[M68KNOMMU]: new style ColdFire UART driver
From: Greg Ungerer
Date: Thu Oct 18 2007 - 21:44:17 EST
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@xxxxxxxxxxx>
---
diff -Naurp linux-2.6.23/drivers/serial/mcf.c linux-2.6.23-uc0/drivers/serial/mcf.c
--- linux-2.6.23/drivers/serial/mcf.c 1970-01-01 10:00:00.000000000 +1000
+++ linux-2.6.23-uc0/drivers/serial/mcf.c 2007-10-19 11:23:15.000000000 +1000
@@ -0,0 +1,653 @@
+/****************************************************************************/
+
+/*
+ * mcf.c -- Freescale ColdFire UART driver
+ *
+ * (C) Copyright 2003-2007, Greg Ungerer <gerg@xxxxxxxxxxxx>
+ *
+ * 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@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Freescale ColdFire UART driver");
+MODULE_LICENSE("GPL");
+
+/****************************************************************************/
-
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