xref: /openbmc/linux/drivers/soc/ti/smartreflex.c (revision 808643ea)
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 	struct clk *fck;
130 	u32 fclk_speed;
131 
132 	/* Try interconnect target module fck first if it already exists */
133 	fck = clk_get(sr->pdev->dev.parent, "fck");
134 	if (IS_ERR(fck)) {
135 		fck = clk_get(&sr->pdev->dev, "fck");
136 		if (IS_ERR(fck)) {
137 			dev_err(&sr->pdev->dev,
138 				"%s: unable to get fck for device %s\n",
139 				__func__, dev_name(&sr->pdev->dev));
140 			return;
141 		}
142 	}
143 
144 	fclk_speed = clk_get_rate(fck);
145 	clk_put(fck);
146 
147 	switch (fclk_speed) {
148 	case 12000000:
149 		sr->clk_length = SRCLKLENGTH_12MHZ_SYSCLK;
150 		break;
151 	case 13000000:
152 		sr->clk_length = SRCLKLENGTH_13MHZ_SYSCLK;
153 		break;
154 	case 19200000:
155 		sr->clk_length = SRCLKLENGTH_19MHZ_SYSCLK;
156 		break;
157 	case 26000000:
158 		sr->clk_length = SRCLKLENGTH_26MHZ_SYSCLK;
159 		break;
160 	case 38400000:
161 		sr->clk_length = SRCLKLENGTH_38MHZ_SYSCLK;
162 		break;
163 	default:
164 		dev_err(&sr->pdev->dev, "%s: Invalid fclk rate: %d\n",
165 			__func__, fclk_speed);
166 		break;
167 	}
168 }
169 
170 static void sr_start_vddautocomp(struct omap_sr *sr)
171 {
172 	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
173 		dev_warn(&sr->pdev->dev,
174 			 "%s: smartreflex class driver not registered\n",
175 			 __func__);
176 		return;
177 	}
178 
179 	if (!sr_class->enable(sr))
180 		sr->autocomp_active = true;
181 }
182 
183 static void sr_stop_vddautocomp(struct omap_sr *sr)
184 {
185 	if (!sr_class || !(sr_class->disable)) {
186 		dev_warn(&sr->pdev->dev,
187 			 "%s: smartreflex class driver not registered\n",
188 			 __func__);
189 		return;
190 	}
191 
192 	if (sr->autocomp_active) {
193 		sr_class->disable(sr, 1);
194 		sr->autocomp_active = false;
195 	}
196 }
197 
198 /*
199  * This function handles the initializations which have to be done
200  * only when both sr device and class driver regiter has
201  * completed. This will be attempted to be called from both sr class
202  * driver register and sr device intializtion API's. Only one call
203  * will ultimately succeed.
204  *
205  * Currently this function registers interrupt handler for a particular SR
206  * if smartreflex class driver is already registered and has
207  * requested for interrupts and the SR interrupt line in present.
208  */
209 static int sr_late_init(struct omap_sr *sr_info)
210 {
211 	struct omap_sr_data *pdata = sr_info->pdev->dev.platform_data;
212 	int ret = 0;
213 
214 	if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
215 		ret = devm_request_irq(&sr_info->pdev->dev, sr_info->irq,
216 				       sr_interrupt, 0, sr_info->name, sr_info);
217 		if (ret)
218 			goto error;
219 		disable_irq(sr_info->irq);
220 	}
221 
222 	if (pdata && pdata->enable_on_init)
223 		sr_start_vddautocomp(sr_info);
224 
225 	return ret;
226 
227 error:
228 	list_del(&sr_info->node);
229 	dev_err(&sr_info->pdev->dev, "%s: ERROR in registering interrupt handler. Smartreflex will not function as desired\n",
230 		__func__);
231 
232 	return ret;
233 }
234 
235 static void sr_v1_disable(struct omap_sr *sr)
236 {
237 	int timeout = 0;
238 	int errconf_val = ERRCONFIG_MCUACCUMINTST | ERRCONFIG_MCUVALIDINTST |
239 			ERRCONFIG_MCUBOUNDINTST;
240 
241 	/* Enable MCUDisableAcknowledge interrupt */
242 	sr_modify_reg(sr, ERRCONFIG_V1,
243 			ERRCONFIG_MCUDISACKINTEN, ERRCONFIG_MCUDISACKINTEN);
244 
245 	/* SRCONFIG - disable SR */
246 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
247 
248 	/* Disable all other SR interrupts and clear the status as needed */
249 	if (sr_read_reg(sr, ERRCONFIG_V1) & ERRCONFIG_VPBOUNDINTST_V1)
250 		errconf_val |= ERRCONFIG_VPBOUNDINTST_V1;
251 	sr_modify_reg(sr, ERRCONFIG_V1,
252 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
253 			ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_VPBOUNDINTEN_V1),
254 			errconf_val);
255 
256 	/*
257 	 * Wait for SR to be disabled.
258 	 * wait until ERRCONFIG.MCUDISACKINTST = 1. Typical latency is 1us.
259 	 */
260 	sr_test_cond_timeout((sr_read_reg(sr, ERRCONFIG_V1) &
261 			     ERRCONFIG_MCUDISACKINTST), SR_DISABLE_TIMEOUT,
262 			     timeout);
263 
264 	if (timeout >= SR_DISABLE_TIMEOUT)
265 		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
266 			 __func__);
267 
268 	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
269 	sr_modify_reg(sr, ERRCONFIG_V1, ERRCONFIG_MCUDISACKINTEN,
270 			ERRCONFIG_MCUDISACKINTST);
271 }
272 
273 static void sr_v2_disable(struct omap_sr *sr)
274 {
275 	int timeout = 0;
276 
277 	/* Enable MCUDisableAcknowledge interrupt */
278 	sr_write_reg(sr, IRQENABLE_SET, IRQENABLE_MCUDISABLEACKINT);
279 
280 	/* SRCONFIG - disable SR */
281 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
282 
283 	/*
284 	 * Disable all other SR interrupts and clear the status
285 	 * write to status register ONLY on need basis - only if status
286 	 * is set.
287 	 */
288 	if (sr_read_reg(sr, ERRCONFIG_V2) & ERRCONFIG_VPBOUNDINTST_V2)
289 		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
290 			ERRCONFIG_VPBOUNDINTST_V2);
291 	else
292 		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
293 				0x0);
294 	sr_write_reg(sr, IRQENABLE_CLR, (IRQENABLE_MCUACCUMINT |
295 			IRQENABLE_MCUVALIDINT |
296 			IRQENABLE_MCUBOUNDSINT));
297 	sr_write_reg(sr, IRQSTATUS, (IRQSTATUS_MCUACCUMINT |
298 			IRQSTATUS_MCVALIDINT |
299 			IRQSTATUS_MCBOUNDSINT));
300 
301 	/*
302 	 * Wait for SR to be disabled.
303 	 * wait until IRQSTATUS.MCUDISACKINTST = 1. Typical latency is 1us.
304 	 */
305 	sr_test_cond_timeout((sr_read_reg(sr, IRQSTATUS) &
306 			     IRQSTATUS_MCUDISABLEACKINT), SR_DISABLE_TIMEOUT,
307 			     timeout);
308 
309 	if (timeout >= SR_DISABLE_TIMEOUT)
310 		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
311 			 __func__);
312 
313 	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
314 	sr_write_reg(sr, IRQENABLE_CLR, IRQENABLE_MCUDISABLEACKINT);
315 	sr_write_reg(sr, IRQSTATUS, IRQSTATUS_MCUDISABLEACKINT);
316 }
317 
318 static struct omap_sr_nvalue_table *sr_retrieve_nvalue_row(
319 				struct omap_sr *sr, u32 efuse_offs)
320 {
321 	int i;
322 
323 	if (!sr->nvalue_table) {
324 		dev_warn(&sr->pdev->dev, "%s: Missing ntarget value table\n",
325 			 __func__);
326 		return NULL;
327 	}
328 
329 	for (i = 0; i < sr->nvalue_count; i++) {
330 		if (sr->nvalue_table[i].efuse_offs == efuse_offs)
331 			return &sr->nvalue_table[i];
332 	}
333 
334 	return NULL;
335 }
336 
337 /* Public Functions */
338 
339 /**
340  * sr_configure_errgen() - Configures the SmartReflex to perform AVS using the
341  *			 error generator module.
342  * @sr:			SR module to be configured.
343  *
344  * This API is to be called from the smartreflex class driver to
345  * configure the error generator module inside the smartreflex module.
346  * SR settings if using the ERROR module inside Smartreflex.
347  * SR CLASS 3 by default uses only the ERROR module where as
348  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
349  * module. Returns 0 on success and error value in case of failure.
350  */
351 int sr_configure_errgen(struct omap_sr *sr)
352 {
353 	u32 sr_config, sr_errconfig, errconfig_offs;
354 	u32 vpboundint_en, vpboundint_st;
355 	u32 senp_en = 0, senn_en = 0;
356 	u8 senp_shift, senn_shift;
357 
358 	if (!sr) {
359 		pr_warn("%s: NULL omap_sr from %pS\n",
360 			__func__, (void *)_RET_IP_);
361 		return -EINVAL;
362 	}
363 
364 	if (!sr->clk_length)
365 		sr_set_clk_length(sr);
366 
367 	senp_en = sr->senp_mod;
368 	senn_en = sr->senn_mod;
369 
370 	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
371 		SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN;
372 
373 	switch (sr->ip_type) {
374 	case SR_TYPE_V1:
375 		sr_config |= SRCONFIG_DELAYCTRL;
376 		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
377 		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
378 		errconfig_offs = ERRCONFIG_V1;
379 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
380 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
381 		break;
382 	case SR_TYPE_V2:
383 		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
384 		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
385 		errconfig_offs = ERRCONFIG_V2;
386 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
387 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
388 		break;
389 	default:
390 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
391 			__func__);
392 		return -EINVAL;
393 	}
394 
395 	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
396 	sr_write_reg(sr, SRCONFIG, sr_config);
397 	sr_errconfig = (sr->err_weight << ERRCONFIG_ERRWEIGHT_SHIFT) |
398 		(sr->err_maxlimit << ERRCONFIG_ERRMAXLIMIT_SHIFT) |
399 		(sr->err_minlimit <<  ERRCONFIG_ERRMINLIMIT_SHIFT);
400 	sr_modify_reg(sr, errconfig_offs, (SR_ERRWEIGHT_MASK |
401 		SR_ERRMAXLIMIT_MASK | SR_ERRMINLIMIT_MASK),
402 		sr_errconfig);
403 
404 	/* Enabling the interrupts if the ERROR module is used */
405 	sr_modify_reg(sr, errconfig_offs, (vpboundint_en | vpboundint_st),
406 		      vpboundint_en);
407 
408 	return 0;
409 }
410 
411 /**
412  * sr_disable_errgen() - Disables SmartReflex AVS module's errgen component
413  * @sr:			SR module to be configured.
414  *
415  * This API is to be called from the smartreflex class driver to
416  * disable the error generator module inside the smartreflex module.
417  *
418  * Returns 0 on success and error value in case of failure.
419  */
420 int sr_disable_errgen(struct omap_sr *sr)
421 {
422 	u32 errconfig_offs;
423 	u32 vpboundint_en, vpboundint_st;
424 
425 	if (!sr) {
426 		pr_warn("%s: NULL omap_sr from %pS\n",
427 			__func__, (void *)_RET_IP_);
428 		return -EINVAL;
429 	}
430 
431 	switch (sr->ip_type) {
432 	case SR_TYPE_V1:
433 		errconfig_offs = ERRCONFIG_V1;
434 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
435 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
436 		break;
437 	case SR_TYPE_V2:
438 		errconfig_offs = ERRCONFIG_V2;
439 		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
440 		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
441 		break;
442 	default:
443 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
444 			__func__);
445 		return -EINVAL;
446 	}
447 
448 	/* Disable the Sensor and errorgen */
449 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);
450 
451 	/*
452 	 * Disable the interrupts of ERROR module
453 	 * NOTE: modify is a read, modify,write - an implicit OCP barrier
454 	 * which is required is present here - sequencing is critical
455 	 * at this point (after errgen is disabled, vpboundint disable)
456 	 */
457 	sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
458 
459 	return 0;
460 }
461 
462 /**
463  * sr_configure_minmax() - Configures the SmartReflex to perform AVS using the
464  *			 minmaxavg module.
465  * @sr:			SR module to be configured.
466  *
467  * This API is to be called from the smartreflex class driver to
468  * configure the minmaxavg module inside the smartreflex module.
469  * SR settings if using the ERROR module inside Smartreflex.
470  * SR CLASS 3 by default uses only the ERROR module where as
471  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
472  * module. Returns 0 on success and error value in case of failure.
473  */
474 int sr_configure_minmax(struct omap_sr *sr)
475 {
476 	u32 sr_config, sr_avgwt;
477 	u32 senp_en = 0, senn_en = 0;
478 	u8 senp_shift, senn_shift;
479 
480 	if (!sr) {
481 		pr_warn("%s: NULL omap_sr from %pS\n",
482 			__func__, (void *)_RET_IP_);
483 		return -EINVAL;
484 	}
485 
486 	if (!sr->clk_length)
487 		sr_set_clk_length(sr);
488 
489 	senp_en = sr->senp_mod;
490 	senn_en = sr->senn_mod;
491 
492 	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
493 		SRCONFIG_SENENABLE |
494 		(sr->accum_data << SRCONFIG_ACCUMDATA_SHIFT);
495 
496 	switch (sr->ip_type) {
497 	case SR_TYPE_V1:
498 		sr_config |= SRCONFIG_DELAYCTRL;
499 		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
500 		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
501 		break;
502 	case SR_TYPE_V2:
503 		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
504 		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
505 		break;
506 	default:
507 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
508 			__func__);
509 		return -EINVAL;
510 	}
511 
512 	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
513 	sr_write_reg(sr, SRCONFIG, sr_config);
514 	sr_avgwt = (sr->senp_avgweight << AVGWEIGHT_SENPAVGWEIGHT_SHIFT) |
515 		(sr->senn_avgweight << AVGWEIGHT_SENNAVGWEIGHT_SHIFT);
516 	sr_write_reg(sr, AVGWEIGHT, sr_avgwt);
517 
518 	/*
519 	 * Enabling the interrupts if MINMAXAVG module is used.
520 	 * TODO: check if all the interrupts are mandatory
521 	 */
522 	switch (sr->ip_type) {
523 	case SR_TYPE_V1:
524 		sr_modify_reg(sr, ERRCONFIG_V1,
525 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
526 			ERRCONFIG_MCUBOUNDINTEN),
527 			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUACCUMINTST |
528 			 ERRCONFIG_MCUVALIDINTEN | ERRCONFIG_MCUVALIDINTST |
529 			 ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_MCUBOUNDINTST));
530 		break;
531 	case SR_TYPE_V2:
532 		sr_write_reg(sr, IRQSTATUS,
533 			IRQSTATUS_MCUACCUMINT | IRQSTATUS_MCVALIDINT |
534 			IRQSTATUS_MCBOUNDSINT | IRQSTATUS_MCUDISABLEACKINT);
535 		sr_write_reg(sr, IRQENABLE_SET,
536 			IRQENABLE_MCUACCUMINT | IRQENABLE_MCUVALIDINT |
537 			IRQENABLE_MCUBOUNDSINT | IRQENABLE_MCUDISABLEACKINT);
538 		break;
539 	default:
540 		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex module without specifying the ip\n",
541 			__func__);
542 		return -EINVAL;
543 	}
544 
545 	return 0;
546 }
547 
548 /**
549  * sr_enable() - Enables the smartreflex module.
550  * @sr:		pointer to which the SR module to be configured belongs to.
551  * @volt:	The voltage at which the Voltage domain associated with
552  *		the smartreflex module is operating at.
553  *		This is required only to program the correct Ntarget value.
554  *
555  * This API is to be called from the smartreflex class driver to
556  * enable a smartreflex module. Returns 0 on success. Returns error
557  * value if the voltage passed is wrong or if ntarget value is wrong.
558  */
559 int sr_enable(struct omap_sr *sr, unsigned long volt)
560 {
561 	struct omap_volt_data *volt_data;
562 	struct omap_sr_nvalue_table *nvalue_row;
563 	int ret;
564 
565 	if (!sr) {
566 		pr_warn("%s: NULL omap_sr from %pS\n",
567 			__func__, (void *)_RET_IP_);
568 		return -EINVAL;
569 	}
570 
571 	volt_data = omap_voltage_get_voltdata(sr->voltdm, volt);
572 
573 	if (IS_ERR(volt_data)) {
574 		dev_warn(&sr->pdev->dev, "%s: Unable to get voltage table for nominal voltage %ld\n",
575 			 __func__, volt);
576 		return PTR_ERR(volt_data);
577 	}
578 
579 	nvalue_row = sr_retrieve_nvalue_row(sr, volt_data->sr_efuse_offs);
580 
581 	if (!nvalue_row) {
582 		dev_warn(&sr->pdev->dev, "%s: failure getting SR data for this voltage %ld\n",
583 			 __func__, volt);
584 		return -ENODATA;
585 	}
586 
587 	/* errminlimit is opp dependent and hence linked to voltage */
588 	sr->err_minlimit = nvalue_row->errminlimit;
589 
590 	pm_runtime_get_sync(&sr->pdev->dev);
591 
592 	/* Check if SR is already enabled. If yes do nothing */
593 	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE)
594 		return 0;
595 
596 	/* Configure SR */
597 	ret = sr_class->configure(sr);
598 	if (ret)
599 		return ret;
600 
601 	sr_write_reg(sr, NVALUERECIPROCAL, nvalue_row->nvalue);
602 
603 	/* SRCONFIG - enable SR */
604 	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, SRCONFIG_SRENABLE);
605 	return 0;
606 }
607 
608 /**
609  * sr_disable() - Disables the smartreflex module.
610  * @sr:		pointer to which the SR module to be configured belongs to.
611  *
612  * This API is to be called from the smartreflex class driver to
613  * disable a smartreflex module.
614  */
615 void sr_disable(struct omap_sr *sr)
616 {
617 	if (!sr) {
618 		pr_warn("%s: NULL omap_sr from %pS\n",
619 			__func__, (void *)_RET_IP_);
620 		return;
621 	}
622 
623 	/* Check if SR clocks are already disabled. If yes do nothing */
624 	if (pm_runtime_suspended(&sr->pdev->dev))
625 		return;
626 
627 	/*
628 	 * Disable SR if only it is indeed enabled. Else just
629 	 * disable the clocks.
630 	 */
631 	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE) {
632 		switch (sr->ip_type) {
633 		case SR_TYPE_V1:
634 			sr_v1_disable(sr);
635 			break;
636 		case SR_TYPE_V2:
637 			sr_v2_disable(sr);
638 			break;
639 		default:
640 			dev_err(&sr->pdev->dev, "UNKNOWN IP type %d\n",
641 				sr->ip_type);
642 		}
643 	}
644 
645 	pm_runtime_put_sync_suspend(&sr->pdev->dev);
646 }
647 
648 /**
649  * sr_register_class() - API to register a smartreflex class parameters.
650  * @class_data:	The structure containing various sr class specific data.
651  *
652  * This API is to be called by the smartreflex class driver to register itself
653  * with the smartreflex driver during init. Returns 0 on success else the
654  * error value.
655  */
656 int sr_register_class(struct omap_sr_class_data *class_data)
657 {
658 	struct omap_sr *sr_info;
659 
660 	if (!class_data) {
661 		pr_warn("%s:, Smartreflex class data passed is NULL\n",
662 			__func__);
663 		return -EINVAL;
664 	}
665 
666 	if (sr_class) {
667 		pr_warn("%s: Smartreflex class driver already registered\n",
668 			__func__);
669 		return -EBUSY;
670 	}
671 
672 	sr_class = class_data;
673 
674 	/*
675 	 * Call into late init to do initializations that require
676 	 * both sr driver and sr class driver to be initiallized.
677 	 */
678 	list_for_each_entry(sr_info, &sr_list, node)
679 		sr_late_init(sr_info);
680 
681 	return 0;
682 }
683 
684 /**
685  * omap_sr_enable() -  API to enable SR clocks and to call into the
686  *			registered smartreflex class enable API.
687  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
688  *
689  * This API is to be called from the kernel in order to enable
690  * a particular smartreflex module. This API will do the initial
691  * configurations to turn on the smartreflex module and in turn call
692  * into the registered smartreflex class enable API.
693  */
694 void omap_sr_enable(struct voltagedomain *voltdm)
695 {
696 	struct omap_sr *sr = _sr_lookup(voltdm);
697 
698 	if (IS_ERR(sr)) {
699 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
700 		return;
701 	}
702 
703 	if (!sr->autocomp_active)
704 		return;
705 
706 	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
707 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
708 			 __func__);
709 		return;
710 	}
711 
712 	sr_class->enable(sr);
713 }
714 
715 /**
716  * omap_sr_disable() - API to disable SR without resetting the voltage
717  *			processor voltage
718  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
719  *
720  * This API is to be called from the kernel in order to disable
721  * a particular smartreflex module. This API will in turn call
722  * into the registered smartreflex class disable API. This API will tell
723  * the smartreflex class disable not to reset the VP voltage after
724  * disabling smartreflex.
725  */
726 void omap_sr_disable(struct voltagedomain *voltdm)
727 {
728 	struct omap_sr *sr = _sr_lookup(voltdm);
729 
730 	if (IS_ERR(sr)) {
731 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
732 		return;
733 	}
734 
735 	if (!sr->autocomp_active)
736 		return;
737 
738 	if (!sr_class || !(sr_class->disable)) {
739 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
740 			 __func__);
741 		return;
742 	}
743 
744 	sr_class->disable(sr, 0);
745 }
746 
747 /**
748  * omap_sr_disable_reset_volt() - API to disable SR and reset the
749  *				voltage processor voltage
750  * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
751  *
752  * This API is to be called from the kernel in order to disable
753  * a particular smartreflex module. This API will in turn call
754  * into the registered smartreflex class disable API. This API will tell
755  * the smartreflex class disable to reset the VP voltage after
756  * disabling smartreflex.
757  */
758 void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
759 {
760 	struct omap_sr *sr = _sr_lookup(voltdm);
761 
762 	if (IS_ERR(sr)) {
763 		pr_warn("%s: omap_sr struct for voltdm not found\n", __func__);
764 		return;
765 	}
766 
767 	if (!sr->autocomp_active)
768 		return;
769 
770 	if (!sr_class || !(sr_class->disable)) {
771 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not registered\n",
772 			 __func__);
773 		return;
774 	}
775 
776 	sr_class->disable(sr, 1);
777 }
778 
779 /* PM Debug FS entries to enable and disable smartreflex. */
780 static int omap_sr_autocomp_show(void *data, u64 *val)
781 {
782 	struct omap_sr *sr_info = data;
783 
784 	if (!sr_info) {
785 		pr_warn("%s: omap_sr struct not found\n", __func__);
786 		return -EINVAL;
787 	}
788 
789 	*val = sr_info->autocomp_active;
790 
791 	return 0;
792 }
793 
794 static int omap_sr_autocomp_store(void *data, u64 val)
795 {
796 	struct omap_sr *sr_info = data;
797 
798 	if (!sr_info) {
799 		pr_warn("%s: omap_sr struct not found\n", __func__);
800 		return -EINVAL;
801 	}
802 
803 	/* Sanity check */
804 	if (val > 1) {
805 		pr_warn("%s: Invalid argument %lld\n", __func__, val);
806 		return -EINVAL;
807 	}
808 
809 	/* control enable/disable only if there is a delta in value */
810 	if (sr_info->autocomp_active != val) {
811 		if (!val)
812 			sr_stop_vddautocomp(sr_info);
813 		else
814 			sr_start_vddautocomp(sr_info);
815 	}
816 
817 	return 0;
818 }
819 
820 DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
821 			omap_sr_autocomp_store, "%llu\n");
822 
823 static int omap_sr_probe(struct platform_device *pdev)
824 {
825 	struct omap_sr *sr_info;
826 	struct omap_sr_data *pdata = pdev->dev.platform_data;
827 	struct resource *mem, *irq;
828 	struct dentry *nvalue_dir;
829 	int i, ret = 0;
830 
831 	sr_info = devm_kzalloc(&pdev->dev, sizeof(struct omap_sr), GFP_KERNEL);
832 	if (!sr_info)
833 		return -ENOMEM;
834 
835 	sr_info->name = devm_kzalloc(&pdev->dev,
836 				     SMARTREFLEX_NAME_LEN, GFP_KERNEL);
837 	if (!sr_info->name)
838 		return -ENOMEM;
839 
840 	platform_set_drvdata(pdev, sr_info);
841 
842 	if (!pdata) {
843 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
844 		return -EINVAL;
845 	}
846 
847 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
848 	sr_info->base = devm_ioremap_resource(&pdev->dev, mem);
849 	if (IS_ERR(sr_info->base))
850 		return PTR_ERR(sr_info->base);
851 
852 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
853 
854 	pm_runtime_enable(&pdev->dev);
855 	pm_runtime_irq_safe(&pdev->dev);
856 
857 	snprintf(sr_info->name, SMARTREFLEX_NAME_LEN, "%s", pdata->name);
858 
859 	sr_info->pdev = pdev;
860 	sr_info->srid = pdev->id;
861 	sr_info->voltdm = pdata->voltdm;
862 	sr_info->nvalue_table = pdata->nvalue_table;
863 	sr_info->nvalue_count = pdata->nvalue_count;
864 	sr_info->senn_mod = pdata->senn_mod;
865 	sr_info->senp_mod = pdata->senp_mod;
866 	sr_info->err_weight = pdata->err_weight;
867 	sr_info->err_maxlimit = pdata->err_maxlimit;
868 	sr_info->accum_data = pdata->accum_data;
869 	sr_info->senn_avgweight = pdata->senn_avgweight;
870 	sr_info->senp_avgweight = pdata->senp_avgweight;
871 	sr_info->autocomp_active = false;
872 	sr_info->ip_type = pdata->ip_type;
873 
874 	if (irq)
875 		sr_info->irq = irq->start;
876 
877 	sr_set_clk_length(sr_info);
878 
879 	list_add(&sr_info->node, &sr_list);
880 
881 	ret = pm_runtime_get_sync(&pdev->dev);
882 	if (ret < 0) {
883 		pm_runtime_put_noidle(&pdev->dev);
884 		goto err_list_del;
885 	}
886 
887 	/*
888 	 * Call into late init to do initializations that require
889 	 * both sr driver and sr class driver to be initiallized.
890 	 */
891 	if (sr_class) {
892 		ret = sr_late_init(sr_info);
893 		if (ret) {
894 			pr_warn("%s: Error in SR late init\n", __func__);
895 			goto err_list_del;
896 		}
897 	}
898 
899 	dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
900 	if (!sr_dbg_dir)
901 		sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
902 
903 	sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
904 
905 	debugfs_create_file("autocomp", S_IRUGO | S_IWUSR, sr_info->dbg_dir,
906 			    sr_info, &pm_sr_fops);
907 	debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
908 			   &sr_info->err_weight);
909 	debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
910 			   &sr_info->err_maxlimit);
911 
912 	nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
913 
914 	if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
915 		dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
916 			 __func__, sr_info->name);
917 
918 		ret = -ENODATA;
919 		goto err_debugfs;
920 	}
921 
922 	for (i = 0; i < sr_info->nvalue_count; i++) {
923 		char name[NVALUE_NAME_LEN + 1];
924 
925 		snprintf(name, sizeof(name), "volt_%lu",
926 				sr_info->nvalue_table[i].volt_nominal);
927 		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
928 				   &(sr_info->nvalue_table[i].nvalue));
929 		snprintf(name, sizeof(name), "errminlimit_%lu",
930 			 sr_info->nvalue_table[i].volt_nominal);
931 		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
932 				   &(sr_info->nvalue_table[i].errminlimit));
933 
934 	}
935 
936 	pm_runtime_put_sync(&pdev->dev);
937 
938 	return ret;
939 
940 err_debugfs:
941 	debugfs_remove_recursive(sr_info->dbg_dir);
942 err_list_del:
943 	list_del(&sr_info->node);
944 
945 	pm_runtime_put_sync(&pdev->dev);
946 
947 	return ret;
948 }
949 
950 static int omap_sr_remove(struct platform_device *pdev)
951 {
952 	struct omap_sr_data *pdata = pdev->dev.platform_data;
953 	struct omap_sr *sr_info;
954 
955 	if (!pdata) {
956 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
957 		return -EINVAL;
958 	}
959 
960 	sr_info = _sr_lookup(pdata->voltdm);
961 	if (IS_ERR(sr_info)) {
962 		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
963 			__func__);
964 		return PTR_ERR(sr_info);
965 	}
966 
967 	if (sr_info->autocomp_active)
968 		sr_stop_vddautocomp(sr_info);
969 	debugfs_remove_recursive(sr_info->dbg_dir);
970 
971 	pm_runtime_disable(&pdev->dev);
972 	list_del(&sr_info->node);
973 	return 0;
974 }
975 
976 static void omap_sr_shutdown(struct platform_device *pdev)
977 {
978 	struct omap_sr_data *pdata = pdev->dev.platform_data;
979 	struct omap_sr *sr_info;
980 
981 	if (!pdata) {
982 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
983 		return;
984 	}
985 
986 	sr_info = _sr_lookup(pdata->voltdm);
987 	if (IS_ERR(sr_info)) {
988 		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
989 			__func__);
990 		return;
991 	}
992 
993 	if (sr_info->autocomp_active)
994 		sr_stop_vddautocomp(sr_info);
995 
996 	return;
997 }
998 
999 static const struct of_device_id omap_sr_match[] = {
1000 	{ .compatible = "ti,omap3-smartreflex-core", },
1001 	{ .compatible = "ti,omap3-smartreflex-mpu-iva", },
1002 	{ .compatible = "ti,omap4-smartreflex-core", },
1003 	{ .compatible = "ti,omap4-smartreflex-mpu", },
1004 	{ .compatible = "ti,omap4-smartreflex-iva", },
1005 	{  },
1006 };
1007 MODULE_DEVICE_TABLE(of, omap_sr_match);
1008 
1009 static struct platform_driver smartreflex_driver = {
1010 	.probe		= omap_sr_probe,
1011 	.remove         = omap_sr_remove,
1012 	.shutdown	= omap_sr_shutdown,
1013 	.driver		= {
1014 		.name	= DRIVER_NAME,
1015 		.of_match_table	= omap_sr_match,
1016 	},
1017 };
1018 
1019 static int __init sr_init(void)
1020 {
1021 	int ret = 0;
1022 
1023 	ret = platform_driver_register(&smartreflex_driver);
1024 	if (ret) {
1025 		pr_err("%s: platform driver register failed for SR\n",
1026 		       __func__);
1027 		return ret;
1028 	}
1029 
1030 	return 0;
1031 }
1032 late_initcall(sr_init);
1033 
1034 static void __exit sr_exit(void)
1035 {
1036 	platform_driver_unregister(&smartreflex_driver);
1037 }
1038 module_exit(sr_exit);
1039 
1040 MODULE_DESCRIPTION("OMAP Smartreflex Driver");
1041 MODULE_LICENSE("GPL");
1042 MODULE_ALIAS("platform:" DRIVER_NAME);
1043 MODULE_AUTHOR("Texas Instruments Inc");
1044