packages/devs/serial/v85x/v850/v2_0/src/v85x_v850_serial.c

   1 //==========================================================================
   2 //
   3 //      io/serial/v85x/v85x_v850_serial.c
   4 //
   5 //      NEC V850 Serial I/O Interface Module (interrupt driven)
   6 //
   7 //==========================================================================
   8 //####ECOSGPLCOPYRIGHTBEGIN####
   9 // -------------------------------------------
  10 // This file is part of eCos, the Embedded Configurable Operating System.
  11 // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
  12 //
  13 // eCos is free software; you can redistribute it and/or modify it under
  14 // the terms of the GNU General Public License as published by the Free
  15 // Software Foundation; either version 2 or (at your option) any later version.
  16 //
  17 // eCos is distributed in the hope that it will be useful, but WITHOUT ANY
  18 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20 // for more details.
  21 //
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  23 // with eCos; if not, write to the Free Software Foundation, Inc.,
  24 // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25 //
  26 // As a special exception, if other files instantiate templates or use macros
  27 // or inline functions from this file, or you compile this file and link it
  28 // with other works to produce a work based on this file, this file does not
  29 // by itself cause the resulting work to be covered by the GNU General Public
  30 // License. However the source code for this file must still be made available
  31 // in accordance with section (3) of the GNU General Public License.
  32 //
  33 // This exception does not invalidate any other reasons why a work based on
  34 // this file might be covered by the GNU General Public License.
  35 //
  36 // Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
  37 // at http://sources.redhat.com/ecos/ecos-license/
  38 // -------------------------------------------
  39 //####ECOSGPLCOPYRIGHTEND####
  40 //==========================================================================
  41 //#####DESCRIPTIONBEGIN####
  42 //
  43 // Author(s):    gthomas
  44 // Contributors: gthomas,jlarmour
  45 // Date:         2001-03-21
  46 // Purpose:      V850 Serial I/O module (interrupt driven version)
  47 // Description:
  48 //
  49 //####DESCRIPTIONEND####
  50 //
  51 //==========================================================================
  52
  53 #include <pkgconf/system.h>
  54 #include <pkgconf/io_serial.h>
  55 #include <pkgconf/io.h>
  56 #ifdef CYGPKG_KERNEL
  57 #include <pkgconf/kernel.h>
  58 #endif
  59 #include CYGBLD_HAL_TARGET_H
  60
  61 #include <cyg/io/io.h>
  62 #include <cyg/hal/hal_intr.h>
  63 #include <cyg/io/devtab.h>
  64 #include <cyg/io/serial.h>
  65 #include <cyg/infra/diag.h>
  66
  67 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
  68 #include <cyg/kernel/kapi.h>
  69 #endif
  70
  71 #ifdef CYGPKG_IO_SERIAL_V85X_V850
  72
  73 #include "v85x_v850_serial.h"
  74
  75 typedef struct v850_serial_info {
  76     CYG_ADDRWORD   base;
  77     CYG_WORD       int_num;
  78     cyg_interrupt  serial_interrupt[3];
  79     cyg_handle_t   serial_interrupt_handle[3];
  80     cyg_bool       tx_busy;
  81 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
  82     cyg_alarm      tx_timeout;
  83     cyg_handle_t   tx_timeout_handle;
  84 #endif
  85 } v850_serial_info;
  86
  87 static bool v850_serial_init(struct cyg_devtab_entry *tab);
  88 static bool v850_serial_putc(serial_channel *chan, unsigned char c);
  89 static Cyg_ErrNo v850_serial_lookup(struct cyg_devtab_entry **tab,
  90                                     struct cyg_devtab_entry *sub_tab,
  91                                     const char *name);
  92 static unsigned char v850_serial_getc(serial_channel *chan);
  93 static Cyg_ErrNo v850_serial_set_config(serial_channel *chan, cyg_uint32 key,
  94                                         const void *xbuf, cyg_uint32 *len);
  95 static void v850_serial_start_xmit(serial_channel *chan);
  96 static void v850_serial_stop_xmit(serial_channel *chan);
  97
  98 static cyg_uint32 v850_serial_ISR(cyg_vector_t vector, cyg_addrword_t data);
  99 static void       v850_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data);
 100
 101 static SERIAL_FUNS(v850_serial_funs,
 102                    v850_serial_putc,
 103                    v850_serial_getc,
 104                    v850_serial_set_config,
 105                    v850_serial_start_xmit,
 106                    v850_serial_stop_xmit
 107     );
 108
 109 #ifdef CYGPKG_IO_SERIAL_V85X_V850_SERIAL0
 110 static v850_serial_info v850_serial_info0 = {V850_REG_ASIM0,
 111                                              CYGNUM_HAL_VECTOR_INTSER0};
 112 #if CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE > 0
 113 static unsigned char v850_serial_out_buf0[CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE];
 114 static unsigned char v850_serial_in_buf0[CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BUFSIZE];
 115
 116 static SERIAL_CHANNEL_USING_INTERRUPTS(v850_serial_channel0,
 117                                        v850_serial_funs,
 118                                        v850_serial_info0,
 119                                        CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BAUD),
 120                                        CYG_SERIAL_STOP_DEFAULT,
 121                                        CYG_SERIAL_PARITY_DEFAULT,
 122                                        CYG_SERIAL_WORD_LENGTH_DEFAULT,
 123                                        CYG_SERIAL_FLAGS_DEFAULT,
 124                                        &v850_serial_out_buf0[0], sizeof(v850_serial_out_buf0),
 125                                        &v850_serial_in_buf0[0], sizeof(v850_serial_in_buf0)
 126     );
 127 #else
 128 static SERIAL_CHANNEL(v850_serial_channel0,
 129                       v850_serial_funs,
 130                       v850_serial_info0,
 131                       CYG_SERIAL_BAUD_RATE(CYGNUM_IO_SERIAL_V85X_V850_SERIAL0_BAUD),
 132                       CYG_SERIAL_STOP_DEFAULT,
 133                       CYG_SERIAL_PARITY_DEFAULT,
 134                       CYG_SERIAL_WORD_LENGTH_DEFAULT,
 135                       CYG_SERIAL_FLAGS_DEFAULT
 136     );
 137 #endif
 138
 139 DEVTAB_ENTRY(v850_serial_io0,
 140              CYGDAT_IO_SERIAL_V85X_V850_SERIAL0_NAME,
 141              0,                     // Does not depend on a lower level interface
 142              &cyg_io_serial_devio,
 143              v850_serial_init,
 144              v850_serial_lookup,     // Serial driver may need initializing
 145              &v850_serial_channel0
 146     );
 147 #endif //  CYGPKG_IO_SERIAL_V85X_V850_SERIAL0
 148
 149 // Internal function to actually configure the hardware to desired baud rate, etc.
 150 static bool
 151 v850_serial_config_port(serial_channel *chan, cyg_serial_info_t *new_config, bool init)
 152 {
 153     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 154     volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;
 155     unsigned char parity = select_parity[new_config->parity];
 156     unsigned char word_length = select_word_length[new_config->word_length-CYGNUM_SERIAL_WORD_LENGTH_5];
 157     unsigned char stop_bits = select_stop_bits[new_config->stop];
 158     int divisor, count;
 159
 160     if ((select_baud[new_config->baud].count == 0) ||
 161         (word_length == 0xFF) ||
 162         (parity == 0xFF) ||
 163         (stop_bits == 0xFF)) {
 164         return false;  // Unsupported configuration
 165     }
 166     port->asim = ASIM_TxRx_Tx | ASIM_TxRx_Rx | parity | word_length | stop_bits;
 167     count = select_baud[new_config->baud].count;
 168     divisor = select_baud[new_config->baud].divisor;
 169
 170     while (count > 0xFF) {
 171         count >>= 1;
 172         divisor++;
 173     }
 174
 175     port->brgc = count;
 176
 177     port->brgm = divisor & 0x07;
 178 #if CYGINT_HAL_V850_VARIANT_SB1
 179     port->brgm1 = divisor >> 3;
 180 #endif
 181
 182     if (new_config != &chan->config) {
 183         chan->config = *new_config;
 184     }
 185     return true;
 186 }
 187
 188 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
 189 //
 190 // The serial ports on the V850 are incredibly stupid.  There is no
 191 // interface status register which can tell you if it is possible to
 192 // read or write a character!  The only way to discern this is by using
 193 // interrupts [or at least an interrupt register and polling it].  Thus
 194 // the serial transmit code has a problem in that it will be required by
 195 // upper layers to "send until full".  The only way to decide "not full" is
 196 // that an interrupt has happened.  If the serial driver is being mixed
 197 // with diagnostic I/O, then serial transmit interrupts will possibly be
 198 // lost.
 199 //
 200 // This code attempts to compenstate by using a kernel alarm to reset the
 201 // "device is busy" flag after some timeout.  The timeout period will be
 202 // sufficiently long so as to not interfere with normal interrupt handling.
 203 //
 204 static void
 205 v850_serial_tx_timeout(cyg_handle_t alarm, cyg_addrword_t p)
 206 {
 207     v850_serial_info *v850_chan = (v850_serial_info *)p;
 208     v850_chan->tx_busy = false;
 209 }
 210 #endif
 211
 212 // Function to initialize the device.  Called at bootstrap time.
 213 static bool
 214 v850_serial_init(struct cyg_devtab_entry *tab)
 215 {
 216     int i;
 217     serial_channel *chan = (serial_channel *)tab->priv;
 218     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 219 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
 220     cyg_handle_t h;
 221 #endif
 222 #ifdef CYGDBG_IO_INIT
 223     diag_printf("V850 SERIAL init - dev: %x.%d\n", v850_chan->base, v850_chan->int_num);
 224 #endif
 225     (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
 226     if (chan->out_cbuf.len != 0) {
 227         for (i = 0;  i < 3;  i++) {
 228             cyg_drv_interrupt_create(v850_chan->int_num+i,
 229                                      99,                     // Priority - unused
 230                                      (cyg_addrword_t)chan,   // Data item passed to interrupt handler
 231                                      v850_serial_ISR,
 232                                      v850_serial_DSR,
 233                                      &v850_chan->serial_interrupt_handle[i],
 234                                      &v850_chan->serial_interrupt[i]);
 235             cyg_drv_interrupt_attach(v850_chan->serial_interrupt_handle[i]);
 236             cyg_drv_interrupt_unmask(v850_chan->int_num+i);
 237 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
 238             cyg_clock_to_counter(cyg_real_time_clock(), &h);
 239             cyg_alarm_create(h, v850_serial_tx_timeout, (cyg_addrword_t)v850_chan,
 240                              &v850_chan->tx_timeout_handle, &v850_chan->tx_timeout);
 241 #endif
 242         }
 243     }
 244     v850_chan->tx_busy = false;
 245     return v850_serial_config_port(chan, &chan->config, true);
 246 }
 247
 248 // This routine is called when the device is "looked" up (i.e. attached)
 249 static Cyg_ErrNo
 250 v850_serial_lookup(struct cyg_devtab_entry **tab,
 251                   struct cyg_devtab_entry *sub_tab,
 252                   const char *name)
 253 {
 254     serial_channel *chan = (serial_channel *)(*tab)->priv;
 255     (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
 256     return ENOERR;
 257 }
 258
 259 // Send a character to the device output buffer.
 260 // Return 'true' if character is sent to device
 261 static bool
 262 v850_serial_putc(serial_channel *chan, unsigned char c)
 263 {
 264     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 265     volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;
 266     if (!v850_chan->tx_busy) {
 267         v850_chan->tx_busy = true;
 268         port->txs = c;
 269 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
 270         cyg_alarm_initialize(v850_chan->tx_timeout_handle, cyg_current_time()+10, 0);
 271 #endif
 272         return true;
 273     } else {
 274         return false;  // Couldn't send, tx was busy
 275     }
 276 }
 277
 278 // Fetch a character from the device input buffer, waiting if necessary
 279 static unsigned char
 280 v850_serial_getc(serial_channel *chan)
 281 {
 282     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 283     volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;
 284     return port->rxs;
 285 }
 286
 287 // Set up the device characteristics; baud rate, etc.
 288 static Cyg_ErrNo
 289 v850_serial_set_config(serial_channel *chan, cyg_uint32 key,
 290                        const void *xbuf, cyg_uint32 *len)
 291 {
 292     switch (key) {
 293     case CYG_IO_SET_CONFIG_SERIAL_INFO:
 294       {
 295         cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;
 296         if ( *len < sizeof(cyg_serial_info_t) ) {
 297             return -EINVAL;
 298         }
 299         *len = sizeof(cyg_serial_info_t);
 300         if ( true != v850_serial_config_port(chan, config, false) )
 301             return -EINVAL;
 302       }
 303       break;
 304     default:
 305         return -EINVAL;
 306     }
 307     return ENOERR;
 308 }
 309
 310 // Enable the transmitter on the device
 311 static void
 312 v850_serial_start_xmit(serial_channel *chan)
 313 {
 314     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 315     (chan->callbacks->xmt_char)(chan);  // Kick transmitter (if necessary)
 316     cyg_drv_interrupt_unmask(v850_chan->int_num+INT_Tx);  // Enable Tx interrupt
 317 }
 318
 319 // Disable the transmitter on the device
 320 static void
 321 v850_serial_stop_xmit(serial_channel *chan)
 322 {
 323     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 324     cyg_drv_interrupt_mask(v850_chan->int_num+INT_Tx);  // Disable Tx interrupt
 325 }
 326
 327 // Serial I/O - low level interrupt handler (ISR)
 328 static cyg_uint32
 329 v850_serial_ISR(cyg_vector_t vector, cyg_addrword_t data)
 330 {
 331     cyg_drv_interrupt_mask(vector);
 332     cyg_drv_interrupt_acknowledge(vector);
 333     return CYG_ISR_CALL_DSR;  // Cause DSR to be run
 334 }
 335
 336 // Serial I/O - high level interrupt handler (DSR)
 337 static void
 338 v850_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
 339 {
 340     serial_channel *chan = (serial_channel *)data;
 341     v850_serial_info *v850_chan = (v850_serial_info *)chan->dev_priv;
 342     volatile struct serial_port *port = (volatile struct serial_port *)v850_chan->base;
 343     switch (vector-(v850_chan->int_num)) {
 344     case INT_ERR:
 345     case INT_Rx:
 346         (chan->callbacks->rcv_char)(chan, port->rxs);
 347         break;
 348     case INT_Tx:
 349         v850_chan->tx_busy = false;
 350 #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK
 351         cyg_alarm_initialize(v850_chan->tx_timeout_handle, 0, 0);
 352 #endif
 353         (chan->callbacks->xmt_char)(chan);
 354         break;
 355     }
 356     cyg_drv_interrupt_unmask(vector);
 357 }
 358 #endif
 359
 360 // EOF v85x_v850_serial.c