path: root/drivers/serial/cpm_uart/cpm_uart_core.c

/*
 *  linux/drivers/serial/cpm_uart.c
 *
 *  Driver for CPM (SCC/SMC) serial ports; core driver
 *
 *  Based on arch/ppc/cpm2_io/uart.c by Dan Malek
 *  Based on ppc8xx.c by Thomas Gleixner
 *  Based on drivers/serial/amba.c by Russell King
 *
 *  Maintainer: Kumar Gala (kumar.gala@freescale.com) (CPM2)
 *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
 *
 *  Copyright (C) 2004 Freescale Semiconductor, Inc.
 *            (C) 2004 Intracom, S.A.
 *            (C) 2005 MontaVista Software, Inc. by Vitaly Bordug <vbordug@ru.mvista.com>
 *
 * 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <linux/bootmem.h>
#include <linux/dma-mapping.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/delay.h>

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

#include <linux/serial_core.h>
#include <linux/kernel.h>

#include "cpm_uart.h"

/***********************************************************************/

/* Track which ports are configured as uarts */
int cpm_uart_port_map[UART_NR];
/* How many ports did we config as uarts */
int cpm_uart_nr;

/**************************************************************/

static int  cpm_uart_tx_pump(struct uart_port *port);
static void cpm_uart_init_smc(struct uart_cpm_port *pinfo);
static void cpm_uart_init_scc(struct uart_cpm_port *pinfo);
static void cpm_uart_initbd(struct uart_cpm_port *pinfo);

/**************************************************************/

static inline unsigned long cpu2cpm_addr(void *addr)
{
	if ((unsigned long)addr >= CPM_ADDR)
		return (unsigned long)addr;
	return virt_to_bus(addr);
}

static inline void *cpm2cpu_addr(unsigned long addr)
{
	if (addr >= CPM_ADDR)
		return (void *)addr;
	return bus_to_virt(addr);
}

/*
 * Check, if transmit buffers are processed
*/
static unsigned int cpm_uart_tx_empty(struct uart_port *port)
{
	struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
	volatile cbd_t *bdp = pinfo->tx_bd_base;
	int ret = 0;

	while (1) {
		if (bdp->cbd_sc & BD_SC_READY)
			break;

		if (bdp->cbd_sc & BD_SC_WRAP) {
			ret = TIOCSER_TEMT;
			break;
		}
		bdp++;
	}

	pr_debug("CPM uart[%d]:tx_empty: %d\n", port->line, ret);

	return ret;
}

static void cpm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	/* Whee. Do nothing. */
}

static unsigned int cpm_uart_get_mctrl(struct uart_port *port)
{
	/* Whee. Do nothing. */
	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
}

/*
 * Stop transmitter
 */
static void cpm_uart_stop_tx(struct uart_port *port, unsigned int tty_stop)
{
	struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
	volatile smc_t *smcp = pinfo->smcp;
	volatile scc_t *sccp =