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_priv {
106 	void __iomem *tmon_base;
107 	struct device *dev;
108 	struct thermal_zone_device *thermal;
109 };
110 
111 static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
112 				int *offset)
113 {
114 	*slope = thermal_zone_get_slope(tz);
115 	*offset = thermal_zone_get_offset(tz);
116 }
117 
118 /* Convert a HW code to a temperature reading (millidegree celsius) */
119 static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
120 					u32 code)
121 {
122 	const int val = code & AVS_TMON_TEMP_MASK;
123 	int slope, offset;
124 
125 	avs_tmon_get_coeffs(tz, &slope, &offset);
126 
127 	return slope * val + offset;
128 }
129 
130 /*
131  * Convert a temperature value (millidegree celsius) to a HW code
132  *
133  * @temp: temperature to convert
134  * @low: if true, round toward the low side
135  */
136 static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
137 					int temp, bool low)
138 {
139 	int slope, offset;
140 
141 	if (temp < AVS_TMON_TEMP_MIN)
142 		return AVS_TMON_TEMP_MAX; /* Maximum code value */
143 
144 	avs_tmon_get_coeffs(tz, &slope, &offset);
145 
146 	if (temp >= offset)
147 		return 0;	/* Minimum code value */
148 
149 	if (low)
150 		return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
151 	else
152 		return (u32)((offset - temp) / abs(slope));
153 }
154 
155 static int brcmstb_get_temp(void *data, int *temp)
156 {
157 	struct brcmstb_thermal_priv *priv = data;
158 	u32 val;
159 	long t;
160 
161 	val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
162 
163 	if (!(val & AVS_TMON_STATUS_valid_msk)) {
164 		dev_err(priv->dev, "reading not valid\n");
165 		return -EIO;
166 	}
167 
168 	val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
169 
170 	t = avs_tmon_code_to_temp(priv->thermal, val);
171 	if (t < 0)
172 		*temp = 0;
173 	else
174 		*temp = t;
175 
176 	return 0;
177 }
178 
179 static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
180 				 enum avs_tmon_trip_type type, int en)
181 {
182 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
183 	u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
184 
185 	dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
186 
187 	if (en)
188 		val |= trip->enable_mask;
189 	else
190 		val &= ~trip->enable_mask;
191 
192 	__raw_writel(val, priv->tmon_base + trip->enable_offs);
193 }
194 
195 static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
196 				  enum avs_tmon_trip_type type)
197 {
198 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
199 	u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
200 
201 	val &= trip->reg_msk;
202 	val >>= trip->reg_shift;
203 
204 	return avs_tmon_code_to_temp(priv->thermal, val);
205 }
206 
207 static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
208 				   enum avs_tmon_trip_type type,
209 				   int temp)
210 {
211 	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
212 	u32 val, orig;
213 
214 	dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
215 
216 	/* round toward low temp for the low interrupt */
217 	val = avs_tmon_temp_to_code(priv->thermal, temp,
218 				    type == TMON_TRIP_TYPE_LOW);
219 
220 	val <<= trip->reg_shift;
221 	val &= trip->reg_msk;
222 
223 	orig = __raw_readl(priv->tmon_base + trip->reg_offs);
224 	orig &= ~trip->reg_msk;
225 	orig |= val;
226 	__raw_writel(orig, priv->tmon_base + trip->reg_offs);
227 }
228 
229 static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
230 {
231 	u32 val;
232 
233 	val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
234 	return avs_tmon_code_to_temp(priv->thermal, val);
235 }
236 
237 static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
238 {
239 	struct brcmstb_thermal_priv *priv = data;
240 	int low, high, intr;
241 
242 	low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
243 	high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
244 	intr = avs_tmon_get_intr_temp(priv);
245 
246 	dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
247 			low, intr, high);
248 
249 	/* Disable high-temp until next threshold shift */
250 	if (intr >= high)
251 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
252 	/* Disable low-temp until next threshold shift */
253 	if (intr <= low)
254 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
255 
256 	/*
257 	 * Notify using the interrupt temperature, in case the temperature
258 	 * changes before it can next be read out
259 	 */
260 	thermal_zone_device_update(priv->thermal, intr);
261 
262 	return IRQ_HANDLED;
263 }
264 
265 static int brcmstb_set_trips(void *data, int low, int high)
266 {
267 	struct brcmstb_thermal_priv *priv = data;
268 
269 	dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
270 
271 	/*
272 	 * Disable low-temp if "low" is too small. As per thermal framework
273 	 * API, we use -INT_MAX rather than INT_MIN.
274 	 */
275 	if (low <= -INT_MAX) {
276 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
277 	} else {
278 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
279 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
280 	}
281 
282 	/* Disable high-temp if "high" is too big. */
283 	if (high == INT_MAX) {
284 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
285 	} else {
286 		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
287 		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
288 	}
289 
290 	return 0;
291 }
292 
293 static const struct thermal_zone_of_device_ops of_ops = {
294 	.get_temp	= brcmstb_get_temp,
295 	.set_trips	= brcmstb_set_trips,
296 };
297 
298 static const struct of_device_id brcmstb_thermal_id_table[] = {
299 	{ .compatible = "brcm,avs-tmon" },
300 	{},
301 };
302 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
303 
304 static int brcmstb_thermal_probe(struct platform_device *pdev)
305 {
306 	struct thermal_zone_device *thermal;
307 	struct brcmstb_thermal_priv *priv;
308 	struct resource *res;
309 	int irq, ret;
310 
311 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
312 	if (!priv)
313 		return -ENOMEM;
314 
315 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
316 	priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
317 	if (IS_ERR(priv->tmon_base))
318 		return PTR_ERR(priv->tmon_base);
319 
320 	priv->dev = &pdev->dev;
321 	platform_set_drvdata(pdev, priv);
322 
323 	thermal = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv,
324 						       &of_ops);
325 	if (IS_ERR(thermal)) {
326 		ret = PTR_ERR(thermal);
327 		dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
328 		return ret;
329 	}
330 
331 	priv->thermal = thermal;
332 
333 	irq = platform_get_irq(pdev, 0);
334 	if (irq < 0) {
335 		dev_err(&pdev->dev, "could not get IRQ\n");
336 		return irq;
337 	}
338 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
339 					brcmstb_tmon_irq_thread, IRQF_ONESHOT,
340 					DRV_NAME, priv);
341 	if (ret < 0) {
342 		dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
343 		return ret;
344 	}
345 
346 	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
347 
348 	return 0;
349 }
350 
351 static struct platform_driver brcmstb_thermal_driver = {
352 	.probe = brcmstb_thermal_probe,
353 	.driver = {
354 		.name = DRV_NAME,
355 		.of_match_table = brcmstb_thermal_id_table,
356 	},
357 };
358 module_platform_driver(brcmstb_thermal_driver);
359 
360 MODULE_LICENSE("GPL v2");
361 MODULE_AUTHOR("Brian Norris");
362 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
363