path: root/drivers/serial/bfin_5xx.c

/*
 * Blackfin On-Chip Serial Driver
 *
 * Copyright 2006-2008 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>

#ifdef CONFIG_KGDB_UART
#include <linux/kgdb.h>
#include <asm/irq_regs.h>
#endif

#include <asm/gpio.h>
#include <mach/bfin_serial_5xx.h>

#ifdef CONFIG_SERIAL_BFIN_DMA
#include <linux/dma-mapping.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/cacheflush.h>
#endif

/* UART name and device definitions */
#define BFIN_SERIAL_NAME	"ttyBF"
#define BFIN_SERIAL_MAJOR	204
#define BFIN_SERIAL_MINOR	64

static struct bfin_serial_port bfin_serial_ports[BFIN_UART_NR_PORTS];
static int nr_active_ports = ARRAY_SIZE(bfin_serial_resource);

/*
 * Setup for console. Argument comes from the menuconfig
 */
#define DMA_RX_XCOUNT		512
#define DMA_RX_YCOUNT		(PAGE_SIZE / DMA_RX_XCOUNT)

#define DMA_RX_FLUSH_JIFFIES	(HZ / 50)
#define CTS_CHECK_JIFFIES	(HZ / 50)

#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
#else
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
#endif

static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);

/*
 * interrupts are disabled on entry
 */
static void bfin_serial_stop_tx(struct uart_port *port)
{
	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
	struct circ_buf *xmit = &uart->port.info->xmit;

	while (!(UART_GET_LSR(uart) & TEMT))
		cpu_relax();

#ifdef CONFIG_SERIAL_BFIN_DMA
	disable_dma(uart->tx_dma_channel);
	xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
	uart->port.icount.tx += uart->tx_count;
	uart->tx_count = 0;
	uart->tx_done = 1;
#else
#ifdef CONFIG_BF54x
	/* Clear TFI bit */
	UART_PUT_LSR(uart, TFI);
#endif
	UART_CLEAR_IER(uart, ETBEI);
#endif
}

/*
 * port is locked and interrupts are disabled
 */
static void bfin_serial_start_tx(struct uart_port *port)
{
	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

#ifdef CONFIG_SERIAL_BFIN_DMA
	if (uart->tx_done)
		bfin_serial_dma_tx_chars(uart);
#else
	UART_SET_IER(uart, ETBEI);
	bfin_serial_tx_chars(uart);
#endif
}

/*
 * Interrupts are enabled
 */
static void bfin_serial_stop_rx(struct uart_port *port)
{
	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_KGDB_UART
	if (uart->port.line