					DRV_NAME, priv);
350 	if (ret < 0) {
351 		dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
352 		goto err;
353 	}
354 
355 	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
356 
357 	return 0;
358 
359 err:
360 	thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
361 	return ret;
362 }
363 
364 static int brcmstb_thermal_exit(struct platform_device *pdev)
365 {
366 	struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev);
367 	struct thermal_zone_device *thermal = priv->thermal;
368 
369 	if (thermal)
370 		thermal_zone_of_sensor_unregister(&pdev->dev, priv->thermal);
371 
372 	return 0;
373 }
374 
375 static struct platform_driver brcmstb_thermal_driver = {
376 	.probe = brcmstb_thermal_probe,
377 	.remove = brcmstb_thermal_exit,
378 	.driver = {
379 		.name = DRV_NAME,
380 		.of_match_table = brcmstb_thermal_id_table,
381 	},
382 };
383 module_platform_driver(brcmstb_thermal_driver);
384 
385 MODULE_LICENSE("GPL v2");
386 MODULE_AUTHOR("Brian Norris");
387 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
388