m68knommu: new style ColdFire UART driver

A new style serial driver for the Freescale ColdFire UART to replace
the old style one currently in the tree (drivers/serial/mcfserial.c).

Currently this UART is only found in the ColdFire CPU family of parts
(thus I prefixed this patch [M68KNOMMU]).

This has been around for a long while now, tested on all available
platforms.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 653 insertions, 0 deletions

diff --git a/drivers/serial/mcf.c b/drivers/serial/mcf.c
new file mode 100644
index 000000000000..a7d4360ea7df
--- /dev/null
+++ b/drivers/serial/mcf.c
@@ -0,0 +1,653 @@
+/****************************************************************************/
+
+/*
+ *      mcf.c -- Freescale ColdFire UART driver
+ *
+ *      (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.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.
+ */
+
+/****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+#include <asm/coldfire.h>
+#include <asm/mcfsim.h>
+#include <asm/mcfuart.h>
+#include <asm/nettel.h>
+
+/****************************************************************************/
+
+/*
+ *      Some boards implement the DTR/DCD lines using GPIO lines, most
+ *      don't. Dummy out the access macros for those that don't. Those
+ *      that do should define these macros somewhere in there board
+ *      specific inlude files.
+ */
+#if !defined(mcf_getppdcd)
+#define mcf_getppdcd(p)         (1)
+#endif
+#if !defined(mcf_getppdtr)
+#define mcf_getppdtr(p)         (1)
+#endif
+#if !defined(mcf_setppdtr)
+#define mcf_setppdtr(p, v)      do { } while (0)
+#endif
+
+/****************************************************************************/
+
+/*
+ *      Local per-uart structure.
+ */
+struct mcf_uart {
+        struct uart_port        port;
+        unsigned int            sigs;           /* Local copy of line sigs */
+        unsigned char           imr;            /* Local IMR mirror */
+};
+
+/****************************************************************************/
+
+static unsigned int mcf_tx_empty(struct uart_port *port)
+{
+        return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
+                TIOCSER_TEMT : 0;
+}
+
+/****************************************************************************/
+
+static unsigned int mcf_get_mctrl(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+        unsigned int sigs;
+
+        spin_lock_irqsave(&port->lock, flags);
+        sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
+                0 : TIOCM_CTS;
+        sigs |= (pp->sigs & TIOCM_RTS);
+        sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
+        sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
+        spin_unlock_irqrestore(&port->lock, flags);
+        return sigs;
+}
+
+/****************************************************************************/
+
+static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        pp->sigs = sigs;
+        mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
+        if (sigs & TIOCM_RTS)
+                writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
+        else
+                writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_start_tx(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        pp->imr |= MCFUART_UIR_TXREADY;
+        writeb(pp->imr, port->membase + MCFUART_UIMR);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_stop_tx(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        pp->imr &= ~MCFUART_UIR_TXREADY;
+        writeb(pp->imr, port->membase + MCFUART_UIMR);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_stop_rx(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        pp->imr &= ~MCFUART_UIR_RXREADY;
+        writeb(pp->imr, port->membase + MCFUART_UIMR);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_break_ctl(struct uart_port *port, int break_state)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        if (break_state == -1)
+                writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
+        else
+                writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_enable_ms(struct uart_port *port)
+{
+}
+
+/****************************************************************************/
+
+static int mcf_startup(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+
+        /* Reset UART, get it into known state... */
+        writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+        writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+
+        /* Enable the UART transmitter and receiver */
+        writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
+                port->membase + MCFUART_UCR);
+
+        /* Enable RX interrupts now */
+        pp->imr = MCFUART_UIR_RXREADY;
+        writeb(pp->imr, port->membase + MCFUART_UIMR);
+
+        spin_unlock_irqrestore(&port->lock, flags);
+
+        return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_shutdown(struct uart_port *port)
+{
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+
+        /* Disable all interrupts now */
+        pp->imr = 0;
+        writeb(pp->imr, port->membase + MCFUART_UIMR);
+
+        /* Disable UART transmitter and receiver */
+        writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+        writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
+        struct ktermios *old)
+{
+        unsigned long flags;
+        unsigned int baud, baudclk;
+        unsigned char mr1, mr2;
+
+        baud = uart_get_baud_rate(port, termios, old, 0, 230400);
+        baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
+
+        mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
+        mr2 = 0;
+
+        switch (termios->c_cflag & CSIZE) {
+        case CS5: mr1 |= MCFUART_MR1_CS5; break;
+        case CS6: mr1 |= MCFUART_MR1_CS6; break;
+        case CS7: mr1 |= MCFUART_MR1_CS7; break;
+        case CS8:
+        default:  mr1 |= MCFUART_MR1_CS8; break;
+        }
+
+        if (termios->c_cflag & PARENB) {
+                if (termios->c_cflag & CMSPAR) {
+                        if (termios->c_cflag & PARODD)
+                                mr1 |= MCFUART_MR1_PARITYMARK;
+                        else
+                                mr1 |= MCFUART_MR1_PARITYSPACE;
+                } else {
+                        if (termios->c_cflag & PARODD)
+                                mr1 |= MCFUART_MR1_PARITYODD;
+                        else
+                                mr1 |= MCFUART_MR1_PARITYEVEN;
+                }
+        } else {
+                mr1 |= MCFUART_MR1_PARITYNONE;
+        }
+
+        if (termios->c_cflag & CSTOPB)
+                mr2 |= MCFUART_MR2_STOP2;
+        else
+                mr2 |= MCFUART_MR2_STOP1;
+
+        if (termios->c_cflag & CRTSCTS) {
+                mr1 |= MCFUART_MR1_RXRTS;
+                mr2 |= MCFUART_MR2_TXCTS;
+        }
+
+        spin_lock_irqsave(&port->lock, flags);
+        writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+        writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+        writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
+        writeb(mr1, port->membase + MCFUART_UMR);
+        writeb(mr2, port->membase + MCFUART_UMR);
+        writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
+        writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
+        writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
+                port->membase + MCFUART_UCSR);
+        writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
+                port->membase + MCFUART_UCR);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_rx_chars(struct mcf_uart *pp)
+{
+        struct uart_port *port = (struct uart_port *) pp;
+        unsigned char status, ch, flag;
+
+        while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
+                ch = readb(port->membase + MCFUART_URB);
+                flag = TTY_NORMAL;
+                port->icount.rx++;
+
+                if (status & MCFUART_USR_RXERR) {
+                        writeb(MCFUART_UCR_CMDRESETERR,
+                                port->membase + MCFUART_UCR);
+
+                        if (status & MCFUART_USR_RXBREAK) {
+                                port->icount.brk++;
+                                if (uart_handle_break(port))
+                                        continue;
+                        } else if (status & MCFUART_USR_RXPARITY) {
+                                port->icount.parity++;
+                        } else if (status & MCFUART_USR_RXOVERRUN) {
+                                port->icount.overrun++;
+                        } else if (status & MCFUART_USR_RXFRAMING) {
+                                port->icount.frame++;
+                        }
+
+                        status &= port->read_status_mask;
+
+                        if (status & MCFUART_USR_RXBREAK)
+                                flag = TTY_BREAK;
+                        else if (status & MCFUART_USR_RXPARITY)
+                                flag = TTY_PARITY;
+                        else if (status & MCFUART_USR_RXFRAMING)
+                                flag = TTY_FRAME;
+                }
+
+                if (uart_handle_sysrq_char(port, ch))
+                        continue;
+                uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
+        }
+
+        tty_flip_buffer_push(port->info->tty);
+}
+
+/****************************************************************************/
+
+static void mcf_tx_chars(struct mcf_uart *pp)
+{
+        struct uart_port *port = (struct uart_port *) pp;
+        struct circ_buf *xmit = &port->info->xmit;
+
+        if (port->x_char) {
+                /* Send special char - probably flow control */
+                writeb(port->x_char, port->membase + MCFUART_UTB);
+                port->x_char = 0;
+                port->icount.tx++;
+                return;
+        }
+
+        while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
+                if (xmit->head == xmit->tail)
+                        break;
+                writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
+                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
+                port->icount.tx++;
+        }
+
+        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+                uart_write_wakeup(port);
+
+        if (xmit->head == xmit->tail) {
+                pp->imr &= ~MCFUART_UIR_TXREADY;
+                writeb(pp->imr, port->membase + MCFUART_UIMR);
+        }
+}
+
+/****************************************************************************/
+
+static irqreturn_t mcf_interrupt(int irq, void *data)
+{
+        struct uart_port *port = data;
+        struct mcf_uart *pp = (struct mcf_uart *) port;
+        unsigned int isr;
+
+        isr = readb(port->membase + MCFUART_UISR) & pp->imr;
+        if (isr & MCFUART_UIR_RXREADY)
+                mcf_rx_chars(pp);
+        if (isr & MCFUART_UIR_TXREADY)
+                mcf_tx_chars(pp);
+        return IRQ_HANDLED;
+}
+
+/****************************************************************************/
+
+static void mcf_config_port(struct uart_port *port, int flags)
+{
+        port->type = PORT_MCF;
+
+        /* Clear mask, so no surprise interrupts. */
+        writeb(0, port->membase + MCFUART_UIMR);
+
+        if (request_irq(port->irq, mcf_interrupt, IRQF_DISABLED, "UART", port))
+                printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
+                        "interrupt vector=%d\n", port->line, port->irq);
+}
+
+/****************************************************************************/
+
+static const char *mcf_type(struct uart_port *port)
+{
+        return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
+}
+
+/****************************************************************************/
+
+static int mcf_request_port(struct uart_port *port)
+{
+        /* UARTs always present */
+        return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_release_port(struct uart_port *port)
+{
+        /* Nothing to release... */
+}
+
+/****************************************************************************/
+
+static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+        if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
+                return -EINVAL;
+        return 0;
+}
+
+/****************************************************************************/
+
+/*
+ *      Define the basic serial functions we support.
+ */
+static struct uart_ops mcf_uart_ops = {
+        .tx_empty       = mcf_tx_empty,
+        .get_mctrl      = mcf_get_mctrl,
+        .set_mctrl      = mcf_set_mctrl,
+        .start_tx       = mcf_start_tx,
+        .stop_tx        = mcf_stop_tx,
+        .stop_rx        = mcf_stop_rx,
+        .enable_ms      = mcf_enable_ms,
+        .break_ctl      = mcf_break_ctl,
+        .startup        = mcf_startup,
+        .shutdown       = mcf_shutdown,
+        .set_termios    = mcf_set_termios,
+        .type           = mcf_type,
+        .request_port   = mcf_request_port,
+        .release_port   = mcf_release_port,
+        .config_port    = mcf_config_port,
+        .verify_port    = mcf_verify_port,
+};
+
+static struct mcf_uart mcf_ports[3];
+
+#define MCF_MAXPORTS    (sizeof(mcf_ports) / sizeof(struct mcf_uart))
+
+/****************************************************************************/
+#if defined(CONFIG_SERIAL_MCF_CONSOLE)
+/****************************************************************************/
+
+int __init early_mcf_setup(struct mcf_platform_uart *platp)
+{
+        struct uart_port *port;
+        int i;
+
+        for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
+                port = &mcf_ports[i].port;
+
+                port->line = i;
+                port->type = PORT_MCF;
+                port->mapbase = platp[i].mapbase;
+                port->membase = (platp[i].membase) ? platp[i].membase :
+                        (unsigned char __iomem *) port->mapbase;
+                port->iotype = SERIAL_IO_MEM;
+                port->irq = platp[i].irq;
+                port->uartclk = MCF_BUSCLK;
+                port->flags = ASYNC_BOOT_AUTOCONF;
+                port->ops = &mcf_uart_ops;
+        }
+
+        return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_console_putc(struct console *co, const char c)
+{
+        struct uart_port *port = &(mcf_ports + co->index)->port;
+        int i;
+
+        for (i = 0; (i < 0x10000); i++) {
+                if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
+                        break;
+        }
+        writeb(c, port->membase + MCFUART_UTB);
+        for (i = 0; (i < 0x10000); i++) {
+                if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
+                        break;
+        }
+}
+
+/****************************************************************************/
+
+static void mcf_console_write(struct console *co, const char *s, unsigned int count)
+{
+        for (; (count); count--, s++) {
+                mcf_console_putc(co, *s);
+                if (*s == '\n')
+                        mcf_console_putc(co, '\r');
+        }
+}
+
+/****************************************************************************/
+
+static int __init mcf_console_setup(struct console *co, char *options)
+{
+        struct uart_port *port;
+        int baud = CONFIG_SERIAL_MCF_BAUDRATE;
+        int bits = 8;
+        int parity = 'n';
+        int flow = 'n';
+
+        if ((co->index >= 0) && (co->index <= MCF_MAXPORTS))
+                co->index = 0;
+        port = &mcf_ports[co->index].port;
+        if (port->membase == 0)
+                return -ENODEV;
+
+        if (options)
+                uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+        return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+/****************************************************************************/
+
+static struct uart_driver mcf_driver;
+
+static struct console mcf_console = {
+        .name           = "ttyS",
+        .write          = mcf_console_write,
+        .device         = uart_console_device,
+        .setup          = mcf_console_setup,
+        .flags          = CON_PRINTBUFFER,
+        .index          = -1,
+        .data           = &mcf_driver,
+};
+
+static int __init mcf_console_init(void)
+{
+        register_console(&mcf_console);
+        return 0;
+}
+
+console_initcall(mcf_console_init);
+
+#define MCF_CONSOLE     &mcf_console
+
+/****************************************************************************/
+#else
+/****************************************************************************/
+
+#define MCF_CONSOLE     NULL
+
+/****************************************************************************/
+#endif /* CONFIG_MCF_CONSOLE */
+/****************************************************************************/
+
+/*
+ *      Define the mcf UART driver structure.
+ */
+static struct uart_driver mcf_driver = {
+        .owner          = THIS_MODULE,
+        .driver_name    = "mcf",
+        .dev_name       = "ttyS",
+        .major          = TTY_MAJOR,
+        .minor          = 64,
+        .nr             = MCF_MAXPORTS,
+        .cons           = MCF_CONSOLE,
+};
+
+/****************************************************************************/
+
+static int __devinit mcf_probe(struct platform_device *pdev)
+{
+        struct mcf_platform_uart *platp = pdev->dev.platform_data;
+        struct uart_port *port;
+        int i;
+
+        for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
+                port = &mcf_ports[i].port;
+
+                port->line = i;
+                port->type = PORT_MCF;
+                port->mapbase = platp[i].mapbase;
+                port->membase = (platp[i].membase) ? platp[i].membase :
+                        (unsigned char __iomem *) platp[i].mapbase;
+                port->iotype = SERIAL_IO_MEM;
+                port->irq = platp[i].irq;
+                port->uartclk = MCF_BUSCLK;
+                port->ops = &mcf_uart_ops;
+                port->flags = ASYNC_BOOT_AUTOCONF;
+
+                uart_add_one_port(&mcf_driver, port);
+        }
+
+        return 0;
+}
+
+/****************************************************************************/
+
+static int mcf_remove(struct platform_device *pdev)
+{
+        struct uart_port *port;
+        int i;
+
+        for (i = 0; (i < MCF_MAXPORTS); i++) {
+                port = &mcf_ports[i].port;
+                if (port)
+                        uart_remove_one_port(&mcf_driver, port);
+        }
+
+        return 0;
+}
+
+/****************************************************************************/
+
+static struct platform_driver mcf_platform_driver = {
+        .probe          = mcf_probe,
+        .remove         = __devexit_p(mcf_remove),
+        .driver         = {
+                .name   = "mcfuart",
+                .owner  = THIS_MODULE,
+        },
+};
+
+/****************************************************************************/
+
+static int __init mcf_init(void)
+{
+        int rc;
+
+        printk("ColdFire internal UART serial driver\n");
+
+        rc = uart_register_driver(&mcf_driver);
+        if (rc)
+                return rc;
+        rc = platform_driver_register(&mcf_platform_driver);
+        if (rc)
+                return rc;
+        return 0;
+}
+
+/****************************************************************************/
+
+static void __exit mcf_exit(void)
+{
+        platform_driver_unregister(&mcf_platform_driver);
+        uart_unregister_driver(&mcf_driver);
+}
+
+/****************************************************************************/
+
+module_init(mcf_init);
+module_exit(mcf_exit);
+
+MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
+MODULE_DESCRIPTION("Freescale ColdFire UART driver");
+MODULE_LICENSE("GPL");
+
+/****************************************************************************/