brcmstb_thermal.c

  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
 60enum 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
 67struct 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
 78static 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
105struct brcmstb_thermal_params {
106	unsigned int offset;
107	unsigned int mult;
108	const struct thermal_zone_device_ops *of_ops;
109};
110
111struct 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) */
120static 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 */
135static 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
153static 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
175static 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
191static 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
203static 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
225static 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
233static 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
261static 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
289static const struct thermal_zone_device_ops brcmstb_of_ops = {
290	.get_temp	= brcmstb_get_temp,
291};
292
293static const struct brcmstb_thermal_params brcmstb_8nm_params = {
294	.offset	= 418670,
295	.mult	= 509,
296	.of_ops	= &brcmstb_of_ops,
297};
298
299static const struct brcmstb_thermal_params brcmstb_16nm_params = {
300	.offset	= 457829,
301	.mult	= 557,
302	.of_ops	= &brcmstb_of_ops,
303};
304
305static const struct thermal_zone_device_ops brcmstb_28nm_of_ops = {
306	.get_temp	= brcmstb_get_temp,
307	.set_trips	= brcmstb_set_trips,
308};
309
310static const struct brcmstb_thermal_params brcmstb_28nm_params = {
311	.offset	= 410040,
312	.mult	= 487,
313	.of_ops	= &brcmstb_28nm_of_ops,
314};
315
316static const struct of_device_id brcmstb_thermal_id_table[] = {
317	{ .compatible = "brcm,avs-tmon-bcm74110", .data = &brcmstb_8nm_params },
318	{ .compatible = "brcm,avs-tmon-bcm7216", .data = &brcmstb_16nm_params },
319	{ .compatible = "brcm,avs-tmon", .data = &brcmstb_28nm_params },
320	{},
321};
322MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
323
324static int brcmstb_thermal_probe(struct platform_device *pdev)
325{
326	const struct thermal_zone_device_ops *of_ops;
327	struct thermal_zone_device *thermal;
328	struct brcmstb_thermal_priv *priv;
329	int irq, ret;
330
331	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
332	if (!priv)
333		return -ENOMEM;
334
335	priv->temp_params = of_device_get_match_data(&pdev->dev);
336	if (!priv->temp_params)
337		return -EINVAL;
338
339	priv->tmon_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
340	if (IS_ERR(priv->tmon_base))
341		return PTR_ERR(priv->tmon_base);
342
343	priv->dev = &pdev->dev;
344	of_ops = priv->temp_params->of_ops;
345
346	thermal = devm_thermal_of_zone_register(&pdev->dev, 0, priv,
347						of_ops);
348	if (IS_ERR(thermal))
349		return dev_err_probe(&pdev->dev, PTR_ERR(thermal),
350					"could not register sensor\n");
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			return dev_err_probe(&pdev->dev, ret,
362						"could not request IRQ\n");
363	}
364
365	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
366
367	return 0;
368}
369
370static struct platform_driver brcmstb_thermal_driver = {
371	.probe = brcmstb_thermal_probe,
372	.driver = {
373		.name = DRV_NAME,
374		.of_match_table = brcmstb_thermal_id_table,
375	},
376};
377module_platform_driver(brcmstb_thermal_driver);
378
379MODULE_LICENSE("GPL v2");
380MODULE_AUTHOR("Brian Norris");
381MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");