git.gag.com Git - fw/altos/blob - lib/cp-usb.c

   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 /*
  20  * libusb interface to the GPIO pins on a CP2103.
  21  *
  22  * Various magic constants came from the cp210x driver published by silabs.
  23  */
  24
  25 #include "cp-usb.h"
  26 #include <stdio.h>
  27 #include <errno.h>
  28
  29 struct cp_usb {
  30         usb_dev_handle *usb_dev;
  31         uint8_t gpio;
  32 };
  33
  34 #define CP2101_UART     0x00
  35 #define UART_ENABLE     0x0001
  36 #define UART_DISABLE    0x0000
  37 #define REQTYPE_HOST_TO_DEVICE  0x41
  38 #define REQTYPE_DEVICE_TO_HOST  0xc1
  39
  40 static int
  41 cp_usb_gpio_get(struct cp_usb *cp, uint8_t *gpio_get)
  42 {
  43         return usb_control_msg(cp->usb_dev,             /* dev */
  44                                0xc0,                    /* request */
  45                                0xff,                    /* requesttype */
  46                                0x00c2,                  /* value */
  47                                0,                       /* index */
  48                                (char *) gpio_get,       /* bytes */
  49                                1,                       /* size */
  50                                300);                    /* timeout */
  51 }
  52
  53 static int
  54 cp_usb_gpio_set(struct cp_usb *cp, uint8_t mask, uint8_t value)
  55 {
  56         uint16_t gpio_set = ((uint16_t) value << 8) | mask;
  57
  58         return usb_control_msg(cp->usb_dev,             /* dev */
  59                                0x40,                    /* request */
  60                                0xff,                    /* requesttype */
  61                                0x37e1,                  /* value */
  62                                gpio_set,                /* index */
  63                                NULL,                    /* bytes */
  64                                0,                       /* size */
  65                                300);                    /* timeout */
  66 }
  67
  68 static int
  69 cp_usb_uart_enable_disable(struct cp_usb *cp, uint16_t enable)
  70 {
  71         return usb_control_msg(cp->usb_dev,
  72                                CP2101_UART,
  73                                REQTYPE_HOST_TO_DEVICE,
  74                                enable,
  75                                0,
  76                                NULL,
  77                                0,
  78                                300);
  79 }
  80
  81 struct cp_usb *
  82 cp_usb_open(void)
  83 {
  84         struct cp_usb *cp;
  85         usb_dev_handle *dev_handle;
  86         struct usb_device *dev = NULL;
  87         struct usb_bus *bus, *busses;
  88         int interface;
  89         int ret;
  90         uint8_t gpio;
  91
  92         usb_init();
  93         usb_find_busses();
  94         usb_find_devices();
  95
  96         busses = usb_get_busses();
  97         for (bus = busses; bus; bus = bus->next) {
  98                 for (dev = bus->devices; dev; dev = dev->next) {
  99                         if (dev->descriptor.idVendor == 0x10c4 &&
 100                             dev->descriptor.idProduct == 0xea60)
 101                                 break;
 102                 }
 103                 if (dev)
 104                         break;
 105         }
 106         if (!dev){
 107                 perror("No CP2103 found");
 108                 return NULL;
 109         }
 110         cp = calloc(sizeof(struct cp_usb), 1);
 111         interface = 0;
 112         dev_handle = usb_open(dev);
 113         usb_detach_kernel_driver_np(dev_handle, interface);
 114         usb_claim_interface(dev_handle, interface);
 115         cp->usb_dev = dev_handle;
 116         ret = cp_usb_uart_enable_disable(cp, UART_DISABLE);
 117         cp->gpio = 0xf;
 118         ret = cp_usb_gpio_set(cp, 0xf, cp->gpio);
 119         ret = cp_usb_gpio_get(cp, &gpio);
 120         return cp;
 121 }
 122
 123 void
 124 cp_usb_close(struct cp_usb *cp)
 125 {
 126         cp_usb_uart_enable_disable(cp, UART_DISABLE);
 127         usb_close(cp->usb_dev);
 128         free(cp);
 129 }
 130
 131 void
 132 cp_usb_write(struct cp_usb *cp, uint8_t mask, uint8_t value)
 133 {
 134         uint8_t new_gpio;
 135         int ret;
 136
 137         new_gpio = (cp->gpio & ~mask) | (value & mask);
 138         if (new_gpio != cp->gpio) {
 139                 ret = cp_usb_gpio_set(cp, new_gpio ^ cp->gpio, new_gpio);
 140                 if (ret < 0)
 141                         perror("gpio_set");
 142                 cp->gpio = new_gpio;
 143         }
 144 }
 145
 146 uint8_t
 147 cp_usb_read(struct cp_usb *cp)
 148 {
 149         int ret;
 150         uint8_t gpio;
 151
 152         ret = cp_usb_gpio_get(cp, &gpio);
 153         if (ret < 0)
 154                 perror("gpio_get");
 155         return gpio;
 156 }