[PATCH] Mux driver for PA-RISC

A driver for the Mux serial ports in some PA-RISC servers from Ryan Bradetich.

drivers/serial/Kconfig

@@ -317,6 +317,44 @@ config SERIAL_SUNSU
 	  mouse on (PCI) UltraSPARC systems.  Say Y or M if you want to be able
 	  to these serial ports.
 
+config SERIAL_MUX
+	tristate "Serial MUX support"
+	depends on PARISC
+	default y
+	---help---
+	  Saying Y here will enable the hardware MUX serial driver for
+	  the Nova and K class systems.  The hardware MUX is not 8250/16550 
+	  compatible therefore the /dev/ttyB0 device is shared between the 
+	  Serial MUX and the PDC software console.  The following steps 
+	  need to be completed to use the Serial MUX:
+
+	    1. create the device entry (mknod /dev/ttyB0 c 11 0)
+	    2. Edit the /etc/inittab to start a getty listening on /dev/ttyB0
+	    3. Add device ttyB0 to /etc/securetty (if you want to log on as
+		 root on this console.)
+	    4. Change the kernel command console parameter to: console=ttyB0
+
+config SERIAL_MUX_CONSOLE
+        bool "Support for console on serial MUX"
+        depends on SERIAL_MUX
+        default y
+
+config PDC_CONSOLE
+	bool "PDC software console support"
+	depends on PARISC && !SERIAL_MUX
+	default n
+	help
+	  Saying Y here will enable the software based PDC console to be 
+	  used as the system console.  This is useful for machines in 
+	  which the hardware based console has not been written yet.  The
+	  following steps must be competed to use the PDC console:
+
+	    1. create the device entry (mknod /dev/ttyB0 c 11 0)
+	    2. Edit the /etc/inittab to start a getty listening on /dev/ttyB0
+	    3. Add device ttyB0 to /etc/securetty (if you want to log on as
+		 root on this console.)
+	    4. Change the kernel command console parameter to: console=ttyB0
+
 config SERIAL_SUNSAB
 	tristate "Sun Siemens SAB82532 serial support"
 	depends on (SPARC32 || SPARC64) && PCI
@@ -336,12 +374,12 @@ config V850E_NB85E_UART_CONSOLE
 
 config SERIAL_CORE
 	tristate
-	default m if SERIAL_AMBA!=y && SERIAL_CLPS711X!=y && SERIAL_21285!=y && !SERIAL_SA1100 && !SERIAL_ANAKIN && !SERIAL_UART00 && SERIAL_8250!=y && !SERIAL_ROCKETPORT && !SERIAL_SUNCORE && !V850E_NB85E_UART && (SERIAL_AMBA=m || SERIAL_CLPS711X=m || SERIAL_21285=m || SERIAL_8250=m)
-	default y if SERIAL_AMBA=y || SERIAL_CLPS711X=y || SERIAL_21285=y || SERIAL_SA1100 || SERIAL_ANAKIN || SERIAL_UART00 || SERIAL_8250=y || SERIAL_ROCKETPORT || SERIAL_SUNCORE || V850E_NB85E_UART
+	default m if SERIAL_AMBA!=y && SERIAL_CLPS711X!=y && SERIAL_21285!=y && !SERIAL_SA1100 && !SERIAL_ANAKIN && !SERIAL_UART00 && SERIAL_8250!=y && SERIAL_MUX!=y && !SERIAL_ROCKETPORT && !SERIAL_SUNCORE && !V850E_NB85E_UART && (SERIAL_AMBA=m || SERIAL_CLPS711X=m || SERIAL_21285=m || SERIAL_8250=m || SERIAL_MUX=m)
+	default y if SERIAL_AMBA=y || SERIAL_CLPS711X=y || SERIAL_21285=y || SERIAL_SA1100 || SERIAL_ANAKIN || SERIAL_UART00 || SERIAL_8250=y || SERIAL_MUX=y || SERIAL_ROCKETPORT || SERIAL_SUNCORE || V850E_NB85E_UART
 
 config SERIAL_CORE_CONSOLE
 	bool
-	depends on SERIAL_AMBA_CONSOLE || SERIAL_CLPS711X_CONSOLE || SERIAL_21285_CONSOLE || SERIAL_SA1100_CONSOLE || SERIAL_ANAKIN_CONSOLE || SERIAL_UART00_CONSOLE || SERIAL_8250_CONSOLE || SERIAL_SUNCORE || V850E_NB85E_UART_CONSOLE
+	depends on SERIAL_AMBA_CONSOLE || SERIAL_CLPS711X_CONSOLE || SERIAL_21285_CONSOLE || SERIAL_SA1100_CONSOLE || SERIAL_ANAKIN_CONSOLE || SERIAL_UART00_CONSOLE || SERIAL_8250_CONSOLE || SERIAL_MUX_CONSOLE || SERIAL_SUNCORE || V850E_NB85E_UART_CONSOLE
 	default y
 
 config SERIAL_68328

drivers/serial/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_SERIAL_SUNCORE) += suncore.o
 obj-$(CONFIG_SERIAL_SUNZILOG) += sunzilog.o
 obj-$(CONFIG_SERIAL_SUNSU) += sunsu.o
 obj-$(CONFIG_SERIAL_SUNSAB) += sunsab.o
+obj-$(CONFIG_SERIAL_MUX) += mux.o
 obj-$(CONFIG_SERIAL_68328) += 68328serial.o
 obj-$(CONFIG_SERIAL_68360) += 68360serial.o
 obj-$(CONFIG_SERIAL_COLDFIRE) += mcfserial.o

drivers/serial/mux.c

+/*
+** mux.c:
+**	serial driver for the Mux console found in some PA-RISC servers.
+**
+**	(c) Copyright 2002 Ryan Bradetich
+**	(c) Copyright 2002 Hewlett-Packard Company
+**
+** 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 Driver currently only supports the console (port 0) on the MUX.
+** Additional work will be needed on this driver to enable the full
+** functionality of the MUX.
+**
+*/
+
+#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 <asm/io.h>
+
+#ifdef CONFIG_MAGIC_SYSRQ
+#include <linux/sysrq.h>
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/serial_core.h>
+
+#define MUX_NR 1
+
+#define MUX_OFFSET 0x800
+#define MUX_LINE_OFFSET 0x80
+
+#define MUX_FIFO_SIZE 255
+#define MUX_MIN_FREE_SIZE 32
+
+#define MUX_FIFO_DRAIN_DELAY 1
+#define MUX_POLL_DELAY (30 * HZ / 1000) 
+
+#define IO_COMMAND_REG_OFFSET 0x30
+#define IO_STATUS_REG_OFFSET 0x34
+#define IO_DATA_REG_OFFSET 0x3c
+#define IO_DCOUNT_REG_OFFSET 0x40
+#define IO_UCOUNT_REG_OFFSET 0x44
+#define IO_FIFOS_REG_OFFSET 0x48
+
+#define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
+#define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
+#define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
+
+
+static struct uart_port mux_ports[MUX_NR];
+static struct timer_list mux_timer;
+
+#define UART_PUT_CHAR(p, c) __raw_writel((c), (unsigned long)(p)->membase + IO_DATA_REG_OFFSET)
+#define UART_GET_FIFO_CNT(p) __raw_readl((unsigned long)(p)->membase + IO_DCOUNT_REG_OFFSET)
+
+/**
+ * mux_tx_empty - Check if the transmitter fifo is empty.
+ * @port: Ptr to the uart_port.
+ *
+ * This function test if the transmitter fifo for the port
+ * described by 'port' is empty.  If it is empty, this function
+ * should return TIOCSER_TEMT, otherwise return 0.
+ */
+static unsigned int mux_tx_empty(struct uart_port *port)
+{
+	unsigned int cnt = __raw_readl((unsigned long)port->membase 
+				+ IO_DCOUNT_REG_OFFSET);
+
+	return cnt ? 0 : TIOCSER_TEMT;
+} 
+
+/**
+ * mux_set_mctrl - Set the current state of the modem control inputs.
+ * @ports: Ptr to the uart_port.
+ * @mctrl: Modem control bits.
+ *
+ * The Serial MUX does not support CTS, DCD or DSR so this function
+ * is ignored.
+ */
+static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+/**
+ * mux_get_mctrl - Returns the current state of modem control inputs.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial MUX does not support CTS, DCD or DSR so these lines are
+ * treated as permanently active.
+ */
+static unsigned int mux_get_mctrl(struct uart_port *port)
+{ 
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/**
+ * mux_stop_tx - Stop transmitting characters.
+ * @port: Ptr to the uart_port.
+ * @tty_stop: tty layer issue this command?
+ *
+ * The Serial MUX does not support this function.
+ */
+static void mux_stop_tx(struct uart_port *port, unsigned int tty_stop)
+{
+}
+
+/**
+ * mux_start_tx - Start transmitting characters.
+ * @port: Ptr to the uart_port.
+ * @tty_start: tty layer issue this command?
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_start_tx(struct uart_port *port, unsigned int tty_start)
+{
+}
+
+/**
+ * mux_stop_rx - Stop receiving characters.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_stop_rx(struct uart_port *port)
+{
+}
+
+/**
+ * mux_enable_ms - Enable modum status interrupts.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_enable_ms(struct uart_port *port)
+{
+}
+
+/**
+ * mux_break_ctl - Control the transmitssion of a break signal.
+ * @port: Ptr to the uart_port.
+ * @break_state: Raise/Lower the break signal.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+/**
+ * mux_write - Write chars to the mux fifo.
+ * @port: Ptr to the uart_port.
+ *
+ * This function writes all the data from the uart buffer to
+ * the mux fifo.
+ */
+static void mux_write(struct uart_port *port)
+{
+	int count;
+	struct circ_buf *xmit = &port->info->xmit;
+
+	if(port->x_char) {
+		UART_PUT_CHAR(port, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if(uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		mux_stop_tx(port, 0);
+		return;
+	}
+
+	count = (port->fifosize >> 1) - UART_GET_FIFO_CNT(port);
+	do {
+		UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if(uart_circ_empty(xmit))
+			break;
+
+	} while(--count > 0);
+
+	if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		mux_stop_tx(port, 0);
+}
+
+/**
+ * mux_read - Read chars from the mux fifo.
+ * @port: Ptr to the uart_port.
+ *
+ * This reads all available data from the mux's fifo and pushes
+ * the data to the tty layer.
+ */
+static void mux_read(struct uart_port *port)
+{
+	int data;
+	__u32 start_count = port->icount.rx;
+	struct tty_struct *tty = port->info->tty;
+
+	while(1) {
+		data = __raw_readl((unsigned long)port->membase
+						+ IO_DATA_REG_OFFSET);
+
+		if (MUX_STATUS(data))
+			continue;
+
+		if (MUX_EOFIFO(data))
+			break;
+
+		if (tty->flip.count >= TTY_FLIPBUF_SIZE)
+			continue;
+
+		*tty->flip.char_buf_ptr = data & 0xffu;
+		*tty->flip.flag_buf_ptr = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (MUX_BREAK(data)) {
+			port->icount.brk++;
+			if(uart_handle_break(port))
+				continue;
+		}
+
+		if (uart_handle_sysrq_char(port, data & 0xffu, NULL))
+			continue;
+
+		tty->flip.flag_buf_ptr++;
+		tty->flip.char_buf_ptr++;
+		tty->flip.count++;
+	}
+	
+	if (start_count != port->icount.rx) {
+		tty_flip_buffer_push(tty);
+	}
+}
+
+/**
+ * mux_startup - Initialize the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Grab any resources needed for this port and start the
+ * mux timer.
+ */
+static int mux_startup(struct uart_port *port)
+{
+	mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+	return 0;
+}
+
+/**
+ * mux_shutdown - Disable the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Release any resources needed for the port.
+ */
+static void mux_shutdown(struct uart_port *port)
+{
+}
+
+/**
+ * mux_change_speed - Chane port parameters.
+ * @port: Ptr to the uart_port.
+ * @cflag: character flags.
+ * @iflag: interrupt flags.
+ * @quot: 
+ *
+ * The Serial Mux does not support this function.
+ */
+static void
+mux_change_speed(struct uart_port *port, unsigned int cflag,
+			unsigned int iflag, unsigned int quot)
+{
+}
+
+/**
+ * mux_type - Describe the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Return a pointer to a string constant describing the
+ * specified port.
+ */
+static const char *mux_type(struct uart_port *port)
+{
+	return "Mux";
+}
+
+/**
+ * release_port - Release memory and IO regions.
+ * @port: Ptr to the uart_port.
+ * 
+ * Release any memory and IO region resources currently in use by
+ * the port.
+ */
+static void mux_release_port(struct uart_port *port)
+{
+}
+
+/**
+ * mux_request_port - Request memory and IO regions.
+ * @port: Ptr to the uart_port.
+ *
+ * Request any memory and IO region resources required by the port.
+ * If any fail, no resources should be registered when this function
+ * returns, and it should return -EBUSY on failure.
+ */
+static int mux_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/**
+ * mux_config_port - Perform port autoconfiguration.
+ * @port: Ptr to the uart_port.
+ * @type: Bitmask of required configurations.
+ *
+ * Perform any autoconfiguration steps for the port.  This functino is
+ * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
+ * [Note: This is required for now because of a bug in the Serial core.
+ *  rmk has already submitted a patch to linus, should be available for
+ *  2.5.47.]
+ */
+static void mux_config_port(struct uart_port *port, int type)
+{
+	port->type = PORT_MUX;
+}
+
+/**
+ * mux_verify_port - Verify the port information.
+ * @port: Ptr to the uart_port.
+ * @ser: Ptr to the serial information.
+ *
+ * Verify the new serial port information contained within serinfo is
+ * suitable for this port type.
+ */
+static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if(port->membase == NULL)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * mux_drv_poll - Mux poll function.   
+ * @unused: Unused variable
+ *
+ * This function periodically polls the Serial MUX to check for new data.
+ */
+static void mux_poll(unsigned long unused)
+{  
+	struct uart_port *port = &mux_ports[0];
+
+	mux_read(port);
+	mux_write(port);
+	mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+}
+
+
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+static struct console mux_console = {
+	.name =		"ttyB",
+	.flags =	CON_PRINTBUFFER,
+	.index =	0,
+};
+#define MUX_CONSOLE	&mux_console
+#else
+#define MUX_CONSOLE	NULL
+#endif
+
+static struct uart_ops mux_pops = {
+	.tx_empty =		mux_tx_empty,
+	.set_mctrl =		mux_set_mctrl,
+	.get_mctrl =		mux_get_mctrl,
+	.stop_tx =		mux_stop_tx,
+	.start_tx =		mux_start_tx,
+	.stop_rx =		mux_stop_rx,
+	.enable_ms =		mux_enable_ms,
+	.break_ctl =		mux_break_ctl,
+	.startup =		mux_startup,
+	.shutdown =		mux_shutdown,
+	.change_speed =		mux_change_speed,
+	.type =			mux_type,
+	.release_port =		mux_release_port,
+	.request_port =		mux_request_port,
+	.config_port =		mux_config_port,
+	.verify_port =		mux_verify_port,
+};
+
+static struct uart_driver mux_reg = {
+	.owner =		THIS_MODULE,
+	.driver_name =		"ttyB",
+#ifdef CONFIG_DEVFS_FS
+	.dev_name =		"ttyB%d",
+#else
+	.dev_name =		"ttyB%d",
+#endif
+	.major =		MUX_MAJOR,
+	.minor =		0,
+	.nr =			MUX_NR, 
+	.cons =			MUX_CONSOLE,
+};
+
+/**
+ * mux_probe - Determine if the Serial Mux should claim this device.
+ * @dev: The parisc device.
+ *
+ * Deterimine if the Serial Mux should claim this chip (return 0)
+ * or not (return 1).
+ */
+static int __init mux_probe(struct parisc_device *dev)
+{
+	int i, ret;
+	struct uart_port *port = &mux_ports[0];
+
+	init_timer(&mux_timer);
+	mux_timer.function = mux_poll;
+
+	printk(KERN_INFO "Serial mux driver Revision: 0.1\n");
+
+	ret = uart_register_driver(&mux_reg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < MUX_NR; i++) {
+		port = &mux_ports[i];
+
+		port->iobase	= 0;
+		port->mapbase	= dev->hpa + MUX_OFFSET + (i * MUX_LINE_OFFSET);
+		port->membase	= ioremap(port->mapbase, MUX_LINE_OFFSET);
+		port->iotype	= SERIAL_IO_MEM;
+		port->type	= PORT_MUX;
+		port->irq	= SERIAL_IRQ_NONE;
+		port->uartclk	= 0;
+		port->fifosize	= MUX_FIFO_SIZE;
+		port->ops	= &mux_pops;
+		port->flags	= UPF_BOOT_AUTOCONF;
+		port->line	= 0;
+
+		uart_add_one_port(&mux_reg, port);
+	}
+
+	return 0;
+}
+
+static struct parisc_device_id mux_tbl[] = {
+	{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(parisc, mux_tbl);
+
+static struct parisc_driver mux_driver = {
+	.name     = "Serial MUX driver",
+	.id_table = mux_tbl,
+	.probe    = mux_probe,
+};
+
+/**
+ * mux_init - Serial MUX initalization procedure.
+ *
+ * Register the Serial MUX driver.
+ */
+static int __init mux_init(void)
+{
+	return register_parisc_driver(&mux_driver);
+}
+
+/**
+ * mux_exit - Serial MUX cleanup procedure.
+ *
+ * Unregister the Serial MUX driver from the tty layer.
+ */
+static void __exit mux_exit(void)
+{
+	int i;
+
+	for (i = 0; i < MUX_NR; i++) {
+		uart_remove_one_port(&mux_reg, &mux_ports[i]);
+	}
+
+	uart_unregister_driver(&mux_reg);
+}
+
+module_init(mux_init);
+module_exit(mux_exit);
+
+MODULE_AUTHOR("Ryan Bradetich");
+MODULE_DESCRIPTION("Serial MUX driver");
+MODULE_LICENSE("GPL");

include/linux/major.h

@@ -33,6 +33,7 @@
 #define MD_MAJOR        9
 #define MISC_MAJOR	10
 #define SCSI_CDROM_MAJOR 11
+#define MUX_MAJOR	11	/* PA-RISC only */
 #define QIC02_TAPE_MAJOR 12
 #define XT_DISK_MAJOR	13
 #define SOUND_MAJOR	14