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/of.h>
21 #include <linux/platform_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 = thermal_zone_device_priv(tz);
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 		return -EIO;
163 
164 	val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
165 
166 	t = avs_tmon_code_to_temp(priv, val);
167 	if (t < 0)
168 		*temp = 0;
169 	else
170 		*temp = t;
171 
172 	return 0;
173 }
174 
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 
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, val);
201 }
202 
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, 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 
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, val);
231 }
232 
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 
261 static int brcmstb_set_trips(struct thermal_zone_device *tz, int low, int high)
262 {
263 	struct brcmstb_thermal_priv *priv = thermal_zone_device_priv(tz);
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 const struct thermal_zone_device_ops brcmstb_16nm_of_ops = {
290 	.get_temp	= brcmstb_get_temp,
291 };
292 
293 static const struct brcmstb_thermal_params brcmstb_16nm_params = {
294 	.offset	= 457829,
295 	.mult	= 557,
296 	.of_ops	= &brcmstb_16nm_of_ops,
297 };
298 
299 static const struct thermal_zone_device_ops brcmstb_28nm_of_ops = {
300 	.get_temp	= brcmstb_get_temp,
301 	.set_trips	= brcmstb_set_trips,
302 };
303 
304 static const struct brcmstb_thermal_params brcmstb_28nm_params = {
305 	.offset	= 410040,
306 	.mult	= 487,
307 	.of_ops	= &brcmstb_28nm_of_ops,
308 };
309 
310 static const struct of_device_id brcmstb_thermal_id_table[] = {
311 	{ .compatible = "brcm,avs-tmon-bcm7216", .data = &brcmstb_16nm_params },
312 	{ .compatible = "brcm,avs-tmon", .data = &brcmstb_28nm_params },
313 	{},
314 };
315 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
316 
317 static int brcmstb_thermal_probe(struct platform_device *pdev)
318 {
319 	const struct thermal_zone_device_ops *of_ops;
320 	struct thermal_zone_device *thermal;
321 	struct brcmstb_thermal_priv *priv;
322 	int irq, ret;
323 
324 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
325 	if (!priv)
326 		return -ENOMEM;
327 
328 	priv->temp_params = of_device_get_match_data(&pdev->dev);
329 	if (!priv->temp_params)
330 		return -EINVAL;
331 
332 	priv->tmon_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
333 	if (IS_ERR(priv->tmon_base))
334 		return PTR_ERR(priv->tmon_base);
335 
336 	priv->dev = &pdev->dev;
337 	platform_set_drvdata(pdev, priv);
338 	of_ops = priv->temp_params->of_ops;
339 
340 	thermal = devm_thermal_of_zone_register(&pdev->dev, 0, priv,
341 						of_ops);
342 	if (IS_ERR(thermal)) {
343 		ret = PTR_ERR(thermal);
344 		dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
345 		return ret;
346 	}
347 
348 	priv->thermal = thermal;
349 
350 	irq = platform_get_irq_optional(pdev, 0);
351 	if (irq >= 0) {
352 		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
353 						brcmstb_tmon_irq_thread,
354 						IRQF_ONESHOT,
355 						DRV_NAME, priv);
356 		if (ret < 0) {
357 			dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
358 			return ret;
359 		}
360 	}
361 
362 	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
363 
364 	return 0;
365 }
366 
367 static struct platform_driver brcmstb_thermal_driver = {
368 	.probe = brcmstb_thermal_probe,
369 	.driver = {
370 		.name = DRV_NAME,
371 		.of_match_table = brcmstb_thermal_id_table,
372 	},
373 };
374 module_platform_driver(brcmstb_thermal_driver);
375 
376 MODULE_LICENSE("GPL v2");
377 MODULE_AUTHOR("Brian Norris");
378 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
379