-/*!
- * \file
- * <!--
- * Copyright 2000 Bernardo Innocenti <bernie@codewiz.org>
- * Copyright 2003,2004 Develer S.r.l. (http://www.develer.com/)
- * This file is part of DevLib - See devlib/README for information.
- * -->
- *
- * \version $Id$
- *
- * \author Bernardo Innocenti <bernie@develer.com>
- *
- * \brief AVR UART and SPI I/O driver
- */
-
-/*
- * $Log$
- * Revision 1.4 2004/06/03 11:27:09 bernie
- * Add dual-license information.
- *
- * Revision 1.3 2004/06/02 21:35:24 aleph
- * Serial enhancements: interruptible receive handler and 8 bit serial status for AVR; remove volatile attribute to FIFOBuffer, useless for new fifobuf routens
- *
- * Revision 1.2 2004/05/23 18:21:53 bernie
- * Trim CVS logs and cleanup header info.
- *
- */
-
-#include "ser.h"
-#include "ser_p.h"
-#include "kdebug.h"
-#include "config.h"
-#include "hw.h"
-#include <mware/fifobuf.h>
-
-extern struct Serial ser_handles[SER_CNT];
-
-struct AvrSerial
-{
- struct SerialHardware hw;
- struct Serial* serial;
-};
-
-
-/* Hardware handshake */
-#define RTS_ON
-#define RTS_OFF
-#define IS_CTS_ON true
-#define IS_CTS_OFF false
-
-
-/* SPI port and pin configuration */
-#define SPI_PORT PORTB
-#define SPI_DDR DDRB
-#define SPI_SCK_BIT PORTB1
-#define SPI_MOSI_BIT PORTB2
-#define SPI_MISO_BIT PORTB3
-
-
-#ifdef __AVR_ATmega103__
- /* Macro for ATmega103 compatibility */
- #define UCSR0B UCR
- #define UDR0 UDR
- #define UCSR0A USR
- #define UBRR0L UBRR
-#else
- #define UCR UCSR0B
- #define UDR UDR0
- #define USR UCSR0A
-#endif
-
-
-/* Transmission fill byte */
-#define SER_FILL_BYTE 0xAA
-
-
-static void uart0_enabletxirq(UNUSED(struct SerialHardware *ctx))
-{
-#ifdef CONFIG_SER_TXFILL
- UCSR0B = BV(RXCIE) | BV(UDRIE) | BV(RXEN) | BV(TXEN) | BV(UCSZ2);
-#else
- UCSR0B = BV(RXCIE) | BV(UDRIE) | BV(RXEN) | BV(TXEN);
-#endif
-}
-
-static void uart0_init(struct SerialHardware *_hw, struct Serial *ser)
-{
- struct AvrSerial *hw = (struct AvrSerial *)_hw;
- hw->serial = ser;
-
- /* Set TX port as input with pull-up enabled to avoid
- * noise on the remote RX when TX is disabled */
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
- DDRE &= ~BV(PORTE1);
- PORTE |= BV(PORTE1);
- ENABLE_IRQRESTORE(flags);
-
- /* TODO: explain why TX is disabled whenever possible */
-#ifdef CONFIG_SER_TXFILL
- /*!
- * Set multiprocessor mode and 9 bit data frame.
- * The receiver keep MPCM bit always on. When useful data
- * is trasmitted the ninth bit is set. Receiver consider the
- * frame as address info and receive it.
- * When useless fill bytes are sent the ninth bit is cleared
- * and the receiver will ignore them, avoiding useless triggering
- * of RXC interrupt.
- */
- UCSR0A = BV(MPCM);
- UCSR0B = BV(RXCIE) | BV(RXEN) | BV(UCSZ2);
-#else
- UCSR0B = BV(RXCIE) | BV(RXEN);
-#endif
-
- RTS_ON;
-}
-
-static void uart0_cleanup(UNUSED(struct SerialHardware *ctx))
-{
- UCSR0B = 0;
-}
-
-static void uart0_setbaudrate(UNUSED(struct SerialHardware *ctx), unsigned long rate)
-{
- // Compute baud-rate period
- uint16_t period = (((CLOCK_FREQ / 16UL) + (rate / 2)) / rate) - 1;
-
-#ifndef __AVR_ATmega103__
- UBRR0H = (period) >> 8;
-#endif
- UBRR0L = (period);
-}
-
-
-#ifndef __AVR_ATmega103__
-
-static void uart1_enabletxirq(UNUSED(struct SerialHardware *ctx))
-{
- UCSR1B = BV(RXCIE) | BV(UDRIE) | BV(RXEN) | BV(TXEN);
-}
-
-static void uart1_init(struct SerialHardware *_hw, struct Serial *ser)
-{
- struct AvrSerial *hw = (struct AvrSerial *)_hw;
- hw->serial = ser;
-
- /* Set TX port as input with pull-up enabled to avoid
- * noise on the remote RX when TX is disabled */
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
- DDRD &= ~BV(PORTD3);
- PORTD |= BV(PORTD3);
- ENABLE_IRQRESTORE(flags);
-
- /* TODO: explain why TX is disabled whenever possible */
- UCSR1B = BV(RXCIE) | BV(RXEN);
-
- RTS_ON;
-}
-
-static void uart1_cleanup(UNUSED(struct SerialHardware *ctx))
-{
- UCSR1B = 0;
-}
-
-static void uart1_setbaudrate(UNUSED(struct SerialHardware *ctx), unsigned long rate)
-{
- // Compute baud-rate period
- uint16_t period = (((CLOCK_FREQ / 16UL) + (rate / 2)) / rate) - 1;
-
- UBRR1H = (period) >> 8;
- UBRR1L = (period);
-}
-
-static void uart0_setparity(UNUSED(struct SerialHardware *ctx), int parity)
-{
- UCSR0C |= (parity) << UPM0;
-}
-
-static void uart1_setparity(UNUSED(struct SerialHardware *ctx), int parity)
-{
- UCSR1C |= (parity) << UPM0;
-}
-
-#endif /* !__AVR_ATmega103__ */
-
-
-static void spi_init(struct SerialHardware *_hw, struct Serial *ser)
-{
- struct AvrSerial *hw = (struct AvrSerial *)_hw;
- hw->serial = ser;
-
- /* MOSI and SCK out, MISO in */
- SPI_DDR |= BV(SPI_MOSI_BIT) | BV(SPI_SCK_BIT);
- SPI_DDR &= ~BV(SPI_MISO_BIT);
- /* Enable SPI, IRQ on, Master, CPU_CLOCK/16 */
- SPCR = BV(SPE) | BV(SPIE) | BV(MSTR) | BV(SPR0);
-}
-
-static void spi_cleanup(UNUSED(struct SerialHardware *ctx))
-{
- SPCR = 0;
- /* Set all pins as inputs */
- SPI_DDR &= ~(BV(SPI_MISO_BIT) | BV(SPI_MOSI_BIT) | BV(SPI_SCK_BIT));
-}
-
-
-
-#if defined(CONFIG_SER_HW_HANDSHAKE)
-
-//! This interrupt is triggered when the CTS line goes high
-SIGNAL(SIG_CTS)
-{
- // Re-enable UDR empty interrupt and TX, then disable CTS interrupt
- UCR = BV(RXCIE) | BV(UDRIE) | BV(RXEN) | BV(TXEN);
- cbi(EIMSK, EIMSKB_CTS);
-}
-
-#endif // CONFIG_SER_HW_HANDSHAKE
-
-
-/*!
- * Serial 0 TX interrupt handler
- */
-#ifdef __AVR_ATmega103__
-SIGNAL(SIG_UART_DATA)
-#else
-SIGNAL(SIG_UART0_DATA)
-#endif
-{
- if (fifo_isempty(&ser_handles[SER_UART0].txfifo))
- {
-#ifdef CONFIG_SER_TXFILL
- /*
- * To avoid audio interference: always transmit useless char.
- * Send the byte with the ninth bit cleared, the receiver in MCPM mode
- * will ignore it.
- */
- UCSR0B &= ~BV(TXB8);
- UDR0 = SER_FILL_BYTE;
-#else
- /* Disable UDR empty interrupt and transmitter */
- UCR = BV(RXCIE) | BV(RXEN);
-#endif
- }
-#if defined(CONFIG_SER_HWHANDSHAKE)
- else if (IS_CTS_OFF)
- {
- // disable rx interrupt and tx, enable CTS interrupt
- UCR = BV(RXCIE) | BV(RXEN);
- sbi(EIFR, EIMSKB_CTS);
- sbi(EIMSK, EIMSKB_CTS);
- }
-#endif // CONFIG_SER_HWHANDSHAKE
- else
- {
-#ifdef CONFIG_SER_TXFILL
- /* Send with ninth bit set. Receiver in MCPM mode will receive it */
- UCSR0B |= BV(TXB8);
-#endif
- UDR = fifo_pop(&ser_handles[SER_UART0].txfifo);
- }
-}
-
-/*!
- * Serial 1 TX interrupt handler
- */
-#ifndef __AVR_ATmega103__
-SIGNAL(SIG_UART1_DATA)
-{
- if (fifo_isempty(&ser_handles[SER_UART1].txfifo))
- {
- /* Disable UDR empty interrupt and transmitter */
- UCSR1B = BV(RXCIE) | BV(RXEN);
- }
-#if defined(CONFIG_SER_HWHANDSHAKE)
- else if (IS_CTS_OFF)
- {
- // disable rx interrupt and tx, enable CTS interrupt
- UCSR1B = BV(RXCIE) | BV(RXEN);
- sbi(EIFR, EIMSKB_CTS);
- sbi(EIMSK, EIMSKB_CTS);
- }
-#endif // CONFIG_SER_HWHANDSHAKE
- else
- UDR1 = fifo_pop(&ser_handles[SER_UART1].txfifo);
-}
-#endif /* !__AVR_ATmega103__ */
-
-
-/*!
- * Serial 0 RX complete interrupt handler.
- *
- * This handler is interruptible.
- * Interrupt are reenabled as soon as recv complete interrupt is
- * disabled. Using INTERRUPT() is troublesome when the serial
- * is heavily loaded, because and interrupt could be retriggered
- * when executing the handler prologue before RXCIE is disabled.
- */
-#ifdef __AVR_ATmega103__
-SIGNAL(SIG_UART_RECV)
-#else
-SIGNAL(SIG_UART0_RECV)
-#endif
-{
- /* Disable Recv complete IRQ */
- UCR &= ~BV(RXCIE);
- ENABLE_INTS;
-
- /* Should be read before UDR */
- ser_handles[SER_UART0].status |= USR & (SERRF_RXSROVERRUN | SERRF_FRAMEERROR);
-
- /* To clear the RXC flag we must _always_ read the UDR even when we're
- * not going to accept the incoming data, otherwise a new interrupt
- * will occur once the handler terminates.
- */
- char c = UDR;
-
- if (fifo_isfull(&ser_handles[SER_UART0].rxfifo))
- ser_handles[SER_UART0].status |= SERRF_RXFIFOOVERRUN;
- else
- {
- fifo_push(&ser_handles[SER_UART0].rxfifo, c);
-#if defined(CONFIG_SER_HW_HANDSHAKE)
- if (fifo_isfull(&ser_handles[SER_UART0].rxfifo))
- RTS_OFF;
-#endif
- }
- /* Reenable receive complete int */
- UCR |= BV(RXCIE);
-}
-
-/*!
- * Serial 1 RX complete interrupt handler.
- *
- * This handler is interruptible.
- * Interrupt are reenabled as soon as recv complete interrupt is
- * disabled. Using INTERRUPT() is troublesome when the serial
- * is heavily loaded, because and interrupt could be retriggered
- * when executing the handler prologue before RXCIE is disabled.
- */
-#ifndef __AVR_ATmega103__
-SIGNAL(SIG_UART1_RECV)
-{
- /* Disable Recv complete IRQ */
- UCSR0B &= ~BV(RXCIE);
- ENABLE_INTS;
-
- /* Should be read before UDR */
- ser_handles[SER_UART1].status |= UCSR1A & (SERRF_RXSROVERRUN | SERRF_FRAMEERROR);
-
- /* To avoid an IRQ storm, we must _always_ read the UDR even when we're
- * not going to accept the incoming data
- */
- char c = UDR1;
-
- if (fifo_isfull(&ser_handles[SER_UART1].rxfifo))
- ser_handles[SER_UART1].status |= SERRF_RXFIFOOVERRUN;
- else
- {
- fifo_push(&ser_handles[SER_UART1].rxfifo, c);
-#if defined(CONFIG_SER_HW_HANDSHAKE)
- if (fifo_isfull(&ser_handles[SER_UART1].rxfifo))
- RTS_OFF;
-#endif
- }
- /* Reenable receive complete int */
- UCSR0B |= BV(RXCIE);
-}
-#endif /* !__AVR_ATmega103__ */
-
-
-/*
- * SPI Flag: true if we are transmitting/receiving with the SPI.
- *
- * This kludge is necessary because the SPI sends and receives bytes
- * at the same time and the SPI IRQ is unique for send/receive.
- * The only way to start transmission is to write data in SPDR (this
- * is done by ser_spi_starttx()). We do this *only* if a transfer is
- * not already started.
- */
-static volatile bool spi_sending = false;
-
-static void spi_starttx(UNUSED(struct SerialHardware *ctx))
-{
- cpuflags_t flags;
-
- DISABLE_IRQSAVE(flags);
-
- /* Send data only if the SPI is not already transmitting */
- if (!spi_sending && !fifo_isempty(&ser_handles[SER_SPI].txfifo))
- {
- SPDR = fifo_pop(&ser_handles[SER_SPI].txfifo);
- spi_sending = true;
- }
-
- ENABLE_IRQRESTORE(flags);
-}
-
-/*!
- * SPI interrupt handler
- */
-SIGNAL(SIG_SPI)
-{
- /* Read incoming byte. */
- if (!fifo_isfull(&ser_handles[SER_SPI].rxfifo))
- fifo_push(&ser_handles[SER_SPI].rxfifo, SPDR);
- /*
- * FIXME
- else
- ser_handles[SER_SPI].status |= SERRF_RXFIFOOVERRUN;
- */
-
- /* Send */
- if (!fifo_isempty(&ser_handles[SER_SPI].txfifo))
- SPDR = fifo_pop(&ser_handles[SER_SPI].txfifo);
- else
- spi_sending = false;
-}
-
-
-/*
-
-#pragma vector = UART_TXC_vect
-__interrupt void UART_TXC_interrupt(void)
-{
- UCSRB &= ~TXCIE;
- ReceiveMode();
- UCSRB = RXCIE | RXEN | TXEN; //Abilito l'Interrupt in ricezione e RX e TX
-}
-*/
-
-
-static const struct SerialHardwareVT UART0_VT =
-{
- .init = uart0_init,
- .cleanup = uart0_cleanup,
- .setbaudrate = uart0_setbaudrate,
- .setparity = uart0_setparity,
- .enabletxirq = uart0_enabletxirq,
-};
-
-static const struct SerialHardwareVT UART1_VT =
-{
- .init = uart1_init,
- .cleanup = uart1_cleanup,
- .setbaudrate = uart1_setbaudrate,
- .setparity = uart1_setparity,
- .enabletxirq = uart1_enabletxirq,
-};
-
-static const struct SerialHardwareVT SPI_VT =
-{
- .init = spi_init,
- .cleanup = spi_cleanup,
- .enabletxirq = spi_starttx,
-};
-
-static struct AvrSerial UARTDescs[SER_CNT] =
-{
- {
- .hw = { .table = &UART0_VT },
- },
-
- {
- .hw = { .table = &UART1_VT },
- },
-
- {
- .hw = { .table = &SPI_VT },
- },
-};
-
-struct SerialHardware* ser_hw_getdesc(int unit)
-{
- ASSERT(unit < SER_CNT);
- return &UARTDescs[unit].hw;
-}