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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This file is part of STM32 ADC driver
4  *
5  * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
6  * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
7  *
8  * Inspired from: fsl-imx25-tsadc
9  *
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/clk.h>
14 #include <linux/interrupt.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/irqdesc.h>
17 #include <linux/irqdomain.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of_device.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regmap.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/slab.h>
27 #include <linux/units.h>
28 
29 #include "stm32-adc-core.h"
30 
31 #define STM32_ADC_CORE_SLEEP_DELAY_MS	2000
32 
33 /* SYSCFG registers */
34 #define STM32MP1_SYSCFG_PMCSETR		0x04
35 #define STM32MP1_SYSCFG_PMCCLRR		0x44
36 
37 /* SYSCFG bit fields */
38 #define STM32MP1_SYSCFG_ANASWVDD_MASK	BIT(9)
39 
40 /* SYSCFG capability flags */
41 #define HAS_VBOOSTER		BIT(0)
42 #define HAS_ANASWVDD		BIT(1)
43 
44 /**
45  * struct stm32_adc_common_regs - stm32 common registers
46  * @csr:	common status register offset
47  * @ccr:	common control register offset
48  * @eoc_msk:    array of eoc (end of conversion flag) masks in csr for adc1..n
49  * @ovr_msk:    array of ovr (overrun flag) masks in csr for adc1..n
50  * @ier:	interrupt enable register offset for each adc
51  * @eocie_msk:	end of conversion interrupt enable mask in @ier
52  */
53 struct stm32_adc_common_regs {
54 	u32 csr;
55 	u32 ccr;
56 	u32 eoc_msk[STM32_ADC_MAX_ADCS];
57 	u32 ovr_msk[STM32_ADC_MAX_ADCS];
58 	u32 ier;
59 	u32 eocie_msk;
60 };
61 
62 struct stm32_adc_priv;
63 
64 /**
65  * struct stm32_adc_priv_cfg - stm32 core compatible configuration data
66  * @regs:	common registers for all instances
67  * @clk_sel:	clock selection routine
68  * @max_clk_rate_hz: maximum analog clock rate (Hz, from datasheet)
69  * @ipid:	adc identification number
70  * @has_syscfg: SYSCFG capability flags
71  * @num_irqs:	number of interrupt lines
72  * @num_adcs:   maximum number of ADC instances in the common registers
73  */
74 struct stm32_adc_priv_cfg {
75 	const struct stm32_adc_common_regs *regs;
76 	int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *);
77 	u32 max_clk_rate_hz;
78 	u32 ipid;
79 	unsigned int has_syscfg;
80 	unsigned int num_irqs;
81 	unsigned int num_adcs;
82 };
83 
84 /**
85  * struct stm32_adc_priv - stm32 ADC core private data
86  * @irq:		irq(s) for ADC block
87  * @nb_adc_max:		actual maximum number of instance per ADC block
88  * @domain:		irq domain reference
89  * @aclk:		clock reference for the analog circuitry
90  * @bclk:		bus clock common for all ADCs, depends on part used
91  * @max_clk_rate:	desired maximum clock rate
92  * @booster:		booster supply reference
93  * @vdd:		vdd supply reference
94  * @vdda:		vdda analog supply reference
95  * @vref:		regulator reference
96  * @vdd_uv:		vdd supply voltage (microvolts)
97  * @vdda_uv:		vdda supply voltage (microvolts)
98  * @cfg:		compatible configuration data
99  * @common:		common data for all ADC instances
100  * @ccr_bak:		backup CCR in low power mode
101  * @syscfg:		reference to syscon, system control registers
102  */
103 struct stm32_adc_priv {
104 	int				irq[STM32_ADC_MAX_ADCS];
105 	unsigned int			nb_adc_max;
106 	struct irq_domain		*domain;
107 	struct clk			*aclk;
108 	struct clk			*bclk;
109 	u32				max_clk_rate;
110 	struct regulator		*booster;
111 	struct regulator		*vdd;
112 	struct regulator		*vdda;
113 	struct regulator		*vref;
114 	int				vdd_uv;
115 	int				vdda_uv;
116 	const struct stm32_adc_priv_cfg	*cfg;
117 	struct stm32_adc_common		common;
118 	u32				ccr_bak;
119 	struct regmap			*syscfg;
120 };
121 
to_stm32_adc_priv(struct stm32_adc_common * com)122 static struct stm32_adc_priv *to_stm32_adc_priv(struct stm32_adc_common *com)
123 {
124 	return container_of(com, struct stm32_adc_priv, common);
125 }
126 
127 /* STM32F4 ADC internal common clock prescaler division ratios */
128 static int stm32f4_pclk_div[] = {2, 4, 6, 8};
129 
130 /**
131  * stm32f4_adc_clk_sel() - Select stm32f4 ADC common clock prescaler
132  * @pdev: platform device
133  * @priv: stm32 ADC core private data
134  * Select clock prescaler used for analog conversions, before using ADC.
135  */
stm32f4_adc_clk_sel(struct platform_device * pdev,struct stm32_adc_priv * priv)136 static int stm32f4_adc_clk_sel(struct platform_device *pdev,
137 			       struct stm32_adc_priv *priv)
138 {
139 	unsigned long rate;
140 	u32 val;
141 	int i;
142 
143 	/* stm32f4 has one clk input for analog (mandatory), enforce it here */
144 	if (!priv->aclk) {
145 		dev_err(&pdev->dev, "No 'adc' clock found\n");
146 		return -ENOENT;
147 	}
148 
149 	rate = clk_get_rate(priv->aclk);
150 	if (!rate) {
151 		dev_err(&pdev->dev, "Invalid clock rate: 0\n");
152 		return -EINVAL;
153 	}
154 
155 	for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
156 		if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate)
157 			break;
158 	}
159 	if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
160 		dev_err(&pdev->dev, "adc clk selection failed\n");
161 		return -EINVAL;
162 	}
163 
164 	priv->common.rate = rate / stm32f4_pclk_div[i];
165 	val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
166 	val &= ~STM32F4_ADC_ADCPRE_MASK;
167 	val |= i << STM32F4_ADC_ADCPRE_SHIFT;
168 	writel_relaxed(val, priv->common.base + STM32F4_ADC_CCR);
169 
170 	dev_dbg(&pdev->dev, "Using analog clock source at %ld kHz\n",
171 		priv->common.rate / 1000);
172 
173 	return 0;
174 }
175 
176 /**
177  * struct stm32h7_adc_ck_spec - specification for stm32h7 adc clock
178  * @ckmode: ADC clock mode, Async or sync with prescaler.
179  * @presc: prescaler bitfield for async clock mode
180  * @div: prescaler division ratio
181  */
182 struct stm32h7_adc_ck_spec {
183 	u32 ckmode;
184 	u32 presc;
185 	int div;
186 };
187 
188 static const struct stm32h7_adc_ck_spec stm32h7_adc_ckmodes_spec[] = {
189 	/* 00: CK_ADC[1..3]: Asynchronous clock modes */
190 	{ 0, 0, 1 },
191 	{ 0, 1, 2 },
192 	{ 0, 2, 4 },
193 	{ 0, 3, 6 },
194 	{ 0, 4, 8 },
195 	{ 0, 5, 10 },
196 	{ 0, 6, 12 },
197 	{ 0, 7, 16 },
198 	{ 0, 8, 32 },
199 	{ 0, 9, 64 },
200 	{ 0, 10, 128 },
201 	{ 0, 11, 256 },
202 	/* HCLK used: Synchronous clock modes (1, 2 or 4 prescaler) */
203 	{ 1, 0, 1 },
204 	{ 2, 0, 2 },
205 	{ 3, 0, 4 },
206 };
207 
stm32h7_adc_clk_sel(struct platform_device * pdev,struct stm32_adc_priv * priv)208 static int stm32h7_adc_clk_sel(struct platform_device *pdev,
209 			       struct stm32_adc_priv *priv)
210 {
211 	u32 ckmode, presc, val;
212 	unsigned long rate;
213 	int i, div, duty;
214 
215 	/* stm32h7 bus clock is common for all ADC instances (mandatory) */
216 	if (!priv->bclk) {
217 		dev_err(&pdev->dev, "No 'bus' clock found\n");
218 		return -ENOENT;
219 	}
220 
221 	/*
222 	 * stm32h7 can use either 'bus' or 'adc' clock for analog circuitry.
223 	 * So, choice is to have bus clock mandatory and adc clock optional.
224 	 * If optional 'adc' clock has been found, then try to use it first.
225 	 */
226 	if (priv->aclk) {
227 		/*
228 		 * Asynchronous clock modes (e.g. ckmode == 0)
229 		 * From spec: PLL output musn't exceed max rate
230 		 */
231 		rate = clk_get_rate(priv->aclk);
232 		if (!rate) {
233 			dev_err(&pdev->dev, "Invalid adc clock rate: 0\n");
234 			return -EINVAL;
235 		}
236 
237 		/* If duty is an error, kindly use at least /2 divider */
238 		duty = clk_get_scaled_duty_cycle(priv->aclk, 100);
239 		if (duty < 0)
240 			dev_warn(&pdev->dev, "adc clock duty: %d\n", duty);
241 
242 		for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
243 			ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
244 			presc = stm32h7_adc_ckmodes_spec[i].presc;
245 			div = stm32h7_adc_ckmodes_spec[i].div;
246 
247 			if (ckmode)
248 				continue;
249 
250 			/*
251 			 * For proper operation, clock duty cycle range is 49%
252 			 * to 51%. Apply at least /2 prescaler otherwise.
253 			 */
254 			if (div == 1 && (duty < 49 || duty > 51))
255 				continue;
256 
257 			if ((rate / div) <= priv->max_clk_rate)
258 				goto out;
259 		}
260 	}
261 
262 	/* Synchronous clock modes (e.g. ckmode is 1, 2 or 3) */
263 	rate = clk_get_rate(priv->bclk);
264 	if (!rate) {
265 		dev_err(&pdev->dev, "Invalid bus clock rate: 0\n");
266 		return -EINVAL;
267 	}
268 
269 	duty = clk_get_scaled_duty_cycle(priv->bclk, 100);
270 	if (duty < 0)
271 		dev_warn(&pdev->dev, "bus clock duty: %d\n", duty);
272 
273 	for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
274 		ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
275 		presc = stm32h7_adc_ckmodes_spec[i].presc;
276 		div = stm32h7_adc_ckmodes_spec[i].div;
277 
278 		if (!ckmode)
279 			continue;
280 
281 		if (div == 1 && (duty < 49 || duty > 51))
282 			continue;
283 
284 		if ((rate / div) <= priv->max_clk_rate)
285 			goto out;
286 	}
287 
288 	dev_err(&pdev->dev, "adc clk selection failed\n");
289 	return -EINVAL;
290 
291 out:
292 	/* rate used later by each ADC instance to control BOOST mode */
293 	priv->common.rate = rate / div;
294 
295 	/* Set common clock mode and prescaler */
296 	val = readl_relaxed(priv->common.base + STM32H7_ADC_CCR);
297 	val &= ~(STM32H7_CKMODE_MASK | STM32H7_PRESC_MASK);
298 	val |= ckmode << STM32H7_CKMODE_SHIFT;
299 	val |= presc << STM32H7_PRESC_SHIFT;
300 	writel_relaxed(val, priv->common.base + STM32H7_ADC_CCR);
301 
302 	dev_dbg(&pdev->dev, "Using %s clock/%d source at %ld kHz\n",
303 		ckmode ? "bus" : "adc", div, priv->common.rate / 1000);
304 
305 	return 0;
306 }
307 
308 /* STM32F4 common registers definitions */
309 static const struct stm32_adc_common_regs stm32f4_adc_common_regs = {
310 	.csr = STM32F4_ADC_CSR,
311 	.ccr = STM32F4_ADC_CCR,
312 	.eoc_msk = { STM32F4_EOC1, STM32F4_EOC2, STM32F4_EOC3 },
313 	.ovr_msk = { STM32F4_OVR1, STM32F4_OVR2, STM32F4_OVR3 },
314 	.ier = STM32F4_ADC_CR1,
315 	.eocie_msk = STM32F4_EOCIE,
316 };
317 
318 /* STM32H7 common registers definitions */
319 static const struct stm32_adc_common_regs stm32h7_adc_common_regs = {
320 	.csr = STM32H7_ADC_CSR,
321 	.ccr = STM32H7_ADC_CCR,
322 	.eoc_msk = { STM32H7_EOC_MST, STM32H7_EOC_SLV },
323 	.ovr_msk = { STM32H7_OVR_MST, STM32H7_OVR_SLV },
324 	.ier = STM32H7_ADC_IER,
325 	.eocie_msk = STM32H7_EOCIE,
326 };
327 
328 /* STM32MP13 common registers definitions */
329 static const struct stm32_adc_common_regs stm32mp13_adc_common_regs = {
330 	.csr = STM32H7_ADC_CSR,
331 	.ccr = STM32H7_ADC_CCR,
332 	.eoc_msk = { STM32H7_EOC_MST },
333 	.ovr_msk = { STM32H7_OVR_MST },
334 	.ier = STM32H7_ADC_IER,
335 	.eocie_msk = STM32H7_EOCIE,
336 };
337 
338 static const unsigned int stm32_adc_offset[STM32_ADC_MAX_ADCS] = {
339 	0, STM32_ADC_OFFSET, STM32_ADC_OFFSET * 2,
340 };
341 
stm32_adc_eoc_enabled(struct stm32_adc_priv * priv,unsigned int adc)342 static unsigned int stm32_adc_eoc_enabled(struct stm32_adc_priv *priv,
343 					  unsigned int adc)
344 {
345 	u32 ier, offset = stm32_adc_offset[adc];
346 
347 	ier = readl_relaxed(priv->common.base + offset + priv->cfg->regs->ier);
348 
349 	return ier & priv->cfg->regs->eocie_msk;
350 }
351 
352 /* ADC common interrupt for all instances */
stm32_adc_irq_handler(struct irq_desc * desc)353 static void stm32_adc_irq_handler(struct irq_desc *desc)
354 {
355 	struct stm32_adc_priv *priv = irq_desc_get_handler_data(desc);
356 	struct irq_chip *chip = irq_desc_get_chip(desc);
357 	int i;
358 	u32 status;
359 
360 	chained_irq_enter(chip, desc);
361 	status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
362 
363 	/*
364 	 * End of conversion may be handled by using IRQ or DMA. There may be a
365 	 * race here when two conversions complete at the same time on several
366 	 * ADCs. EOC may be read 'set' for several ADCs, with:
367 	 * - an ADC configured to use DMA (EOC triggers the DMA request, and
368 	 *   is then automatically cleared by DR read in hardware)
369 	 * - an ADC configured to use IRQs (EOCIE bit is set. The handler must
370 	 *   be called in this case)
371 	 * So both EOC status bit in CSR and EOCIE control bit must be checked
372 	 * before invoking the interrupt handler (e.g. call ISR only for
373 	 * IRQ-enabled ADCs).
374 	 */
375 	for (i = 0; i < priv->nb_adc_max; i++) {
376 		if ((status & priv->cfg->regs->eoc_msk[i] &&
377 		     stm32_adc_eoc_enabled(priv, i)) ||
378 		     (status & priv->cfg->regs->ovr_msk[i]))
379 			generic_handle_domain_irq(priv->domain, i);
380 	}
381 
382 	chained_irq_exit(chip, desc);
383 };
384 
stm32_adc_domain_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)385 static int stm32_adc_domain_map(struct irq_domain *d, unsigned int irq,
386 				irq_hw_number_t hwirq)
387 {
388 	irq_set_chip_data(irq, d->host_data);
389 	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_level_irq);
390 
391 	return 0;
392 }
393 
stm32_adc_domain_unmap(struct irq_domain * d,unsigned int irq)394 static void stm32_adc_domain_unmap(struct irq_domain *d, unsigned int irq)
395 {
396 	irq_set_chip_and_handler(irq, NULL, NULL);
397 	irq_set_chip_data(irq, NULL);
398 }
399 
400 static const struct irq_domain_ops stm32_adc_domain_ops = {
401 	.map = stm32_adc_domain_map,
402 	.unmap  = stm32_adc_domain_unmap,
403 	.xlate = irq_domain_xlate_onecell,
404 };
405 
stm32_adc_irq_probe(struct platform_device * pdev,struct stm32_adc_priv * priv)406 static int stm32_adc_irq_probe(struct platform_device *pdev,
407 			       struct stm32_adc_priv *priv)
408 {
409 	struct device_node *np = pdev->dev.of_node;
410 	unsigned int i;
411 
412 	/*
413 	 * Interrupt(s) must be provided, depending on the compatible:
414 	 * - stm32f4/h7 shares a common interrupt line.
415 	 * - stm32mp1, has one line per ADC
416 	 */
417 	for (i = 0; i < priv->cfg->num_irqs; i++) {
418 		priv->irq[i] = platform_get_irq(pdev, i);
419 		if (priv->irq[i] < 0)
420 			return priv->irq[i];
421 	}
422 
423 	priv->domain = irq_domain_add_simple(np, STM32_ADC_MAX_ADCS, 0,
424 					     &stm32_adc_domain_ops,
425 					     priv);
426 	if (!priv->domain) {
427 		dev_err(&pdev->dev, "Failed to add irq domain\n");
428 		return -ENOMEM;
429 	}
430 
431 	for (i = 0; i < priv->cfg->num_irqs; i++)
432 		irq_set_chained_handler_and_data(priv->irq[i],
433 						 stm32_adc_irq_handler, priv);
434 
435 	return 0;
436 }
437 
stm32_adc_irq_remove(struct platform_device * pdev,struct stm32_adc_priv * priv)438 static void stm32_adc_irq_remove(struct platform_device *pdev,
439 				 struct stm32_adc_priv *priv)
440 {
441 	int hwirq;
442 	unsigned int i;
443 
444 	for (hwirq = 0; hwirq < priv->nb_adc_max; hwirq++)
445 		irq_dispose_mapping(irq_find_mapping(priv->domain, hwirq));
446 	irq_domain_remove(priv->domain);
447 
448 	for (i = 0; i < priv->cfg->num_irqs; i++)
449 		irq_set_chained_handler(priv->irq[i], NULL);
450 }
451 
stm32_adc_core_switches_supply_en(struct stm32_adc_priv * priv,struct device * dev)452 static int stm32_adc_core_switches_supply_en(struct stm32_adc_priv *priv,
453 					     struct device *dev)
454 {
455 	int ret;
456 
457 	/*
458 	 * On STM32H7 and STM32MP1, the ADC inputs are multiplexed with analog
459 	 * switches (via PCSEL) which have reduced performances when their
460 	 * supply is below 2.7V (vdda by default):
461 	 * - Voltage booster can be used, to get full ADC performances
462 	 *   (increases power consumption).
463 	 * - Vdd can be used to supply them, if above 2.7V (STM32MP1 only).
464 	 *
465 	 * Recommended settings for ANASWVDD and EN_BOOSTER:
466 	 * - vdda < 2.7V but vdd > 2.7V: ANASWVDD = 1, EN_BOOSTER = 0 (stm32mp1)
467 	 * - vdda < 2.7V and vdd < 2.7V: ANASWVDD = 0, EN_BOOSTER = 1
468 	 * - vdda >= 2.7V:               ANASWVDD = 0, EN_BOOSTER = 0 (default)
469 	 */
470 	if (priv->vdda_uv < 2700000) {
471 		if (priv->syscfg && priv->vdd_uv > 2700000) {
472 			ret = regulator_enable(priv->vdd);
473 			if (ret < 0) {
474 				dev_err(dev, "vdd enable failed %d\n", ret);
475 				return ret;
476 			}
477 
478 			ret = regmap_write(priv->syscfg,
479 					   STM32MP1_SYSCFG_PMCSETR,
480 					   STM32MP1_SYSCFG_ANASWVDD_MASK);
481 			if (ret < 0) {
482 				regulator_disable(priv->vdd);
483 				dev_err(dev, "vdd select failed, %d\n", ret);
484 				return ret;
485 			}
486 			dev_dbg(dev, "analog switches supplied by vdd\n");
487 
488 			return 0;
489 		}
490 
491 		if (priv->booster) {
492 			/*
493 			 * This is optional, as this is a trade-off between
494 			 * analog performance and power consumption.
495 			 */
496 			ret = regulator_enable(priv->booster);
497 			if (ret < 0) {
498 				dev_err(dev, "booster enable failed %d\n", ret);
499 				return ret;
500 			}
501 			dev_dbg(dev, "analog switches supplied by booster\n");
502 
503 			return 0;
504 		}
505 	}
506 
507 	/* Fallback using vdda (default), nothing to do */
508 	dev_dbg(dev, "analog switches supplied by vdda (%d uV)\n",
509 		priv->vdda_uv);
510 
511 	return 0;
512 }
513 
stm32_adc_core_switches_supply_dis(struct stm32_adc_priv * priv)514 static void stm32_adc_core_switches_supply_dis(struct stm32_adc_priv *priv)
515 {
516 	if (priv->vdda_uv < 2700000) {
517 		if (priv->syscfg && priv->vdd_uv > 2700000) {
518 			regmap_write(priv->syscfg, STM32MP1_SYSCFG_PMCCLRR,
519 				     STM32MP1_SYSCFG_ANASWVDD_MASK);
520 			regulator_disable(priv->vdd);
521 			return;
522 		}
523 		if (priv->booster)
524 			regulator_disable(priv->booster);
525 	}
526 }
527 
stm32_adc_core_hw_start(struct device * dev)528 static int stm32_adc_core_hw_start(struct device *dev)
529 {
530 	struct stm32_adc_common *common = dev_get_drvdata(dev);
531 	struct stm32_adc_priv *priv = to_stm32_adc_priv(common);
532 	int ret;
533 
534 	ret = regulator_enable(priv->vdda);
535 	if (ret < 0) {
536 		dev_err(dev, "vdda enable failed %d\n", ret);
537 		return ret;
538 	}
539 
540 	ret = regulator_get_voltage(priv->vdda);
541 	if (ret < 0) {
542 		dev_err(dev, "vdda get voltage failed, %d\n", ret);
543 		goto err_vdda_disable;
544 	}
545 	priv->vdda_uv = ret;
546 
547 	ret = stm32_adc_core_switches_supply_en(priv, dev);
548 	if (ret < 0)
549 		goto err_vdda_disable;
550 
551 	ret = regulator_enable(priv->vref);
552 	if (ret < 0) {
553 		dev_err(dev, "vref enable failed\n");
554 		goto err_switches_dis;
555 	}
556 
557 	ret = clk_prepare_enable(priv->bclk);
558 	if (ret < 0) {
559 		dev_err(dev, "bus clk enable failed\n");
560 		goto err_regulator_disable;
561 	}
562 
563 	ret = clk_prepare_enable(priv->aclk);
564 	if (ret < 0) {
565 		dev_err(dev, "adc clk enable failed\n");
566 		goto err_bclk_disable;
567 	}
568 
569 	writel_relaxed(priv->ccr_bak, priv->common.base + priv->cfg->regs->ccr);
570 
571 	return 0;
572 
573 err_bclk_disable:
574 	clk_disable_unprepare(priv->bclk);
575 err_regulator_disable:
576 	regulator_disable(priv->vref);
577 err_switches_dis:
578 	stm32_adc_core_switches_supply_dis(priv);
579 err_vdda_disable:
580 	regulator_disable(priv->vdda);
581 
582 	return ret;
583 }
584 
stm32_adc_core_hw_stop(struct device * dev)585 static void stm32_adc_core_hw_stop(struct device *dev)
586 {
587 	struct stm32_adc_common *common = dev_get_drvdata(dev);
588 	struct stm32_adc_priv *priv = to_stm32_adc_priv(common);
589 
590 	/* Backup CCR that may be lost (depends on power state to achieve) */
591 	priv->ccr_bak = readl_relaxed(priv->common.base + priv->cfg->regs->ccr);
592 	clk_disable_unprepare(priv->aclk);
593 	clk_disable_unprepare(priv->bclk);
594 	regulator_disable(priv->vref);
595 	stm32_adc_core_switches_supply_dis(priv);
596 	regulator_disable(priv->vdda);
597 }
598 
stm32_adc_core_switches_probe(struct device * dev,struct stm32_adc_priv * priv)599 static int stm32_adc_core_switches_probe(struct device *dev,
600 					 struct stm32_adc_priv *priv)
601 {
602 	struct device_node *np = dev->of_node;
603 	int ret;
604 
605 	/* Analog switches supply can be controlled by syscfg (optional) */
606 	priv->syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
607 	if (IS_ERR(priv->syscfg)) {
608 		ret = PTR_ERR(priv->syscfg);
609 		if (ret != -ENODEV)
610 			return dev_err_probe(dev, ret, "Can't probe syscfg\n");
611 
612 		priv->syscfg = NULL;
613 	}
614 
615 	/* Booster can be used to supply analog switches (optional) */
616 	if (priv->cfg->has_syscfg & HAS_VBOOSTER &&
617 	    of_property_read_bool(np, "booster-supply")) {
618 		priv->booster = devm_regulator_get_optional(dev, "booster");
619 		if (IS_ERR(priv->booster)) {
620 			ret = PTR_ERR(priv->booster);
621 			if (ret != -ENODEV)
622 				return dev_err_probe(dev, ret, "can't get booster\n");
623 
624 			priv->booster = NULL;
625 		}
626 	}
627 
628 	/* Vdd can be used to supply analog switches (optional) */
629 	if (priv->cfg->has_syscfg & HAS_ANASWVDD &&
630 	    of_property_read_bool(np, "vdd-supply")) {
631 		priv->vdd = devm_regulator_get_optional(dev, "vdd");
632 		if (IS_ERR(priv->vdd)) {
633 			ret = PTR_ERR(priv->vdd);
634 			if (ret != -ENODEV)
635 				return dev_err_probe(dev, ret, "can't get vdd\n");
636 
637 			priv->vdd = NULL;
638 		}
639 	}
640 
641 	if (priv->vdd) {
642 		ret = regulator_enable(priv->vdd);
643 		if (ret < 0) {
644 			dev_err(dev, "vdd enable failed %d\n", ret);
645 			return ret;
646 		}
647 
648 		ret = regulator_get_voltage(priv->vdd);
649 		if (ret < 0) {
650 			dev_err(dev, "vdd get voltage failed %d\n", ret);
651 			regulator_disable(priv->vdd);
652 			return ret;
653 		}
654 		priv->vdd_uv = ret;
655 
656 		regulator_disable(priv->vdd);
657 	}
658 
659 	return 0;
660 }
661 
stm32_adc_probe_identification(struct platform_device * pdev,struct stm32_adc_priv * priv)662 static int stm32_adc_probe_identification(struct platform_device *pdev,
663 					  struct stm32_adc_priv *priv)
664 {
665 	struct device_node *np = pdev->dev.of_node;
666 	struct device_node *child;
667 	const char *compat;
668 	int ret, count = 0;
669 	u32 id, val;
670 
671 	if (!priv->cfg->ipid)
672 		return 0;
673 
674 	id = FIELD_GET(STM32MP1_IPIDR_MASK,
675 		       readl_relaxed(priv->common.base + STM32MP1_ADC_IPDR));
676 	if (id != priv->cfg->ipid) {
677 		dev_err(&pdev->dev, "Unexpected IP version: 0x%x", id);
678 		return -EINVAL;
679 	}
680 
681 	for_each_child_of_node(np, child) {
682 		ret = of_property_read_string(child, "compatible", &compat);
683 		if (ret)
684 			continue;
685 		/* Count child nodes with stm32 adc compatible */
686 		if (strstr(compat, "st,stm32") && strstr(compat, "adc"))
687 			count++;
688 	}
689 
690 	val = readl_relaxed(priv->common.base + STM32MP1_ADC_HWCFGR0);
691 	priv->nb_adc_max = FIELD_GET(STM32MP1_ADCNUM_MASK, val);
692 	if (count > priv->nb_adc_max) {
693 		dev_err(&pdev->dev, "Unexpected child number: %d", count);
694 		return -EINVAL;
695 	}
696 
697 	val = readl_relaxed(priv->common.base + STM32MP1_ADC_VERR);
698 	dev_dbg(&pdev->dev, "ADC version: %lu.%lu\n",
699 		FIELD_GET(STM32MP1_MAJREV_MASK, val),
700 		FIELD_GET(STM32MP1_MINREV_MASK, val));
701 
702 	return 0;
703 }
704 
stm32_adc_probe(struct platform_device * pdev)705 static int stm32_adc_probe(struct platform_device *pdev)
706 {
707 	struct stm32_adc_priv *priv;
708 	struct device *dev = &pdev->dev;
709 	struct device_node *np = pdev->dev.of_node;
710 	const struct of_device_id *of_id;
711 
712 	struct resource *res;
713 	u32 max_rate;
714 	int ret;
715 
716 	if (!pdev->dev.of_node)
717 		return -ENODEV;
718 
719 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
720 	if (!priv)
721 		return -ENOMEM;
722 	platform_set_drvdata(pdev, &priv->common);
723 
724 	of_id = of_match_device(dev->driver->of_match_table, dev);
725 	if (!of_id)
726 		return -ENODEV;
727 
728 	priv->cfg = (const struct stm32_adc_priv_cfg *)of_id->data;
729 	priv->nb_adc_max = priv->cfg->num_adcs;
730 	spin_lock_init(&priv->common.lock);
731 
732 	priv->common.base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
733 	if (IS_ERR(priv->common.base))
734 		return PTR_ERR(priv->common.base);
735 	priv->common.phys_base = res->start;
736 
737 	priv->vdda = devm_regulator_get(&pdev->dev, "vdda");
738 	if (IS_ERR(priv->vdda))
739 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->vdda),
740 				     "vdda get failed\n");
741 
742 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
743 	if (IS_ERR(priv->vref))
744 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->vref),
745 				     "vref get failed\n");
746 
747 	priv->aclk = devm_clk_get_optional(&pdev->dev, "adc");
748 	if (IS_ERR(priv->aclk))
749 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->aclk),
750 				     "Can't get 'adc' clock\n");
751 
752 	priv->bclk = devm_clk_get_optional(&pdev->dev, "bus");
753 	if (IS_ERR(priv->bclk))
754 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->bclk),
755 				     "Can't get 'bus' clock\n");
756 
757 	ret = stm32_adc_core_switches_probe(dev, priv);
758 	if (ret)
759 		return ret;
760 
761 	pm_runtime_get_noresume(dev);
762 	pm_runtime_set_active(dev);
763 	pm_runtime_set_autosuspend_delay(dev, STM32_ADC_CORE_SLEEP_DELAY_MS);
764 	pm_runtime_use_autosuspend(dev);
765 	pm_runtime_enable(dev);
766 
767 	ret = stm32_adc_core_hw_start(dev);
768 	if (ret)
769 		goto err_pm_stop;
770 
771 	ret = stm32_adc_probe_identification(pdev, priv);
772 	if (ret < 0)
773 		goto err_hw_stop;
774 
775 	ret = regulator_get_voltage(priv->vref);
776 	if (ret < 0) {
777 		dev_err(&pdev->dev, "vref get voltage failed, %d\n", ret);
778 		goto err_hw_stop;
779 	}
780 	priv->common.vref_mv = ret / 1000;
781 	dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv);
782 
783 	ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz",
784 				   &max_rate);
785 	if (!ret)
786 		priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz);
787 	else
788 		priv->max_clk_rate = priv->cfg->max_clk_rate_hz;
789 
790 	ret = priv->cfg->clk_sel(pdev, priv);
791 	if (ret < 0)
792 		goto err_hw_stop;
793 
794 	ret = stm32_adc_irq_probe(pdev, priv);
795 	if (ret < 0)
796 		goto err_hw_stop;
797 
798 	ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
799 	if (ret < 0) {
800 		dev_err(&pdev->dev, "failed to populate DT children\n");
801 		goto err_irq_remove;
802 	}
803 
804 	pm_runtime_mark_last_busy(dev);
805 	pm_runtime_put_autosuspend(dev);
806 
807 	return 0;
808 
809 err_irq_remove:
810 	stm32_adc_irq_remove(pdev, priv);
811 err_hw_stop:
812 	stm32_adc_core_hw_stop(dev);
813 err_pm_stop:
814 	pm_runtime_disable(dev);
815 	pm_runtime_set_suspended(dev);
816 	pm_runtime_put_noidle(dev);
817 
818 	return ret;
819 }
820 
stm32_adc_remove(struct platform_device * pdev)821 static int stm32_adc_remove(struct platform_device *pdev)
822 {
823 	struct stm32_adc_common *common = platform_get_drvdata(pdev);
824 	struct stm32_adc_priv *priv = to_stm32_adc_priv(common);
825 
826 	pm_runtime_get_sync(&pdev->dev);
827 	of_platform_depopulate(&pdev->dev);
828 	stm32_adc_irq_remove(pdev, priv);
829 	stm32_adc_core_hw_stop(&pdev->dev);
830 	pm_runtime_disable(&pdev->dev);
831 	pm_runtime_set_suspended(&pdev->dev);
832 	pm_runtime_put_noidle(&pdev->dev);
833 
834 	return 0;
835 }
836 
stm32_adc_core_runtime_suspend(struct device * dev)837 static int stm32_adc_core_runtime_suspend(struct device *dev)
838 {
839 	stm32_adc_core_hw_stop(dev);
840 
841 	return 0;
842 }
843 
stm32_adc_core_runtime_resume(struct device * dev)844 static int stm32_adc_core_runtime_resume(struct device *dev)
845 {
846 	return stm32_adc_core_hw_start(dev);
847 }
848 
stm32_adc_core_runtime_idle(struct device * dev)849 static int stm32_adc_core_runtime_idle(struct device *dev)
850 {
851 	pm_runtime_mark_last_busy(dev);
852 
853 	return 0;
854 }
855 
856 static DEFINE_RUNTIME_DEV_PM_OPS(stm32_adc_core_pm_ops,
857 				stm32_adc_core_runtime_suspend,
858 				stm32_adc_core_runtime_resume,
859 				stm32_adc_core_runtime_idle);
860 
861 static const struct stm32_adc_priv_cfg stm32f4_adc_priv_cfg = {
862 	.regs = &stm32f4_adc_common_regs,
863 	.clk_sel = stm32f4_adc_clk_sel,
864 	.max_clk_rate_hz = 36000000,
865 	.num_irqs = 1,
866 	.num_adcs = 3,
867 };
868 
869 static const struct stm32_adc_priv_cfg stm32h7_adc_priv_cfg = {
870 	.regs = &stm32h7_adc_common_regs,
871 	.clk_sel = stm32h7_adc_clk_sel,
872 	.max_clk_rate_hz = 36000000,
873 	.has_syscfg = HAS_VBOOSTER,
874 	.num_irqs = 1,
875 	.num_adcs = 2,
876 };
877 
878 static const struct stm32_adc_priv_cfg stm32mp1_adc_priv_cfg = {
879 	.regs = &stm32h7_adc_common_regs,
880 	.clk_sel = stm32h7_adc_clk_sel,
881 	.max_clk_rate_hz = 36000000,
882 	.has_syscfg = HAS_VBOOSTER | HAS_ANASWVDD,
883 	.ipid = STM32MP15_IPIDR_NUMBER,
884 	.num_irqs = 2,
885 };
886 
887 static const struct stm32_adc_priv_cfg stm32mp13_adc_priv_cfg = {
888 	.regs = &stm32mp13_adc_common_regs,
889 	.clk_sel = stm32h7_adc_clk_sel,
890 	.max_clk_rate_hz = 75 * HZ_PER_MHZ,
891 	.ipid = STM32MP13_IPIDR_NUMBER,
892 	.num_irqs = 1,
893 };
894 
895 static const struct of_device_id stm32_adc_of_match[] = {
896 	{
897 		.compatible = "st,stm32f4-adc-core",
898 		.data = (void *)&stm32f4_adc_priv_cfg
899 	}, {
900 		.compatible = "st,stm32h7-adc-core",
901 		.data = (void *)&stm32h7_adc_priv_cfg
902 	}, {
903 		.compatible = "st,stm32mp1-adc-core",
904 		.data = (void *)&stm32mp1_adc_priv_cfg
905 	}, {
906 		.compatible = "st,stm32mp13-adc-core",
907 		.data = (void *)&stm32mp13_adc_priv_cfg
908 	}, {
909 	},
910 };
911 MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
912 
913 static struct platform_driver stm32_adc_driver = {
914 	.probe = stm32_adc_probe,
915 	.remove = stm32_adc_remove,
916 	.driver = {
917 		.name = "stm32-adc-core",
918 		.of_match_table = stm32_adc_of_match,
919 		.pm = pm_ptr(&stm32_adc_core_pm_ops),
920 	},
921 };
922 module_platform_driver(stm32_adc_driver);
923 
924 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
925 MODULE_DESCRIPTION("STMicroelectronics STM32 ADC core driver");
926 MODULE_LICENSE("GPL v2");
927 MODULE_ALIAS("platform:stm32-adc-core");
928