ulpi.c

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/*
 * Copyright 2008 Sascha Hauer, Pengutronix <[email protected]>
 * Copyright 2009 Daniel Mack <[email protected]>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/usb/otg.h>
#include <linux/usb/ulpi.h>

#include <mach/ulpi.h>

/* ULPIVIEW register bits */
#define ULPIVW_WU       (1 << 31)   /* Wakeup */
#define ULPIVW_RUN      (1 << 30)   /* read/write run */
#define ULPIVW_WRITE        (1 << 29)   /* 0 = read  1 = write */
#define ULPIVW_SS       (1 << 27)   /* SyncState */
#define ULPIVW_PORT_MASK    0x07    /* Port field */
#define ULPIVW_PORT_SHIFT   24
#define ULPIVW_ADDR_MASK    0xff    /* data address field */
#define ULPIVW_ADDR_SHIFT   16
#define ULPIVW_RDATA_MASK   0xff    /* read data field */
#define ULPIVW_RDATA_SHIFT  8
#define ULPIVW_WDATA_MASK   0xff    /* write data field */
#define ULPIVW_WDATA_SHIFT  0

static int ulpi_poll(void __iomem *view, u32 bit)
{
    int timeout = 10000;

    while (timeout--) {
        u32 data = __raw_readl(view);

        if (!(data & bit))
            return 0;

        cpu_relax();
    };

    printk(KERN_WARNING "timeout polling for ULPI device\n");

    return -ETIMEDOUT;
}

static int ulpi_read(struct usb_phy *otg, u32 reg)
{
    int ret;
    void __iomem *view = otg->io_priv;

    /* make sure interface is running */
    if (!(__raw_readl(view) & ULPIVW_SS)) {
        __raw_writel(ULPIVW_WU, view);

        /* wait for wakeup */
        ret = ulpi_poll(view, ULPIVW_WU);
        if (ret)
            return ret;
    }

    /* read the register */
    __raw_writel((ULPIVW_RUN | (reg << ULPIVW_ADDR_SHIFT)), view);

    /* wait for completion */
    ret = ulpi_poll(view, ULPIVW_RUN);
    if (ret)
        return ret;

    return (__raw_readl(view) >> ULPIVW_RDATA_SHIFT) & ULPIVW_RDATA_MASK;
}

static int ulpi_write(struct usb_phy *otg, u32 val, u32 reg)
{
    int ret;
    void __iomem *view = otg->io_priv;

    /* make sure the interface is running */
    if (!(__raw_readl(view) & ULPIVW_SS)) {
        __raw_writel(ULPIVW_WU, view);
        /* wait for wakeup */
        ret = ulpi_poll(view, ULPIVW_WU);
        if (ret)
            return ret;
    }

    __raw_writel((ULPIVW_RUN | ULPIVW_WRITE |
              (reg << ULPIVW_ADDR_SHIFT) |
              ((val & ULPIVW_WDATA_MASK) << ULPIVW_WDATA_SHIFT)), view);

    /* wait for completion */
    return ulpi_poll(view, ULPIVW_RUN);
}

struct usb_phy_io_ops mxc_ulpi_access_ops = {
    .read   = ulpi_read,
    .write  = ulpi_write,
};
EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);

struct usb_phy *imx_otg_ulpi_create(unsigned int flags)
{
    return otg_ulpi_create(&mxc_ulpi_access_ops, flags);
}