pl2303.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 /* According to POSIX.1-2001 */
   4 #include <sys/select.h>
   5 #include <string.h>
   6 #include <sys/time.h>
   7 #include <sys/types.h>
   8 #include <unistd.h>
   9 #include <termios.h>
  10 #include <fcntl.h>
  11 #include <signal.h>
  12 #include <usb.h>
  13 #include <getopt.h>
  14
  15
  16 #define _GNU_SOURCE
  17 #include <getopt.h>
  18
  19
  20 #define I_VENDOR_NUM        0x67b
  21 #define I_PRODUCT_NUM       0x2303
  22
  23
  24 #define VENDOR_READ_REQUEST_TYPE        0xc0
  25 #define VENDOR_READ_REQUEST             0x01
  26
  27 #define VENDOR_WRITE_REQUEST_TYPE       0x40
  28 #define VENDOR_WRITE_REQUEST            0x01
  29
  30
  31
  32 /* Get current GPIO register from PL2303 */
  33 char gpio_read_reg(usb_dev_handle *h)
  34 {
  35         char buf;
  36         int bytes = usb_control_msg(
  37                 h,             // handle obtained with usb_open()
  38                 VENDOR_READ_REQUEST_TYPE, // bRequestType
  39                 VENDOR_READ_REQUEST,      // bRequest
  40                 0x0081,              // wValue
  41                 0,              // wIndex
  42                 &buf,             // pointer to destination buffer
  43                 1,  // wLength
  44                 100
  45                 );
  46         handle_error(bytes);
  47         return buf;
  48 }
  49
  50 void gpio_write_reg(usb_dev_handle *h, unsigned char reg)
  51 {
  52         int bytes = usb_control_msg(
  53                 h,             // handle obtained with usb_open()
  54                 VENDOR_WRITE_REQUEST_TYPE, // bRequestType
  55                 VENDOR_WRITE_REQUEST,      // bRequest
  56                 1,              // wValue
  57                 reg,              // wIndex
  58                 0,             // pointer to destination buffer
  59                 0,  // wLength
  60                 6000
  61                 );
  62         handle_error(bytes);
  63
  64 }
  65
  66 int gpio_dir_shift(int gpio) {
  67         if (gpio == 0)
  68                 return 4;
  69         if (gpio == 1)
  70                 return 5;
  71         return 4; /* default to 0 */
  72 }
  73
  74 int gpio_val_shift(int gpio) {
  75         if (gpio == 0)
  76                 return 6;
  77         if (gpio == 1)
  78                 return 7;
  79         return 6; /* default to 0 */
  80 }
  81
  82
  83 void gpio_out(usb_dev_handle *h, int gpio, int value)
  84 {
  85         int shift_dir = gpio_dir_shift(gpio);
  86         int shift_val = gpio_val_shift(gpio);
  87         unsigned char reg = gpio_read_reg(h);
  88         reg |= (1 << shift_dir);
  89         reg &= ~(1 << shift_val);
  90         reg |= (value << shift_val);
  91         gpio_write_reg(h, reg);
  92 }
  93
  94 void gpio_in(usb_dev_handle *h, int gpio, int pullup)
  95 {
  96         int shift_dir = gpio_dir_shift(gpio);
  97         int shift_val = gpio_val_shift(gpio);
  98
  99         unsigned char reg = gpio_read_reg(h);
 100         reg &= ~(1 << shift_dir);
 101         reg &= ~(1 << shift_val);
 102         reg |= (pullup << shift_val);
 103         gpio_write_reg(h, reg);
 104 }
 105
 106 int gpio_read(usb_dev_handle *h, int gpio)
 107 {
 108         unsigned char r = gpio_read_reg(h);
 109         int shift = gpio_val_shift(gpio);
 110         return (r & (1<<shift));
 111 }
 112
 113 extern usb_dev_handle *nc_usb_open(int vendor, int product, char *vendor_name, char *product_name, char *serial);
 114 void check_handle(usb_dev_handle **h, const char* manuf, const char* product, const char* serial)
 115 {
 116         if (*h)
 117                 return;
 118
 119         *h = nc_usb_open(I_VENDOR_NUM, I_PRODUCT_NUM, manuf, product, serial);
 120         if (!(*h)) {
 121                 fprintf(stderr, "No PL2303 USB device %04x:%04x found ;(\n", I_VENDOR_NUM, I_PRODUCT_NUM);
 122                 exit(1);
 123         }
 124 }