LXR linux/arch/arm/plat-mxc/ulpi.c

   1/*
   2 * Copyright 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
   3 * Copyright 2009 Daniel Mack <daniel@caiaq.de>
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License
   7 * as published by the Free Software Foundation; either version 2
   8 * of the License, or (at your option) any later version.
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  17 * MA  02110-1301, USA.
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/kernel.h>
  22#include <linux/io.h>
  23#include <linux/delay.h>
  24#include <linux/usb/otg.h>
  25
  26#include <mach/ulpi.h>
  27
  28/* ULPIVIEW register bits */
  29#define ULPIVW_WU               (1 << 31)       /* Wakeup */
  30#define ULPIVW_RUN              (1 << 30)       /* read/write run */
  31#define ULPIVW_WRITE            (1 << 29)       /* 0 = read  1 = write */
  32#define ULPIVW_SS               (1 << 27)       /* SyncState */
  33#define ULPIVW_PORT_MASK        0x07    /* Port field */
  34#define ULPIVW_PORT_SHIFT       24
  35#define ULPIVW_ADDR_MASK        0xff    /* data address field */
  36#define ULPIVW_ADDR_SHIFT       16
  37#define ULPIVW_RDATA_MASK       0xff    /* read data field */
  38#define ULPIVW_RDATA_SHIFT      8
  39#define ULPIVW_WDATA_MASK       0xff    /* write data field */
  40#define ULPIVW_WDATA_SHIFT      0
  41
  42static int ulpi_poll(void __iomem *view, u32 bit)
  43{
  44        int timeout = 10000;
  45
  46        while (timeout--) {
  47                u32 data = __raw_readl(view);
  48
  49                if (!(data & bit))
  50                        return 0;
  51
  52                cpu_relax();
  53        };
  54
  55        printk(KERN_WARNING "timeout polling for ULPI device\n");
  56
  57        return -ETIMEDOUT;
  58}
  59
  60static int ulpi_read(struct otg_transceiver *otg, u32 reg)
  61{
  62        int ret;
  63        void __iomem *view = otg->io_priv;
  64
  65        /* make sure interface is running */
  66        if (!(__raw_readl(view) & ULPIVW_SS)) {
  67                __raw_writel(ULPIVW_WU, view);
  68
  69                /* wait for wakeup */
  70                ret = ulpi_poll(view, ULPIVW_WU);
  71                if (ret)
  72                        return ret;
  73        }
  74
  75        /* read the register */
  76        __raw_writel((ULPIVW_RUN | (reg << ULPIVW_ADDR_SHIFT)), view);
  77
  78        /* wait for completion */
  79        ret = ulpi_poll(view, ULPIVW_RUN);
  80        if (ret)
  81                return ret;
  82
  83        return (__raw_readl(view) >> ULPIVW_RDATA_SHIFT) & ULPIVW_RDATA_MASK;
  84}
  85
  86static int ulpi_write(struct otg_transceiver *otg, u32 val, u32 reg)
  87{
  88        int ret;
  89        void __iomem *view = otg->io_priv;
  90
  91        /* make sure the interface is running */
  92        if (!(__raw_readl(view) & ULPIVW_SS)) {
  93                __raw_writel(ULPIVW_WU, view);
  94                /* wait for wakeup */
  95                ret = ulpi_poll(view, ULPIVW_WU);
  96                if (ret)
  97                        return ret;
  98        }
  99
 100        __raw_writel((ULPIVW_RUN | ULPIVW_WRITE |
 101                      (reg << ULPIVW_ADDR_SHIFT) |
 102                      ((val & ULPIVW_WDATA_MASK) << ULPIVW_WDATA_SHIFT)), view);
 103
 104        /* wait for completion */
 105        return ulpi_poll(view, ULPIVW_RUN);
 106}
 107
 108struct otg_io_access_ops mxc_ulpi_access_ops = {
 109        .read   = ulpi_read,
 110        .write  = ulpi_write,
 111};
 112EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);
 113
 114