diff options
Diffstat (limited to 'drivers/tty/serial/sn_console.c')
| -rw-r--r-- | drivers/tty/serial/sn_console.c | 1073 |
1 files changed, 1073 insertions, 0 deletions
diff --git a/drivers/tty/serial/sn_console.c b/drivers/tty/serial/sn_console.c new file mode 100644 index 000000000..33e94e56d --- /dev/null +++ b/drivers/tty/serial/sn_console.c @@ -0,0 +1,1073 @@ +/* + * C-Brick Serial Port (and console) driver for SGI Altix machines. + * + * This driver is NOT suitable for talking to the l1-controller for + * anything other than 'console activities' --- please use the l1 + * driver for that. + * + * + * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/NoticeExplan + */ + +#include <linux/interrupt.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/console.h> +#include <linux/module.h> +#include <linux/sysrq.h> +#include <linux/circ_buf.h> +#include <linux/serial_reg.h> +#include <linux/delay.h> /* for mdelay */ +#include <linux/miscdevice.h> +#include <linux/serial_core.h> + +#include <asm/io.h> +#include <asm/sn/simulator.h> +#include <asm/sn/sn_sal.h> + +/* number of characters we can transmit to the SAL console at a time */ +#define SN_SAL_MAX_CHARS 120 + +/* 64K, when we're asynch, it must be at least printk's LOG_BUF_LEN to + * avoid losing chars, (always has to be a power of 2) */ +#define SN_SAL_BUFFER_SIZE (64 * (1 << 10)) + +#define SN_SAL_UART_FIFO_DEPTH 16 +#define SN_SAL_UART_FIFO_SPEED_CPS (9600/10) + +/* sn_transmit_chars() calling args */ +#define TRANSMIT_BUFFERED 0 +#define TRANSMIT_RAW 1 + +/* To use dynamic numbers only and not use the assigned major and minor, + * define the following.. */ + /* #define USE_DYNAMIC_MINOR 1 *//* use dynamic minor number */ +#define USE_DYNAMIC_MINOR 0 /* Don't rely on misc_register dynamic minor */ + +/* Device name we're using */ +#define DEVICE_NAME "ttySG" +#define DEVICE_NAME_DYNAMIC "ttySG0" /* need full name for misc_register */ +/* The major/minor we are using, ignored for USE_DYNAMIC_MINOR */ +#define DEVICE_MAJOR 204 +#define DEVICE_MINOR 40 + +#ifdef CONFIG_MAGIC_SYSRQ +static char sysrq_serial_str[] = "\eSYS"; +static char *sysrq_serial_ptr = sysrq_serial_str; +static unsigned long sysrq_requested; +#endif /* CONFIG_MAGIC_SYSRQ */ + +/* + * Port definition - this kinda drives it all + */ +struct sn_cons_port { + struct timer_list sc_timer; + struct uart_port sc_port; + struct sn_sal_ops { + int (*sal_puts_raw) (const char *s, int len); + int (*sal_puts) (const char *s, int len); + int (*sal_getc) (void); + int (*sal_input_pending) (void); + void (*sal_wakeup_transmit) (struct sn_cons_port *, int); + } *sc_ops; + unsigned long sc_interrupt_timeout; + int sc_is_asynch; +}; + +static struct sn_cons_port sal_console_port; +static int sn_process_input; + +/* Only used if USE_DYNAMIC_MINOR is set to 1 */ +static struct miscdevice misc; /* used with misc_register for dynamic */ + +extern void early_sn_setup(void); + +#undef DEBUG +#ifdef DEBUG +static int sn_debug_printf(const char *fmt, ...); +#define DPRINTF(x...) sn_debug_printf(x) +#else +#define DPRINTF(x...) do { } while (0) +#endif + +/* Prototypes */ +static int snt_hw_puts_raw(const char *, int); +static int snt_hw_puts_buffered(const char *, int); +static int snt_poll_getc(void); +static int snt_poll_input_pending(void); +static int snt_intr_getc(void); +static int snt_intr_input_pending(void); +static void sn_transmit_chars(struct sn_cons_port *, int); + +/* A table for polling: + */ +static struct sn_sal_ops poll_ops = { + .sal_puts_raw = snt_hw_puts_raw, + .sal_puts = snt_hw_puts_raw, + .sal_getc = snt_poll_getc, + .sal_input_pending = snt_poll_input_pending +}; + +/* A table for interrupts enabled */ +static struct sn_sal_ops intr_ops = { + .sal_puts_raw = snt_hw_puts_raw, + .sal_puts = snt_hw_puts_buffered, + .sal_getc = snt_intr_getc, + .sal_input_pending = snt_intr_input_pending, + .sal_wakeup_transmit = sn_transmit_chars +}; + +/* the console does output in two distinctly different ways: + * synchronous (raw) and asynchronous (buffered). initially, early_printk + * does synchronous output. any data written goes directly to the SAL + * to be output (incidentally, it is internally buffered by the SAL) + * after interrupts and timers are initialized and available for use, + * the console init code switches to asynchronous output. this is + * also the earliest opportunity to begin polling for console input. + * after console initialization, console output and tty (serial port) + * output is buffered and sent to the SAL asynchronously (either by + * timer callback or by UART interrupt) */ + +/* routines for running the console in polling mode */ + +/** + * snt_poll_getc - Get a character from the console in polling mode + * + */ +static int snt_poll_getc(void) +{ + int ch; + + ia64_sn_console_getc(&ch); + return ch; +} + +/** + * snt_poll_input_pending - Check if any input is waiting - polling mode. + * + */ +static int snt_poll_input_pending(void) +{ + int status, input; + + status = ia64_sn_console_check(&input); + return !status && input; +} + +/* routines for an interrupt driven console (normal) */ + +/** + * snt_intr_getc - Get a character from the console, interrupt mode + * + */ +static int snt_intr_getc(void) +{ + return ia64_sn_console_readc(); +} + +/** + * snt_intr_input_pending - Check if input is pending, interrupt mode + * + */ +static int snt_intr_input_pending(void) +{ + return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV; +} + +/* these functions are polled and interrupt */ + +/** + * snt_hw_puts_raw - Send raw string to the console, polled or interrupt mode + * @s: String + * @len: Length + * + */ +static int snt_hw_puts_raw(const char *s, int len) +{ + /* this will call the PROM and not return until this is done */ + return ia64_sn_console_putb(s, len); +} + +/** + * snt_hw_puts_buffered - Send string to console, polled or interrupt mode + * @s: String + * @len: Length + * + */ +static int snt_hw_puts_buffered(const char *s, int len) +{ + /* queue data to the PROM */ + return ia64_sn_console_xmit_chars((char *)s, len); +} + +/* uart interface structs + * These functions are associated with the uart_port that the serial core + * infrastructure calls. + * + * Note: Due to how the console works, many routines are no-ops. + */ + +/** + * snp_type - What type of console are we? + * @port: Port to operate with (we ignore since we only have one port) + * + */ +static const char *snp_type(struct uart_port *port) +{ + return ("SGI SN L1"); +} + +/** + * snp_tx_empty - Is the transmitter empty? We pretend we're always empty + * @port: Port to operate on (we ignore since we only have one port) + * + */ +static unsigned int snp_tx_empty(struct uart_port *port) +{ + return 1; +} + +/** + * snp_stop_tx - stop the transmitter - no-op for us + * @port: Port to operat eon - we ignore - no-op function + * + */ +static void snp_stop_tx(struct uart_port *port) +{ +} + +/** + * snp_release_port - Free i/o and resources for port - no-op for us + * @port: Port to operate on - we ignore - no-op function + * + */ +static void snp_release_port(struct uart_port *port) +{ +} + +/** + * snp_shutdown - shut down the port - free irq and disable - no-op for us + * @port: Port to shut down - we ignore + * + */ +static void snp_shutdown(struct uart_port *port) +{ +} + +/** + * snp_set_mctrl - set control lines (dtr, rts, etc) - no-op for our console + * @port: Port to operate on - we ignore + * @mctrl: Lines to set/unset - we ignore + * + */ +static void snp_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ +} + +/** + * snp_get_mctrl - get contorl line info, we just return a static value + * @port: port to operate on - we only have one port so we ignore this + * + */ +static unsigned int snp_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS; +} + +/** + * snp_stop_rx - Stop the receiver - we ignor ethis + * @port: Port to operate on - we ignore + * + */ +static void snp_stop_rx(struct uart_port *port) +{ +} + +/** + * snp_start_tx - Start transmitter + * @port: Port to operate on + * + */ +static void snp_start_tx(struct uart_port *port) +{ + if (sal_console_port.sc_ops->sal_wakeup_transmit) + sal_console_port.sc_ops->sal_wakeup_transmit(&sal_console_port, + TRANSMIT_BUFFERED); + +} + +/** + * snp_break_ctl - handle breaks - ignored by us + * @port: Port to operate on + * @break_state: Break state + * + */ +static void snp_break_ctl(struct uart_port *port, int break_state) +{ +} + +/** + * snp_startup - Start up the serial port - always return 0 (We're always on) + * @port: Port to operate on + * + */ +static int snp_startup(struct uart_port *port) +{ + return 0; +} + +/** + * snp_set_termios - set termios stuff - we ignore these + * @port: port to operate on + * @termios: New settings + * @termios: Old + * + */ +static void +snp_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ +} + +/** + * snp_request_port - allocate resources for port - ignored by us + * @port: port to operate on + * + */ +static int snp_request_port(struct uart_port *port) +{ + return 0; +} + +/** + * snp_config_port - allocate resources, set up - we ignore, we're always on + * @port: Port to operate on + * @flags: flags used for port setup + * + */ +static void snp_config_port(struct uart_port *port, int flags) +{ +} + +/* Associate the uart functions above - given to serial core */ + +static struct uart_ops sn_console_ops = { + .tx_empty = snp_tx_empty, + .set_mctrl = snp_set_mctrl, + .get_mctrl = snp_get_mctrl, + .stop_tx = snp_stop_tx, + .start_tx = snp_start_tx, + .stop_rx = snp_stop_rx, + .break_ctl = snp_break_ctl, + .startup = snp_startup, + .shutdown = snp_shutdown, + .set_termios = snp_set_termios, + .pm = NULL, + .type = snp_type, + .release_port = snp_release_port, + .request_port = snp_request_port, + .config_port = snp_config_port, + .verify_port = NULL, +}; + +/* End of uart struct functions and defines */ + +#ifdef DEBUG + +/** + * sn_debug_printf - close to hardware debugging printf + * @fmt: printf format + * + * This is as "close to the metal" as we can get, used when the driver + * itself may be broken. + * + */ +static int sn_debug_printf(const char *fmt, ...) +{ + static char printk_buf[1024]; + int printed_len; + va_list args; + + va_start(args, fmt); + printed_len = vsnprintf(printk_buf, sizeof(printk_buf), fmt, args); + + if (!sal_console_port.sc_ops) { + sal_console_port.sc_ops = &poll_ops; + early_sn_setup(); + } + sal_console_port.sc_ops->sal_puts_raw(printk_buf, printed_len); + + va_end(args); + return printed_len; +} +#endif /* DEBUG */ + +/* + * Interrupt handling routines. + */ + +/** + * sn_receive_chars - Grab characters, pass them to tty layer + * @port: Port to operate on + * @flags: irq flags + * + * Note: If we're not registered with the serial core infrastructure yet, + * we don't try to send characters to it... + * + */ +static void +sn_receive_chars(struct sn_cons_port *port, unsigned long flags) +{ + struct tty_port *tport = NULL; + int ch; + + if (!port) { + printk(KERN_ERR "sn_receive_chars - port NULL so can't receive\n"); + return; + } + + if (!port->sc_ops) { + printk(KERN_ERR "sn_receive_chars - port->sc_ops NULL so can't receive\n"); + return; + } + + if (port->sc_port.state) { + /* The serial_core stuffs are initialized, use them */ + tport = &port->sc_port.state->port; + } + + while (port->sc_ops->sal_input_pending()) { + ch = port->sc_ops->sal_getc(); + if (ch < 0) { + printk(KERN_ERR "sn_console: An error occurred while " + "obtaining data from the console (0x%0x)\n", ch); + break; + } +#ifdef CONFIG_MAGIC_SYSRQ + if (sysrq_requested) { + unsigned long sysrq_timeout = sysrq_requested + HZ*5; + + sysrq_requested = 0; + if (ch && time_before(jiffies, sysrq_timeout)) { + spin_unlock_irqrestore(&port->sc_port.lock, flags); + handle_sysrq(ch); + spin_lock_irqsave(&port->sc_port.lock, flags); + /* ignore actual sysrq command char */ + continue; + } + } + if (ch == *sysrq_serial_ptr) { + if (!(*++sysrq_serial_ptr)) { + sysrq_requested = jiffies; + sysrq_serial_ptr = sysrq_serial_str; + } + /* + * ignore the whole sysrq string except for the + * leading escape + */ + if (ch != '\e') + continue; + } + else + sysrq_serial_ptr = sysrq_serial_str; +#endif /* CONFIG_MAGIC_SYSRQ */ + + /* record the character to pass up to the tty layer */ + if (tport) { + if (tty_insert_flip_char(tport, ch, TTY_NORMAL) == 0) + break; + } + port->sc_port.icount.rx++; + } + + if (tport) + tty_flip_buffer_push(tport); +} + +/** + * sn_transmit_chars - grab characters from serial core, send off + * @port: Port to operate on + * @raw: Transmit raw or buffered + * + * Note: If we're early, before we're registered with serial core, the + * writes are going through sn_sal_console_write because that's how + * register_console has been set up. We currently could have asynch + * polls calling this function due to sn_sal_switch_to_asynch but we can + * ignore them until we register with the serial core stuffs. + * + */ +static void sn_transmit_chars(struct sn_cons_port *port, int raw) +{ + int xmit_count, tail, head, loops, ii; + int result; + char *start; + struct circ_buf *xmit; + + if (!port) + return; + + BUG_ON(!port->sc_is_asynch); + + if (port->sc_port.state) { + /* We're initialized, using serial core infrastructure */ + xmit = &port->sc_port.state->xmit; + } else { + /* Probably sn_sal_switch_to_asynch has been run but serial core isn't + * initialized yet. Just return. Writes are going through + * sn_sal_console_write (due to register_console) at this time. + */ + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(&port->sc_port)) { + /* Nothing to do. */ + ia64_sn_console_intr_disable(SAL_CONSOLE_INTR_XMIT); + return; + } + + head = xmit->head; + tail = xmit->tail; + start = &xmit->buf[tail]; + + /* twice around gets the tail to the end of the buffer and + * then to the head, if needed */ + loops = (head < tail) ? 2 : 1; + + for (ii = 0; ii < loops; ii++) { + xmit_count = (head < tail) ? + (UART_XMIT_SIZE - tail) : (head - tail); + + if (xmit_count > 0) { + if (raw == TRANSMIT_RAW) + result = + port->sc_ops->sal_puts_raw(start, + xmit_count); + else + result = + port->sc_ops->sal_puts(start, xmit_count); +#ifdef DEBUG + if (!result) + DPRINTF("`"); +#endif + if (result > 0) { + xmit_count -= result; + port->sc_port.icount.tx += result; + tail += result; + tail &= UART_XMIT_SIZE - 1; + xmit->tail = tail; + start = &xmit->buf[tail]; + } + } + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&port->sc_port); + + if (uart_circ_empty(xmit)) + snp_stop_tx(&port->sc_port); /* no-op for us */ +} + +/** + * sn_sal_interrupt - Handle console interrupts + * @irq: irq #, useful for debug statements + * @dev_id: our pointer to our port (sn_cons_port which contains the uart port) + * + */ +static irqreturn_t sn_sal_interrupt(int irq, void *dev_id) +{ + struct sn_cons_port *port = (struct sn_cons_port *)dev_id; + unsigned long flags; + int status = ia64_sn_console_intr_status(); + + if (!port) + return IRQ_NONE; + + spin_lock_irqsave(&port->sc_port.lock, flags); + if (status & SAL_CONSOLE_INTR_RECV) { + sn_receive_chars(port, flags); + } + if (status & SAL_CONSOLE_INTR_XMIT) { + sn_transmit_chars(port, TRANSMIT_BUFFERED); + } + spin_unlock_irqrestore(&port->sc_port.lock, flags); + return IRQ_HANDLED; +} + +/** + * sn_sal_timer_poll - this function handles polled console mode + * @data: A pointer to our sn_cons_port (which contains the uart port) + * + * data is the pointer that init_timer will store for us. This function is + * associated with init_timer to see if there is any console traffic. + * Obviously not used in interrupt mode + * + */ +static void sn_sal_timer_poll(unsigned long data) +{ + struct sn_cons_port *port = (struct sn_cons_port *)data; + unsigned long flags; + + if (!port) + return; + + if (!port->sc_port.irq) { + spin_lock_irqsave(&port->sc_port.lock, flags); + if (sn_process_input) + sn_receive_chars(port, flags); + sn_transmit_chars(port, TRANSMIT_RAW); + spin_unlock_irqrestore(&port->sc_port.lock, flags); + mod_timer(&port->sc_timer, + jiffies + port->sc_interrupt_timeout); + } +} + +/* + * Boot-time initialization code + */ + +/** + * sn_sal_switch_to_asynch - Switch to async mode (as opposed to synch) + * @port: Our sn_cons_port (which contains the uart port) + * + * So this is used by sn_sal_serial_console_init (early on, before we're + * registered with serial core). It's also used by sn_sal_module_init + * right after we've registered with serial core. The later only happens + * if we didn't already come through here via sn_sal_serial_console_init. + * + */ +static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port) +{ + unsigned long flags; + + if (!port) + return; + + DPRINTF("sn_console: about to switch to asynchronous console\n"); + + /* without early_printk, we may be invoked late enough to race + * with other cpus doing console IO at this point, however + * console interrupts will never be enabled */ + spin_lock_irqsave(&port->sc_port.lock, flags); + + /* early_printk invocation may have done this for us */ + if (!port->sc_ops) + port->sc_ops = &poll_ops; + + /* we can't turn on the console interrupt (as request_irq + * calls kmalloc, which isn't set up yet), so we rely on a + * timer to poll for input and push data from the console + * buffer. + */ + init_timer(&port->sc_timer); + port->sc_timer.function = sn_sal_timer_poll; + port->sc_timer.data = (unsigned long)port; + + if (IS_RUNNING_ON_SIMULATOR()) + port->sc_interrupt_timeout = 6; + else { + /* 960cps / 16 char FIFO = 60HZ + * HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */ + port->sc_interrupt_timeout = + HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS; + } + mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout); + + port->sc_is_asynch = 1; + spin_unlock_irqrestore(&port->sc_port.lock, flags); +} + +/** + * sn_sal_switch_to_interrupts - Switch to interrupt driven mode + * @port: Our sn_cons_port (which contains the uart port) + * + * In sn_sal_module_init, after we're registered with serial core and + * the port is added, this function is called to switch us to interrupt + * mode. We were previously in asynch/polling mode (using init_timer). + * + * We attempt to switch to interrupt mode here by calling + * request_irq. If that works out, we enable receive interrupts. + */ +static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port) +{ + unsigned long flags; + + if (port) { + DPRINTF("sn_console: switching to interrupt driven console\n"); + + if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt, + IRQF_SHARED, + "SAL console driver", port) >= 0) { + spin_lock_irqsave(&port->sc_port.lock, flags); + port->sc_port.irq = SGI_UART_VECTOR; + port->sc_ops = &intr_ops; + irq_set_handler(port->sc_port.irq, handle_level_irq); + + /* turn on receive interrupts */ + ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV); + spin_unlock_irqrestore(&port->sc_port.lock, flags); + } + else { + printk(KERN_INFO + "sn_console: console proceeding in polled mode\n"); + } + } +} + +/* + * Kernel console definitions + */ + +static void sn_sal_console_write(struct console *, const char *, unsigned); +static int sn_sal_console_setup(struct console *, char *); +static struct uart_driver sal_console_uart; +extern struct tty_driver *uart_console_device(struct console *, int *); + +static struct console sal_console = { + .name = DEVICE_NAME, + .write = sn_sal_console_write, + .device = uart_console_device, + .setup = sn_sal_console_setup, + .index = -1, /* unspecified */ + .data = &sal_console_uart, +}; + +#define SAL_CONSOLE &sal_console + +static struct uart_driver sal_console_uart = { + .owner = THIS_MODULE, + .driver_name = "sn_console", + .dev_name = DEVICE_NAME, + .major = 0, /* major/minor set at registration time per USE_DYNAMIC_MINOR */ + .minor = 0, + .nr = 1, /* one port */ + .cons = SAL_CONSOLE, +}; + +/** + * sn_sal_module_init - When the kernel loads us, get us rolling w/ serial core + * + * Before this is called, we've been printing kernel messages in a special + * early mode not making use of the serial core infrastructure. When our + * driver is loaded for real, we register the driver and port with serial + * core and try to enable interrupt driven mode. + * + */ +static int __init sn_sal_module_init(void) +{ + int retval; + + if (!ia64_platform_is("sn2")) + return 0; + + printk(KERN_INFO "sn_console: Console driver init\n"); + + if (USE_DYNAMIC_MINOR == 1) { + misc.minor = MISC_DYNAMIC_MINOR; + misc.name = DEVICE_NAME_DYNAMIC; + retval = misc_register(&misc); + if (retval != 0) { + printk(KERN_WARNING "Failed to register console " + "device using misc_register.\n"); + return -ENODEV; + } + sal_console_uart.major = MISC_MAJOR; + sal_console_uart.minor = misc.minor; + } else { + sal_console_uart.major = DEVICE_MAJOR; + sal_console_uart.minor = DEVICE_MINOR; + } + + /* We register the driver and the port before switching to interrupts + * or async above so the proper uart structures are populated */ + + if (uart_register_driver(&sal_console_uart) < 0) { + printk + ("ERROR sn_sal_module_init failed uart_register_driver, line %d\n", + __LINE__); + return -ENODEV; + } + + spin_lock_init(&sal_console_port.sc_port.lock); + + /* Setup the port struct with the minimum needed */ + sal_console_port.sc_port.membase = (char *)1; /* just needs to be non-zero */ + sal_console_port.sc_port.type = PORT_16550A; + sal_console_port.sc_port.fifosize = SN_SAL_MAX_CHARS; + sal_console_port.sc_port.ops = &sn_console_ops; + sal_console_port.sc_port.line = 0; + + if (uart_add_one_port(&sal_console_uart, &sal_console_port.sc_port) < 0) { + /* error - not sure what I'd do - so I'll do nothing */ + printk(KERN_ERR "%s: unable to add port\n", __func__); + } + + /* when this driver is compiled in, the console initialization + * will have already switched us into asynchronous operation + * before we get here through the module initcalls */ + if (!sal_console_port.sc_is_asynch) { + sn_sal_switch_to_asynch(&sal_console_port); + } + + /* at this point (module_init) we can try to turn on interrupts */ + if (!IS_RUNNING_ON_SIMULATOR()) { + sn_sal_switch_to_interrupts(&sal_console_port); + } + sn_process_input = 1; + return 0; +} + +/** + * sn_sal_module_exit - When we're unloaded, remove the driver/port + * + */ +static void __exit sn_sal_module_exit(void) +{ + del_timer_sync(&sal_console_port.sc_timer); + uart_remove_one_port(&sal_console_uart, &sal_console_port.sc_port); + uart_unregister_driver(&sal_console_uart); + misc_deregister(&misc); +} + +module_init(sn_sal_module_init); +module_exit(sn_sal_module_exit); + +/** + * puts_raw_fixed - sn_sal_console_write helper for adding \r's as required + * @puts_raw : puts function to do the writing + * @s: input string + * @count: length + * + * We need a \r ahead of every \n for direct writes through + * ia64_sn_console_putb (what sal_puts_raw below actually does). + * + */ + +static void puts_raw_fixed(int (*puts_raw) (const char *s, int len), + const char *s, int count) +{ + const char *s1; + + /* Output '\r' before each '\n' */ + while ((s1 = memchr(s, '\n', count)) != NULL) { + puts_raw(s, s1 - s); + puts_raw("\r\n", 2); + count -= s1 + 1 - s; + s = s1 + 1; + } + puts_raw(s, count); +} + +/** + * sn_sal_console_write - Print statements before serial core available + * @console: Console to operate on - we ignore since we have just one + * @s: String to send + * @count: length + * + * This is referenced in the console struct. It is used for early + * console printing before we register with serial core and for things + * such as kdb. The console_lock must be held when we get here. + * + * This function has some code for trying to print output even if the lock + * is held. We try to cover the case where a lock holder could have died. + * We don't use this special case code if we're not registered with serial + * core yet. After we're registered with serial core, the only time this + * function would be used is for high level kernel output like magic sys req, + * kdb, and printk's. + */ +static void +sn_sal_console_write(struct console *co, const char *s, unsigned count) +{ + unsigned long flags = 0; + struct sn_cons_port *port = &sal_console_port; + static int stole_lock = 0; + + BUG_ON(!port->sc_is_asynch); + + /* We can't look at the xmit buffer if we're not registered with serial core + * yet. So only do the fancy recovery after registering + */ + if (!port->sc_port.state) { + /* Not yet registered with serial core - simple case */ + puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); + return; + } + + /* somebody really wants this output, might be an + * oops, kdb, panic, etc. make sure they get it. */ + if (spin_is_locked(&port->sc_port.lock)) { + int lhead = port->sc_port.state->xmit.head; + int ltail = port->sc_port.state->xmit.tail; + int counter, got_lock = 0; + + /* + * We attempt to determine if someone has died with the + * lock. We wait ~20 secs after the head and tail ptrs + * stop moving and assume the lock holder is not functional + * and plow ahead. If the lock is freed within the time out + * period we re-get the lock and go ahead normally. We also + * remember if we have plowed ahead so that we don't have + * to wait out the time out period again - the asumption + * is that we will time out again. + */ + + for (counter = 0; counter < 150; mdelay(125), counter++) { + if (!spin_is_locked(&port->sc_port.lock) + || stole_lock) { + if (!stole_lock) { + spin_lock_irqsave(&port->sc_port.lock, + flags); + got_lock = 1; + } + break; + } else { + /* still locked */ + if ((lhead != port->sc_port.state->xmit.head) + || (ltail != + port->sc_port.state->xmit.tail)) { + lhead = + port->sc_port.state->xmit.head; + ltail = + port->sc_port.state->xmit.tail; + counter = 0; + } + } + } + /* flush anything in the serial core xmit buffer, raw */ + sn_transmit_chars(port, 1); + if (got_lock) { + spin_unlock_irqrestore(&port->sc_port.lock, flags); + stole_lock = 0; + } else { + /* fell thru */ + stole_lock = 1; + } + puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); + } else { + stole_lock = 0; + spin_lock_irqsave(&port->sc_port.lock, flags); + sn_transmit_chars(port, 1); + spin_unlock_irqrestore(&port->sc_port.lock, flags); + + puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); + } +} + + +/** + * sn_sal_console_setup - Set up console for early printing + * @co: Console to work with + * @options: Options to set + * + * Altix console doesn't do anything with baud rates, etc, anyway. + * + * This isn't required since not providing the setup function in the + * console struct is ok. However, other patches like KDB plop something + * here so providing it is easier. + * + */ +static int sn_sal_console_setup(struct console *co, char *options) +{ + return 0; +} + +/** + * sn_sal_console_write_early - simple early output routine + * @co - console struct + * @s - string to print + * @count - count + * + * Simple function to provide early output, before even + * sn_sal_serial_console_init is called. Referenced in the + * console struct registerd in sn_serial_console_early_setup. + * + */ +static void __init +sn_sal_console_write_early(struct console *co, const char *s, unsigned count) +{ + puts_raw_fixed(sal_console_port.sc_ops->sal_puts_raw, s, count); +} + +/* Used for very early console printing - again, before + * sn_sal_serial_console_init is run */ +static struct console sal_console_early __initdata = { + .name = "sn_sal", + .write = sn_sal_console_write_early, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/** + * sn_serial_console_early_setup - Sets up early console output support + * + * Register a console early on... This is for output before even + * sn_sal_serial_cosnole_init is called. This function is called from + * setup.c. This allows us to do really early polled writes. When + * sn_sal_serial_console_init is called, this console is unregistered + * and a new one registered. + */ +int __init sn_serial_console_early_setup(void) +{ + if (!ia64_platform_is("sn2")) + return -1; + + sal_console_port.sc_ops = &poll_ops; + spin_lock_init(&sal_console_port.sc_port.lock); + early_sn_setup(); /* Find SAL entry points */ + register_console(&sal_console_early); + + return 0; +} + +/** + * sn_sal_serial_console_init - Early console output - set up for register + * + * This function is called when regular console init happens. Because we + * support even earlier console output with sn_serial_console_early_setup + * (called from setup.c directly), this function unregisters the really + * early console. + * + * Note: Even if setup.c doesn't register sal_console_early, unregistering + * it here doesn't hurt anything. + * + */ +static int __init sn_sal_serial_console_init(void) +{ + if (ia64_platform_is("sn2")) { + sn_sal_switch_to_asynch(&sal_console_port); + DPRINTF("sn_sal_serial_console_init : register console\n"); + register_console(&sal_console); + unregister_console(&sal_console_early); + } + return 0; +} + +console_initcall(sn_sal_serial_console_init); |