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 #include <libusb.h>
  29
  30 struct cp_usb {
  31         usb_dev_handle *usb_dev;
  32         uint8_t gpio;
  33 };
  34
  35 #define CP2101_UART     0x00
  36 #define UART_ENABLE     0x0001
  37 #define UART_DISABLE    0x0000
  38 #define REQTYPE_HOST_TO_DEVICE  0x41
  39 #define REQTYPE_DEVICE_TO_HOST  0xc1
  40
  41 static int
  42 cp_usb_gpio_get(struct cp_usb *cp, uint8_t *gpio_get)
  43 {
  44         return usb_control_msg(cp->usb_dev,             /* dev */
  45                                0xc0,                    /* request */
  46                                0xff,                    /* requesttype */
  47                                0x00c2,                  /* value */
  48                                0,                       /* index */
  49                                (char *) gpio_get,       /* bytes */
  50                                1,                       /* size */
  51                                300);                    /* timeout */
  52 }
  53
  54 static int
  55 cp_usb_gpio_set(struct cp_usb *cp, uint8_t mask, uint8_t value)
  56 {
  57         uint16_t gpio_set = ((uint16_t) value << 8) | mask;
  58
  59         return usb_control_msg(cp->usb_dev,             /* dev */
  60                                0x40,                    /* request */
  61                                0xff,                    /* requesttype */
  62                                0x37e1,                  /* value */
  63                                gpio_set,                /* index */
  64                                NULL,                    /* bytes */
  65                                0,                       /* size */
  66                                300);                    /* timeout */
  67 }
  68
  69 static int
  70 cp_usb_uart_enable_disable(struct cp_usb *cp, uint16_t enable)
  71 {
  72         return usb_control_msg(cp->usb_dev,
  73                                CP2101_UART,
  74                                REQTYPE_HOST_TO_DEVICE,
  75                                enable,
  76                                0,
  77                                NULL,
  78                                0,
  79                                300);
  80 }
  81
  82 struct cp_usb *
  83 cp_usb_open(void)
  84 {
  85         struct cp_usb *cp;
  86         usb_dev_handle *dev_handle;
  87         struct usb_device *dev = NULL;
  88         struct usb_bus *bus, *busses;
  89         int interface;
  90         int ret;
  91         uint8_t gpio;
  92
  93         usb_init();
  94         usb_find_busses();
  95         usb_find_devices();
  96
  97         busses = usb_get_busses();
  98         for (bus = busses; bus; bus = bus->next) {
  99                 for (dev = bus->devices; dev; dev = dev->next) {
 100                         if (dev->descriptor.idVendor == 0x10c4 &&
 101                             dev->descriptor.idProduct == 0xea60)
 102                                 break;
 103                 }
 104                 if (dev)
 105                         break;
 106         }
 107         if (!dev){
 108                 perror("No CP2103 found");
 109                 return NULL;
 110         }
 111         cp = calloc(sizeof(struct cp_usb), 1);
 112         interface = 0;
 113         dev_handle = usb_open(dev);
 114         usb_detach_kernel_driver_np(dev_handle, interface);
 115         usb_claim_interface(dev_handle, interface);
 116         cp->usb_dev = dev_handle;
 117         ret = cp_usb_uart_enable_disable(cp, UART_DISABLE);
 118         cp->gpio = 0xf;
 119         ret = cp_usb_gpio_set(cp, 0xf, cp->gpio);
 120         ret = cp_usb_gpio_get(cp, &gpio);
 121         return cp;
 122 }
 123
 124 void
 125 cp_usb_close(struct cp_usb *cp)
 126 {
 127         cp_usb_uart_enable_disable(cp, UART_DISABLE);
 128         usb_close(cp->usb_dev);
 129         free(cp);
 130 }
 131
 132 void
 133 cp_usb_write(struct cp_usb *cp, uint8_t mask, uint8_t value)
 134 {
 135         uint8_t new_gpio;
 136         int ret;
 137
 138         new_gpio = (cp->gpio & ~mask) | (value & mask);
 139         if (new_gpio != cp->gpio) {
 140                 ret = cp_usb_gpio_set(cp, new_gpio ^ cp->gpio, new_gpio);
 141                 if (ret < 0)
 142                         perror("gpio_set");
 143                 cp->gpio = new_gpio;
 144         }
 145 }
 146
 147 uint8_t
 148 cp_usb_read(struct cp_usb *cp)
 149 {
 150         int ret;
 151         uint8_t gpio;
 152
 153         ret = cp_usb_gpio_get(cp, &gpio);
 154         if (ret < 0)
 155                 perror("gpio_get");
 156         return gpio;
 157 }