platform/imx/drivers/imx_uart.c

/*
 * Copyright (C) 2015 Freescale Semiconductor, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <debug.h>
#include <reg.h>
#include <dev/uart.h>
#include <imx-regs.h>

#define READ32(addr)		(*REG32(addr))
#define WRITE32(val, addr)	(READ32(addr) = val)

/* Register definitions */
#define URXD	0x0  /* Receiver Register */
#define UTXD	0x40 /* Transmitter Register */
#define UCR1	0x80 /* Control Register 1 */
#define UCR2	0x84 /* Control Register 2 */
#define UCR3	0x88 /* Control Register 3 */
#define UCR4	0x8c /* Control Register 4 */
#define UFCR	0x90 /* FIFO Control Register */
#define USR1	0x94 /* Status Register 1 */
#define USR2	0x98 /* Status Register 2 */
#define UESC	0x9c /* Escape Character Register */
#define UTIM	0xa0 /* Escape Timer Register */
#define UBIR	0xa4 /* BRM Incremental Register */
#define UBMR	0xa8 /* BRM Modulator Register */
#define UBRC	0xac /* Baud Rate Count Register */
#define UTS 	0xb4 /* UART Test Register (mx31) */

/* UART Control Register Bit Fields.*/
#define  URXD_CHARRDY	(1<<15)
#define  URXD_ERR	(1<<14)
#define  URXD_OVRRUN	(1<<13)
#define  URXD_FRMERR	(1<<12)
#define  URXD_BRK	(1<<11)
#define  URXD_PRERR	(1<<10)
#define  URXD_RX_DATA	(0xFF)
#define  UCR1_ADEN	(1<<15) /* Auto dectect interrupt */
#define  UCR1_ADBR	(1<<14) /* Auto detect baud rate */
#define  UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
#define  UCR1_IDEN	(1<<12) /* Idle condition interrupt */
#define  UCR1_RRDYEN	(1<<9)  /* Recv ready interrupt enable */
#define  UCR1_RDMAEN	(1<<8)  /* Recv ready DMA enable */
#define  UCR1_IREN	(1<<7)  /* Infrared interface enable */
#define  UCR1_TXMPTYEN	(1<<6)  /* Transimitter empty interrupt enable */
#define  UCR1_RTSDEN	(1<<5)  /* RTS delta interrupt enable */
#define  UCR1_SNDBRK	(1<<4)  /* Send break */
#define  UCR1_TDMAEN	(1<<3)  /* Transmitter ready DMA enable */
#define  UCR1_UARTCLKEN	(1<<2)  /* UART clock enabled */
#define  UCR1_DOZE	(1<<1)  /* Doze */
#define  UCR1_UARTEN	(1<<0)  /* UART enabled */

#define  UTS_FRCPERR	(1<<13) /* Force parity error */
#define  UTS_LOOP	(1<<12) /* Loop tx and rx */
#define  UTS_TXEMPTY	(1<<6)  /* TxFIFO empty */
#define  UTS_RXEMPTY	(1<<5)  /* RxFIFO empty */
#define  UTS_TXFULL	(1<<4)  /* TxFIFO full */
#define  UTS_RXFULL	(1<<3)  /* RxFIFO full */
#define  UTS_SOFTRST	(1<<0)  /* Software reset */
#define  UART_BASE	(SOC_REGS_VIRT + (CONFIG_CONSOLE_TTY_BASE - SOC_REGS_PHY))

void uart_init(void)
{
	/*
	 * Do nothing, debug uart share with normal world,
	 * everything for uart intialization were done in bootloader.
	 */
}

void uart_flush_tx(int port)
{
	while (!(READ32(UART_BASE + UTS) & UTS_TXEMPTY))
		;
}

int uart_getc(int port, bool wait)
{
	if (wait)
		while (READ32(UART_BASE + UTS) & UTS_RXEMPTY);
	else if (!(READ32(UART_BASE + UTS) & UTS_RXEMPTY))
		return -1;

	return (READ32(UART_BASE + URXD) & URXD_RX_DATA);
}

int uart_putc(int port, char c )
{
	if (c == '\n')
		uart_putc(0, '\r');

	WRITE32(c, UART_BASE + UTXD);

	/* wait until sent */
	while (!(READ32(UART_BASE + UTS) & UTS_TXEMPTY))
		;

	return 0;
}