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
  42 static 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
  60 static 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
  86 static 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
 108 struct otg_io_access_ops mxc_ulpi_access_ops = {
 109         .read   = ulpi_read,
 110         .write  = ulpi_write,
 111 };
 112 EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);
 113