ulpi.c

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/*
 * Generic ULPI USB transceiver support
 *
 * Copyright (C) 2009 Daniel Mack <[email protected]>
 *
 * Based on sources from
 *
 *   Sascha Hauer <[email protected]>
 *   Freescale Semiconductors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>
#include <linux/usb/ulpi.h>


struct ulpi_info {
    unsigned int    id;
    char        *name;
};

#define ULPI_ID(vendor, product) (((vendor) << 16) | (product))
#define ULPI_INFO(_id, _name)       \
    {               \
        .id = (_id),    \
        .name   = (_name),  \
    }

/* ULPI hardcoded IDs, used for probing */
static struct ulpi_info ulpi_ids[] = {
    ULPI_INFO(ULPI_ID(0x04cc, 0x1504), "NXP ISP1504"),
    ULPI_INFO(ULPI_ID(0x0424, 0x0006), "SMSC USB331x"),
};

static int ulpi_set_otg_flags(struct usb_phy *phy)
{
    unsigned int flags = ULPI_OTG_CTRL_DP_PULLDOWN |
                 ULPI_OTG_CTRL_DM_PULLDOWN;

    if (phy->flags & ULPI_OTG_ID_PULLUP)
        flags |= ULPI_OTG_CTRL_ID_PULLUP;

    /*
     * ULPI Specification rev.1.1 default
     * for Dp/DmPulldown is enabled.
     */
    if (phy->flags & ULPI_OTG_DP_PULLDOWN_DIS)
        flags &= ~ULPI_OTG_CTRL_DP_PULLDOWN;

    if (phy->flags & ULPI_OTG_DM_PULLDOWN_DIS)
        flags &= ~ULPI_OTG_CTRL_DM_PULLDOWN;

    if (phy->flags & ULPI_OTG_EXTVBUSIND)
        flags |= ULPI_OTG_CTRL_EXTVBUSIND;

    return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
}

static int ulpi_set_fc_flags(struct usb_phy *phy)
{
    unsigned int flags = 0;

    /*
     * ULPI Specification rev.1.1 default
     * for XcvrSelect is Full Speed.
     */
    if (phy->flags & ULPI_FC_HS)
        flags |= ULPI_FUNC_CTRL_HIGH_SPEED;
    else if (phy->flags & ULPI_FC_LS)
        flags |= ULPI_FUNC_CTRL_LOW_SPEED;
    else if (phy->flags & ULPI_FC_FS4LS)
        flags |= ULPI_FUNC_CTRL_FS4LS;
    else
        flags |= ULPI_FUNC_CTRL_FULL_SPEED;

    if (phy->flags & ULPI_FC_TERMSEL)
        flags |= ULPI_FUNC_CTRL_TERMSELECT;

    /*
     * ULPI Specification rev.1.1 default
     * for OpMode is Normal Operation.
     */
    if (phy->flags & ULPI_FC_OP_NODRV)
        flags |= ULPI_FUNC_CTRL_OPMODE_NONDRIVING;
    else if (phy->flags & ULPI_FC_OP_DIS_NRZI)
        flags |= ULPI_FUNC_CTRL_OPMODE_DISABLE_NRZI;
    else if (phy->flags & ULPI_FC_OP_NSYNC_NEOP)
        flags |= ULPI_FUNC_CTRL_OPMODE_NOSYNC_NOEOP;
    else
        flags |= ULPI_FUNC_CTRL_OPMODE_NORMAL;

    /*
     * ULPI Specification rev.1.1 default
     * for SuspendM is Powered.
     */
    flags |= ULPI_FUNC_CTRL_SUSPENDM;

    return usb_phy_io_write(phy, flags, ULPI_FUNC_CTRL);
}

static int ulpi_set_ic_flags(struct usb_phy *phy)
{
    unsigned int flags = 0;

    if (phy->flags & ULPI_IC_AUTORESUME)
        flags |= ULPI_IFC_CTRL_AUTORESUME;

    if (phy->flags & ULPI_IC_EXTVBUS_INDINV)
        flags |= ULPI_IFC_CTRL_EXTERNAL_VBUS;

    if (phy->flags & ULPI_IC_IND_PASSTHRU)
        flags |= ULPI_IFC_CTRL_PASSTHRU;

    if (phy->flags & ULPI_IC_PROTECT_DIS)
        flags |= ULPI_IFC_CTRL_PROTECT_IFC_DISABLE;

    return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
}

static int ulpi_set_flags(struct usb_phy *phy)
{
    int ret;

    ret = ulpi_set_otg_flags(phy);
    if (ret)
        return ret;

    ret = ulpi_set_ic_flags(phy);
    if (ret)
        return ret;

    return ulpi_set_fc_flags(phy);
}

static int ulpi_check_integrity(struct usb_phy *phy)
{
    int ret, i;
    unsigned int val = 0x55;

    for (i = 0; i < 2; i++) {
        ret = usb_phy_io_write(phy, val, ULPI_SCRATCH);
        if (ret < 0)
            return ret;

        ret = usb_phy_io_read(phy, ULPI_SCRATCH);
        if (ret < 0)
            return ret;

        if (ret != val) {
            pr_err("ULPI integrity check: failed!");
            return -ENODEV;
        }
        val = val << 1;
    }

    pr_info("ULPI integrity check: passed.\n");

    return 0;
}

static int ulpi_init(struct usb_phy *phy)
{
    int i, vid, pid, ret;
    u32 ulpi_id = 0;

    for (i = 0; i < 4; i++) {
        ret = usb_phy_io_read(phy, ULPI_PRODUCT_ID_HIGH - i);
        if (ret < 0)
            return ret;
        ulpi_id = (ulpi_id << 8) | ret;
    }
    vid = ulpi_id & 0xffff;
    pid = ulpi_id >> 16;

    pr_info("ULPI transceiver vendor/product ID 0x%04x/0x%04x\n", vid, pid);

    for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++) {
        if (ulpi_ids[i].id == ULPI_ID(vid, pid)) {
            pr_info("Found %s ULPI transceiver.\n",
                ulpi_ids[i].name);
            break;
        }
    }

    ret = ulpi_check_integrity(phy);
    if (ret)
        return ret;

    return ulpi_set_flags(phy);
}

static int ulpi_set_host(struct usb_otg *otg, struct usb_bus *host)
{
    struct usb_phy *phy = otg->phy;
    unsigned int flags = usb_phy_io_read(phy, ULPI_IFC_CTRL);

    if (!host) {
        otg->host = NULL;
        return 0;
    }

    otg->host = host;

    flags &= ~(ULPI_IFC_CTRL_6_PIN_SERIAL_MODE |
           ULPI_IFC_CTRL_3_PIN_SERIAL_MODE |
           ULPI_IFC_CTRL_CARKITMODE);

    if (phy->flags & ULPI_IC_6PIN_SERIAL)
        flags |= ULPI_IFC_CTRL_6_PIN_SERIAL_MODE;
    else if (phy->flags & ULPI_IC_3PIN_SERIAL)
        flags |= ULPI_IFC_CTRL_3_PIN_SERIAL_MODE;
    else if (phy->flags & ULPI_IC_CARKIT)
        flags |= ULPI_IFC_CTRL_CARKITMODE;

    return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
}

static int ulpi_set_vbus(struct usb_otg *otg, bool on)
{
    struct usb_phy *phy = otg->phy;
    unsigned int flags = usb_phy_io_read(phy, ULPI_OTG_CTRL);

    flags &= ~(ULPI_OTG_CTRL_DRVVBUS | ULPI_OTG_CTRL_DRVVBUS_EXT);

    if (on) {
        if (phy->flags & ULPI_OTG_DRVVBUS)
            flags |= ULPI_OTG_CTRL_DRVVBUS;

        if (phy->flags & ULPI_OTG_DRVVBUS_EXT)
            flags |= ULPI_OTG_CTRL_DRVVBUS_EXT;
    }

    return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
}

struct usb_phy *
otg_ulpi_create(struct usb_phy_io_ops *ops,
        unsigned int flags)
{
    struct usb_phy *phy;
    struct usb_otg *otg;

    phy = kzalloc(sizeof(*phy), GFP_KERNEL);
    if (!phy)
        return NULL;

    otg = kzalloc(sizeof(*otg), GFP_KERNEL);
    if (!otg) {
        kfree(phy);
        return NULL;
    }

    phy->label  = "ULPI";
    phy->flags  = flags;
    phy->io_ops = ops;
    phy->otg    = otg;
    phy->init   = ulpi_init;

    otg->phy    = phy;
    otg->set_host   = ulpi_set_host;
    otg->set_vbus   = ulpi_set_vbus;

    return phy;
}
EXPORT_SYMBOL_GPL(otg_ulpi_create);