smartreflex.c

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/*
 * OMAP SmartReflex Voltage Control
 *
 * Author: Thara Gopinath   <[email protected]>
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 * Thara Gopinath <[email protected]>
 *
 * Copyright (C) 2008 Nokia Corporation
 * Kalle Jokiniemi
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Lesly A M <[email protected]>
 *
 * 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>

#include <plat/cpu.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 */

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;
}

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;
}

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;
}

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;
}

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);
}

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;
}

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);
}

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);
}

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);
}

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_free_name;
    }

    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_debugfs;
    }

    (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_iounmap:
    list_del(&sr_info->node);
    iounmap(sr_info->base);
err_free_name:
    kfree(sr_info->name);
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");