drivers/usb/otg/ulpi.c

   1 /*
   2  * Generic ULPI USB transceiver support
   3  *
   4  * Copyright (C) 2009 Daniel Mack <daniel@caiaq.de>
   5  *
   6  * Based on sources from
   7  *
   8  *   Sascha Hauer <s.hauer@pengutronix.de>
   9  *   Freescale Semiconductors
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/usb.h>
  29 #include <linux/usb/otg.h>
  30 #include <linux/usb/ulpi.h>
  31
  32 /* ULPI register addresses */
  33 #define ULPI_VID_LOW         0x00    /* Vendor ID low */
  34 #define ULPI_VID_HIGH        0x01    /* Vendor ID high */
  35 #define ULPI_PID_LOW         0x02    /* Product ID low */
  36 #define ULPI_PID_HIGH        0x03    /* Product ID high */
  37 #define ULPI_ITFCTL          0x07    /* Interface Control */
  38 #define ULPI_OTGCTL          0x0A    /* OTG Control */
  39
  40 /* add to above register address to access Set/Clear functions */
  41 #define ULPI_REG_SET         0x01
  42 #define ULPI_REG_CLEAR       0x02
  43
  44 /* ULPI OTG Control Register bits */
  45 #define ID_PULL_UP              (1 << 0)        /* enable ID Pull Up */
  46 #define DP_PULL_DOWN            (1 << 1)        /* enable DP Pull Down */
  47 #define DM_PULL_DOWN            (1 << 2)        /* enable DM Pull Down */
  48 #define DISCHRG_VBUS            (1 << 3)        /* Discharge Vbus */
  49 #define CHRG_VBUS               (1 << 4)        /* Charge Vbus */
  50 #define DRV_VBUS                (1 << 5)        /* Drive Vbus */
  51 #define DRV_VBUS_EXT            (1 << 6)        /* Drive Vbus external */
  52 #define USE_EXT_VBUS_IND        (1 << 7)        /* Use ext. Vbus indicator */
  53
  54 #define ULPI_ID(vendor, product) (((vendor) << 16) | (product))
  55
  56 #define TR_FLAG(flags, a, b)    (((flags) & a) ? b : 0)
  57
  58 /* ULPI hardcoded IDs, used for probing */
  59 static unsigned int ulpi_ids[] = {
  60         ULPI_ID(0x04cc, 0x1504),        /* NXP ISP1504 */
  61 };
  62
  63 static int ulpi_set_flags(struct otg_transceiver *otg)
  64 {
  65         unsigned int flags = 0;
  66
  67         if (otg->flags & USB_OTG_PULLUP_ID)
  68                 flags |= ID_PULL_UP;
  69
  70         if (otg->flags & USB_OTG_PULLDOWN_DM)
  71                 flags |= DM_PULL_DOWN;
  72
  73         if (otg->flags & USB_OTG_PULLDOWN_DP)
  74                 flags |= DP_PULL_DOWN;
  75
  76         if (otg->flags & USB_OTG_EXT_VBUS_INDICATOR)
  77                 flags |= USE_EXT_VBUS_IND;
  78
  79         return otg_io_write(otg, flags, ULPI_OTGCTL + ULPI_REG_SET);
  80 }
  81
  82 static int ulpi_init(struct otg_transceiver *otg)
  83 {
  84         int i, vid, pid;
  85
  86         vid = (otg_io_read(otg, ULPI_VID_HIGH) << 8) |
  87                otg_io_read(otg, ULPI_VID_LOW);
  88         pid = (otg_io_read(otg, ULPI_PID_HIGH) << 8) |
  89                otg_io_read(otg, ULPI_PID_LOW);
  90
  91         pr_info("ULPI transceiver vendor/product ID 0x%04x/0x%04x\n", vid, pid);
  92
  93         for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++)
  94                 if (ulpi_ids[i] == ULPI_ID(vid, pid))
  95                         return ulpi_set_flags(otg);
  96
  97         pr_err("ULPI ID does not match any known transceiver.\n");
  98         return -ENODEV;
  99 }
 100
 101 static int ulpi_set_vbus(struct otg_transceiver *otg, bool on)
 102 {
 103         unsigned int flags = otg_io_read(otg, ULPI_OTGCTL);
 104
 105         flags &= ~(DRV_VBUS | DRV_VBUS_EXT);
 106
 107         if (on) {
 108                 if (otg->flags & USB_OTG_DRV_VBUS)
 109                         flags |= DRV_VBUS;
 110
 111                 if (otg->flags & USB_OTG_DRV_VBUS_EXT)
 112                         flags |= DRV_VBUS_EXT;
 113         }
 114
 115         return otg_io_write(otg, flags, ULPI_OTGCTL + ULPI_REG_SET);
 116 }
 117
 118 struct otg_transceiver *
 119 otg_ulpi_create(struct otg_io_access_ops *ops,
 120                 unsigned int flags)
 121 {
 122         struct otg_transceiver *otg;
 123
 124         otg = kzalloc(sizeof(*otg), GFP_KERNEL);
 125         if (!otg)
 126                 return NULL;
 127
 128         otg->label      = "ULPI";
 129         otg->flags      = flags;
 130         otg->io_ops     = ops;
 131         otg->init       = ulpi_init;
 132         otg->set_vbus   = ulpi_set_vbus;
 133
 134         return otg;
 135 }
 136 EXPORT_SYMBOL_GPL(otg_ulpi_create);
 137