xref: /linux/drivers/thermal/imx91_thermal.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2025 NXP.
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/err.h>
9 #include <linux/interrupt.h>
10 #include <linux/iopoll.h>
11 #include <linux/nvmem-consumer.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/thermal.h>
18 #include <linux/units.h>
19 
20 #define REG_SET					0x4
21 #define REG_CLR					0x8
22 #define REG_TOG					0xc
23 
24 #define IMX91_TMU_CTRL0				0x0
25 #define   IMX91_TMU_CTRL0_THR1_IE		BIT(9)
26 #define   IMX91_TMU_CTRL0_THR1_MASK		GENMASK(3, 2)
27 #define   IMX91_TMU_CTRL0_CLR_FLT1		BIT(21)
28 
29 #define IMX91_TMU_THR_MODE_LE			0
30 #define IMX91_TMU_THR_MODE_GE			1
31 
32 #define IMX91_TMU_STAT0				0x10
33 #define   IMX91_TMU_STAT0_THR1_IF		BIT(9)
34 #define   IMX91_TMU_STAT0_THR1_STAT		BIT(13)
35 #define   IMX91_TMU_STAT0_DRDY0_IF_MASK		BIT(16)
36 
37 #define IMX91_TMU_DATA0				0x20
38 
39 #define IMX91_TMU_CTRL1				0x200
40 #define IMX91_TMU_CTRL1_EN			BIT(31)
41 #define IMX91_TMU_CTRL1_START			BIT(30)
42 #define IMX91_TMU_CTRL1_STOP			BIT(29)
43 #define IMX91_TMU_CTRL1_RES_MASK		GENMASK(19, 18)
44 #define IMX91_TMU_CTRL1_MEAS_MODE_MASK		GENMASK(25, 24)
45 #define   IMX91_TMU_CTRL1_MEAS_MODE_SINGLE	0
46 #define   IMX91_TMU_CTRL1_MEAS_MODE_CONTINUES	1
47 #define   IMX91_TMU_CTRL1_MEAS_MODE_PERIODIC	2
48 
49 #define IMX91_TMU_THR_CTRL01			0x30
50 #define   IMX91_TMU_THR_CTRL01_THR1_MASK	GENMASK(31, 16)
51 
52 #define IMX91_TMU_REF_DIV			0x280
53 #define IMX91_TMU_DIV_EN			BIT(31)
54 #define IMX91_TMU_DIV_MASK			GENMASK(23, 16)
55 #define IMX91_TMU_DIV_MAX			255
56 
57 #define IMX91_TMU_PUD_ST_CTRL			0x2b0
58 #define IMX91_TMU_PUDL_MASK			GENMASK(23, 16)
59 
60 #define IMX91_TMU_TRIM1				0x2e0
61 #define IMX91_TMU_TRIM2				0x2f0
62 
63 #define IMX91_TMU_TEMP_LOW_LIMIT		-40000
64 #define IMX91_TMU_TEMP_HIGH_LIMIT		125000
65 
66 #define IMX91_TMU_DEFAULT_TRIM1_CONFIG		0xb561bc2d
67 #define IMX91_TMU_DEFAULT_TRIM2_CONFIG		0x65d4
68 
69 #define IMX91_TMU_PERIOD_CTRL			0x270
70 #define   IMX91_TMU_PERIOD_CTRL_MEAS_MASK	GENMASK(23, 0)
71 
72 #define IMX91_TMP_FRAC				64
73 
74 struct imx91_tmu {
75 	void __iomem *base;
76 	struct clk *clk;
77 	struct device *dev;
78 	struct thermal_zone_device *tzd;
79 };
80 
81 static void imx91_tmu_start(struct imx91_tmu *tmu, bool start)
82 {
83 	u32 val = start ? IMX91_TMU_CTRL1_START : IMX91_TMU_CTRL1_STOP;
84 
85 	writel_relaxed(val, tmu->base + IMX91_TMU_CTRL1 + REG_SET);
86 }
87 
88 static void imx91_tmu_enable(struct imx91_tmu *tmu, bool enable)
89 {
90 	u32 reg = IMX91_TMU_CTRL1;
91 
92 	reg += enable ? REG_SET : REG_CLR;
93 
94 	writel_relaxed(IMX91_TMU_CTRL1_EN, tmu->base + reg);
95 }
96 
97 static int imx91_tmu_to_mcelsius(int x)
98 {
99 	return x * MILLIDEGREE_PER_DEGREE / IMX91_TMP_FRAC;
100 }
101 
102 static int imx91_tmu_from_mcelsius(int x)
103 {
104 	return x * IMX91_TMP_FRAC / MILLIDEGREE_PER_DEGREE;
105 }
106 
107 static int imx91_tmu_get_temp(struct thermal_zone_device *tz, int *temp)
108 {
109 	struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
110 	s16 data;
111 
112 	/* DATA0 is 16bit signed number */
113 	data = readw_relaxed(tmu->base + IMX91_TMU_DATA0);
114 	*temp = imx91_tmu_to_mcelsius(data);
115 
116 	return 0;
117 }
118 
119 static int imx91_tmu_set_trips(struct thermal_zone_device *tz, int low, int high)
120 {
121 	struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
122 	int val;
123 
124 	if (high >= IMX91_TMU_TEMP_HIGH_LIMIT)
125 		return -EINVAL;
126 
127 	writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
128 
129 	/* Comparator1 for temperature threshold */
130 	writel_relaxed(IMX91_TMU_THR_CTRL01_THR1_MASK, tmu->base + IMX91_TMU_THR_CTRL01 + REG_CLR);
131 	val = FIELD_PREP(IMX91_TMU_THR_CTRL01_THR1_MASK, imx91_tmu_from_mcelsius(high));
132 
133 	writel_relaxed(val, tmu->base + IMX91_TMU_THR_CTRL01 + REG_SET);
134 
135 	writel_relaxed(IMX91_TMU_STAT0_THR1_IF, tmu->base + IMX91_TMU_STAT0 + REG_CLR);
136 
137 	writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_SET);
138 
139 	return 0;
140 }
141 
142 static int imx91_init_from_nvmem_cells(struct imx91_tmu *tmu)
143 {
144 	struct device *dev = tmu->dev;
145 	u32 trim1, trim2;
146 	int ret;
147 
148 	ret = nvmem_cell_read_u32(dev, "trim1", &trim1);
149 	if (ret)
150 		return ret;
151 
152 	ret = nvmem_cell_read_u32(dev, "trim2", &trim2);
153 	if (ret)
154 		return ret;
155 
156 	if (trim1 == 0 || trim2 == 0)
157 		return -EINVAL;
158 
159 	writel_relaxed(trim1, tmu->base + IMX91_TMU_TRIM1);
160 	writel_relaxed(trim2, tmu->base + IMX91_TMU_TRIM2);
161 
162 	return 0;
163 }
164 
165 static void imx91_tmu_action_remove(void *data)
166 {
167 	struct imx91_tmu *tmu = data;
168 
169 	/* disable tmu */
170 	imx91_tmu_enable(tmu, false);
171 }
172 
173 static irqreturn_t imx91_tmu_alarm_irq(int irq, void *data)
174 {
175 	struct imx91_tmu *tmu = data;
176 	u32 val;
177 
178 	val = readl_relaxed(tmu->base + IMX91_TMU_STAT0);
179 
180 	/* Check if comparison interrupt occurred */
181 	if (val & IMX91_TMU_STAT0_THR1_IF) {
182 		/* Clear irq flag and disable interrupt until reconfigured */
183 		writel(IMX91_TMU_STAT0_THR1_IF, tmu->base + IMX91_TMU_STAT0 + REG_CLR);
184 		writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
185 
186 		return IRQ_WAKE_THREAD;
187 	}
188 
189 	return IRQ_NONE;
190 }
191 
192 static irqreturn_t imx91_tmu_alarm_irq_thread(int irq, void *data)
193 {
194 	struct imx91_tmu *tmu = data;
195 
196 	thermal_zone_device_update(tmu->tzd, THERMAL_EVENT_UNSPECIFIED);
197 
198 	return IRQ_HANDLED;
199 }
200 
201 static int imx91_tmu_change_mode(struct thermal_zone_device *tz, enum thermal_device_mode mode)
202 {
203 	struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
204 	int ret;
205 
206 	if (mode == THERMAL_DEVICE_ENABLED) {
207 		ret = pm_runtime_get(tmu->dev);
208 		if (ret < 0)
209 			return ret;
210 
211 		writel_relaxed(IMX91_TMU_CTRL0_THR1_IE | IMX91_TMU_CTRL0_THR1_MASK,
212 			       tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
213 
214 		writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL0_THR1_MASK, IMX91_TMU_THR_MODE_GE),
215 			       tmu->base + IMX91_TMU_CTRL0 + REG_SET);
216 		imx91_tmu_start(tmu, true);
217 	} else {
218 		writel_relaxed(IMX91_TMU_CTRL0_THR1_IE, tmu->base + IMX91_TMU_CTRL0 + REG_CLR);
219 		imx91_tmu_start(tmu, false);
220 		pm_runtime_put(tmu->dev);
221 	}
222 
223 	return 0;
224 }
225 
226 static struct thermal_zone_device_ops tmu_tz_ops = {
227 	.get_temp = imx91_tmu_get_temp,
228 	.change_mode = imx91_tmu_change_mode,
229 	.set_trips = imx91_tmu_set_trips,
230 };
231 
232 static int imx91_tmu_probe(struct platform_device *pdev)
233 {
234 	struct device *dev = &pdev->dev;
235 	struct imx91_tmu *tmu;
236 	unsigned long rate;
237 	int irq, ret;
238 	u32 div;
239 
240 	tmu = devm_kzalloc(dev, sizeof(struct imx91_tmu), GFP_KERNEL);
241 	if (!tmu)
242 		return -ENOMEM;
243 
244 	tmu->dev = dev;
245 
246 	tmu->base = devm_platform_ioremap_resource(pdev, 0);
247 	if (IS_ERR(tmu->base))
248 		return dev_err_probe(dev, PTR_ERR(tmu->base), "failed to get io resource");
249 
250 	tmu->clk = devm_clk_get_enabled(dev, NULL);
251 	if (IS_ERR(tmu->clk))
252 		return dev_err_probe(dev, PTR_ERR(tmu->clk), "failed to get tmu clock\n");
253 
254 	platform_set_drvdata(pdev, tmu);
255 
256 	/* disable the monitor during initialization */
257 	imx91_tmu_enable(tmu, false);
258 	imx91_tmu_start(tmu, false);
259 
260 	ret = imx91_init_from_nvmem_cells(tmu);
261 	if (ret) {
262 		dev_warn(dev, "can't get trim value, use default settings\n");
263 
264 		writel_relaxed(IMX91_TMU_DEFAULT_TRIM1_CONFIG, tmu->base + IMX91_TMU_TRIM1);
265 		writel_relaxed(IMX91_TMU_DEFAULT_TRIM2_CONFIG, tmu->base + IMX91_TMU_TRIM2);
266 	}
267 
268 	/* The typical conv clk is 4MHz, the output freq is 'rate / (div + 1)' */
269 	rate = clk_get_rate(tmu->clk);
270 	div = (rate / (4 * HZ_PER_MHZ)) - 1;
271 	if (div > IMX91_TMU_DIV_MAX)
272 		return dev_err_probe(dev, -EINVAL, "clock divider exceed hardware limitation");
273 
274 	/* Set divider value and enable divider */
275 	writel_relaxed(IMX91_TMU_DIV_EN | FIELD_PREP(IMX91_TMU_DIV_MASK, div),
276 		       tmu->base + IMX91_TMU_REF_DIV);
277 
278 	/* Set max power up delay: 'Tpud(ms) = 0xFF * 1000 / 4000000' */
279 	writel_relaxed(FIELD_PREP(IMX91_TMU_PUDL_MASK, 100U), tmu->base + IMX91_TMU_PUD_ST_CTRL);
280 
281 	/*
282 	 * Set resolution mode
283 	 * 00b - Conversion time = 0.59325 ms
284 	 * 01b - Conversion time = 1.10525 ms
285 	 * 10b - Conversion time = 2.12925 ms
286 	 * 11b - Conversion time = 4.17725 ms
287 	 */
288 	writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL1_RES_MASK, 0x3),
289 		       tmu->base + IMX91_TMU_CTRL1 + REG_CLR);
290 	writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL1_RES_MASK, 0x1),
291 		       tmu->base + IMX91_TMU_CTRL1 + REG_SET);
292 
293 	writel_relaxed(IMX91_TMU_CTRL1_MEAS_MODE_MASK, tmu->base + IMX91_TMU_CTRL1 + REG_CLR);
294 	writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL1_MEAS_MODE_MASK,
295 				  IMX91_TMU_CTRL1_MEAS_MODE_PERIODIC),
296 		       tmu->base + IMX91_TMU_CTRL1 + REG_SET);
297 
298 	/*
299 	 * Set Periodic Measurement Frequency to 25Hz:
300 	 * tMEAS_FREQ = tCONV_CLK * PERIOD_CTRL[MEAS_FREQ]
301 	 */
302 	writel_relaxed(FIELD_PREP(IMX91_TMU_PERIOD_CTRL_MEAS_MASK, 4 * HZ_PER_MHZ / 25),
303 		       tmu->base + IMX91_TMU_PERIOD_CTRL);
304 
305 	imx91_tmu_enable(tmu, true);
306 	ret = devm_add_action(dev, imx91_tmu_action_remove, tmu);
307 	if (ret)
308 		return dev_err_probe(dev, ret, "Failure to add action imx91_tmu_action_remove()\n");
309 
310 	pm_runtime_set_active(dev);
311 	pm_runtime_get_noresume(dev);
312 	ret = devm_pm_runtime_enable(dev);
313 	if (ret)
314 		return ret;
315 
316 	tmu->tzd = devm_thermal_of_zone_register(dev, 0, tmu, &tmu_tz_ops);
317 	if (IS_ERR(tmu->tzd))
318 		return dev_err_probe(dev, PTR_ERR(tmu->tzd),
319 				     "failed to register thermal zone sensor\n");
320 
321 	irq = platform_get_irq(pdev, 0);
322 	if (irq < 0)
323 		return irq;
324 
325 	ret = devm_request_threaded_irq(dev, irq, imx91_tmu_alarm_irq,
326 					imx91_tmu_alarm_irq_thread,
327 					IRQF_ONESHOT, "imx91_thermal", tmu);
328 
329 	if (ret < 0)
330 		return dev_err_probe(dev, ret, "failed to request alarm irq\n");
331 
332 	pm_runtime_put(dev);
333 
334 	return 0;
335 }
336 
337 static int imx91_tmu_runtime_suspend(struct device *dev)
338 {
339 	struct imx91_tmu *tmu = dev_get_drvdata(dev);
340 
341 	/* disable tmu */
342 	imx91_tmu_enable(tmu, false);
343 
344 	clk_disable_unprepare(tmu->clk);
345 
346 	return 0;
347 }
348 
349 static int imx91_tmu_runtime_resume(struct device *dev)
350 {
351 	struct imx91_tmu *tmu = dev_get_drvdata(dev);
352 	int ret;
353 
354 	ret = clk_prepare_enable(tmu->clk);
355 	if (ret)
356 		return ret;
357 
358 	imx91_tmu_enable(tmu, true);
359 
360 	return 0;
361 }
362 
363 static DEFINE_RUNTIME_DEV_PM_OPS(imx91_tmu_pm_ops, imx91_tmu_runtime_suspend,
364 				 imx91_tmu_runtime_resume, NULL);
365 
366 static const struct of_device_id imx91_tmu_table[] = {
367 	{ .compatible = "fsl,imx91-tmu", },
368 	{ },
369 };
370 MODULE_DEVICE_TABLE(of, imx91_tmu_table);
371 
372 static struct platform_driver imx91_tmu = {
373 	.driver = {
374 		.name	= "imx91_thermal",
375 		.pm	= pm_ptr(&imx91_tmu_pm_ops),
376 		.of_match_table = imx91_tmu_table,
377 	},
378 	.probe = imx91_tmu_probe,
379 };
380 module_platform_driver(imx91_tmu);
381 
382 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
383 MODULE_DESCRIPTION("i.MX91 Thermal Monitor Unit driver");
384 MODULE_LICENSE("GPL");
385