mayhem-firmware/firmware/chibios/os/hal/platforms/LPC11xx/serial_lld.c

299 lines
8.0 KiB
C
Executable File

/*
ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* @file LPC11xx/serial_lld.c
* @brief LPC11xx low level serial driver code.
*
* @addtogroup SERIAL
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_SERIAL || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
#if LPC11xx_SERIAL_USE_UART0 || defined(__DOXYGEN__)
/** @brief UART0 serial driver identifier.*/
SerialDriver SD1;
#endif
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/** @brief Driver default configuration.*/
static const SerialConfig default_config = {
SERIAL_DEFAULT_BITRATE,
LCR_WL8 | LCR_STOP1 | LCR_NOPARITY,
FCR_TRIGGER0
};
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief UART initialization.
*
* @param[in] sdp communication channel associated to the UART
* @param[in] config the architecture-dependent serial driver configuration
*/
static void uart_init(SerialDriver *sdp, const SerialConfig *config) {
LPC_UART_TypeDef *u = sdp->uart;
uint32_t div = LPC11xx_SERIAL_UART0_PCLK / (config->sc_speed << 4);
u->LCR = config->sc_lcr | LCR_DLAB;
u->DLL = div;
u->DLM = div >> 8;
u->LCR = config->sc_lcr;
u->FCR = FCR_ENABLE | FCR_RXRESET | FCR_TXRESET | config->sc_fcr;
u->ACR = 0;
u->FDR = 0x10;
u->TER = TER_ENABLE;
u->IER = IER_RBR | IER_STATUS;
}
/**
* @brief UART de-initialization.
*
* @param[in] u pointer to an UART I/O block
*/
static void uart_deinit(LPC_UART_TypeDef *u) {
u->LCR = LCR_DLAB;
u->DLL = 1;
u->DLM = 0;
u->LCR = 0;
u->FDR = 0x10;
u->IER = 0;
u->FCR = FCR_RXRESET | FCR_TXRESET;
u->ACR = 0;
u->TER = TER_ENABLE;
}
/**
* @brief Error handling routine.
*
* @param[in] sdp communication channel associated to the UART
* @param[in] err UART LSR register value
*/
static void set_error(SerialDriver *sdp, IOREG32 err) {
flagsmask_t sts = 0;
if (err & LSR_OVERRUN)
sts |= SD_OVERRUN_ERROR;
if (err & LSR_PARITY)
sts |= SD_PARITY_ERROR;
if (err & LSR_FRAMING)
sts |= SD_FRAMING_ERROR;
if (err & LSR_BREAK)
sts |= SD_BREAK_DETECTED;
chSysLockFromIsr();
chnAddFlagsI(sdp, sts);
chSysUnlockFromIsr();
}
/**
* @brief Common IRQ handler.
* @note Tries hard to clear all the pending interrupt sources, we don't
* want to go through the whole ISR and have another interrupt soon
* after.
*
* @param[in] u pointer to an UART I/O block
* @param[in] sdp communication channel associated to the UART
*/
static void serve_interrupt(SerialDriver *sdp) {
LPC_UART_TypeDef *u = sdp->uart;
while (TRUE) {
switch (u->IIR & IIR_SRC_MASK) {
case IIR_SRC_NONE:
return;
case IIR_SRC_ERROR:
set_error(sdp, u->LSR);
break;
case IIR_SRC_TIMEOUT:
case IIR_SRC_RX:
chSysLockFromIsr();
if (chIQIsEmptyI(&sdp->iqueue))
chnAddFlagsI(sdp, CHN_INPUT_AVAILABLE);
chSysUnlockFromIsr();
while (u->LSR & LSR_RBR_FULL) {
chSysLockFromIsr();
if (chIQPutI(&sdp->iqueue, u->RBR) < Q_OK)
chnAddFlagsI(sdp, SD_OVERRUN_ERROR);
chSysUnlockFromIsr();
}
break;
case IIR_SRC_TX:
{
int i = LPC11xx_SERIAL_FIFO_PRELOAD;
do {
msg_t b;
chSysLockFromIsr();
b = chOQGetI(&sdp->oqueue);
chSysUnlockFromIsr();
if (b < Q_OK) {
u->IER &= ~IER_THRE;
chSysLockFromIsr();
chnAddFlagsI(sdp, CHN_OUTPUT_EMPTY);
chSysUnlockFromIsr();
break;
}
u->THR = b;
} while (--i);
}
break;
default:
(void) u->THR;
(void) u->RBR;
}
}
}
/**
* @brief Attempts a TX FIFO preload.
*/
static void preload(SerialDriver *sdp) {
LPC_UART_TypeDef *u = sdp->uart;
if (u->LSR & LSR_THRE) {
int i = LPC11xx_SERIAL_FIFO_PRELOAD;
do {
msg_t b = chOQGetI(&sdp->oqueue);
if (b < Q_OK) {
chnAddFlagsI(sdp, CHN_OUTPUT_EMPTY);
return;
}
u->THR = b;
} while (--i);
}
u->IER |= IER_THRE;
}
/**
* @brief Driver SD1 output notification.
*/
#if LPC11xx_SERIAL_USE_UART0 || defined(__DOXYGEN__)
static void notify1(GenericQueue *qp) {
(void)qp;
preload(&SD1);
}
#endif
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/**
* @brief UART0 IRQ handler.
*
* @isr
*/
#if LPC11xx_SERIAL_USE_UART0 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(Vector94) {
CH_IRQ_PROLOGUE();
serve_interrupt(&SD1);
CH_IRQ_EPILOGUE();
}
#endif
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level serial driver initialization.
*
* @notapi
*/
void sd_lld_init(void) {
#if LPC11xx_SERIAL_USE_UART0
sdObjectInit(&SD1, NULL, notify1);
SD1.uart = LPC_UART;
LPC_IOCON->PIO1_6 = 0xC1; /* RDX without resistors. */
LPC_IOCON->PIO1_7 = 0xC1; /* TDX without resistors. */
#endif
}
/**
* @brief Low level serial driver configuration and (re)start.
*
* @param[in] sdp pointer to a @p SerialDriver object
* @param[in] config the architecture-dependent serial driver configuration.
* If this parameter is set to @p NULL then a default
* configuration is used.
*
* @notapi
*/
void sd_lld_start(SerialDriver *sdp, const SerialConfig *config) {
if (config == NULL)
config = &default_config;
if (sdp->state == SD_STOP) {
#if LPC11xx_SERIAL_USE_UART0
if (&SD1 == sdp) {
LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 12);
LPC_SYSCON->UARTCLKDIV = LPC11xx_SERIAL_UART0CLKDIV;
nvicEnableVector(UART_IRQn,
CORTEX_PRIORITY_MASK(LPC11xx_SERIAL_UART0_IRQ_PRIORITY));
}
#endif
}
uart_init(sdp, config);
}
/**
* @brief Low level serial driver stop.
* @details De-initializes the UART, stops the associated clock, resets the
* interrupt vector.
*
* @param[in] sdp pointer to a @p SerialDriver object
*
* @notapi
*/
void sd_lld_stop(SerialDriver *sdp) {
if (sdp->state == SD_READY) {
uart_deinit(sdp->uart);
#if LPC11xx_SERIAL_USE_UART0
if (&SD1 == sdp) {
LPC_SYSCON->UARTCLKDIV = 0;
LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 12);
nvicDisableVector(UART_IRQn);
return;
}
#endif
}
}
#endif /* HAL_USE_SERIAL */
/** @} */