--- /dev/null
+/* 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>
+
+#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) {
+ 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 = &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;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ 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++;
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* 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 = 10000;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ while (limit-- > 0) {
+ long status = hypervisor_con_putchar(CON_BREAK);
+ if (status == HV_EOK)
+ break;
+ }
+
+ 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 = 10000;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ while (limit-- > 0) {
+ long status = hypervisor_con_putchar(c);
+ if (status == HV_EOK)
+ break;
+ }
+
+ 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 int sunhv_console_setup(struct console *con, char *options)
+{
+ return 0;
+}
+
+static struct console sunhv_console = {
+ .name = "ttyS",
+ .write = sunhv_console_write,
+ .device = uart_console_device,
+ .setup = sunhv_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &sunhv_reg,
+};
+
+static void __init sunhv_console_init(void)
+{
+ if (con_is_present())
+ return;
+
+ sunhv_console.index = 0;
+ register_console(&sunhv_console);
+}
+
+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;
+
+ port->line = 0;
+ port->ops = &sunhv_pops;
+ port->type = PORT_SUNHV;
+ port->uartclk = ( 29491200 / 16 ); /* arbitrary */
+
+ /* XXX Get interrupt. XXX */
+ if (request_irq(0 /* XXX */, sunhv_interrupt,
+ SA_SHIRQ, "serial(sunhv)", port)) {
+ printk("sunhv: Cannot get IRQ %x\n",
+ 0 /* XXX */);
+ kfree(port);
+ return -ENODEV;
+ }
+
+ sunhv_reg.minor = sunserial_current_minor;
+ sunhv_reg.nr = 1;
+ sunhv_reg.cons = &sunhv_console;
+
+ ret = uart_register_driver(&sunhv_reg);
+ if (ret < 0) {
+ free_irq(0 /* XXX */, up);
+ kfree(port);
+
+ return ret;
+ }
+
+ sunhv_port = port;
+
+ sunserial_current_minor += 1;
+
+ sunhv_console_init();
+
+ uart_add_one_port(&sunhv_reg, port);
+
+ return 0;
+}
+
+static void __exit sunhv_exit(void)
+{
+ struct uart_port *port = sunhv_port;
+
+ BUG_ON(!port);
+
+ uart_remove_one_port(&sunhv_reg, port);
+ free_irq(0 /* XXX */, 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");
projects / openwrt / staging / blogic.git / commitdiff