05ab301463
Add uart_insert_char(), which handles inserting characters into the flip buffer. This helper function handles the correct semantics for handling overrun in addition to inserting normal characters. Signed-off-by: Russell King <rmk@arm.linux.org.uk>
596 lines
13 KiB
C
596 lines
13 KiB
C
/*
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* linux/drivers/char/clps711x.c
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*
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* Driver for CLPS711x serial ports
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*
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
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*
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* Copyright 1999 ARM Limited
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* $Id: clps711x.c,v 1.42 2002/07/28 10:03:28 rmk Exp $
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*
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*/
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#include <linux/config.h>
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#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
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#define SUPPORT_SYSRQ
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#endif
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/sysrq.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/serial_core.h>
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#include <linux/serial.h>
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#include <asm/hardware.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#include <asm/hardware/clps7111.h>
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#define UART_NR 2
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#define SERIAL_CLPS711X_MAJOR 204
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#define SERIAL_CLPS711X_MINOR 40
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#define SERIAL_CLPS711X_NR UART_NR
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/*
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* We use the relevant SYSCON register as a base address for these ports.
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*/
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#define UBRLCR(port) ((port)->iobase + UBRLCR1 - SYSCON1)
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#define UARTDR(port) ((port)->iobase + UARTDR1 - SYSCON1)
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#define SYSFLG(port) ((port)->iobase + SYSFLG1 - SYSCON1)
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#define SYSCON(port) ((port)->iobase + SYSCON1 - SYSCON1)
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#define TX_IRQ(port) ((port)->irq)
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#define RX_IRQ(port) ((port)->irq + 1)
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#define UART_ANY_ERR (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR)
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#define tx_enabled(port) ((port)->unused[0])
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static void
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clps711xuart_stop_tx(struct uart_port *port, unsigned int tty_stop)
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{
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if (tx_enabled(port)) {
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disable_irq(TX_IRQ(port));
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tx_enabled(port) = 0;
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}
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}
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static void
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clps711xuart_start_tx(struct uart_port *port, unsigned int tty_start)
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{
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if (!tx_enabled(port)) {
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enable_irq(TX_IRQ(port));
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tx_enabled(port) = 1;
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}
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}
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static void clps711xuart_stop_rx(struct uart_port *port)
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{
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disable_irq(RX_IRQ(port));
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}
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static void clps711xuart_enable_ms(struct uart_port *port)
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{
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}
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static irqreturn_t clps711xuart_int_rx(int irq, void *dev_id, struct pt_regs *regs)
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{
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struct uart_port *port = dev_id;
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struct tty_struct *tty = port->info->tty;
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unsigned int status, ch, flg, ignored = 0;
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status = clps_readl(SYSFLG(port));
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while (!(status & SYSFLG_URXFE)) {
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ch = clps_readl(UARTDR(port));
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if (tty->flip.count >= TTY_FLIPBUF_SIZE)
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goto ignore_char;
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port->icount.rx++;
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flg = TTY_NORMAL;
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/*
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* Note that the error handling code is
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* out of the main execution path
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*/
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if (unlikely(ch & UART_ANY_ERR)) {
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if (ch & UARTDR_PARERR)
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port->icount.parity++;
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else if (ch & UARTDR_FRMERR)
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port->icount.frame++;
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if (ch & UARTDR_OVERR)
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port->icount.overrun++;
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ch &= port->read_status_mask;
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if (ch & UARTDR_PARERR)
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flg = TTY_PARITY;
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else if (ch & UARTDR_FRMERR)
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flg = TTY_FRAME;
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#ifdef SUPPORT_SYSRQ
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port->sysrq = 0;
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#endif
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}
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if (uart_handle_sysrq_char(port, ch, regs))
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goto ignore_char;
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/*
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* CHECK: does overrun affect the current character?
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* ASSUMPTION: it does not.
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*/
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uart_insert_char(port, ch, UARTDR_OVERR, ch, flg);
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ignore_char:
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status = clps_readl(SYSFLG(port));
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}
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tty_flip_buffer_push(tty);
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return IRQ_HANDLED;
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}
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static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id, struct pt_regs *regs)
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{
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struct uart_port *port = dev_id;
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struct circ_buf *xmit = &port->info->xmit;
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int count;
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if (port->x_char) {
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clps_writel(port->x_char, UARTDR(port));
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port->icount.tx++;
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port->x_char = 0;
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return IRQ_HANDLED;
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}
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if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
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clps711xuart_stop_tx(port, 0);
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return IRQ_HANDLED;
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}
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count = port->fifosize >> 1;
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do {
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clps_writel(xmit->buf[xmit->tail], UARTDR(port));
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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port->icount.tx++;
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if (uart_circ_empty(xmit))
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break;
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} while (--count > 0);
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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if (uart_circ_empty(xmit))
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clps711xuart_stop_tx(port, 0);
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return IRQ_HANDLED;
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}
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static unsigned int clps711xuart_tx_empty(struct uart_port *port)
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{
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unsigned int status = clps_readl(SYSFLG(port));
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return status & SYSFLG_UBUSY ? 0 : TIOCSER_TEMT;
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}
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static unsigned int clps711xuart_get_mctrl(struct uart_port *port)
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{
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unsigned int port_addr;
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unsigned int result = 0;
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unsigned int status;
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port_addr = SYSFLG(port);
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if (port_addr == SYSFLG1) {
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status = clps_readl(SYSFLG1);
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if (status & SYSFLG1_DCD)
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result |= TIOCM_CAR;
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if (status & SYSFLG1_DSR)
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result |= TIOCM_DSR;
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if (status & SYSFLG1_CTS)
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result |= TIOCM_CTS;
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}
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return result;
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}
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static void
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clps711xuart_set_mctrl_null(struct uart_port *port, unsigned int mctrl)
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{
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}
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static void clps711xuart_break_ctl(struct uart_port *port, int break_state)
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{
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unsigned long flags;
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unsigned int ubrlcr;
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spin_lock_irqsave(&port->lock, flags);
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ubrlcr = clps_readl(UBRLCR(port));
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if (break_state == -1)
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ubrlcr |= UBRLCR_BREAK;
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else
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ubrlcr &= ~UBRLCR_BREAK;
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clps_writel(ubrlcr, UBRLCR(port));
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static int clps711xuart_startup(struct uart_port *port)
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{
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unsigned int syscon;
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int retval;
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tx_enabled(port) = 1;
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/*
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* Allocate the IRQs
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*/
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retval = request_irq(TX_IRQ(port), clps711xuart_int_tx, 0,
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"clps711xuart_tx", port);
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if (retval)
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return retval;
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retval = request_irq(RX_IRQ(port), clps711xuart_int_rx, 0,
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"clps711xuart_rx", port);
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if (retval) {
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free_irq(TX_IRQ(port), port);
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return retval;
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}
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/*
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* enable the port
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*/
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syscon = clps_readl(SYSCON(port));
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syscon |= SYSCON_UARTEN;
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clps_writel(syscon, SYSCON(port));
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return 0;
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}
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static void clps711xuart_shutdown(struct uart_port *port)
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{
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unsigned int ubrlcr, syscon;
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/*
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* Free the interrupt
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*/
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free_irq(TX_IRQ(port), port); /* TX interrupt */
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free_irq(RX_IRQ(port), port); /* RX interrupt */
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/*
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* disable the port
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*/
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syscon = clps_readl(SYSCON(port));
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syscon &= ~SYSCON_UARTEN;
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clps_writel(syscon, SYSCON(port));
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/*
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* disable break condition and fifos
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*/
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ubrlcr = clps_readl(UBRLCR(port));
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ubrlcr &= ~(UBRLCR_FIFOEN | UBRLCR_BREAK);
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clps_writel(ubrlcr, UBRLCR(port));
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}
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static void
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clps711xuart_set_termios(struct uart_port *port, struct termios *termios,
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struct termios *old)
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{
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unsigned int ubrlcr, baud, quot;
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unsigned long flags;
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/*
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* We don't implement CREAD.
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*/
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termios->c_cflag |= CREAD;
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/*
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* Ask the core to calculate the divisor for us.
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*/
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
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quot = uart_get_divisor(port, baud);
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switch (termios->c_cflag & CSIZE) {
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case CS5:
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ubrlcr = UBRLCR_WRDLEN5;
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break;
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case CS6:
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ubrlcr = UBRLCR_WRDLEN6;
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break;
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case CS7:
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ubrlcr = UBRLCR_WRDLEN7;
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break;
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default: // CS8
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ubrlcr = UBRLCR_WRDLEN8;
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break;
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}
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if (termios->c_cflag & CSTOPB)
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ubrlcr |= UBRLCR_XSTOP;
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if (termios->c_cflag & PARENB) {
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ubrlcr |= UBRLCR_PRTEN;
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if (!(termios->c_cflag & PARODD))
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ubrlcr |= UBRLCR_EVENPRT;
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}
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if (port->fifosize > 1)
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ubrlcr |= UBRLCR_FIFOEN;
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spin_lock_irqsave(&port->lock, flags);
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/*
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* Update the per-port timeout.
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*/
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uart_update_timeout(port, termios->c_cflag, baud);
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port->read_status_mask = UARTDR_OVERR;
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if (termios->c_iflag & INPCK)
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port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
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/*
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* Characters to ignore
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*/
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port->ignore_status_mask = 0;
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if (termios->c_iflag & IGNPAR)
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port->ignore_status_mask |= UARTDR_FRMERR | UARTDR_PARERR;
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if (termios->c_iflag & IGNBRK) {
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/*
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* If we're ignoring parity and break indicators,
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* ignore overruns to (for real raw support).
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*/
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if (termios->c_iflag & IGNPAR)
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port->ignore_status_mask |= UARTDR_OVERR;
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}
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quot -= 1;
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clps_writel(ubrlcr | quot, UBRLCR(port));
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static const char *clps711xuart_type(struct uart_port *port)
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{
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return port->type == PORT_CLPS711X ? "CLPS711x" : NULL;
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}
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/*
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* Configure/autoconfigure the port.
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*/
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static void clps711xuart_config_port(struct uart_port *port, int flags)
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{
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if (flags & UART_CONFIG_TYPE)
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port->type = PORT_CLPS711X;
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}
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static void clps711xuart_release_port(struct uart_port *port)
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{
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}
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static int clps711xuart_request_port(struct uart_port *port)
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{
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return 0;
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}
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static struct uart_ops clps711x_pops = {
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.tx_empty = clps711xuart_tx_empty,
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.set_mctrl = clps711xuart_set_mctrl_null,
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.get_mctrl = clps711xuart_get_mctrl,
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.stop_tx = clps711xuart_stop_tx,
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.start_tx = clps711xuart_start_tx,
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.stop_rx = clps711xuart_stop_rx,
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.enable_ms = clps711xuart_enable_ms,
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.break_ctl = clps711xuart_break_ctl,
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.startup = clps711xuart_startup,
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.shutdown = clps711xuart_shutdown,
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.set_termios = clps711xuart_set_termios,
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.type = clps711xuart_type,
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.config_port = clps711xuart_config_port,
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.release_port = clps711xuart_release_port,
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.request_port = clps711xuart_request_port,
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};
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static struct uart_port clps711x_ports[UART_NR] = {
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{
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.iobase = SYSCON1,
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.irq = IRQ_UTXINT1, /* IRQ_URXINT1, IRQ_UMSINT */
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.uartclk = 3686400,
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.fifosize = 16,
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.ops = &clps711x_pops,
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.line = 0,
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.flags = ASYNC_BOOT_AUTOCONF,
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},
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{
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.iobase = SYSCON2,
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.irq = IRQ_UTXINT2, /* IRQ_URXINT2 */
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.uartclk = 3686400,
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.fifosize = 16,
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.ops = &clps711x_pops,
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.line = 1,
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.flags = ASYNC_BOOT_AUTOCONF,
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}
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};
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#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
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/*
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* Print a string to the serial port trying not to disturb
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* any possible real use of the port...
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*
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* The console_lock must be held when we get here.
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*
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* Note that this is called with interrupts already disabled
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*/
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static void
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clps711xuart_console_write(struct console *co, const char *s,
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unsigned int count)
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{
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struct uart_port *port = clps711x_ports + co->index;
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unsigned int status, syscon;
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int i;
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/*
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* Ensure that the port is enabled.
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*/
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syscon = clps_readl(SYSCON(port));
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clps_writel(syscon | SYSCON_UARTEN, SYSCON(port));
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/*
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* Now, do each character
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*/
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for (i = 0; i < count; i++) {
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do {
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status = clps_readl(SYSFLG(port));
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} while (status & SYSFLG_UTXFF);
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clps_writel(s[i], UARTDR(port));
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if (s[i] == '\n') {
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do {
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status = clps_readl(SYSFLG(port));
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} while (status & SYSFLG_UTXFF);
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clps_writel('\r', UARTDR(port));
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}
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}
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/*
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* Finally, wait for transmitter to become empty
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* and restore the uart state.
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*/
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do {
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status = clps_readl(SYSFLG(port));
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} while (status & SYSFLG_UBUSY);
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clps_writel(syscon, SYSCON(port));
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}
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static void __init
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clps711xuart_console_get_options(struct uart_port *port, int *baud,
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int *parity, int *bits)
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{
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if (clps_readl(SYSCON(port)) & SYSCON_UARTEN) {
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unsigned int ubrlcr, quot;
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ubrlcr = clps_readl(UBRLCR(port));
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*parity = 'n';
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if (ubrlcr & UBRLCR_PRTEN) {
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if (ubrlcr & UBRLCR_EVENPRT)
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*parity = 'e';
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else
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*parity = 'o';
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}
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if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
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*bits = 7;
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else
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*bits = 8;
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quot = ubrlcr & UBRLCR_BAUD_MASK;
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*baud = port->uartclk / (16 * (quot + 1));
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}
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}
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static int __init clps711xuart_console_setup(struct console *co, char *options)
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{
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struct uart_port *port;
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int baud = 38400;
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int bits = 8;
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int parity = 'n';
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int flow = 'n';
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/*
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* Check whether an invalid uart number has been specified, and
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* if so, search for the first available port that does have
|
|
* console support.
|
|
*/
|
|
port = uart_get_console(clps711x_ports, UART_NR, co);
|
|
|
|
if (options)
|
|
uart_parse_options(options, &baud, &parity, &bits, &flow);
|
|
else
|
|
clps711xuart_console_get_options(port, &baud, &parity, &bits);
|
|
|
|
return uart_set_options(port, co, baud, parity, bits, flow);
|
|
}
|
|
|
|
extern struct uart_driver clps711x_reg;
|
|
static struct console clps711x_console = {
|
|
.name = "ttyCL",
|
|
.write = clps711xuart_console_write,
|
|
.device = uart_console_device,
|
|
.setup = clps711xuart_console_setup,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = -1,
|
|
.data = &clps711x_reg,
|
|
};
|
|
|
|
static int __init clps711xuart_console_init(void)
|
|
{
|
|
register_console(&clps711x_console);
|
|
return 0;
|
|
}
|
|
console_initcall(clps711xuart_console_init);
|
|
|
|
#define CLPS711X_CONSOLE &clps711x_console
|
|
#else
|
|
#define CLPS711X_CONSOLE NULL
|
|
#endif
|
|
|
|
static struct uart_driver clps711x_reg = {
|
|
.driver_name = "ttyCL",
|
|
.dev_name = "ttyCL",
|
|
.major = SERIAL_CLPS711X_MAJOR,
|
|
.minor = SERIAL_CLPS711X_MINOR,
|
|
.nr = UART_NR,
|
|
|
|
.cons = CLPS711X_CONSOLE,
|
|
};
|
|
|
|
static int __init clps711xuart_init(void)
|
|
{
|
|
int ret, i;
|
|
|
|
printk(KERN_INFO "Serial: CLPS711x driver $Revision: 1.42 $\n");
|
|
|
|
ret = uart_register_driver(&clps711x_reg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < UART_NR; i++)
|
|
uart_add_one_port(&clps711x_reg, &clps711x_ports[i]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit clps711xuart_exit(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < UART_NR; i++)
|
|
uart_remove_one_port(&clps711x_reg, &clps711x_ports[i]);
|
|
|
|
uart_unregister_driver(&clps711x_reg);
|
|
}
|
|
|
|
module_init(clps711xuart_init);
|
|
module_exit(clps711xuart_exit);
|
|
|
|
MODULE_AUTHOR("Deep Blue Solutions Ltd");
|
|
MODULE_DESCRIPTION("CLPS-711x generic serial driver $Revision: 1.42 $");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_CHARDEV(SERIAL_CLPS711X_MAJOR, SERIAL_CLPS711X_MINOR);
|