text: /*
   * OMAP SmartReflex Voltage Control
   *
   * Author: Thara Gopinath	<thara@ti.com>
   *
   * Copyright (C) 2012 Texas Instruments, Inc.
   * Thara Gopinath <thara@ti.com>
   *
   * Copyright (C) 2008 Nokia Corporation
   * Kalle Jokiniemi
   *
   * Copyright (C) 2007 Texas Instruments, Inc.
   * Lesly A M <x0080970@ti.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  #include <linux/debugfs.h>
  #include <linux/delay.h>
  #include <linux/slab.h>
  #include <linux/pm_runtime.h>
  #include <linux/power/smartreflex.h>
  
  #define SMARTREFLEX_NAME_LEN	16
  #define NVALUE_NAME_LEN		40
  #define SR_DISABLE_TIMEOUT	200
  
  /* sr_list contains all the instances of smartreflex module */
  static LIST_HEAD(sr_list);
  
  static struct omap_sr_class_data *sr_class;
  static struct omap_sr_pmic_data *sr_pmic_data;
  static struct dentry		*sr_dbg_dir;
  
  static inline void sr_write_reg(struct omap_sr *sr, unsigned offset, u32 value)
  {
  	__raw_writel(value, (sr->base + offset));
  }
  
  static inline void sr_modify_reg(struct omap_sr *sr, unsigned offset, u32 mask,
  					u32 value)
  {
  	u32 reg_val;
  
  	/*
  	 * Smartreflex error config register is special as it contains
  	 * certain status bits which if written a 1 into means a clear
  	 * of those bits. So in order to make sure no accidental write of
  	 * 1 happens to those status bits, do a clear of them in the read
  	 * value. This mean this API doesn't rewrite values in these bits
  	 * if they are currently set, but does allow the caller to write
  	 * those bits.
  	 */
  	if (sr->ip_type == SR_TYPE_V1 && offset == ERRCONFIG_V1)
  		mask |= ERRCONFIG_STATUS_V1_MASK;
  	else if (sr->ip_type == SR_TYPE_V2 && offset == ERRCONFIG_V2)
  		mask |= ERRCONFIG_VPBOUNDINTST_V2;
  
  	reg_val = __raw_readl(sr->base + offset);
  	reg_val &= ~mask;
  
  	value &= mask;
  
  	reg_val |= value;
  
  	__raw_writel(reg_val, (sr->base + offset));
  }
  
  static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
  {
  	return __raw_readl(sr->base + offset);
  }
  
  static struct omap_sr *_sr_lookup(struct voltagedomain *voltdm)
  {
  	struct omap_sr *sr_info;
  
  	if (!voltdm) {
  		pr_err("%s: Null voltage domain passed!\n", __func__);
  		return ERR_PTR(-EINVAL);
  	}
  
  	list_for_each_entry(sr_info, &sr_list, node) {
  		if (voltdm == sr_info->voltdm)
  			return sr_info;
  	}
  
  	return ERR_PTR(-ENODATA);
  }
  
  static irqreturn_t sr_interrupt(int irq, void *data)
  {
  	struct omap_sr *sr_info = data;
  	u32 status = 0;
  
  	switch (sr_info->ip_type) {
  	case SR_TYPE_V1:
  		/* Read the status bits */
  		status = sr_read_reg(sr_info, ERRCONFIG_V1);
  
  		/* Clear them by writing back */
  		sr_write_reg(sr_info, ERRCONFIG_V1, status);
  		break;
  	case SR_TYPE_V2:
  		/* Read the status bits */
  		status = sr_read_reg(sr_info, IRQSTATUS);
  
  		/* Clear them by writing back */
  		sr_write_reg(sr_info, IRQSTATUS, status);
  		break;
  	default:
  		dev_err(&sr_info->pdev->dev, "UNKNOWN IP type %d\n",
  			sr_info->ip_type);
  		return IRQ_NONE;
  	}
  
  	if (sr_class->notify)
  		sr_class->notify(sr_info, status);
  
  	return IRQ_HANDLED;
  }
  
  static void sr_set_clk_length(struct omap_sr *sr)
  {
  	struct clk *sys_ck;
  	u32 sys_clk_speed;
  
  	if (cpu_is_omap34xx())
  		sys_ck = clk_get(NULL, "sys_ck");
  	else
  		sys_ck = clk_get(NULL, "sys_clkin_ck");
  
  	if (IS_ERR(sys_ck)) {
  		dev_err(&sr->pdev->dev, "%s: unable to get sys clk\n",
  			__func__);
  		return;
  	}
  
  	sys_clk_speed = clk_get_rate(sys_ck);
  	clk_put(sys_ck);
  
  	switch (sys_clk_speed) {
  	case 12000000:
  		sr->clk_length = SRCLKLENGTH_12MHZ_SYSCLK;
  		break;
  	case 13000000:
  		sr->clk_length = SRCLKLENGTH_13MHZ_SYSCLK;
  		break;
  	case 19200000:
  		sr->clk_length = SRCLKLENGTH_19MHZ_SYSCLK;
  		break;
  	case 26000000:
  		sr->clk_length = SRCLKLENGTH_26MHZ_SYSCLK;
  		break;
  	case 38400000:
  		sr->clk_length = SRCLKLENGTH_38MHZ_SYSCLK;
  		break;
  	default:
  		dev_err(&sr->pdev->dev, "%s: Invalid sysclk value: %d\n",
  			__func__, sys_clk_speed);
  		break;
  	}
  }
  
  static void sr_set_regfields(struct omap_sr *sr)
  {
  	/*
  	 * For time being these values are defined in smartreflex.h
  	 * and populated during init. May be they can be moved to board
  	 * file or pmic specific data structure. In that case these structure
  	 * fields will have to be populated using the pdata or pmic structure.
  	 */
  	if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
  		sr->err_weight = OMAP3430_SR_ERRWEIGHT;
  		sr->err_maxlimit = OMAP3430_SR_ERRMAXLIMIT;
  		sr->accum_data = OMAP3430_SR_ACCUMDATA;
  		if (!(strcmp(sr->name, "smartreflex_mpu_iva"))) {
  			sr->senn_avgweight = OMAP3430_SR1_SENNAVGWEIGHT;
  			sr->senp_avgweight = OMAP3430_SR1_SENPAVGWEIGHT;
  		} else {
  			sr->senn_avgweight = OMAP3430_SR2_SENNAVGWEIGHT;
  			sr->senp_avgweight = OMAP3430_SR2_SENPAVGWEIGHT;
  		}
  	}
  }
  
  static void sr_start_vddautocomp(struct omap_sr *sr)
  {
  	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
  		dev_warn(&sr->pdev->dev,
  			"%s: smartreflex class driver not registered\n",
  			__func__);
  		return;
  	}
  
  	if (!sr_class->enable(sr))
  		sr->autocomp_active = true;
  }
  
  static void sr_stop_vddautocomp(struct omap_sr *sr)
  {
  	if (!sr_class || !(sr_class->disable)) {
  		dev_warn(&sr->pdev->dev,
  			"%s: smartreflex class driver not registered\n",
  			__func__);
  		return;
  	}
  
  	if (sr->autocomp_active) {
  		sr_class->disable(sr, 1);
  		sr->autocomp_active = false;
  	}
  }
  
  /*
   * This function handles the intializations which have to be done
   * only when both sr device and class driver regiter has
   * completed. This will be attempted to be called from both sr class
   * driver register and sr device intializtion API's. Only one call
   * will ultimately succeed.
   *
   * Currently this function registers interrupt handler for a particular SR
   * if smartreflex class driver is already registered and has
   * requested for interrupts and the SR interrupt line in present.
   */
  static int sr_late_init(struct omap_sr *sr_info)
  {
  	struct omap_sr_data *pdata = sr_info->pdev->dev.platform_data;
  	struct resource *mem;
  	int ret = 0;
  
  	if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
  		ret = request_irq(sr_info->irq, sr_interrupt,
  				  0, sr_info->name, sr_info);
  		if (ret)
  			goto error;
  		disable_irq(sr_info->irq);
  	}
  
  	if (pdata && pdata->enable_on_init)
  		sr_start_vddautocomp(sr_info);
  
  	return ret;
  
  error:
  	iounmap(sr_info->base);
  	mem = platform_get_resource(sr_info->pdev, IORESOURCE_MEM, 0);
  	release_mem_region(mem->start, resource_size(mem));
  	list_del(&sr_info->node);
  	dev_err(&sr_info->pdev->dev, "%s: ERROR in registering"
  		"interrupt handler. Smartreflex will"
  		"not function as desired\n", __func__);
  	kfree(sr_info);
  
  	return ret;
  }
  
  static void sr_v1_disable(struct omap_sr *sr)
  {
  	int timeout = 0;
  	int errconf_val = ERRCONFIG_MCUACCUMINTST | ERRCONFIG_MCUVALIDINTST |
  			ERRCONFIG_MCUBOUNDINTST;
  
  	/* Enable MCUDisableAcknowledge interrupt */
  	sr_modify_reg(sr, ERRCONFIG_V1,
  			ERRCONFIG_MCUDISACKINTEN, ERRCONFIG_MCUDISACKINTEN);
  
  	/* SRCONFIG - disable SR */
  	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
  
  	/* Disable all other SR interrupts and clear the status as needed */
  	if (sr_read_reg(sr, ERRCONFIG_V1) & ERRCONFIG_VPBOUNDINTST_V1)
  		errconf_val |= ERRCONFIG_VPBOUNDINTST_V1;
  	sr_modify_reg(sr, ERRCONFIG_V1,
  			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
  			ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_VPBOUNDINTEN_V1),
  			errconf_val);
  
  	/*
  	 * Wait for SR to be disabled.
  	 * wait until ERRCONFIG.MCUDISACKINTST = 1. Typical latency is 1us.
  	 */
  	sr_test_cond_timeout((sr_read_reg(sr, ERRCONFIG_V1) &
  			     ERRCONFIG_MCUDISACKINTST), SR_DISABLE_TIMEOUT,
  			     timeout);
  
  	if (timeout >= SR_DISABLE_TIMEOUT)
  		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
  			__func__);
  
  	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
  	sr_modify_reg(sr, ERRCONFIG_V1, ERRCONFIG_MCUDISACKINTEN,
  			ERRCONFIG_MCUDISACKINTST);
  }
  
  static void sr_v2_disable(struct omap_sr *sr)
  {
  	int timeout = 0;
  
  	/* Enable MCUDisableAcknowledge interrupt */
  	sr_write_reg(sr, IRQENABLE_SET, IRQENABLE_MCUDISABLEACKINT);
  
  	/* SRCONFIG - disable SR */
  	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
  
  	/*
  	 * Disable all other SR interrupts and clear the status
  	 * write to status register ONLY on need basis - only if status
  	 * is set.
  	 */
  	if (sr_read_reg(sr, ERRCONFIG_V2) & ERRCONFIG_VPBOUNDINTST_V2)
  		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
  			ERRCONFIG_VPBOUNDINTST_V2);
  	else
  		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
  				0x0);
  	sr_write_reg(sr, IRQENABLE_CLR, (IRQENABLE_MCUACCUMINT |
  			IRQENABLE_MCUVALIDINT |
  			IRQENABLE_MCUBOUNDSINT));
  	sr_write_reg(sr, IRQSTATUS, (IRQSTATUS_MCUACCUMINT |
  			IRQSTATUS_MCVALIDINT |
  			IRQSTATUS_MCBOUNDSINT));
  
  	/*
  	 * Wait for SR to be disabled.
  	 * wait until IRQSTATUS.MCUDISACKINTST = 1. Typical latency is 1us.
  	 */
  	sr_test_cond_timeout((sr_read_reg(sr, IRQSTATUS) &
  			     IRQSTATUS_MCUDISABLEACKINT), SR_DISABLE_TIMEOUT,
  			     timeout);
  
  	if (timeout >= SR_DISABLE_TIMEOUT)
  		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
  			__func__);
  
  	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
  	sr_write_reg(sr, IRQENABLE_CLR, IRQENABLE_MCUDISABLEACKINT);
  	sr_write_reg(sr, IRQSTATUS, IRQSTATUS_MCUDISABLEACKINT);
  }
  
  static struct omap_sr_nvalue_table *sr_retrieve_nvalue_row(
  				struct omap_sr *sr, u32 efuse_offs)
  {
  	int i;
  
  	if (!sr->nvalue_table) {
  		dev_warn(&sr->pdev->dev, "%s: Missing ntarget value table\n",
  			__func__);
  		return NULL;
  	}
  
  	for (i = 0; i < sr->nvalue_count; i++) {
  		if (sr->nvalue_table[i].efuse_offs == efuse_offs)
  			return &sr->nvalue_table[i];
  	}
  
  	return NULL;
  }
  
  /* Public Functions */
  
  /**
   * sr_configure_errgen() - Configures the smrtreflex to perform AVS using the
   *			 error generator module.
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the smartreflex class driver to
   * configure the error generator module inside the smartreflex module.
   * SR settings if using the ERROR module inside Smartreflex.
   * SR CLASS 3 by default uses only the ERROR module where as
   * SR CLASS 2 can choose between ERROR module and MINMAXAVG
   * module. Returns 0 on success and error value in case of failure.
   */
  int sr_configure_errgen(struct voltagedomain *voltdm)
  {
  	u32 sr_config, sr_errconfig, errconfig_offs;
  	u32 vpboundint_en, vpboundint_st;
  	u32 senp_en = 0, senn_en = 0;
  	u8 senp_shift, senn_shift;
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return PTR_ERR(sr);
  	}
  
  	if (!sr->clk_length)
  		sr_set_clk_length(sr);
  
  	senp_en = sr->senp_mod;
  	senn_en = sr->senn_mod;
  
  	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
  		SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN;
  
  	switch (sr->ip_type) {
  	case SR_TYPE_V1:
  		sr_config |= SRCONFIG_DELAYCTRL;
  		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
  		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
  		errconfig_offs = ERRCONFIG_V1;
  		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
  		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
  		break;
  	case SR_TYPE_V2:
  		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
  		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
  		errconfig_offs = ERRCONFIG_V2;
  		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
  		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
  		break;
  	default:
  		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
  			"module without specifying the ip\n", __func__);
  		return -EINVAL;
  	}
  
  	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
  	sr_write_reg(sr, SRCONFIG, sr_config);
  	sr_errconfig = (sr->err_weight << ERRCONFIG_ERRWEIGHT_SHIFT) |
  		(sr->err_maxlimit << ERRCONFIG_ERRMAXLIMIT_SHIFT) |
  		(sr->err_minlimit <<  ERRCONFIG_ERRMINLIMIT_SHIFT);
  	sr_modify_reg(sr, errconfig_offs, (SR_ERRWEIGHT_MASK |
  		SR_ERRMAXLIMIT_MASK | SR_ERRMINLIMIT_MASK),
  		sr_errconfig);
  
  	/* Enabling the interrupts if the ERROR module is used */
  	sr_modify_reg(sr, errconfig_offs, (vpboundint_en | vpboundint_st),
  		      vpboundint_en);
  
  	return 0;
  }
  
  /**
   * sr_disable_errgen() - Disables SmartReflex AVS module's errgen component
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the smartreflex class driver to
   * disable the error generator module inside the smartreflex module.
   *
   * Returns 0 on success and error value in case of failure.
   */
  int sr_disable_errgen(struct voltagedomain *voltdm)
  {
  	u32 errconfig_offs;
  	u32 vpboundint_en, vpboundint_st;
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return PTR_ERR(sr);
  	}
  
  	switch (sr->ip_type) {
  	case SR_TYPE_V1:
  		errconfig_offs = ERRCONFIG_V1;
  		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
  		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
  		break;
  	case SR_TYPE_V2:
  		errconfig_offs = ERRCONFIG_V2;
  		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
  		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
  		break;
  	default:
  		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
  			"module without specifying the ip\n", __func__);
  		return -EINVAL;
  	}
  
  	/* Disable the interrupts of ERROR module */
  	sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
  
  	/* Disable the Sensor and errorgen */
  	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);
  
  	return 0;
  }
  
  /**
   * sr_configure_minmax() - Configures the smrtreflex to perform AVS using the
   *			 minmaxavg module.
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the smartreflex class driver to
   * configure the minmaxavg module inside the smartreflex module.
   * SR settings if using the ERROR module inside Smartreflex.
   * SR CLASS 3 by default uses only the ERROR module where as
   * SR CLASS 2 can choose between ERROR module and MINMAXAVG
   * module. Returns 0 on success and error value in case of failure.
   */
  int sr_configure_minmax(struct voltagedomain *voltdm)
  {
  	u32 sr_config, sr_avgwt;
  	u32 senp_en = 0, senn_en = 0;
  	u8 senp_shift, senn_shift;
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return PTR_ERR(sr);
  	}
  
  	if (!sr->clk_length)
  		sr_set_clk_length(sr);
  
  	senp_en = sr->senp_mod;
  	senn_en = sr->senn_mod;
  
  	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
  		SRCONFIG_SENENABLE |
  		(sr->accum_data << SRCONFIG_ACCUMDATA_SHIFT);
  
  	switch (sr->ip_type) {
  	case SR_TYPE_V1:
  		sr_config |= SRCONFIG_DELAYCTRL;
  		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
  		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
  		break;
  	case SR_TYPE_V2:
  		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
  		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
  		break;
  	default:
  		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
  			"module without specifying the ip\n", __func__);
  		return -EINVAL;
  	}
  
  	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
  	sr_write_reg(sr, SRCONFIG, sr_config);
  	sr_avgwt = (sr->senp_avgweight << AVGWEIGHT_SENPAVGWEIGHT_SHIFT) |
  		(sr->senn_avgweight << AVGWEIGHT_SENNAVGWEIGHT_SHIFT);
  	sr_write_reg(sr, AVGWEIGHT, sr_avgwt);
  
  	/*
  	 * Enabling the interrupts if MINMAXAVG module is used.
  	 * TODO: check if all the interrupts are mandatory
  	 */
  	switch (sr->ip_type) {
  	case SR_TYPE_V1:
  		sr_modify_reg(sr, ERRCONFIG_V1,
  			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
  			ERRCONFIG_MCUBOUNDINTEN),
  			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUACCUMINTST |
  			 ERRCONFIG_MCUVALIDINTEN | ERRCONFIG_MCUVALIDINTST |
  			 ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_MCUBOUNDINTST));
  		break;
  	case SR_TYPE_V2:
  		sr_write_reg(sr, IRQSTATUS,
  			IRQSTATUS_MCUACCUMINT | IRQSTATUS_MCVALIDINT |
  			IRQSTATUS_MCBOUNDSINT | IRQSTATUS_MCUDISABLEACKINT);
  		sr_write_reg(sr, IRQENABLE_SET,
  			IRQENABLE_MCUACCUMINT | IRQENABLE_MCUVALIDINT |
  			IRQENABLE_MCUBOUNDSINT | IRQENABLE_MCUDISABLEACKINT);
  		break;
  	default:
  		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
  			"module without specifying the ip\n", __func__);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /**
   * sr_enable() - Enables the smartreflex module.
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   * @volt:	The voltage at which the Voltage domain associated with
   *		the smartreflex module is operating at.
   *		This is required only to program the correct Ntarget value.
   *
   * This API is to be called from the smartreflex class driver to
   * enable a smartreflex module. Returns 0 on success. Returns error
   * value if the voltage passed is wrong or if ntarget value is wrong.
   */
  int sr_enable(struct voltagedomain *voltdm, unsigned long volt)
  {
  	struct omap_volt_data *volt_data;
  	struct omap_sr *sr = _sr_lookup(voltdm);
  	struct omap_sr_nvalue_table *nvalue_row;
  	int ret;
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return PTR_ERR(sr);
  	}
  
  	volt_data = omap_voltage_get_voltdata(sr->voltdm, volt);
  
  	if (IS_ERR(volt_data)) {
  		dev_warn(&sr->pdev->dev, "%s: Unable to get voltage table"
  			"for nominal voltage %ld\n", __func__, volt);
  		return PTR_ERR(volt_data);
  	}
  
  	nvalue_row = sr_retrieve_nvalue_row(sr, volt_data->sr_efuse_offs);
  
  	if (!nvalue_row) {
  		dev_warn(&sr->pdev->dev, "%s: failure getting SR data for this voltage %ld\n",
  			 __func__, volt);
  		return -ENODATA;
  	}
  
  	/* errminlimit is opp dependent and hence linked to voltage */
  	sr->err_minlimit = nvalue_row->errminlimit;
  
  	pm_runtime_get_sync(&sr->pdev->dev);
  
  	/* Check if SR is already enabled. If yes do nothing */
  	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE)
  		return 0;
  
  	/* Configure SR */
  	ret = sr_class->configure(sr);
  	if (ret)
  		return ret;
  
  	sr_write_reg(sr, NVALUERECIPROCAL, nvalue_row->nvalue);
  
  	/* SRCONFIG - enable SR */
  	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, SRCONFIG_SRENABLE);
  	return 0;
  }
  
  /**
   * sr_disable() - Disables the smartreflex module.
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the smartreflex class driver to
   * disable a smartreflex module.
   */
  void sr_disable(struct voltagedomain *voltdm)
  {
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return;
  	}
  
  	/* Check if SR clocks are already disabled. If yes do nothing */
  	if (pm_runtime_suspended(&sr->pdev->dev))
  		return;
  
  	/*
  	 * Disable SR if only it is indeed enabled. Else just
  	 * disable the clocks.
  	 */
  	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE) {
  		switch (sr->ip_type) {
  		case SR_TYPE_V1:
  			sr_v1_disable(sr);
  			break;
  		case SR_TYPE_V2:
  			sr_v2_disable(sr);
  			break;
  		default:
  			dev_err(&sr->pdev->dev, "UNKNOWN IP type %d\n",
  				sr->ip_type);
  		}
  	}
  
  	pm_runtime_put_sync_suspend(&sr->pdev->dev);
  }
  
  /**
   * sr_register_class() - API to register a smartreflex class parameters.
   * @class_data:	The structure containing various sr class specific data.
   *
   * This API is to be called by the smartreflex class driver to register itself
   * with the smartreflex driver during init. Returns 0 on success else the
   * error value.
   */
  int sr_register_class(struct omap_sr_class_data *class_data)
  {
  	struct omap_sr *sr_info;
  
  	if (!class_data) {
  		pr_warning("%s:, Smartreflex class data passed is NULL\n",
  			__func__);
  		return -EINVAL;
  	}
  
  	if (sr_class) {
  		pr_warning("%s: Smartreflex class driver already registered\n",
  			__func__);
  		return -EBUSY;
  	}
  
  	sr_class = class_data;
  
  	/*
  	 * Call into late init to do intializations that require
  	 * both sr driver and sr class driver to be initiallized.
  	 */
  	list_for_each_entry(sr_info, &sr_list, node)
  		sr_late_init(sr_info);
  
  	return 0;
  }
  
  /**
   * omap_sr_enable() -  API to enable SR clocks and to call into the
   *			registered smartreflex class enable API.
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the kernel in order to enable
   * a particular smartreflex module. This API will do the initial
   * configurations to turn on the smartreflex module and in turn call
   * into the registered smartreflex class enable API.
   */
  void omap_sr_enable(struct voltagedomain *voltdm)
  {
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return;
  	}
  
  	if (!sr->autocomp_active)
  		return;
  
  	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
  		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
  			"registered\n", __func__);
  		return;
  	}
  
  	sr_class->enable(sr);
  }
  
  /**
   * omap_sr_disable() - API to disable SR without resetting the voltage
   *			processor voltage
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the kernel in order to disable
   * a particular smartreflex module. This API will in turn call
   * into the registered smartreflex class disable API. This API will tell
   * the smartreflex class disable not to reset the VP voltage after
   * disabling smartreflex.
   */
  void omap_sr_disable(struct voltagedomain *voltdm)
  {
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return;
  	}
  
  	if (!sr->autocomp_active)
  		return;
  
  	if (!sr_class || !(sr_class->disable)) {
  		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
  			"registered\n", __func__);
  		return;
  	}
  
  	sr_class->disable(sr, 0);
  }
  
  /**
   * omap_sr_disable_reset_volt() - API to disable SR and reset the
   *				voltage processor voltage
   * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
   *
   * This API is to be called from the kernel in order to disable
   * a particular smartreflex module. This API will in turn call
   * into the registered smartreflex class disable API. This API will tell
   * the smartreflex class disable to reset the VP voltage after
   * disabling smartreflex.
   */
  void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
  {
  	struct omap_sr *sr = _sr_lookup(voltdm);
  
  	if (IS_ERR(sr)) {
  		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
  		return;
  	}
  
  	if (!sr->autocomp_active)
  		return;
  
  	if (!sr_class || !(sr_class->disable)) {
  		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
  			"registered\n", __func__);
  		return;
  	}
  
  	sr_class->disable(sr, 1);
  }
  
  /**
   * omap_sr_register_pmic() - API to register pmic specific info.
   * @pmic_data:	The structure containing pmic specific data.
   *
   * This API is to be called from the PMIC specific code to register with
   * smartreflex driver pmic specific info. Currently the only info required
   * is the smartreflex init on the PMIC side.
   */
  void omap_sr_register_pmic(struct omap_sr_pmic_data *pmic_data)
  {
  	if (!pmic_data) {
  		pr_warning("%s: Trying to register NULL PMIC data structure"
  			"with smartreflex\n", __func__);
  		return;
  	}
  
  	sr_pmic_data = pmic_data;
  }
  
  /* PM Debug FS entries to enable and disable smartreflex. */
  static int omap_sr_autocomp_show(void *data, u64 *val)
  {
  	struct omap_sr *sr_info = data;
  
  	if (!sr_info) {
  		pr_warning("%s: omap_sr struct not found\n", __func__);
  		return -EINVAL;
  	}
  
  	*val = sr_info->autocomp_active;
  
  	return 0;
  }
  
  static int omap_sr_autocomp_store(void *data, u64 val)
  {
  	struct omap_sr *sr_info = data;
  
  	if (!sr_info) {
  		pr_warning("%s: omap_sr struct not found\n", __func__);
  		return -EINVAL;
  	}
  
  	/* Sanity check */
  	if (val > 1) {
  		pr_warning("%s: Invalid argument %lld\n", __func__, val);
  		return -EINVAL;
  	}
  
  	/* control enable/disable only if there is a delta in value */
  	if (sr_info->autocomp_active != val) {
  		if (!val)
  			sr_stop_vddautocomp(sr_info);
  		else
  			sr_start_vddautocomp(sr_info);
  	}
  
  	return 0;
  }
  
  DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
  			omap_sr_autocomp_store, "%llu\n");
  
  static int __init omap_sr_probe(struct platform_device *pdev)
  {
  	struct omap_sr *sr_info;
  	struct omap_sr_data *pdata = pdev->dev.platform_data;
  	struct resource *mem, *irq;
  	struct dentry *nvalue_dir;
  	int i, ret = 0;
  
  	sr_info = kzalloc(sizeof(struct omap_sr), GFP_KERNEL);
  	if (!sr_info) {
  		dev_err(&pdev->dev, "%s: unable to allocate sr_info\n",
  			__func__);
  		return -ENOMEM;
  	}
  
  	platform_set_drvdata(pdev, sr_info);
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
  		ret = -EINVAL;
  		goto err_free_devinfo;
  	}
  
  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!mem) {
  		dev_err(&pdev->dev, "%s: no mem resource\n", __func__);
  		ret = -ENODEV;
  		goto err_free_devinfo;
  	}
  
  	mem = request_mem_region(mem->start, resource_size(mem),
  					dev_name(&pdev->dev));
  	if (!mem) {
  		dev_err(&pdev->dev, "%s: no mem region\n", __func__);
  		ret = -EBUSY;
  		goto err_free_devinfo;
  	}
  
  	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
  
  	pm_runtime_enable(&pdev->dev);
  	pm_runtime_irq_safe(&pdev->dev);
  
  	sr_info->name = kasprintf(GFP_KERNEL, "%s", pdata->name);
  	if (!sr_info->name) {
  		dev_err(&pdev->dev, "%s: Unable to alloc SR instance name\n",
  			__func__);
  		ret = -ENOMEM;
  		goto err_release_region;
  	}
  
  	sr_info->pdev = pdev;
  	sr_info->srid = pdev->id;
  	sr_info->voltdm = pdata->voltdm;
  	sr_info->nvalue_table = pdata->nvalue_table;
  	sr_info->nvalue_count = pdata->nvalue_count;
  	sr_info->senn_mod = pdata->senn_mod;
  	sr_info->senp_mod = pdata->senp_mod;
  	sr_info->autocomp_active = false;
  	sr_info->ip_type = pdata->ip_type;
  	sr_info->base = ioremap(mem->start, resource_size(mem));
  	if (!sr_info->base) {
  		dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
  		ret = -ENOMEM;
  		goto err_release_region;
  	}
  
  	if (irq)
  		sr_info->irq = irq->start;
  
  	sr_set_clk_length(sr_info);
  	sr_set_regfields(sr_info);
  
  	list_add(&sr_info->node, &sr_list);
  
  	/*
  	 * Call into late init to do intializations that require
  	 * both sr driver and sr class driver to be initiallized.
  	 */
  	if (sr_class) {
  		ret = sr_late_init(sr_info);
  		if (ret) {
  			pr_warning("%s: Error in SR late init\n", __func__);
  			goto err_iounmap;
  		}
  	}
  
  	dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
  	if (!sr_dbg_dir) {
  		sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
  		if (IS_ERR_OR_NULL(sr_dbg_dir)) {
  			ret = PTR_ERR(sr_dbg_dir);
  			pr_err("%s:sr debugfs dir creation failed(%d)\n",
  				__func__, ret);
  			goto err_iounmap;
  		}
  	}
  
  	sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
  	if (IS_ERR_OR_NULL(sr_info->dbg_dir)) {
  		dev_err(&pdev->dev, "%s: Unable to create debugfs directory\n",
  			__func__);
  		ret = PTR_ERR(sr_info->dbg_dir);
  		goto err_free_name;
  	}
  
  	(void) debugfs_create_file("autocomp", S_IRUGO | S_IWUSR,
  			sr_info->dbg_dir, (void *)sr_info, &pm_sr_fops);
  	(void) debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
  			&sr_info->err_weight);
  	(void) debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
  			&sr_info->err_maxlimit);
  
  	nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
  	if (IS_ERR_OR_NULL(nvalue_dir)) {
  		dev_err(&pdev->dev, "%s: Unable to create debugfs directory"
  			"for n-values\n", __func__);
  		ret = PTR_ERR(nvalue_dir);
  		goto err_debugfs;
  	}
  
  	if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
  		dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
  			 __func__, sr_info->name);
  
  		ret = -ENODATA;
  		goto err_debugfs;
  	}
  
  	for (i = 0; i < sr_info->nvalue_count; i++) {
  		char name[NVALUE_NAME_LEN + 1];
  
  		snprintf(name, sizeof(name), "volt_%lu",
  				sr_info->nvalue_table[i].volt_nominal);
  		(void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
  				&(sr_info->nvalue_table[i].nvalue));
  		snprintf(name, sizeof(name), "errminlimit_%lu",
  			 sr_info->nvalue_table[i].volt_nominal);
  		(void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
  				&(sr_info->nvalue_table[i].errminlimit));
  
  	}
  
  	return ret;
  
  err_debugfs:
  	debugfs_remove_recursive(sr_info->dbg_dir);
  err_free_name:
  	kfree(sr_info->name);
  err_iounmap:
  	list_del(&sr_info->node);
  	iounmap(sr_info->base);
  err_release_region:
  	release_mem_region(mem->start, resource_size(mem));
  err_free_devinfo:
  	kfree(sr_info);
  
  	return ret;
  }
  
  static int __devexit omap_sr_remove(struct platform_device *pdev)
  {
  	struct omap_sr_data *pdata = pdev->dev.platform_data;
  	struct omap_sr *sr_info;
  	struct resource *mem;
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
  		return -EINVAL;
  	}
  
  	sr_info = _sr_lookup(pdata->voltdm);
  	if (IS_ERR(sr_info)) {
  		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
  			__func__);
  		return PTR_ERR(sr_info);
  	}
  
  	if (sr_info->autocomp_active)
  		sr_stop_vddautocomp(sr_info);
  	if (sr_info->dbg_dir)
  		debugfs_remove_recursive(sr_info->dbg_dir);
  
  	list_del(&sr_info->node);
  	iounmap(sr_info->base);
  	kfree(sr_info->name);
  	kfree(sr_info);
  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	release_mem_region(mem->start, resource_size(mem));
  
  	return 0;
  }
  
  static void __devexit omap_sr_shutdown(struct platform_device *pdev)
  {
  	struct omap_sr_data *pdata = pdev->dev.platform_data;
  	struct omap_sr *sr_info;
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
  		return;
  	}
  
  	sr_info = _sr_lookup(pdata->voltdm);
  	if (IS_ERR(sr_info)) {
  		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
  			__func__);
  		return;
  	}
  
  	if (sr_info->autocomp_active)
  		sr_stop_vddautocomp(sr_info);
  
  	return;
  }
  
  static struct platform_driver smartreflex_driver = {
  	.remove         = __devexit_p(omap_sr_remove),
  	.shutdown	= __devexit_p(omap_sr_shutdown),
  	.driver		= {
  		.name	= "smartreflex",
  	},
  };
  
  static int __init sr_init(void)
  {
  	int ret = 0;
  
  	/*
  	 * sr_init is a late init. If by then a pmic specific API is not
  	 * registered either there is no need for anything to be done on
  	 * the PMIC side or somebody has forgotten to register a PMIC
  	 * handler. Warn for the second condition.
  	 */
  	if (sr_pmic_data && sr_pmic_data->sr_pmic_init)
  		sr_pmic_data->sr_pmic_init();
  	else
  		pr_warning("%s: No PMIC hook to init smartreflex\n", __func__);
  
  	ret = platform_driver_probe(&smartreflex_driver, omap_sr_probe);
  	if (ret) {
  		pr_err("%s: platform driver register failed for SR\n",
  			__func__);
  		return ret;
  	}
  
  	return 0;
  }
  late_initcall(sr_init);
  
  static void __exit sr_exit(void)
  {
  	platform_driver_unregister(&smartreflex_driver);
  }
  module_exit(sr_exit);
  
  MODULE_DESCRIPTION("OMAP Smartreflex Driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:" DRIVER_NAME);
  MODULE_AUTHOR("Texas Instruments Inc");
  