xref: /linux/drivers/soc/ti/smartreflex.c (revision 52990390f91c1c39ca742fc8f390b29891d95127)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * OMAP SmartReflex Voltage Control
4  *
5  * Author: Thara Gopinath	<thara@ti.com>
6  *
7  * Copyright (C) 2012 Texas Instruments, Inc.
8  * Thara Gopinath <thara@ti.com>
9  *
10  * Copyright (C) 2008 Nokia Corporation
11  * Kalle Jokiniemi
12  *
13  * Copyright (C) 2007 Texas Instruments, Inc.
14  * Lesly A M <x0080970@ti.com>
15  */
16 
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/interrupt.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/debugfs.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/power/smartreflex.h>
27 
28 #define DRIVER_NAME	"smartreflex"
29 #define SMARTREFLEX_NAME_LEN	32
30 #define NVALUE_NAME_LEN		40
31 #define SR_DISABLE_TIMEOUT	200
32 
33 /* sr_list contains all the instances of smartreflex module */
34 static LIST_HEAD(sr_list);
35 
36 static struct omap_sr_class_data *sr_class;
37 static struct dentry		*sr_dbg_dir;
38 
39 static inline void sr_write_reg(struct omap_sr *sr, unsigned offset, u32 value)
40 {
41 	__raw_writel(value, (sr->base + offset));
42 }
43 
44 static inline void sr_modify_reg(struct omap_sr *sr, unsigned offset, u32 mask,
45 					u32 value)
46 {
47 	u32 reg_val;
48 
49 	/*
50 	 * Smartreflex error config register is special as it contains
51 	 * certain status bits which if written a 1 into means a clear
52 	 * of those bits. So in order to make sure no accidental write of
53 	 * 1 happens to those status bits, do a clear of them in the read
54 	 * value. This mean this API doesn't rewrite values in these bits
55 	 * if they are currently set, but does allow the caller to write
56 	 * those bits.
57 	 */
58 	if (sr->ip_type == SR_TYPE_V1 && offset == ERRCONFIG_V1)
59 		mask |= ERRCONFIG_STATUS_V1_MASK;
60 	else if (sr->ip_type == SR_TYPE_V2 && offset == ERRCONFIG_V2)
61 		mask |= ERRCONFIG_VPBOUNDINTST_V2;
62 
63 	reg_val = __raw_readl(sr->base + offset);
64 	reg_val &= ~mask;
65 
66 	value &= mask;
67 
68 	reg_val |= value;
69 
70 	__raw_writel(reg_val, (sr->base + offset));
71 }
72 
73 static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
74 {
75 	return __raw_readl(sr->base + offset);
76 }
77 
78 static struct omap_sr *_sr_lookup(struct voltagedomain *voltdm)
79 {
80 	struct omap_sr *sr_info;
81 
82 	if (!voltdm) {
83 		pr_err("%s: Null voltage domain passed!\n", __func__);
84 		return ERR_PTR(-EINVAL);
85 	}
86 
87 	list_for_each_entry(sr_info, &sr_list, node) {
88 		if (voltdm == sr_info->voltdm)
89 			return sr_info;
90 	}
91 
92 	return ERR_PTR(-ENODATA);
93 }
94 
95 static irqreturn_t sr_interrupt(int irq, void *data)
96 {
97 	struct omap_sr *sr_info = data;
98 	u32 status = 0;
99 
100 	switch (sr_info->ip_type) {
101 	case SR_TYPE_V1:
102 		/* Read the status bits */
103 		status = sr_read_reg(sr_info, ERRCONFIG_V1);
104 
105 		/* Clear them by writing back */
106 		sr_write_reg(sr_info, ERRCONFIG_V1, status);
107 		break;
108 	case SR_TYPE_V2:
109 		/* Read the status bits */
110 		status = sr_read_reg(sr_info, IRQSTATUS);
111 
112 		/* Clear them by writing back */
113 		sr_write_reg(sr_info, IRQSTATUS, status);
114 		break;
115 	default:
116 		dev_err(&sr_info->pdev->dev, "UNKNOWN IP type %d\n",
117 			sr_info->ip_type);
118 		return IRQ_NONE;
119 	}
120 
121 	if (sr_class->notify)
122 		sr_class->notify(sr_info, status);
123 
124 	return IRQ_HANDLED;
125 }
126 
127 static void sr_set_clk_length(struct omap_sr *sr)
128 {
129 	u32 fclk_speed;
130 
131 	/* Try interconnect target module fck first if it already exists */
132 	if (IS_ERR(sr->fck))
133 		return;
134 
135 	fclk_speed = clk_get_rate(sr->fck);
136 
137 	switch (fclk_speed) {
138 	case 12000000:
139 		sr->clk_length = SRCLKLENGTH_12MHZ_SYSCLK;
140 		break;
141 	case 13000000:
142 		sr->clk_length = SRCLKLENGTH_13MHZ_SYSCLK;
143 		break;
144 	case 19200000:
145 		sr->clk_length = SRCLKLENGTH_19MHZ_SYSCLK;
146 		break;
147 	case 26000000:
148 		sr->clk_length = SRCLKLENGTH_26MHZ_SYSCLK;
149 		break;
150 	case 38400000:
151 		sr->clk_length = SRCLKLENGTH_38MHZ_SYSCLK;
152 		break;
153 	default:
154 		dev_err(&sr->pdev->dev, "%s: Invalid fclk rate: %d\n",
155 			__func__, fclk_speed);
156 		break;
157 	}
158 }
159 
160 static void sr_start_vddautocomp(struct omap_sr *sr)
161 {
162 	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
163 		dev_warn(&sr->pdev->dev,
164 			 "%s: smartreflex class driver not registered\n",
165 			 __func__);
166 		return;
167 	}
168 
169 	if (!sr_class->enable(sr))
170 		sr->autocomp_active = true;
171 }
172 
173 static void sr_stop_vddautocomp(struct omap_sr *sr)
174 {
175 	if (!sr_class || !(sr_class->disable)) {
176 		dev_warn(&sr->pdev->dev,
177 			 "%s: smartreflex class driver not registered\n",
178 			 __func__);
179 		return;
180 	}
181 
182 	if (sr->autocomp_active) {
183 		sr_class->disable(sr, 1);
184 		sr->autocomp_active = false;
185 	}
186 }
187 
188 /*
189  * This function handles the initializations which have to be done
190  * only when both sr device and class driver regiter has
191  * completed. This will be attempted to be called from both sr class
192  * driver register and sr device intializtion API's. Only one call
193  * will ultimately succeed.
194  *
195  * Currently this function registers interrupt handler for a particular SR
196  * if smartreflex class driver is already registered and has
197  * requested for interrupts and the SR interrupt line in present.
198  */
199 static int sr_late_init(struct omap_sr *sr_info)
200 {
201 	int ret = 0;
202 
203 	if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
204 		ret = devm_request_irq(&sr_info->pdev->dev, sr_info->irq,
205 				       sr_interrupt, 0, sr_info->name, sr_info);
206 		if (ret)
207 			goto error;
208 		disable_irq(sr_info->irq);
209 	}
210 
211 	return ret;
212 
213 error:
214 	list_del(&sr_info->node);
215 	dev_err(&sr_info->pdev->dev, "%s: ERROR in registering interrupt handler. Smartreflex will not function as desired\n",
216 		__func__);
217 
218 	return ret;
219 }
220 
221 static void sr_v1_disable(struct omap_sr *sr)
222 {
223 	int timeout = 0;
224 	int errconf_val = ERRCONFIG_MCUACCUMINTST | ERRCONFIG_MCUVALIDINTST |
225 			ERRCONFIG_MCUBOUNDINTST;
226 
227 	/* Enable MCUDisableAcknowledge interrupt */
228 	sr_modify_reg(sr, ERRCONFIG_V1,
229 			ERRCONFIG_MCUDISACKINTEN, ERRCONFIG_MCUDISACKINTEN);
230 
231 	/* SRCONFIG - disable SR */
232 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
233 
234 	/* Disable all other SR interrupts and clear the status as needed */
235 	if (sr_read_reg(sr, ERRCONFIG_V1) & ERRCONFIG_VPBOUNDINTST_V1)
236 		errconf_val |= ERRCONFIG_VPBOUNDINTST_V1;
237 	sr_modify_reg(sr, ERRCONFIG_V1,
238 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
239 			ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_VPBOUNDINTEN_V1),
240 			errconf_val);
241 
242 	/*
243 	 * Wait for SR to be disabled.
244 	 * wait until ERRCONFIG.MCUDISACKINTST = 1. Typical latency is 1us.
245 	 */
246 	sr_test_cond_timeout((sr_read_reg(sr, ERRCONFIG_V1) &
247 			     ERRCONFIG_MCUDISACKINTST), SR_DISABLE_TIMEOUT,
248 			     timeout);
249 
250 	if (timeout >= SR_DISABLE_TIMEOUT)
251 		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
252 			 __func__);
253 
254 	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
255 	sr_modify_reg(sr, ERRCONFIG_V1, ERRCONFIG_MCUDISACKINTEN,
256 			ERRCONFIG_MCUDISACKINTST);
257 }
258 
259 static void sr_v2_disable(struct omap_sr *sr)
260 {
261 	int timeout = 0;
262 
263 	/* Enable MCUDisableAcknowledge interrupt */
264 	sr_write_reg(sr, IRQENABLE_SET, IRQENABLE_MCUDISABLEACKINT);
265 
266 	/* SRCONFIG - disable SR */
267 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
268 
269 	/*
270 	 * Disable all other SR interrupts and clear the status
271 	 * write to status register ONLY on need basis - only if status
272 	 * is set.
273 	 */
274 	if (sr_read_reg(sr, ERRCONFIG_V2) & ERRCONFIG_VPBOUNDINTST_V2)
275 		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
276 			ERRCONFIG_VPBOUNDINTST_V2);
277 	else
278 		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
279 				0x0);
280 	sr_write_reg(sr, IRQENABLE_CLR, (IRQENABLE_MCUACCUMINT |
281 			IRQENABLE_MCUVALIDINT |
282 			IRQENABLE_MCUBOUNDSINT));
283 	sr_write_reg(sr, IRQSTATUS, (IRQSTATUS_MCUACCUMINT |
284 			IRQSTATUS_MCVALIDINT |
285 			IRQSTATUS_MCBOUNDSINT));
286 
287 	/*
288 	 * Wait for SR to be disabled.
289 	 * wait until IRQSTATUS.MCUDISACKINTST = 1. Typical latency is 1us.
290 	 */
291 	sr_test_cond_timeout((sr_read_reg(sr, IRQSTATUS) &
292 			     IRQSTATUS_MCUDISABLEACKINT), SR_DISABLE_TIMEOUT,
293 			     timeout);
294 
295 	if (timeout >= SR_DISABLE_TIMEOUT)
296 		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
297 			 __func__);
298 
299 	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
300 	sr_write_reg(sr, IRQENABLE_CLR, IRQENABLE_MCUDISABLEACKINT);
301 	sr_write_reg(sr, IRQSTATUS, IRQSTATUS_MCUDISABLEACKINT);
302 }
303 
304 static struct omap_sr_nvalue_table *sr_retrieve_nvalue_row(
305 				struct omap_sr *sr, u32 efuse_offs)
306 {
307 	int i;
308 
309 	if (!sr->nvalue_table) {
310 		dev_warn(&sr->pdev->dev, "%s: Missing ntarget value table\n",
311 			 __func__);
312 		return NULL;
313 	}
314 
315 	for (i = 0; i < sr->nvalue_count; i++) {
316 		if (sr->nvalue_table[i].efuse_offs == efuse_offs)
317 			return &sr->nvalue_table[i];
318 	}
319 
320 	return NULL;
321 }
322 
323 /* Public Functions */
324 
325 /**
326  * sr_configure_errgen() - Configures the SmartReflex to perform AVS using the
327  *			 error generator module.
328  * @sr:			SR module to be configured.
329  *
330  * This API is to be called from the smartreflex class driver to
331  * configure the error generator module inside the smartreflex module.
332  * SR settings if using the ERROR module inside Smartreflex.
333  * SR CLASS 3 by default uses only the ERROR module where as
334  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
335  * module. Returns 0 on success and error value in case of failure.
336  */
337 int sr_configure_errgen(struct omap_sr *sr)
338 {
339 	u32 sr_config, sr_errconfig, errconfig_offs;
340 	u32 vpboundint_en, vpboundint_st;
341 	u32 senp_en = 0, senn_en = 0;
342 	u8 senp_shift, senn_shift;
343 
344 	if (!sr) {
345 		pr_warn("%s: NULL omap_sr from %pS\n",
346 			__func__, (void *)_RET_IP_);
347 		return -EINVAL;
348 	}
349 
350 	if (!sr->clk_length)
351 		sr_set_clk_length(sr);
352 
353 	senp_en = sr->senp_mod;
354 	senn_en = sr->senn_mod;
355 
356 	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
357 		SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN;
358 
359 	switch (sr->ip_type) {
360 	case SR_TYPE_V1:
361 		sr_config |= SRCONFIG_DELAYCTRL;
362 		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
363 		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
364 		errconfig_offs = ERRCONFIG_V1;
365 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
366 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
367 		break;
368 	case SR_TYPE_V2:
369 		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
370 		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
371 		errconfig_offs = ERRCONFIG_V2;
372 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
373 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
374 		break;
375 	default:
376 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
377 			__func__);
378 		return -EINVAL;
379 	}
380 
381 	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
382 	sr_write_reg(sr, SRCONFIG, sr_config);
383 	sr_errconfig = (sr->err_weight << ERRCONFIG_ERRWEIGHT_SHIFT) |
384 		(sr->err_maxlimit << ERRCONFIG_ERRMAXLIMIT_SHIFT) |
385 		(sr->err_minlimit <<  ERRCONFIG_ERRMINLIMIT_SHIFT);
386 	sr_modify_reg(sr, errconfig_offs, (SR_ERRWEIGHT_MASK |
387 		SR_ERRMAXLIMIT_MASK | SR_ERRMINLIMIT_MASK),
388 		sr_errconfig);
389 
390 	/* Enabling the interrupts if the ERROR module is used */
391 	sr_modify_reg(sr, errconfig_offs, (vpboundint_en | vpboundint_st),
392 		      vpboundint_en);
393 
394 	return 0;
395 }
396 
397 /**
398  * sr_disable_errgen() - Disables SmartReflex AVS module's errgen component
399  * @sr:			SR module to be configured.
400  *
401  * This API is to be called from the smartreflex class driver to
402  * disable the error generator module inside the smartreflex module.
403  *
404  * Returns 0 on success and error value in case of failure.
405  */
406 int sr_disable_errgen(struct omap_sr *sr)
407 {
408 	u32 errconfig_offs;
409 	u32 vpboundint_en, vpboundint_st;
410 
411 	if (!sr) {
412 		pr_warn("%s: NULL omap_sr from %pS\n",
413 			__func__, (void *)_RET_IP_);
414 		return -EINVAL;
415 	}
416 
417 	switch (sr->ip_type) {
418 	case SR_TYPE_V1:
419 		errconfig_offs = ERRCONFIG_V1;
420 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
421 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
422 		break;
423 	case SR_TYPE_V2:
424 		errconfig_offs = ERRCONFIG_V2;
425 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
426 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
427 		break;
428 	default:
429 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
430 			__func__);
431 		return -EINVAL;
432 	}
433 
434 	/* Disable the Sensor and errorgen */
435 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);
436 
437 	/*
438 	 * Disable the interrupts of ERROR module
439 	 * NOTE: modify is a read, modify,write - an implicit OCP barrier
440 	 * which is required is present here - sequencing is critical
441 	 * at this point (after errgen is disabled, vpboundint disable)
442 	 */
443 	sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
444 
445 	return 0;
446 }
447 
448 /**
449  * sr_configure_minmax() - Configures the SmartReflex to perform AVS using the
450  *			 minmaxavg module.
451  * @sr:			SR module to be configured.
452  *
453  * This API is to be called from the smartreflex class driver to
454  * configure the minmaxavg module inside the smartreflex module.
455  * SR settings if using the ERROR module inside Smartreflex.
456  * SR CLASS 3 by default uses only the ERROR module where as
457  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
458  * module. Returns 0 on success and error value in case of failure.
459  */
460 int sr_configure_minmax(struct omap_sr *sr)
461 {
462 	u32 sr_config, sr_avgwt;
463 	u32 senp_en = 0, senn_en = 0;
464 	u8 senp_shift, senn_shift;
465 
466 	if (!sr) {
467 		pr_warn("%s: NULL omap_sr from %pS\n",
468 			__func__, (void *)_RET_IP_);
469 		return -EINVAL;
470 	}
471 
472 	if (!sr->clk_length)
473 		sr_set_clk_length(sr);
474 
475 	senp_en = sr->senp_mod;
476 	senn_en = sr->senn_mod;
477 
478 	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
479 		SRCONFIG_SENENABLE |
480 		(sr->accum_data << SRCONFIG_ACCUMDATA_SHIFT);
481 
482 	switch (sr->ip_type) {
483 	case SR_TYPE_V1:
484 		sr_config |= SRCONFIG_DELAYCTRL;
485 		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
486 		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
487 		break;
488 	case SR_TYPE_V2:
489 		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
490 		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
491 		break;
492 	default:
493 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
494 			__func__);
495 		return -EINVAL;
496 	}
497 
498 	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
499 	sr_write_reg(sr, SRCONFIG, sr_config);
500 	sr_avgwt = (sr->senp_avgweight << AVGWEIGHT_SENPAVGWEIGHT_SHIFT) |
501 		(sr->senn_avgweight << AVGWEIGHT_SENNAVGWEIGHT_SHIFT);
502 	sr_write_reg(sr, AVGWEIGHT, sr_avgwt);
503 
504 	/*
505 	 * Enabling the interrupts if MINMAXAVG module is used.
506 	 * TODO: check if all the interrupts are mandatory
507 	 */
508 	switch (sr->ip_type) {
509 	case SR_TYPE_V1:
510 		sr_modify_reg(sr, ERRCONFIG_V1,
511 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
512 			ERRCONFIG_MCUBOUNDINTEN),
513 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUACCUMINTST |
514 			 ERRCONFIG_MCUVALIDINTEN | ERRCONFIG_MCUVALIDINTST |
515 			 ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_MCUBOUNDINTST));
516 		break;
517 	case SR_TYPE_V2:
518 		sr_write_reg(sr, IRQSTATUS,
519 			IRQSTATUS_MCUACCUMINT | IRQSTATUS_MCVALIDINT |
520 			IRQSTATUS_MCBOUNDSINT | IRQSTATUS_MCUDISABLEACKINT);
521 		sr_write_reg(sr, IRQENABLE_SET,
522 			IRQENABLE_MCUACCUMINT | IRQENABLE_MCUVALIDINT |
523 			IRQENABLE_MCUBOUNDSINT | IRQENABLE_MCUDISABLEACKINT);
524 		break;
525 	default:
526 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
527 			__func__);
528 		return -EINVAL;
529 	}
530 
531 	return 0;
532 }
533 
534 /**
535  * sr_enable() - Enables the smartreflex module.
536  * @sr:		pointer to which the SR module to be configured belongs to.
537  * @volt:	The voltage at which the Voltage domain associated with
538  *		the smartreflex module is operating at.
539  *		This is required only to program the correct Ntarget value.
540  *
541  * This API is to be called from the smartreflex class driver to
542  * enable a smartreflex module. Returns 0 on success. Returns error
543  * value if the voltage passed is wrong or if ntarget value is wrong.
544  */
545 int sr_enable(struct omap_sr *sr, unsigned long volt)
546 {
547 	struct omap_volt_data *volt_data;
548 	struct omap_sr_nvalue_table *nvalue_row;
549 	int ret;
550 
551 	if (!sr) {
552 		pr_warn("%s: NULL omap_sr from %pS\n",
553 			__func__, (void *)_RET_IP_);
554 		return -EINVAL;
555 	}
556 
557 	volt_data = omap_voltage_get_voltdata(sr->voltdm, volt);
558 
559 	if (IS_ERR(volt_data)) {
560 		dev_warn(&sr->pdev->dev, "%s: Unable to get voltage table for nominal voltage %ld\n",
561 			 __func__, volt);
562 		return PTR_ERR(volt_data);
563 	}
564 
565 	nvalue_row = sr_retrieve_nvalue_row(sr, volt_data->sr_efuse_offs);
566 
567 	if (!nvalue_row) {
568 		dev_warn(&sr->pdev->dev, "%s: failure getting SR data for this voltage %ld\n",
569 			 __func__, volt);
570 		return -ENODATA;
571 	}
572 
573 	/* errminlimit is opp dependent and hence linked to voltage */
574 	sr->err_minlimit = nvalue_row->errminlimit;
575 
576 	clk_enable(sr->fck);
577 
578 	/* Check if SR is already enabled. If yes do nothing */
579 	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE)
580 		goto out_enabled;
581 
582 	/* Configure SR */
583 	ret = sr_class->configure(sr);
584 	if (ret)
585 		goto out_enabled;
586 
587 	sr_write_reg(sr, NVALUERECIPROCAL, nvalue_row->nvalue);
588 
589 	/* SRCONFIG - enable SR */
590 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, SRCONFIG_SRENABLE);
591 
592 out_enabled:
593 	sr->enabled = 1;
594 
595 	return 0;
596 }
597 
598 /**
599  * sr_disable() - Disables the smartreflex module.
600  * @sr:		pointer to which the SR module to be configured belongs to.
601  *
602  * This API is to be called from the smartreflex class driver to
603  * disable a smartreflex module.
604  */
605 void sr_disable(struct omap_sr *sr)
606 {
607 	if (!sr) {
608 		pr_warn("%s: NULL omap_sr from %pS\n",
609 			__func__, (void *)_RET_IP_);
610 		return;
611 	}
612 
613 	/* Check if SR clocks are already disabled. If yes do nothing */
614 	if (!sr->enabled)
615 		return;
616 
617 	/*
618 	 * Disable SR if only it is indeed enabled. Else just
619 	 * disable the clocks.
620 	 */
621 	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE) {
622 		switch (sr->ip_type) {
623 		case SR_TYPE_V1:
624 			sr_v1_disable(sr);
625 			break;
626 		case SR_TYPE_V2:
627 			sr_v2_disable(sr);
628 			break;
629 		default:
630 			dev_err(&sr->pdev->dev, "UNKNOWN IP type %d\n",
631 				sr->ip_type);
632 		}
633 	}
634 
635 	clk_disable(sr->fck);
636 	sr->enabled = 0;
637 }
638 
639 /**
640  * sr_register_class() - API to register a smartreflex class parameters.
641  * @class_data:	The structure containing various sr class specific data.
642  *
643  * This API is to be called by the smartreflex class driver to register itself
644  * with the smartreflex driver during init. Returns 0 on success else the
645  * error value.
646  */
647 int sr_register_class(struct omap_sr_class_data *class_data)
648 {
649 	struct omap_sr *sr_info;
650 
651 	if (!class_data) {
652 		pr_warn("%s:, Smartreflex class data passed is NULL\n",
653 			__func__);
654 		return -EINVAL;
655 	}
656 
657 	if (sr_class) {
658 		pr_warn("%s: Smartreflex class driver already registered\n",
659 			__func__);
660 		return -EBUSY;
661 	}
662 
663 	sr_class = class_data;
664 
665 	/*
666 	 * Call into late init to do initializations that require
667 	 * both sr driver and sr class driver to be initiallized.
668 	 */
669 	list_for_each_entry(sr_info, &sr_list, node)
670 		sr_late_init(sr_info);
671 
672 	return 0;
673 }
674 
675 /**
676  * omap_sr_enable() -  API to enable SR clocks and to call into the
677  *			registered smartreflex class enable API.
678  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
679  *
680  * This API is to be called from the kernel in order to enable
681  * a particular smartreflex module. This API will do the initial
682  * configurations to turn on the smartreflex module and in turn call
683  * into the registered smartreflex class enable API.
684  */
685 void omap_sr_enable(struct voltagedomain *voltdm)
686 {
687 	struct omap_sr *sr = _sr_lookup(voltdm);
688 
689 	if (IS_ERR(sr)) {
690 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
691 		return;
692 	}
693 
694 	if (!sr->autocomp_active)
695 		return;
696 
697 	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
698 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
699 			 __func__);
700 		return;
701 	}
702 
703 	sr_class->enable(sr);
704 }
705 
706 /**
707  * omap_sr_disable() - API to disable SR without resetting the voltage
708  *			processor voltage
709  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
710  *
711  * This API is to be called from the kernel in order to disable
712  * a particular smartreflex module. This API will in turn call
713  * into the registered smartreflex class disable API. This API will tell
714  * the smartreflex class disable not to reset the VP voltage after
715  * disabling smartreflex.
716  */
717 void omap_sr_disable(struct voltagedomain *voltdm)
718 {
719 	struct omap_sr *sr = _sr_lookup(voltdm);
720 
721 	if (IS_ERR(sr)) {
722 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
723 		return;
724 	}
725 
726 	if (!sr->autocomp_active)
727 		return;
728 
729 	if (!sr_class || !(sr_class->disable)) {
730 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
731 			 __func__);
732 		return;
733 	}
734 
735 	sr_class->disable(sr, 0);
736 }
737 
738 /**
739  * omap_sr_disable_reset_volt() - API to disable SR and reset the
740  *				voltage processor voltage
741  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
742  *
743  * This API is to be called from the kernel in order to disable
744  * a particular smartreflex module. This API will in turn call
745  * into the registered smartreflex class disable API. This API will tell
746  * the smartreflex class disable to reset the VP voltage after
747  * disabling smartreflex.
748  */
749 void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
750 {
751 	struct omap_sr *sr = _sr_lookup(voltdm);
752 
753 	if (IS_ERR(sr)) {
754 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
755 		return;
756 	}
757 
758 	if (!sr->autocomp_active)
759 		return;
760 
761 	if (!sr_class || !(sr_class->disable)) {
762 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
763 			 __func__);
764 		return;
765 	}
766 
767 	sr_class->disable(sr, 1);
768 }
769 
770 /* PM Debug FS entries to enable and disable smartreflex. */
771 static int omap_sr_autocomp_show(void *data, u64 *val)
772 {
773 	struct omap_sr *sr_info = data;
774 
775 	if (!sr_info) {
776 		pr_warn("%s: omap_sr struct not found\n", __func__);
777 		return -EINVAL;
778 	}
779 
780 	*val = sr_info->autocomp_active;
781 
782 	return 0;
783 }
784 
785 static int omap_sr_autocomp_store(void *data, u64 val)
786 {
787 	struct omap_sr *sr_info = data;
788 
789 	if (!sr_info) {
790 		pr_warn("%s: omap_sr struct not found\n", __func__);
791 		return -EINVAL;
792 	}
793 
794 	/* Sanity check */
795 	if (val > 1) {
796 		pr_warn("%s: Invalid argument %lld\n", __func__, val);
797 		return -EINVAL;
798 	}
799 
800 	/* control enable/disable only if there is a delta in value */
801 	if (sr_info->autocomp_active != val) {
802 		if (!val)
803 			sr_stop_vddautocomp(sr_info);
804 		else
805 			sr_start_vddautocomp(sr_info);
806 	}
807 
808 	return 0;
809 }
810 
811 DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
812 			omap_sr_autocomp_store, "%llu\n");
813 
814 static int omap_sr_probe(struct platform_device *pdev)
815 {
816 	struct omap_sr *sr_info;
817 	struct omap_sr_data *pdata = pdev->dev.platform_data;
818 	struct resource *mem;
819 	struct dentry *nvalue_dir;
820 	int i, ret = 0;
821 
822 	sr_info = devm_kzalloc(&pdev->dev, sizeof(struct omap_sr), GFP_KERNEL);
823 	if (!sr_info)
824 		return -ENOMEM;
825 
826 	sr_info->name = devm_kzalloc(&pdev->dev,
827 				     SMARTREFLEX_NAME_LEN, GFP_KERNEL);
828 	if (!sr_info->name)
829 		return -ENOMEM;
830 
831 	platform_set_drvdata(pdev, sr_info);
832 
833 	if (!pdata) {
834 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
835 		return -EINVAL;
836 	}
837 
838 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
839 	sr_info->base = devm_ioremap_resource(&pdev->dev, mem);
840 	if (IS_ERR(sr_info->base))
841 		return PTR_ERR(sr_info->base);
842 
843 	ret = platform_get_irq_optional(pdev, 0);
844 	if (ret < 0 && ret != -ENXIO)
845 		return dev_err_probe(&pdev->dev, ret, "failed to get IRQ resource\n");
846 	if (ret > 0)
847 		sr_info->irq = ret;
848 
849 	sr_info->fck = devm_clk_get(pdev->dev.parent, "fck");
850 	if (IS_ERR(sr_info->fck))
851 		return PTR_ERR(sr_info->fck);
852 	clk_prepare(sr_info->fck);
853 
854 	pm_runtime_enable(&pdev->dev);
855 
856 	snprintf(sr_info->name, SMARTREFLEX_NAME_LEN, "%s", pdata->name);
857 
858 	sr_info->pdev = pdev;
859 	sr_info->srid = pdev->id;
860 	sr_info->voltdm = pdata->voltdm;
861 	sr_info->nvalue_table = pdata->nvalue_table;
862 	sr_info->nvalue_count = pdata->nvalue_count;
863 	sr_info->senn_mod = pdata->senn_mod;
864 	sr_info->senp_mod = pdata->senp_mod;
865 	sr_info->err_weight = pdata->err_weight;
866 	sr_info->err_maxlimit = pdata->err_maxlimit;
867 	sr_info->accum_data = pdata->accum_data;
868 	sr_info->senn_avgweight = pdata->senn_avgweight;
869 	sr_info->senp_avgweight = pdata->senp_avgweight;
870 	sr_info->autocomp_active = false;
871 	sr_info->ip_type = pdata->ip_type;
872 
873 	sr_set_clk_length(sr_info);
874 
875 	list_add(&sr_info->node, &sr_list);
876 
877 	/*
878 	 * Call into late init to do initializations that require
879 	 * both sr driver and sr class driver to be initiallized.
880 	 */
881 	if (sr_class) {
882 		ret = sr_late_init(sr_info);
883 		if (ret) {
884 			pr_warn("%s: Error in SR late init\n", __func__);
885 			goto err_list_del;
886 		}
887 	}
888 
889 	dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
890 	if (!sr_dbg_dir)
891 		sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
892 
893 	sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
894 
895 	debugfs_create_file("autocomp", S_IRUGO | S_IWUSR, sr_info->dbg_dir,
896 			    sr_info, &pm_sr_fops);
897 	debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
898 			   &sr_info->err_weight);
899 	debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
900 			   &sr_info->err_maxlimit);
901 
902 	nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
903 
904 	if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
905 		dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
906 			 __func__, sr_info->name);
907 
908 		ret = -ENODATA;
909 		goto err_debugfs;
910 	}
911 
912 	for (i = 0; i < sr_info->nvalue_count; i++) {
913 		char name[NVALUE_NAME_LEN + 1];
914 
915 		snprintf(name, sizeof(name), "volt_%lu",
916 				sr_info->nvalue_table[i].volt_nominal);
917 		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
918 				   &(sr_info->nvalue_table[i].nvalue));
919 		snprintf(name, sizeof(name), "errminlimit_%lu",
920 			 sr_info->nvalue_table[i].volt_nominal);
921 		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
922 				   &(sr_info->nvalue_table[i].errminlimit));
923 
924 	}
925 
926 	return 0;
927 
928 err_debugfs:
929 	debugfs_remove_recursive(sr_info->dbg_dir);
930 err_list_del:
931 	pm_runtime_disable(&pdev->dev);
932 	list_del(&sr_info->node);
933 	clk_unprepare(sr_info->fck);
934 
935 	return ret;
936 }
937 
938 static int omap_sr_remove(struct platform_device *pdev)
939 {
940 	struct device *dev = &pdev->dev;
941 	struct omap_sr *sr_info = platform_get_drvdata(pdev);
942 
943 	if (sr_info->autocomp_active)
944 		sr_stop_vddautocomp(sr_info);
945 	debugfs_remove_recursive(sr_info->dbg_dir);
946 
947 	pm_runtime_disable(dev);
948 	clk_unprepare(sr_info->fck);
949 	list_del(&sr_info->node);
950 	return 0;
951 }
952 
953 static void omap_sr_shutdown(struct platform_device *pdev)
954 {
955 	struct omap_sr *sr_info = platform_get_drvdata(pdev);
956 
957 	if (sr_info->autocomp_active)
958 		sr_stop_vddautocomp(sr_info);
959 
960 	return;
961 }
962 
963 static const struct of_device_id omap_sr_match[] = {
964 	{ .compatible = "ti,omap3-smartreflex-core", },
965 	{ .compatible = "ti,omap3-smartreflex-mpu-iva", },
966 	{ .compatible = "ti,omap4-smartreflex-core", },
967 	{ .compatible = "ti,omap4-smartreflex-mpu", },
968 	{ .compatible = "ti,omap4-smartreflex-iva", },
969 	{  },
970 };
971 MODULE_DEVICE_TABLE(of, omap_sr_match);
972 
973 static struct platform_driver smartreflex_driver = {
974 	.probe		= omap_sr_probe,
975 	.remove         = omap_sr_remove,
976 	.shutdown	= omap_sr_shutdown,
977 	.driver		= {
978 		.name	= DRIVER_NAME,
979 		.of_match_table	= omap_sr_match,
980 	},
981 };
982 
983 static int __init sr_init(void)
984 {
985 	int ret = 0;
986 
987 	ret = platform_driver_register(&smartreflex_driver);
988 	if (ret) {
989 		pr_err("%s: platform driver register failed for SR\n",
990 		       __func__);
991 		return ret;
992 	}
993 
994 	return 0;
995 }
996 late_initcall(sr_init);
997 
998 static void __exit sr_exit(void)
999 {
1000 	platform_driver_unregister(&smartreflex_driver);
1001 }
1002 module_exit(sr_exit);
1003 
1004 MODULE_DESCRIPTION("OMAP Smartreflex Driver");
1005 MODULE_LICENSE("GPL");
1006 MODULE_ALIAS("platform:" DRIVER_NAME);
1007 MODULE_AUTHOR("Texas Instruments Inc");
1008