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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 int8_t                  ao_btm_stdio;
  21 __xdata uint8_t         ao_btm_connected;
  22
  23 #define AO_BTM_MAX_REPLY        16
  24 __xdata char            ao_btm_reply[AO_BTM_MAX_REPLY];
  25
  26 extern volatile __xdata struct ao_fifo  ao_usart1_rx_fifo;
  27
  28 /*
  29  * Read a line of data from the serial port, truncating
  30  * it after a few characters.
  31  */
  32
  33 uint8_t
  34 ao_btm_get_line(void)
  35 {
  36         uint8_t ao_btm_reply_len = 0;
  37         char c;
  38
  39         for (;;) {
  40
  41                 while ((c = ao_serial_pollchar()) != AO_READ_AGAIN) {
  42                         if (ao_btm_reply_len < sizeof (ao_btm_reply))
  43                                 ao_btm_reply[ao_btm_reply_len++] = c;
  44                         if (c == '\r' || c == '\n')
  45                                 goto done;
  46                 }
  47                 for (c = 0; c < 10; c++) {
  48                         ao_delay(AO_MS_TO_TICKS(10));
  49                         if (!ao_fifo_empty(ao_usart1_rx_fifo))
  50                                 break;
  51                 }
  52                 if (c == 10)
  53                         goto done;
  54         }
  55 done:
  56         for (c = ao_btm_reply_len; c < sizeof (ao_btm_reply);)
  57                 ao_btm_reply[c++] = '\0';
  58         return ao_btm_reply_len;
  59 }
  60
  61 /*
  62  * Drain the serial port completely
  63  */
  64 void
  65 ao_btm_drain()
  66 {
  67         while (ao_btm_get_line())
  68                 ;
  69 }
  70
  71 /*
  72  * Set the stdio echo for the bluetooth link
  73  */
  74 void
  75 ao_btm_echo(uint8_t echo)
  76 {
  77         ao_stdios[ao_btm_stdio].echo = echo;
  78 }
  79
  80 /*
  81  * Delay between command charaters; the BT module
  82  * can't keep up with 57600 baud
  83  */
  84
  85 void
  86 ao_btm_putchar(char c)
  87 {
  88         ao_serial_putchar(c);
  89         ao_delay(1);
  90 }
  91
  92 /*
  93  * Wait for the bluetooth device to return
  94  * status from the previously executed command
  95  */
  96 uint8_t
  97 ao_btm_wait_reply(void)
  98 {
  99         for (;;) {
 100                 ao_btm_get_line();
 101                 if (!strncmp(ao_btm_reply, "OK", 2))
 102                         return 1;
 103                 if (!strncmp(ao_btm_reply, "ERROR", 5))
 104                         return -1;
 105                 if (ao_btm_reply[0] == '\0')
 106                         return 0;
 107         }
 108 }
 109
 110 void
 111 ao_btm_string(__code char *cmd)
 112 {
 113         char    c;
 114
 115         while (c = *cmd++)
 116                 ao_btm_putchar(c);
 117 }
 118
 119 uint8_t
 120 ao_btm_cmd(__code char *cmd)
 121 {
 122         ao_btm_drain();
 123         ao_btm_string(cmd);
 124         return ao_btm_wait_reply();
 125 }
 126
 127 uint8_t
 128 ao_btm_set_name(void)
 129 {
 130         char    sn[8];
 131         char    *s = sn + 8;
 132         char    c;
 133         int     n;
 134         ao_btm_string("ATN=TeleBT-");
 135         *--s = '\0';
 136         *--s = '\r';
 137         n = ao_serial_number;
 138         do {
 139                 *--s = '0' + n % 10;
 140         } while (n /= 10);
 141         while ((c = *s++))
 142                 ao_btm_putchar(c);
 143         return ao_btm_wait_reply();
 144 }
 145
 146 uint8_t
 147 ao_btm_try_speed(uint8_t speed)
 148 {
 149         ao_serial_set_speed(speed);
 150         ao_btm_drain();
 151         (void) ao_btm_cmd("\rATE0\rATQ0\r");
 152         if (ao_btm_cmd("AT\r") == 1)
 153                 return 1;
 154         return 0;
 155 }
 156
 157 /*
 158  * A thread to initialize the bluetooth device and
 159  * hang around to blink the LED when connected
 160  */
 161 void
 162 ao_btm(void)
 163 {
 164         /*
 165          * Wait for the bluetooth device to boot
 166          */
 167         ao_delay(AO_SEC_TO_TICKS(3));
 168
 169         /*
 170          * The first time we connect, the BTM-180 comes up at 19200 baud.
 171          * After that, it will remember and come up at 57600 baud. So, see
 172          * if it is already running at 57600 baud, and if that doesn't work
 173          * then tell it to switch to 57600 from 19200 baud.
 174          */
 175         while (!ao_btm_try_speed(AO_SERIAL_SPEED_57600)) {
 176                 ao_delay(AO_SEC_TO_TICKS(1));
 177                 if (ao_btm_try_speed(AO_SERIAL_SPEED_19200))
 178                         ao_btm_cmd("ATL4\r");
 179                 ao_delay(AO_SEC_TO_TICKS(1));
 180         }
 181
 182         /* Disable echo */
 183         ao_btm_cmd("ATE0\r");
 184
 185         /* Enable flow control */
 186         ao_btm_cmd("ATC1\r");
 187
 188         /* Set the reported name to something we can find on the host */
 189         ao_btm_set_name();
 190
 191         /* Turn off status reporting */
 192         ao_btm_cmd("ATQ1\r");
 193
 194         ao_btm_stdio = ao_add_stdio(ao_serial_pollchar,
 195                                     ao_serial_putchar,
 196                                     NULL);
 197         ao_btm_echo(0);
 198
 199         for (;;) {
 200                 while (!ao_btm_connected)
 201                         ao_sleep(&ao_btm_connected);
 202                 while (ao_btm_connected) {
 203                         ao_led_for(AO_LED_GREEN, AO_MS_TO_TICKS(20));
 204                         ao_delay(AO_SEC_TO_TICKS(3));
 205                 }
 206         }
 207 }
 208
 209 __xdata struct ao_task ao_btm_task;
 210
 211 void
 212 ao_btm_check_link() __critical
 213 {
 214         if (P2_1) {
 215                 ao_btm_connected = 0;
 216                 PICTL |= PICTL_P2ICON;
 217         } else {
 218                 ao_btm_connected = 1;
 219                 PICTL &= ~PICTL_P2ICON;
 220         }
 221 }
 222
 223 void
 224 ao_btm_isr(void)
 225 {
 226         if (P2IFG & (1 << 1)) {
 227                 ao_btm_check_link();
 228                 ao_wakeup(&ao_btm_connected);
 229         }
 230         P2IFG = 0;
 231 }
 232
 233 void
 234 ao_btm_init (void)
 235 {
 236         ao_serial_init();
 237         ao_serial_set_speed(AO_SERIAL_SPEED_19200);
 238
 239         /*
 240          * Configure link status line
 241          */
 242
 243         /* Set P2_1 to input, pull-down */
 244         P2DIR &= ~(1 << 1);
 245         P2INP |= P2INP_MDP2_1_TRISTATE;
 246
 247         /* Enable P2 interrupts */
 248         IEN2 |= IEN2_P2IE;
 249         ao_btm_check_link();
 250         PICTL |= PICTL_P2IEN;
 251
 252         ao_add_task(&ao_btm_task, ao_btm, "bt");
 253 }