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