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   1 /*
   2  * Copyright © 2011 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; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include "ao.h"
  19
  20 uint8_t                 ao_btm_running;
  21 int8_t                  ao_btm_stdio;
  22 __xdata uint8_t         ao_btm_connected;
  23
  24 void
  25 ao_btm_putchar(char c);
  26
  27 #define AO_BTM_MAX_REPLY        16
  28 __xdata char            ao_btm_reply[AO_BTM_MAX_REPLY];
  29
  30 extern volatile __xdata struct ao_fifo  ao_usart1_rx_fifo;
  31
  32 /*
  33  * Read a line of data from the serial port, truncating
  34  * it after a few characters.
  35  */
  36
  37 uint8_t
  38 ao_btm_get_line(void)
  39 {
  40         uint8_t ao_btm_reply_len = 0;
  41         char c;
  42
  43         for (;;) {
  44
  45                 while ((c = ao_serial_pollchar()) != AO_READ_AGAIN) {
  46                         if (ao_btm_reply_len < sizeof (ao_btm_reply))
  47                                 ao_btm_reply[ao_btm_reply_len++] = c;
  48                         if (c == '\r' || c == '\n')
  49                                 goto done;
  50                 }
  51                 for (c = 0; c < 10; c++) {
  52                         ao_delay(AO_MS_TO_TICKS(10));
  53                         if (!ao_fifo_empty(ao_usart1_rx_fifo))
  54                                 break;
  55                 }
  56                 if (c == 10)
  57                         goto done;
  58         }
  59 done:
  60         for (c = ao_btm_reply_len; c < sizeof (ao_btm_reply);)
  61                 ao_btm_reply[c++] = '\0';
  62         return ao_btm_reply_len;
  63 }
  64
  65 /*
  66  * Drain the serial port completely
  67  */
  68 void
  69 ao_btm_drain()
  70 {
  71         while (ao_btm_get_line())
  72                 ;
  73 }
  74
  75 /*
  76  * Set the stdio echo for the bluetooth link
  77  */
  78 void
  79 ao_btm_echo(uint8_t echo)
  80 {
  81         ao_stdios[ao_btm_stdio].echo = echo;
  82 }
  83
  84 /*
  85  * A command line pre-processor to detect connect/disconnect messages
  86  * and update the internal state
  87  */
  88
  89 uint8_t
  90 ao_cmd_filter(void)
  91 {
  92         if (ao_cur_stdio != ao_btm_stdio)
  93                 return 0;
  94         ao_cmd_lex();
  95         while (ao_cmd_lex_c != '\n') {
  96                 if (ao_match_word("CONNECT"))
  97                         return 1;
  98                 if (ao_match_word("DISCONNECT"))
  99                         return 1;
 100                 if (ao_match_word("ERROR"))
 101                         return 1;
 102                 if (ao_match_word("OK"))
 103                         return 1;
 104                 ao_cmd_lex();
 105         }
 106         ao_cmd_status = 0;
 107         return 0;
 108 }
 109
 110 /*
 111  * Delay between command charaters; the BT module
 112  * can't keep up with 57600 baud
 113  */
 114
 115 void
 116 ao_btm_putchar(char c)
 117 {
 118         ao_serial_putchar(c);
 119         ao_delay(1);
 120 }
 121
 122 /*
 123  * Wait for the bluetooth device to return
 124  * status from the previously executed command
 125  */
 126 uint8_t
 127 ao_btm_wait_reply(void)
 128 {
 129         for (;;) {
 130                 ao_btm_get_line();
 131                 if (!strncmp(ao_btm_reply, "OK", 2))
 132                         return 1;
 133                 if (!strncmp(ao_btm_reply, "ERROR", 5))
 134                         return -1;
 135                 if (ao_btm_reply[0] == '\0')
 136                         return 0;
 137         }
 138 }
 139
 140 void
 141 ao_btm_string(__code char *cmd)
 142 {
 143         char    c;
 144
 145         while (c = *cmd++)
 146                 ao_btm_putchar(c);
 147 }
 148
 149 uint8_t
 150 ao_btm_cmd(__code char *cmd)
 151 {
 152         ao_btm_drain();
 153         ao_btm_string(cmd);
 154         return ao_btm_wait_reply();
 155 }
 156
 157 uint8_t
 158 ao_btm_set_name(void)
 159 {
 160         char    sn[8];
 161         char    *s = sn + 8;
 162         char    c;
 163         int     n;
 164         ao_btm_string("ATN=TeleBT-");
 165         *--s = '\0';
 166         *--s = '\r';
 167         n = ao_serial_number;
 168         do {
 169                 *--s = '0' + n % 10;
 170         } while (n /= 10);
 171         while ((c = *s++))
 172                 ao_btm_putchar(c);
 173         return ao_btm_wait_reply();
 174 }
 175
 176 uint8_t
 177 ao_btm_try_speed(uint8_t speed)
 178 {
 179         ao_serial_set_speed(speed);
 180         ao_btm_drain();
 181         (void) ao_btm_cmd("\rATE0\rATQ0\r");
 182         if (ao_btm_cmd("AT\r") == 1)
 183                 return 1;
 184         return 0;
 185 }
 186
 187 /*
 188  * A thread to initialize the bluetooth device and
 189  * hang around to blink the LED when connected
 190  */
 191 void
 192 ao_btm(void)
 193 {
 194         /*
 195          * Wait for the bluetooth device to boot
 196          */
 197         ao_delay(AO_SEC_TO_TICKS(3));
 198
 199         /*
 200          * The first time we connect, the BTM-180 comes up at 19200 baud.
 201          * After that, it will remember and come up at 57600 baud. So, see
 202          * if it is already running at 57600 baud, and if that doesn't work
 203          * then tell it to switch to 57600 from 19200 baud.
 204          */
 205         while (!ao_btm_try_speed(AO_SERIAL_SPEED_57600)) {
 206                 ao_delay(AO_SEC_TO_TICKS(1));
 207                 if (ao_btm_try_speed(AO_SERIAL_SPEED_19200))
 208                         ao_btm_cmd("ATL4\r");
 209                 ao_delay(AO_SEC_TO_TICKS(1));
 210         }
 211
 212         /* Disable echo */
 213         ao_btm_cmd("ATE0\r");
 214
 215         /* Enable flow control */
 216         ao_btm_cmd("ATC1\r");
 217
 218         /* Set the reported name to something we can find on the host */
 219         ao_btm_set_name();
 220
 221         /* Turn off status reporting */
 222         ao_btm_cmd("ATQ1\r");
 223
 224         ao_btm_stdio = ao_add_stdio(ao_serial_pollchar,
 225                                     ao_serial_putchar,
 226                                     NULL);
 227         ao_btm_echo(0);
 228
 229         ao_btm_running = 1;
 230         for (;;) {
 231                 while (!ao_btm_connected)
 232                         ao_sleep(&ao_btm_connected);
 233                 while (ao_btm_connected) {
 234                         ao_led_for(AO_LED_GREEN, AO_MS_TO_TICKS(20));
 235                         ao_delay(AO_SEC_TO_TICKS(3));
 236                 }
 237         }
 238 }
 239
 240 __xdata struct ao_task ao_btm_task;
 241
 242 void
 243 ao_btm_check_link() __critical
 244 {
 245         if (P2_1) {
 246                 ao_btm_connected = 0;
 247                 PICTL |= PICTL_P2ICON;
 248         } else {
 249                 ao_btm_connected = 1;
 250                 PICTL &= ~PICTL_P2ICON;
 251         }
 252 }
 253
 254 void
 255 ao_btm_isr(void)
 256 {
 257         if (P2IFG & (1 << 1)) {
 258                 ao_btm_check_link();
 259                 ao_wakeup(&ao_btm_connected);
 260         }
 261         P2IFG = 0;
 262 }
 263
 264 void
 265 ao_btm_init (void)
 266 {
 267         ao_serial_init();
 268         ao_serial_set_speed(AO_SERIAL_SPEED_19200);
 269
 270         /*
 271          * Configure link status line
 272          */
 273
 274         /* Set P2_1 to input, pull-down */
 275         P2DIR &= ~(1 << 1);
 276         P2INP |= P2INP_MDP2_1_TRISTATE;
 277
 278         /* Enable P2 interrupts */
 279         IEN2 |= IEN2_P2IE;
 280         ao_btm_check_link();
 281         PICTL |= PICTL_P2IEN;
 282
 283         ao_add_task(&ao_btm_task, ao_btm, "bt");
 284 }