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   1 /*
   2  * Copyright © 2008 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include "cp-usb-async.h"
  24 #include "ccdbg-debug.h"
  25
  26 #define MAX_OUTSTANDING         256
  27 #define CP_TIMEOUT              1000    /* ms */
  28
  29 struct cp_usb_packet {
  30         struct libusb_transfer  *transfer;
  31         enum { packet_read, packet_write } direction;
  32         unsigned char           data[9];
  33         uint8_t                 *valuep;
  34 };
  35
  36 struct cp_usb_async {
  37         libusb_context          *ctx;
  38         libusb_device_handle    *handle;
  39         struct cp_usb_packet    packet[MAX_OUTSTANDING];
  40         int                     p, ack;
  41         uint8_t                 value;
  42         uint8_t                 set;
  43 };
  44
  45 struct cp_usb_async *
  46 cp_usb_async_open(void)
  47 {
  48         struct cp_usb_async *cp;
  49         int ret;
  50
  51         cp = calloc(sizeof (struct cp_usb_async), 1);
  52         if (!cp)
  53                 return NULL;
  54         ret = libusb_init(&cp->ctx);
  55         if (ret) {
  56                 free(cp);
  57                 return NULL;
  58         }
  59         cp->handle = libusb_open_device_with_vid_pid(cp->ctx,
  60                                                      0x10c4, 0xea60);
  61         cp->ack = -1;
  62         if (!cp->handle) {
  63                 libusb_exit(cp->ctx);
  64                 free(cp);
  65                 return NULL;
  66         }
  67         cp->value = 0;
  68         cp->set = 0;
  69         return cp;
  70 }
  71
  72 void
  73 cp_usb_async_close(struct cp_usb_async *cp)
  74 {
  75         libusb_close(cp->handle);
  76         libusb_exit(cp->ctx);
  77         free(cp);
  78 }
  79
  80 static void
  81 cp_usb_async_transfer_callback(struct libusb_transfer *transfer)
  82 {
  83         struct cp_usb_async *cp = transfer->user_data;
  84         int p;
  85
  86         for (p = 0; p < cp->p; p++)
  87                 if (cp->packet[p].transfer == transfer)
  88                         break;
  89         if (p == cp->p) {
  90                 fprintf(stderr, "unknown transfer\n");
  91                 return;
  92         }
  93         switch (cp->packet[p].direction) {
  94         case packet_read:
  95                 ccdbg_debug(CC_DEBUG_USB_ASYNC, "ack read %d 0x%02x\n",
  96                             p, cp->packet[p].data[8]);
  97                 *cp->packet[p].valuep = cp->packet[p].data[8];
  98                 break;
  99         case packet_write:
 100                 ccdbg_debug(CC_DEBUG_USB_ASYNC, "ack write %d\n", p);
 101                 break;
 102         }
 103         if (p > cp->ack)
 104                 cp->ack = p;
 105 }
 106
 107 void
 108 cp_usb_async_write(struct cp_usb_async *cp, uint8_t mask, uint8_t value)
 109 {
 110         int     p;
 111         uint16_t gpio_set;
 112         int     ret;
 113
 114         if (cp->set) {
 115                 value = (cp->value & ~mask) | (value & mask);
 116                 mask = value ^ cp->value;
 117         }
 118         cp->set = 1;
 119         cp->value = value;
 120         gpio_set = ((uint16_t) value << 8) | mask;
 121         if (cp->p == MAX_OUTSTANDING)
 122                 cp_usb_async_sync(cp);
 123         p = cp->p;
 124         if (!cp->packet[p].transfer)
 125                 cp->packet[p].transfer = libusb_alloc_transfer(0);
 126         cp->packet[p].direction = packet_write;
 127         libusb_fill_control_setup(cp->packet[p].data,
 128                                   0x40,                 /* request */
 129                                   0xff,                 /* request type */
 130                                   0x37e1,               /* value */
 131                                   gpio_set,             /* index */
 132                                   0);                   /* length */
 133
 134         libusb_fill_control_transfer(cp->packet[p].transfer,
 135                                      cp->handle,
 136                                      cp->packet[p].data,
 137                                      cp_usb_async_transfer_callback,
 138                                      cp,
 139                                      CP_TIMEOUT);
 140         ccdbg_debug(CC_DEBUG_USB_ASYNC, "Write packet %d 0x%x 0x%x\n", p, mask, value);
 141         ret = libusb_submit_transfer(cp->packet[p].transfer);
 142         if (ret)
 143                 fprintf(stderr, "libusb_submit_transfer failed %d\n", ret);
 144         cp->p++;
 145 }
 146
 147 void
 148 cp_usb_async_read(struct cp_usb_async *cp, uint8_t *valuep)
 149 {
 150         int     p;
 151         int     ret;
 152
 153         if (cp->p == MAX_OUTSTANDING)
 154                 cp_usb_async_sync(cp);
 155         p = cp->p;
 156         if (!cp->packet[p].transfer)
 157                 cp->packet[p].transfer = libusb_alloc_transfer(0);
 158         cp->packet[p].valuep = valuep;
 159         cp->packet[p].direction = packet_read;
 160         libusb_fill_control_setup(cp->packet[p].data,
 161                                   0xc0,                 /* request */
 162                                   0xff,                 /* request type */
 163                                   0x00c2,               /* value */
 164                                   0,                    /* index */
 165                                   1);                   /* length */
 166
 167         libusb_fill_control_transfer(cp->packet[p].transfer,
 168                                      cp->handle,
 169                                      cp->packet[p].data,
 170                                      cp_usb_async_transfer_callback,
 171                                      cp,
 172                                      CP_TIMEOUT);
 173         ccdbg_debug(CC_DEBUG_USB_ASYNC, "Read packet %d\n", p);
 174         ret = libusb_submit_transfer(cp->packet[p].transfer);
 175         if (ret)
 176                 fprintf(stderr, "libusb_submit_transfer failed %d\n", ret);
 177         cp->p++;
 178 }
 179
 180 void
 181 cp_usb_async_sync(struct cp_usb_async *cp)
 182 {
 183         while (cp->ack < cp->p - 1) {
 184                 libusb_handle_events(cp->ctx);
 185         }
 186         cp->p = 0;
 187         cp->ack = -1;
 188 }