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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2014 by Cástor Muñoz
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdint.h>
#include <stdbool.h>
#include "config.h"
#include "cpu.h"
#include "system.h"
#include "serial.h"
#include "s5l8700.h"
#include "uc87xx.h"
/* Define LOGF_ENABLE to enable logf output in this file */
#define LOGF_ENABLE
#include "logf.h"
/* shall include serial HW configuracion for specific target */
#define NANO2G_UART_CLK_HZ 24000000 /* external OSC0 ??? */
/* This values below are valid with a UCLK of 24MHz */
#define BRDATA_9600 (155) /* 9615 */
#define BRDATA_19200 (77) /* 19231 */
#define BRDATA_28800 (51) /* 28846 */
#define BRDATA_38400 (38) /* 38462 */
#define BRDATA_57600 (25) /* 57692 */
#define BRDATA_115200 (12) /* 115385 */
extern const struct uartc s5l8701_uartc0;
#ifdef IPOD_ACCESSORY_PROTOCOL
void iap_rx_isr(int, char*, char*, uint32_t);
#endif
struct uartc_port ser_port IDATA_ATTR =
{
/* location */
.uartc = &s5l8701_uartc0,
.id = 0,
/* configuration */
.rx_trg = UFCON_RX_FIFO_TRG_4,
.tx_trg = UFCON_TX_FIFO_TRG_EMPTY,
.clksel = UCON_CLKSEL_ECLK,
.clkhz = NANO2G_UART_CLK_HZ,
/* interrupt callbacks */
#ifdef IPOD_ACCESSORY_PROTOCOL
.rx_cb = iap_rx_isr,
#else
.rx_cb = NULL,
#endif
.tx_cb = NULL, /* polling */
};
/*
* serial driver API
*/
void serial_setup(void)
{
uartc_port_open(&ser_port);
/* set a default configuration, Tx and Rx modes are
disabled when the port is initialized */
uartc_port_config(&ser_port, ULCON_DATA_BITS_8,
ULCON_PARITY_NONE, ULCON_STOP_BITS_1);
uartc_port_set_bitrate_raw(&ser_port, BRDATA_115200);
/* enable Tx interrupt request or POLLING mode */
uartc_port_set_tx_mode(&ser_port, UCON_MODE_INTREQ);
logf("[%lu] "MODEL_NAME" port %d ready!",
(uint32_t)USEC_TIMER, ser_port.id);
}
int tx_rdy(void)
{
return uartc_port_tx_ready(&ser_port) ? 1 : 0;
}
void tx_writec(unsigned char c)
{
uartc_port_tx_byte(&ser_port, c);
}
#ifdef IPOD_ACCESSORY_PROTOCOL
#include "iap.h"
static enum {
ABR_STATUS_LAUNCHED, /* ST_SYNC */
ABR_STATUS_SYNCING, /* ST_SOF */
ABR_STATUS_DONE
} abr_status;
void serial_bitrate(int rate)
{
logf("[%lu] serial_bitrate(%d)", (uint32_t)USEC_TIMER, rate);
if (rate == 0) {
/* Using auto-bitrate (ABR) to detect accessory Tx speed:
*
* + Here:
* - Disable Rx logic to clean the FIFO and the shift
* register, thus no Rx data interrupts are generated.
* - Launch ABR and wait for a low pulse in Rx line.
*
* + In ISR, when a low pulse is detected (ideally it is the
* start bit of 0xff):
* - Calculate and configure detected speed.
* - Enable Rx to verify that the next received data frame
* is 0x55 or 0xff:
* - If so, it's assumed bit rate is correctly detected,
* it will not be modified until speed is changed using
* RB options menu.
* - If not, reset iAP state machine and launch a new ABR.
*/
uartc_port_set_rx_mode(&ser_port, UCON_MODE_DISABLED);
uartc_port_abr_start(&ser_port);
abr_status = ABR_STATUS_LAUNCHED;
}
else {
uint32_t brdata;
if (rate == 57600) brdata = BRDATA_57600;
else if (rate == 38400) brdata = BRDATA_38400;
else if (rate == 19200) brdata = BRDATA_19200;
else brdata = BRDATA_9600;
uartc_port_abr_stop(&ser_port); /* abort ABR if already launched */
uartc_port_set_bitrate_raw(&ser_port, brdata);
uartc_port_set_rx_mode(&ser_port, UCON_MODE_INTREQ);
abr_status = ABR_STATUS_DONE;
}
}
void iap_rx_isr(int len, char *data, char *err, uint32_t abr_cnt)
{
/* ignore Rx errors, upper layer will discard bad packets */
(void) err;
static int sync_retry;
if (abr_status == ABR_STATUS_LAUNCHED) {
/* autobauding */
if (abr_cnt) {
#define BR2CNT(s) (NANO2G_UART_CLK_HZ / (unsigned)(s))
if (abr_cnt < BR2CNT(57600*1.1) || abr_cnt > BR2CNT(9600*0.9)) {
/* detected speed out of range, relaunch ABR */
uartc_port_abr_start(&ser_port);
return;
}
/* valid speed detected, select it */
uint32_t brdata;
if (abr_cnt < BR2CNT(48000)) brdata = BRDATA_57600;
else if (abr_cnt < BR2CNT(33600)) brdata = BRDATA_38400;
else if (abr_cnt < BR2CNT(24000)) brdata = BRDATA_28800;
else if (abr_cnt < BR2CNT(14400)) brdata = BRDATA_19200;
else brdata = BRDATA_9600;
/* set detected speed */
uartc_port_set_bitrate_raw(&ser_port, brdata);
uartc_port_set_rx_mode(&ser_port, UCON_MODE_INTREQ);
/* enter SOF state */
iap_getc(0xff);
abr_status = ABR_STATUS_SYNCING;
sync_retry = 2; /* we are expecting [0xff] 0x55 */
}
}
/* process received data */
while (len--)
{
bool sync_done = !iap_getc(*data++);
if (abr_status == ABR_STATUS_SYNCING)
{
if (sync_done) {
abr_status = ABR_STATUS_DONE;
}
else if (--sync_retry == 0) {
/* invalid speed detected, relaunch ABR
discarding remaining data (if any) */
serial_bitrate(0);
break;
}
}
}
}
#endif /* IPOD_ACCESSORY_PROTOCOL */
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