1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Broadcom STB AVS TMON thermal sensor driver
4  *
5  * Copyright (c) 2015-2017 Broadcom
6  */
7 
8 #define DRV_NAME	"brcmstb_thermal"
9 
10 #define pr_fmt(fmt)	DRV_NAME ": " fmt
11 
12 #include <linux/bitops.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/io.h>
16 #include <linux/irqreturn.h>
17 #include <linux/interrupt.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/of_device.h>
22 #include <linux/thermal.h>
23 
24 #define AVS_TMON_STATUS			0x00
25  #define AVS_TMON_STATUS_valid_msk	BIT(11)
26  #define AVS_TMON_STATUS_data_msk	GENMASK(10, 1)
27  #define AVS_TMON_STATUS_data_shift	1
28 
29 #define AVS_TMON_EN_OVERTEMP_RESET	0x04
30  #define AVS_TMON_EN_OVERTEMP_RESET_msk	BIT(0)
31 
32 #define AVS_TMON_RESET_THRESH		0x08
33  #define AVS_TMON_RESET_THRESH_msk	GENMASK(10, 1)
34  #define AVS_TMON_RESET_THRESH_shift	1
35 
36 #define AVS_TMON_INT_IDLE_TIME		0x10
37 
38 #define AVS_TMON_EN_TEMP_INT_SRCS	0x14
39  #define AVS_TMON_EN_TEMP_INT_SRCS_high	BIT(1)
40  #define AVS_TMON_EN_TEMP_INT_SRCS_low	BIT(0)
41 
42 #define AVS_TMON_INT_THRESH		0x18
43  #define AVS_TMON_INT_THRESH_high_msk	GENMASK(26, 17)
44  #define AVS_TMON_INT_THRESH_high_shift	17
45  #define AVS_TMON_INT_THRESH_low_msk	GENMASK(10, 1)
46  #define AVS_TMON_INT_THRESH_low_shift	1
47 
48 #define AVS_TMON_TEMP_INT_CODE		0x1c
49 #define AVS_TMON_TP_TEST_ENABLE		0x20
50 
51 /* Default coefficients */
52 #define AVS_TMON_TEMP_SLOPE		487
53 #define AVS_TMON_TEMP_OFFSET		410040
54 
55 /* HW related temperature constants */
56 #define AVS_TMON_TEMP_MAX		0x3ff
57 #define AVS_TMON_TEMP_MIN		-88161
58 #define AVS_TMON_TEMP_MASK		AVS_TMON_TEMP_MAX
59 
60 enum avs_tmon_trip_type {
61 	TMON_TRIP_TYPE_LOW = 0,
62 	TMON_TRIP_TYPE_HIGH,
63 	TMON_TRIP_TYPE_RESET,
64 	TMON_TRIP_TYPE_MAX,
65 };
66 
67 struct avs_tmon_trip {
68 	/* HW bit to enable the trip */
69 	u32 enable_offs;
70 	u32 enable_mask;
71 
72 	/* HW field to read the trip temperature */
73 	u32 reg_offs;
74 	u32 reg_msk;
75 	int reg_shift;
76 };
77 
78 static struct avs_tmon_trip avs_tmon_trips[] = {
79 	/* Trips when temperature is below threshold */
80 	[TMON_TRIP_TYPE_LOW] = {
81 		.enable_offs	= AVS_TMON_EN_TEMP_INT_SRCS,
82 		.enable_mask	= AVS_TMON_EN_TEMP_INT_SRCS_low,
83 		.reg_offs	= AVS_TMON_INT_THRESH,
84 		.reg_msk	= AVS_TMON_INT_THRESH_low_msk,
85 		.reg_shift	= AVS_TMON_INT_THRESH_low_shift,
86 	},
87 	/* Trips when temperature is above threshold */
88 	[TMON_TRIP_TYPE_HIGH] = {
89 		.enable_offs	= AVS_TMON_EN_TEMP_INT_SRCS,
90 		.enable_mask	= AVS_TMON_EN_TEMP_INT_SRCS_high,
91 		.reg_offs	= AVS_TMON_INT_THRESH,
92 		.reg_msk	= AVS_TMON_INT_THRESH_high_msk,
93 		.reg_shift	= AVS_TMON_INT_THRESH_high_shift,
94 	},
95 	/* Automatically resets chip when above threshold */
96 	[TMON_TRIP_TYPE_RESET] = {
97 		.enable_offs	= AVS_TMON_EN_OVERTEMP_RESET,
98 		.enable_mask	= AVS_TMON_EN_OVERTEMP_RESET_msk,
99 		.reg_offs	= AVS_TMON_RESET_THRESH,
100 		.reg_msk	= AVS_TMON_RESET_THRESH_msk,
101 		.reg_shift	= AVS_TMON_RESET_THRESH_shift,
102 	},
103 };
104 
105 struct brcmstb_thermal_params {
106 	unsigned int offset;
107 	unsigned int mult;
108 	const struct thermal_zone_device_ops *of_ops;
109 };
110 
111 struct brcmstb_thermal_priv {
112 	void __iomem *tmon_base;
113 	struct device *dev;
114 	struct thermal_zone_device *thermal;
115 	/* Process specific thermal parameters used for calculations */
116 	const struct brcmstb_thermal_params *temp_params;
117 };
118 
119 /* Convert a HW code to a temperature reading (millidegree celsius) */
120 static inline int avs_tmon_code_to_temp(struct brcmstb_thermal_priv *priv,
121 					u32 code)
122 {
123 	int offset = priv->temp_params->offset;
124 	int mult = priv->temp_params->mult;
125 
126 	return (offset - (int)((code & AVS_TMON_TEMP_MASK) * mult));
127 }
128 
129 /*
130  * Convert a temperature value (millidegree celsius) to a HW code
131  *
132  * @temp: temperature to convert
133  * @low: if true, round toward the low side
134  */
135 static inline u32 avs_tmon_temp_to_code(struct brcmstb_thermal_priv *priv,
136 					int temp, bool low)
137 {
138 	int offset = priv->temp_params->offset;
139 	int mult = priv->temp_params->mult;
140 
141 	if (temp < AVS_TMON_TEMP_MIN)
142 		return AVS_TMON_TEMP_MAX;	/* Maximum code value */
143 
144 	if (temp >= offset)
145 		return 0;	/* Minimum code value */
146 
147 	if (low)
148 		return (u32)(DIV_ROUND_UP(offset - temp, mult));
149 	else
150 		return (u32)((offset - temp) / mult);
151 }
152 
153 static int brcmstb_get_temp(struct thermal_zone_device *tz, int *temp)
154 {
155 	struct brcmstb_thermal_priv *priv = tz->devdata;
156 	u32 val;
157 	long t;
158 
159 	val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
160 
161 	if (!(val & AVS_TMON_STATUS_valid_msk)) {
162 		dev_err(priv->dev, "reading not valid\n");
163 		return -EIO;
164 	}
165 
166 	val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
167 
168 	t = avs_tmon_code_to_temp(priv, val);
169 	if (t < 0)
170 		*temp = 0;
171 	else
172 		*temp = t;
173 
174 	return 0;
175 }
176 
177 static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
178 				 enum avs_tmon_trip_type type, int en)
179 {
180 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
181 	u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
182 
183 	dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
184 
185 	if (en)
186 		val |= trip->enable_mask;
187 	else
188 		val &= ~trip->enable_mask;
189 
190 	__raw_writel(val, priv->tmon_base + trip->enable_offs);
191 }
192 
193 static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
194 				  enum avs_tmon_trip_type type)
195 {
196 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
197 	u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
198 
199 	val &= trip->reg_msk;
200 	val >>= trip->reg_shift;
201 
202 	return avs_tmon_code_to_temp(priv, val);
203 }
204 
205 static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
206 				   enum avs_tmon_trip_type type,
207 				   int temp)
208 {
209 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
210 	u32 val, orig;
211 
212 	dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
213 
214 	/* round toward low temp for the low interrupt */
215 	val = avs_tmon_temp_to_code(priv, temp,
216 				    type == TMON_TRIP_TYPE_LOW);
217 
218 	val <<= trip->reg_shift;
219 	val &= trip->reg_msk;
220 
221 	orig = __raw_readl(priv->tmon_base + trip->reg_offs);
222 	orig &= ~trip->reg_msk;
223 	orig |= val;
224 	__raw_writel(orig, priv->tmon_base + trip->reg_offs);
225 }
226 
227 static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
228 {
229 	u32 val;
230 
231 	val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
232 	return avs_tmon_code_to_temp(priv, val);
233 }
234 
235 static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
236 {
237 	struct brcmstb_thermal_priv *priv = data;
238 	int low, high, intr;
239 
240 	low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
241 	high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
242 	intr = avs_tmon_get_intr_temp(priv);
243 
244 	dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
245 			low, intr, high);
246 
247 	/* Disable high-temp until next threshold shift */
248 	if (intr >= high)
249 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
250 	/* Disable low-temp until next threshold shift */
251 	if (intr <= low)
252 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
253 
254 	/*
255 	 * Notify using the interrupt temperature, in case the temperature
256 	 * changes before it can next be read out
257 	 */
258 	thermal_zone_device_update(priv->thermal, intr);
259 
260 	return IRQ_HANDLED;
261 }
262 
263 static int brcmstb_set_trips(struct thermal_zone_device *tz, int low, int high)
264 {
265 	struct brcmstb_thermal_priv *priv = tz->devdata;
266 
267 	dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
268 
269 	/*
270 	 * Disable low-temp if "low" is too small. As per thermal framework
271 	 * API, we use -INT_MAX rather than INT_MIN.
272 	 */
273 	if (low <= -INT_MAX) {
274 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
275 	} else {
276 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
277 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
278 	}
279 
280 	/* Disable high-temp if "high" is too big. */
281 	if (high == INT_MAX) {
282 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
283 	} else {
284 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
285 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
286 	}
287 
288 	return 0;
289 }
290 
291 static const struct thermal_zone_device_ops brcmstb_16nm_of_ops = {
292 	.get_temp	= brcmstb_get_temp,
293 };
294 
295 static const struct brcmstb_thermal_params brcmstb_16nm_params = {
296 	.offset	= 457829,
297 	.mult	= 557,
298 	.of_ops	= &brcmstb_16nm_of_ops,
299 };
300 
301 static const struct thermal_zone_device_ops brcmstb_28nm_of_ops = {
302 	.get_temp	= brcmstb_get_temp,
303 	.set_trips	= brcmstb_set_trips,
304 };
305 
306 static const struct brcmstb_thermal_params brcmstb_28nm_params = {
307 	.offset	= 410040,
308 	.mult	= 487,
309 	.of_ops	= &brcmstb_28nm_of_ops,
310 };
311 
312 static const struct of_device_id brcmstb_thermal_id_table[] = {
313 	{ .compatible = "brcm,avs-tmon-bcm7216", .data = &brcmstb_16nm_params },
314 	{ .compatible = "brcm,avs-tmon", .data = &brcmstb_28nm_params },
315 	{},
316 };
317 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
318 
319 static int brcmstb_thermal_probe(struct platform_device *pdev)
320 {
321 	const struct thermal_zone_device_ops *of_ops;
322 	struct thermal_zone_device *thermal;
323 	struct brcmstb_thermal_priv *priv;
324 	struct resource *res;
325 	int irq, ret;
326 
327 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
328 	if (!priv)
329 		return -ENOMEM;
330 
331 	priv->temp_params = of_device_get_match_data(&pdev->dev);
332 	if (!priv->temp_params)
333 		return -EINVAL;
334 
335 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
336 	priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
337 	if (IS_ERR(priv->tmon_base))
338 		return PTR_ERR(priv->tmon_base);
339 
340 	priv->dev = &pdev->dev;
341 	platform_set_drvdata(pdev, priv);
342 	of_ops = priv->temp_params->of_ops;
343 
344 	thermal = devm_thermal_of_zone_register(&pdev->dev, 0, priv,
345 						of_ops);
346 	if (IS_ERR(thermal)) {
347 		ret = PTR_ERR(thermal);
348 		dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
349 		return ret;
350 	}
351 
352 	priv->thermal = thermal;
353 
354 	irq = platform_get_irq_optional(pdev, 0);
355 	if (irq >= 0) {
356 		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
357 						brcmstb_tmon_irq_thread,
358 						IRQF_ONESHOT,
359 						DRV_NAME, priv);
360 		if (ret < 0) {
361 			dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
362 			return ret;
363 		}
364 	}
365 
366 	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
367 
368 	return 0;
369 }
370 
371 static struct platform_driver brcmstb_thermal_driver = {
372 	.probe = brcmstb_thermal_probe,
373 	.driver = {
374 		.name = DRV_NAME,
375 		.of_match_table = brcmstb_thermal_id_table,
376 	},
377 };
378 module_platform_driver(brcmstb_thermal_driver);
379 
380 MODULE_LICENSE("GPL v2");
381 MODULE_AUTHOR("Brian Norris");
382 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
383