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ulpi.c

/*
 * Copyright 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 * Copyright 2009 Daniel Mack <daniel@caiaq.de>
 *
 * 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 <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 otg_transceiver *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 otg_transceiver *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 otg_io_access_ops mxc_ulpi_access_ops = {
      .read = ulpi_read,
      .write      = ulpi_write,
};
EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);


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