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 #include <linux/usb/ulpi.h>
  26
  27 #include <mach/ulpi.h>
  28
  29 /* ULPIVIEW register bits */
  30 #define ULPIVW_WU               (1 << 31)       /* Wakeup */
  31 #define ULPIVW_RUN              (1 << 30)       /* read/write run */
  32 #define ULPIVW_WRITE            (1 << 29)       /* 0 = read  1 = write */
  33 #define ULPIVW_SS               (1 << 27)       /* SyncState */
  34 #define ULPIVW_PORT_MASK        0x07    /* Port field */
  35 #define ULPIVW_PORT_SHIFT       24
  36 #define ULPIVW_ADDR_MASK        0xff    /* data address field */
  37 #define ULPIVW_ADDR_SHIFT       16
  38 #define ULPIVW_RDATA_MASK       0xff    /* read data field */
  39 #define ULPIVW_RDATA_SHIFT      8
  40 #define ULPIVW_WDATA_MASK       0xff    /* write data field */
  41 #define ULPIVW_WDATA_SHIFT      0
  42
  43 static int ulpi_poll(void __iomem *view, u32 bit)
  44 {
  45         int timeout = 10000;
  46
  47         while (timeout--) {
  48                 u32 data = __raw_readl(view);
  49
  50                 if (!(data & bit))
  51                         return 0;
  52
  53                 cpu_relax();
  54         };
  55
  56         printk(KERN_WARNING "timeout polling for ULPI device\n");
  57
  58         return -ETIMEDOUT;
  59 }
  60
  61 static int ulpi_read(struct otg_transceiver *otg, u32 reg)
  62 {
  63         int ret;
  64         void __iomem *view = otg->io_priv;
  65
  66         /* make sure interface is running */
  67         if (!(__raw_readl(view) & ULPIVW_SS)) {
  68                 __raw_writel(ULPIVW_WU, view);
  69
  70                 /* wait for wakeup */
  71                 ret = ulpi_poll(view, ULPIVW_WU);
  72                 if (ret)
  73                         return ret;
  74         }
  75
  76         /* read the register */
  77         __raw_writel((ULPIVW_RUN | (reg << ULPIVW_ADDR_SHIFT)), view);
  78
  79         /* wait for completion */
  80         ret = ulpi_poll(view, ULPIVW_RUN);
  81         if (ret)
  82                 return ret;
  83
  84         return (__raw_readl(view) >> ULPIVW_RDATA_SHIFT) & ULPIVW_RDATA_MASK;
  85 }
  86
  87 static int ulpi_write(struct otg_transceiver *otg, u32 val, u32 reg)
  88 {
  89         int ret;
  90         void __iomem *view = otg->io_priv;
  91
  92         /* make sure the interface is running */
  93         if (!(__raw_readl(view) & ULPIVW_SS)) {
  94                 __raw_writel(ULPIVW_WU, view);
  95                 /* wait for wakeup */
  96                 ret = ulpi_poll(view, ULPIVW_WU);
  97                 if (ret)
  98                         return ret;
  99         }
 100
 101         __raw_writel((ULPIVW_RUN | ULPIVW_WRITE |
 102                       (reg << ULPIVW_ADDR_SHIFT) |
 103                       ((val & ULPIVW_WDATA_MASK) << ULPIVW_WDATA_SHIFT)), view);
 104
 105         /* wait for completion */
 106         return ulpi_poll(view, ULPIVW_RUN);
 107 }
 108
 109 struct otg_io_access_ops mxc_ulpi_access_ops = {
 110         .read   = ulpi_read,
 111         .write  = ulpi_write,
 112 };
 113 EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);
 114
 115 struct otg_transceiver *imx_otg_ulpi_create(unsigned int flags)
 116 {
 117         return otg_ulpi_create(&mxc_ulpi_access_ops, flags);
 118 }