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   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 */
  34static LIST_HEAD(sr_list);
  35
  36static struct omap_sr_class_data *sr_class;
  37static struct dentry		*sr_dbg_dir;
  38
  39static inline void sr_write_reg(struct omap_sr *sr, unsigned offset, u32 value)
  40{
  41	__raw_writel(value, (sr->base + offset));
  42}
  43
  44static 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
  73static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
  74{
  75	return __raw_readl(sr->base + offset);
  76}
  77
  78static 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
  95static 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
 127static 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
 160static 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
 173static 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 */
 199static 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, IRQF_NO_AUTOEN,
 206				       sr_info->name, sr_info);
 207		if (ret)
 208			goto error;
 209	}
 210
 211	return ret;
 212
 213error:
 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
 221static 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
 259static 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
 304static 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 */
 337int 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 */
 406int 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 */
 460int 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 */
 545int 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
 592out_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 */
 605void 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 */
 647int 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 */
 685void 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 */
 717void 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 */
 749void 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. */
 771static 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
 785static 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
 811DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
 812			omap_sr_autocomp_store, "%llu\n");
 813
 814static 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 dentry *nvalue_dir;
 819	int i, ret = 0;
 820
 821	sr_info = devm_kzalloc(&pdev->dev, sizeof(struct omap_sr), GFP_KERNEL);
 822	if (!sr_info)
 823		return -ENOMEM;
 824
 825	sr_info->name = devm_kzalloc(&pdev->dev,
 826				     SMARTREFLEX_NAME_LEN, GFP_KERNEL);
 827	if (!sr_info->name)
 828		return -ENOMEM;
 829
 830	platform_set_drvdata(pdev, sr_info);
 831
 832	if (!pdata) {
 833		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
 834		return -EINVAL;
 835	}
 836
 837	sr_info->base = devm_platform_ioremap_resource(pdev, 0);
 838	if (IS_ERR(sr_info->base))
 839		return PTR_ERR(sr_info->base);
 840
 841	ret = platform_get_irq_optional(pdev, 0);
 842	if (ret < 0 && ret != -ENXIO)
 843		return dev_err_probe(&pdev->dev, ret, "failed to get IRQ resource\n");
 844	if (ret > 0)
 845		sr_info->irq = ret;
 846
 847	sr_info->fck = devm_clk_get(pdev->dev.parent, "fck");
 848	if (IS_ERR(sr_info->fck))
 849		return PTR_ERR(sr_info->fck);
 850	clk_prepare(sr_info->fck);
 851
 852	pm_runtime_enable(&pdev->dev);
 853
 854	snprintf(sr_info->name, SMARTREFLEX_NAME_LEN, "%s", pdata->name);
 855
 856	sr_info->pdev = pdev;
 857	sr_info->srid = pdev->id;
 858	sr_info->voltdm = pdata->voltdm;
 859	sr_info->nvalue_table = pdata->nvalue_table;
 860	sr_info->nvalue_count = pdata->nvalue_count;
 861	sr_info->senn_mod = pdata->senn_mod;
 862	sr_info->senp_mod = pdata->senp_mod;
 863	sr_info->err_weight = pdata->err_weight;
 864	sr_info->err_maxlimit = pdata->err_maxlimit;
 865	sr_info->accum_data = pdata->accum_data;
 866	sr_info->senn_avgweight = pdata->senn_avgweight;
 867	sr_info->senp_avgweight = pdata->senp_avgweight;
 868	sr_info->autocomp_active = false;
 869	sr_info->ip_type = pdata->ip_type;
 870
 871	sr_set_clk_length(sr_info);
 872
 873	list_add(&sr_info->node, &sr_list);
 874
 875	/*
 876	 * Call into late init to do initializations that require
 877	 * both sr driver and sr class driver to be initiallized.
 878	 */
 879	if (sr_class) {
 880		ret = sr_late_init(sr_info);
 881		if (ret) {
 882			pr_warn("%s: Error in SR late init\n", __func__);
 883			goto err_list_del;
 884		}
 885	}
 886
 887	dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
 888	if (!sr_dbg_dir)
 889		sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
 890
 891	sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
 892
 893	debugfs_create_file("autocomp", S_IRUGO | S_IWUSR, sr_info->dbg_dir,
 894			    sr_info, &pm_sr_fops);
 895	debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
 896			   &sr_info->err_weight);
 897	debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
 898			   &sr_info->err_maxlimit);
 899
 900	nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
 901
 902	if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
 903		dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
 904			 __func__, sr_info->name);
 905
 906		ret = -ENODATA;
 907		goto err_debugfs;
 908	}
 909
 910	for (i = 0; i < sr_info->nvalue_count; i++) {
 911		char name[NVALUE_NAME_LEN + 1];
 912
 913		snprintf(name, sizeof(name), "volt_%lu",
 914				sr_info->nvalue_table[i].volt_nominal);
 915		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
 916				   &(sr_info->nvalue_table[i].nvalue));
 917		snprintf(name, sizeof(name), "errminlimit_%lu",
 918			 sr_info->nvalue_table[i].volt_nominal);
 919		debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
 920				   &(sr_info->nvalue_table[i].errminlimit));
 921
 922	}
 923
 924	return 0;
 925
 926err_debugfs:
 927	debugfs_remove_recursive(sr_info->dbg_dir);
 928err_list_del:
 929	pm_runtime_disable(&pdev->dev);
 930	list_del(&sr_info->node);
 931	clk_unprepare(sr_info->fck);
 932
 933	return ret;
 934}
 935
 936static void omap_sr_remove(struct platform_device *pdev)
 937{
 938	struct device *dev = &pdev->dev;
 939	struct omap_sr *sr_info = platform_get_drvdata(pdev);
 940
 941	if (sr_info->autocomp_active)
 942		sr_stop_vddautocomp(sr_info);
 943	debugfs_remove_recursive(sr_info->dbg_dir);
 944
 945	pm_runtime_disable(dev);
 946	clk_unprepare(sr_info->fck);
 947	list_del(&sr_info->node);
 948}
 949
 950static void omap_sr_shutdown(struct platform_device *pdev)
 951{
 952	struct omap_sr *sr_info = platform_get_drvdata(pdev);
 953
 954	if (sr_info->autocomp_active)
 955		sr_stop_vddautocomp(sr_info);
 956
 957	return;
 958}
 959
 960static const struct of_device_id omap_sr_match[] = {
 961	{ .compatible = "ti,omap3-smartreflex-core", },
 962	{ .compatible = "ti,omap3-smartreflex-mpu-iva", },
 963	{ .compatible = "ti,omap4-smartreflex-core", },
 964	{ .compatible = "ti,omap4-smartreflex-mpu", },
 965	{ .compatible = "ti,omap4-smartreflex-iva", },
 966	{  },
 967};
 968MODULE_DEVICE_TABLE(of, omap_sr_match);
 969
 970static struct platform_driver smartreflex_driver = {
 971	.probe		= omap_sr_probe,
 972	.remove         = omap_sr_remove,
 973	.shutdown	= omap_sr_shutdown,
 974	.driver		= {
 975		.name	= DRIVER_NAME,
 976		.of_match_table	= omap_sr_match,
 977	},
 978};
 979
 980static int __init sr_init(void)
 981{
 982	int ret = 0;
 983
 984	ret = platform_driver_register(&smartreflex_driver);
 985	if (ret) {
 986		pr_err("%s: platform driver register failed for SR\n",
 987		       __func__);
 988		return ret;
 989	}
 990
 991	return 0;
 992}
 993late_initcall(sr_init);
 994
 995static void __exit sr_exit(void)
 996{
 997	platform_driver_unregister(&smartreflex_driver);
 998}
 999module_exit(sr_exit);
1000
1001MODULE_DESCRIPTION("OMAP Smartreflex Driver");
1002MODULE_LICENSE("GPL");
1003MODULE_ALIAS("platform:" DRIVER_NAME);
1004MODULE_AUTHOR("Texas Instruments Inc");