diff options
Diffstat (limited to 'drivers/serial/sunhv.c')
| -rw-r--r-- | drivers/serial/sunhv.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/serial/sunhv.c b/drivers/serial/sunhv.c new file mode 100644 index 000000000000..f137804b3133 --- /dev/null +++ b/drivers/serial/sunhv.c @@ -0,0 +1,550 @@ +/* sunhv.c: Serial driver for SUN4V hypervisor console. + * + * Copyright (C) 2006 David S. Miller (davem@davemloft.net) + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/major.h> +#include <linux/circ_buf.h> +#include <linux/serial.h> +#include <linux/sysrq.h> +#include <linux/console.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/init.h> + +#include <asm/hypervisor.h> +#include <asm/spitfire.h> +#include <asm/vdev.h> +#include <asm/oplib.h> +#include <asm/irq.h> + +#if defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/serial_core.h> + +#include "suncore.h" + +#define CON_BREAK ((long)-1) +#define CON_HUP ((long)-2) + +static inline long hypervisor_con_getchar(long *status) +{ + register unsigned long func asm("%o5"); + register unsigned long arg0 asm("%o0"); + register unsigned long arg1 asm("%o1"); + + func = HV_FAST_CONS_GETCHAR; + arg0 = 0; + arg1 = 0; + __asm__ __volatile__("ta %6" + : "=&r" (func), "=&r" (arg0), "=&r" (arg1) + : "0" (func), "1" (arg0), "2" (arg1), + "i" (HV_FAST_TRAP)); + + *status = arg0; + + return (long) arg1; +} + +static inline long hypervisor_con_putchar(long ch) +{ + register unsigned long func asm("%o5"); + register unsigned long arg0 asm("%o0"); + + func = HV_FAST_CONS_PUTCHAR; + arg0 = ch; + __asm__ __volatile__("ta %4" + : "=&r" (func), "=&r" (arg0) + : "0" (func), "1" (arg0), "i" (HV_FAST_TRAP)); + + return (long) arg0; +} + +#define IGNORE_BREAK 0x1 +#define IGNORE_ALL 0x2 + +static int hung_up = 0; + +static struct tty_struct *receive_chars(struct uart_port *port, struct pt_regs *regs) +{ + struct tty_struct *tty = NULL; + int saw_console_brk = 0; + int limit = 10000; + + if (port->info != NULL) /* Unopened serial console */ + tty = port->info->tty; + + while (limit-- > 0) { + long status; + long c = hypervisor_con_getchar(&status); + unsigned char flag; + + if (status == HV_EWOULDBLOCK) + break; + + if (c == CON_BREAK) { + if (uart_handle_break(port)) + continue; + saw_console_brk = 1; + c = 0; + } + + if (c == CON_HUP) { + hung_up = 1; + uart_handle_dcd_change(port, 0); + } else if (hung_up) { + hung_up = 0; + uart_handle_dcd_change(port, 1); + } + + if (tty == NULL) { + uart_handle_sysrq_char(port, c, regs); + continue; + } + + flag = TTY_NORMAL; + port->icount.rx++; + if (c == CON_BREAK) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + flag = TTY_BREAK; + } + + if (uart_handle_sysrq_char(port, c, regs)) + continue; + + if ((port->ignore_status_mask & IGNORE_ALL) || + ((port->ignore_status_mask & IGNORE_BREAK) && + (c == CON_BREAK))) + continue; + + tty_insert_flip_char(tty, c, flag); + } + + if (saw_console_brk) + sun_do_break(); + + return tty; +} + +static void transmit_chars(struct uart_port *port) +{ + struct circ_buf *xmit; + + if (!port->info) + return; + + xmit = &port->info->xmit; + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) + return; + + while (!uart_circ_empty(xmit)) { + long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); + + if (status != HV_EOK) + break; + + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); +} + +static irqreturn_t sunhv_interrupt(int irq, void *dev_id, struct pt_regs *regs) +{ + struct uart_port *port = dev_id; + struct tty_struct *tty; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + tty = receive_chars(port, regs); + transmit_chars(port); + spin_unlock_irqrestore(&port->lock, flags); + + if (tty) + tty_flip_buffer_push(tty); + + return IRQ_HANDLED; +} + +/* port->lock is not held. */ +static unsigned int sunhv_tx_empty(struct uart_port *port) +{ + /* Transmitter is always empty for us. If the circ buffer + * is non-empty or there is an x_char pending, our caller + * will do the right thing and ignore what we return here. + */ + return TIOCSER_TEMT; +} + +/* port->lock held by caller. */ +static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + return; +} + +/* port->lock is held by caller and interrupts are disabled. */ +static unsigned int sunhv_get_mctrl(struct uart_port *port) +{ + return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS; +} + +/* port->lock held by caller. */ +static void sunhv_stop_tx(struct uart_port *port) +{ + return; +} + +/* port->lock held by caller. */ +static void sunhv_start_tx(struct uart_port *port) +{ + struct circ_buf *xmit = &port->info->xmit; + + while (!uart_circ_empty(xmit)) { + long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); + + if (status != HV_EOK) + break; + + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } +} + +/* port->lock is not held. */ +static void sunhv_send_xchar(struct uart_port *port, char ch) +{ + unsigned long flags; + int limit = 10000; + + spin_lock_irqsave(&port->lock, flags); + + while (limit-- > 0) { + long status = hypervisor_con_putchar(ch); + if (status == HV_EOK) + break; + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +/* port->lock held by caller. */ +static void sunhv_stop_rx(struct uart_port *port) +{ +} + +/* port->lock held by caller. */ +static void sunhv_enable_ms(struct uart_port *port) +{ +} + +/* port->lock is not held. */ +static void sunhv_break_ctl(struct uart_port *port, int break_state) +{ + if (break_state) { + unsigned long flags; + int limit = 1000000; + + spin_lock_irqsave(&port->lock, flags); + + while (limit-- > 0) { + long status = hypervisor_con_putchar(CON_BREAK); + if (status == HV_EOK) + break; + udelay(2); + } + + spin_unlock_irqrestore(&port->lock, flags); + } +} + +/* port->lock is not held. */ +static int sunhv_startup(struct uart_port *port) +{ + return 0; +} + +/* port->lock is not held. */ +static void sunhv_shutdown(struct uart_port *port) +{ +} + +/* port->lock is not held. */ +static void sunhv_set_termios(struct uart_port *port, struct termios *termios, + struct termios *old) +{ + unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000); + unsigned int quot = uart_get_divisor(port, baud); + unsigned int iflag, cflag; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + iflag = termios->c_iflag; + cflag = termios->c_cflag; + + port->ignore_status_mask = 0; + if (iflag & IGNBRK) + port->ignore_status_mask |= IGNORE_BREAK; + if ((cflag & CREAD) == 0) + port->ignore_status_mask |= IGNORE_ALL; + + /* XXX */ + uart_update_timeout(port, cflag, + (port->uartclk / (16 * quot))); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *sunhv_type(struct uart_port *port) +{ + return "SUN4V HCONS"; +} + +static void sunhv_release_port(struct uart_port *port) +{ +} + +static int sunhv_request_port(struct uart_port *port) +{ + return 0; +} + +static void sunhv_config_port(struct uart_port *port, int flags) +{ +} + +static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + return -EINVAL; +} + +static struct uart_ops sunhv_pops = { + .tx_empty = sunhv_tx_empty, + .set_mctrl = sunhv_set_mctrl, + .get_mctrl = sunhv_get_mctrl, + .stop_tx = sunhv_stop_tx, + .start_tx = sunhv_start_tx, + .send_xchar = sunhv_send_xchar, + .stop_rx = sunhv_stop_rx, + .enable_ms = sunhv_enable_ms, + .break_ctl = sunhv_break_ctl, + .startup = sunhv_startup, + .shutdown = sunhv_shutdown, + .set_termios = sunhv_set_termios, + .type = sunhv_type, + .release_port = sunhv_release_port, + .request_port = sunhv_request_port, + .config_port = sunhv_config_port, + .verify_port = sunhv_verify_port, +}; + +static struct uart_driver sunhv_reg = { + .owner = THIS_MODULE, + .driver_name = "serial", + .devfs_name = "tts/", + .dev_name = "ttyS", + .major = TTY_MAJOR, +}; + +static struct uart_port *sunhv_port; + +static inline void sunhv_console_putchar(struct uart_port *port, char c) +{ + unsigned long flags; + int limit = 1000000; + + spin_lock_irqsave(&port->lock, flags); + + while (limit-- > 0) { + long status = hypervisor_con_putchar(c); + if (status == HV_EOK) + break; + udelay(2); + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +static void sunhv_console_write(struct console *con, const char *s, unsigned n) +{ + struct uart_port *port = sunhv_port; + int i; + + for (i = 0; i < n; i++) { + if (*s == '\n') + sunhv_console_putchar(port, '\r'); + sunhv_console_putchar(port, *s++); + } +} + +static struct console sunhv_console = { + .name = "ttyHV", + .write = sunhv_console_write, + .device = uart_console_device, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &sunhv_reg, +}; + +static inline struct console *SUNHV_CONSOLE(void) +{ + if (con_is_present()) + return NULL; + + sunhv_console.index = 0; + + return &sunhv_console; +} + +static int __init hv_console_compatible(char *buf, int len) +{ + while (len) { + int this_len; + + if (!strcmp(buf, "qcn")) + return 1; + + this_len = strlen(buf) + 1; + + buf += this_len; + len -= this_len; + } + + return 0; +} + +static unsigned int __init get_interrupt(void) +{ + const char *cons_str = "console"; + const char *compat_str = "compatible"; + int node = prom_getchild(sun4v_vdev_root); + char buf[64]; + int err, len; + + node = prom_searchsiblings(node, cons_str); + if (!node) + return 0; + + len = prom_getproplen(node, compat_str); + if (len == 0 || len == -1) + return 0; + + err = prom_getproperty(node, compat_str, buf, 64); + if (err == -1) + return 0; + + if (!hv_console_compatible(buf, len)) + return 0; + + /* Ok, the this is the OBP node for the sun4v hypervisor + * console device. Decode the interrupt. + */ + return sun4v_vdev_device_interrupt(node); +} + +static int __init sunhv_init(void) +{ + struct uart_port *port; + int ret; + + if (tlb_type != hypervisor) + return -ENODEV; + + port = kmalloc(sizeof(struct uart_port), GFP_KERNEL); + if (unlikely(!port)) + return -ENOMEM; + + memset(port, 0, sizeof(struct uart_port)); + + port->line = 0; + port->ops = &sunhv_pops; + port->type = PORT_SUNHV; + port->uartclk = ( 29491200 / 16 ); /* arbitrary */ + + /* Set this just to make uart_configure_port() happy. */ + port->membase = (unsigned char __iomem *) __pa(port); + + port->irq = get_interrupt(); + if (!port->irq) { + kfree(port); + return -ENODEV; + } + + sunhv_reg.minor = sunserial_current_minor; + sunhv_reg.nr = 1; + + ret = uart_register_driver(&sunhv_reg); + if (ret < 0) { + printk(KERN_ERR "SUNHV: uart_register_driver() failed %d\n", + ret); + kfree(port); + + return ret; + } + + sunhv_reg.tty_driver->name_base = sunhv_reg.minor - 64; + sunserial_current_minor += 1; + + sunhv_reg.cons = SUNHV_CONSOLE(); + + sunhv_port = port; + + ret = uart_add_one_port(&sunhv_reg, port); + if (ret < 0) { + printk(KERN_ERR "SUNHV: uart_add_one_port() failed %d\n", ret); + sunserial_current_minor -= 1; + uart_unregister_driver(&sunhv_reg); + kfree(port); + sunhv_port = NULL; + return -ENODEV; + } + + if (request_irq(port->irq, sunhv_interrupt, + SA_SHIRQ, "serial(sunhv)", port)) { + printk(KERN_ERR "sunhv: Cannot register IRQ\n"); + uart_remove_one_port(&sunhv_reg, port); + sunserial_current_minor -= 1; + uart_unregister_driver(&sunhv_reg); + kfree(port); + sunhv_port = NULL; + return -ENODEV; + } + + return 0; +} + +static void __exit sunhv_exit(void) +{ + struct uart_port *port = sunhv_port; + + BUG_ON(!port); + + free_irq(port->irq, port); + + uart_remove_one_port(&sunhv_reg, port); + sunserial_current_minor -= 1; + + uart_unregister_driver(&sunhv_reg); + + kfree(sunhv_port); + sunhv_port = NULL; +} + +module_init(sunhv_init); +module_exit(sunhv_exit); + +MODULE_AUTHOR("David S. Miller"); +MODULE_DESCRIPTION("SUN4V Hypervisor console driver") +MODULE_LICENSE("GPL"); |
