sr_device.c

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/*
 * OMAP3/OMAP4 smartreflex device file
 *
 * Author: Thara Gopinath   <[email protected]>
 *
 * Based originally on code from smartreflex.c
 * Copyright (C) 2010 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/power/smartreflex.h>

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <plat/omap_device.h>

#include "voltage.h"
#include "control.h"
#include "pm.h"

static bool sr_enable_on_init;

/* Read EFUSE values from control registers for OMAP3430 */
static void __init sr_set_nvalues(struct omap_volt_data *volt_data,
                struct omap_sr_data *sr_data)
{
    struct omap_sr_nvalue_table *nvalue_table;
    int i, j, count = 0;

    sr_data->nvalue_count = 0;
    sr_data->nvalue_table = NULL;

    while (volt_data[count].volt_nominal)
        count++;

    nvalue_table = kzalloc(sizeof(struct omap_sr_nvalue_table)*count,
            GFP_KERNEL);

    if (!nvalue_table) {
        pr_err("OMAP: SmartReflex: cannot allocate memory for n-value table\n");
        return;
    }

    for (i = 0, j = 0; i < count; i++) {
        u32 v;

        /*
         * In OMAP4 the efuse registers are 24 bit aligned.
         * A __raw_readl will fail for non-32 bit aligned address
         * and hence the 8-bit read and shift.
         */
        if (cpu_is_omap44xx()) {
            u16 offset = volt_data[i].sr_efuse_offs;

            v = omap_ctrl_readb(offset) |
                omap_ctrl_readb(offset + 1) << 8 |
                omap_ctrl_readb(offset + 2) << 16;
        } else {
            v = omap_ctrl_readl(volt_data[i].sr_efuse_offs);
        }

        /*
         * Many OMAP SoCs don't have the eFuse values set.
         * For example, pretty much all OMAP3xxx before
         * ES3.something.
         *
         * XXX There needs to be some way for board files or
         * userspace to add these in.
         */
        if (v == 0)
            continue;

        nvalue_table[j].nvalue = v;
        nvalue_table[j].efuse_offs = volt_data[i].sr_efuse_offs;
        nvalue_table[j].errminlimit = volt_data[i].sr_errminlimit;
        nvalue_table[j].volt_nominal = volt_data[i].volt_nominal;

        j++;
    }

    sr_data->nvalue_table = nvalue_table;
    sr_data->nvalue_count = j;
}

static int __init sr_dev_init(struct omap_hwmod *oh, void *user)
{
    struct omap_sr_data *sr_data;
    struct platform_device *pdev;
    struct omap_volt_data *volt_data;
    struct omap_smartreflex_dev_attr *sr_dev_attr;
    char *name = "smartreflex";
    static int i;

    sr_data = kzalloc(sizeof(struct omap_sr_data), GFP_KERNEL);
    if (!sr_data) {
        pr_err("%s: Unable to allocate memory for %s sr_data\n",
               __func__, oh->name);
        return -ENOMEM;
    }

    sr_dev_attr = (struct omap_smartreflex_dev_attr *)oh->dev_attr;
    if (!sr_dev_attr || !sr_dev_attr->sensor_voltdm_name) {
        pr_err("%s: No voltage domain specified for %s. Cannot initialize\n",
               __func__, oh->name);
        goto exit;
    }

    sr_data->name = oh->name;
    sr_data->ip_type = oh->class->rev;
    sr_data->senn_mod = 0x1;
    sr_data->senp_mod = 0x1;

    sr_data->voltdm = voltdm_lookup(sr_dev_attr->sensor_voltdm_name);
    if (!sr_data->voltdm) {
        pr_err("%s: Unable to get voltage domain pointer for VDD %s\n",
            __func__, sr_dev_attr->sensor_voltdm_name);
        goto exit;
    }

    omap_voltage_get_volttable(sr_data->voltdm, &volt_data);
    if (!volt_data) {
        pr_err("%s: No Voltage table registered for VDD%d\n",
               __func__, i + 1);
        goto exit;
    }

    sr_set_nvalues(volt_data, sr_data);

    sr_data->enable_on_init = sr_enable_on_init;

    pdev = omap_device_build(name, i, oh, sr_data, sizeof(*sr_data),
                 NULL, 0, 0);
    if (IS_ERR(pdev))
        pr_warning("%s: Could not build omap_device for %s: %s.\n\n",
            __func__, name, oh->name);
exit:
    i++;
    kfree(sr_data);
    return 0;
}

/*
 * API to be called from board files to enable smartreflex
 * autocompensation at init.
 */
void __init omap_enable_smartreflex_on_init(void)
{
    sr_enable_on_init = true;
}

int __init omap_devinit_smartreflex(void)
{
    return omap_hwmod_for_each_by_class("smartreflex", sr_dev_init, NULL);
}