527 lines
10 KiB
C
527 lines
10 KiB
C
/* sunhv.c: Serial driver for SUN4V hypervisor console.
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*
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* Copyright (C) 2006 David S. Miller (davem@davemloft.net)
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/major.h>
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#include <linux/circ_buf.h>
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#include <linux/serial.h>
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#include <linux/sysrq.h>
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#include <linux/console.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <asm/hypervisor.h>
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#include <asm/spitfire.h>
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#include <asm/prom.h>
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#include <asm/of_device.h>
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#include <asm/irq.h>
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#if defined(CONFIG_MAGIC_SYSRQ)
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#define SUPPORT_SYSRQ
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#endif
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#include <linux/serial_core.h>
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#include "suncore.h"
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#define CON_BREAK ((long)-1)
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#define CON_HUP ((long)-2)
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static inline long hypervisor_con_getchar(long *status)
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{
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register unsigned long func asm("%o5");
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register unsigned long arg0 asm("%o0");
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register unsigned long arg1 asm("%o1");
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func = HV_FAST_CONS_GETCHAR;
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arg0 = 0;
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arg1 = 0;
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__asm__ __volatile__("ta %6"
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: "=&r" (func), "=&r" (arg0), "=&r" (arg1)
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: "0" (func), "1" (arg0), "2" (arg1),
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"i" (HV_FAST_TRAP));
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*status = arg0;
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return (long) arg1;
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}
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static inline long hypervisor_con_putchar(long ch)
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{
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register unsigned long func asm("%o5");
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register unsigned long arg0 asm("%o0");
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func = HV_FAST_CONS_PUTCHAR;
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arg0 = ch;
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__asm__ __volatile__("ta %4"
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: "=&r" (func), "=&r" (arg0)
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: "0" (func), "1" (arg0), "i" (HV_FAST_TRAP));
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return (long) arg0;
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}
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#define IGNORE_BREAK 0x1
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#define IGNORE_ALL 0x2
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static int hung_up = 0;
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static struct tty_struct *receive_chars(struct uart_port *port)
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{
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struct tty_struct *tty = NULL;
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int saw_console_brk = 0;
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int limit = 10000;
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if (port->info != NULL) /* Unopened serial console */
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tty = port->info->tty;
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while (limit-- > 0) {
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long status;
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long c = hypervisor_con_getchar(&status);
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unsigned char flag;
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if (status == HV_EWOULDBLOCK)
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break;
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if (c == CON_BREAK) {
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if (uart_handle_break(port))
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continue;
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saw_console_brk = 1;
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c = 0;
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}
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if (c == CON_HUP) {
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hung_up = 1;
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uart_handle_dcd_change(port, 0);
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} else if (hung_up) {
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hung_up = 0;
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uart_handle_dcd_change(port, 1);
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}
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if (tty == NULL) {
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uart_handle_sysrq_char(port, c);
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continue;
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}
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flag = TTY_NORMAL;
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port->icount.rx++;
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if (c == CON_BREAK) {
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port->icount.brk++;
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if (uart_handle_break(port))
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continue;
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flag = TTY_BREAK;
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}
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if (uart_handle_sysrq_char(port, c))
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continue;
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if ((port->ignore_status_mask & IGNORE_ALL) ||
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((port->ignore_status_mask & IGNORE_BREAK) &&
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(c == CON_BREAK)))
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continue;
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tty_insert_flip_char(tty, c, flag);
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}
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if (saw_console_brk)
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sun_do_break();
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return tty;
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}
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static void transmit_chars(struct uart_port *port)
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{
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struct circ_buf *xmit;
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if (!port->info)
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return;
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xmit = &port->info->xmit;
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if (uart_circ_empty(xmit) || uart_tx_stopped(port))
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return;
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while (!uart_circ_empty(xmit)) {
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long status = hypervisor_con_putchar(xmit->buf[xmit->tail]);
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if (status != HV_EOK)
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break;
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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port->icount.tx++;
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}
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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}
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static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
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{
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struct uart_port *port = dev_id;
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struct tty_struct *tty;
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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tty = receive_chars(port);
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transmit_chars(port);
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spin_unlock_irqrestore(&port->lock, flags);
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if (tty)
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tty_flip_buffer_push(tty);
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return IRQ_HANDLED;
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}
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/* port->lock is not held. */
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static unsigned int sunhv_tx_empty(struct uart_port *port)
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{
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/* Transmitter is always empty for us. If the circ buffer
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* is non-empty or there is an x_char pending, our caller
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* will do the right thing and ignore what we return here.
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*/
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return TIOCSER_TEMT;
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}
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/* port->lock held by caller. */
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static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
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{
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return;
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}
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/* port->lock is held by caller and interrupts are disabled. */
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static unsigned int sunhv_get_mctrl(struct uart_port *port)
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{
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return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
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}
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/* port->lock held by caller. */
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static void sunhv_stop_tx(struct uart_port *port)
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{
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return;
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}
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/* port->lock held by caller. */
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static void sunhv_start_tx(struct uart_port *port)
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{
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struct circ_buf *xmit = &port->info->xmit;
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while (!uart_circ_empty(xmit)) {
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long status = hypervisor_con_putchar(xmit->buf[xmit->tail]);
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if (status != HV_EOK)
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break;
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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port->icount.tx++;
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}
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}
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/* port->lock is not held. */
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static void sunhv_send_xchar(struct uart_port *port, char ch)
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{
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unsigned long flags;
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int limit = 10000;
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spin_lock_irqsave(&port->lock, flags);
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while (limit-- > 0) {
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long status = hypervisor_con_putchar(ch);
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if (status == HV_EOK)
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break;
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}
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spin_unlock_irqrestore(&port->lock, flags);
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}
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/* port->lock held by caller. */
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static void sunhv_stop_rx(struct uart_port *port)
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{
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}
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/* port->lock held by caller. */
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static void sunhv_enable_ms(struct uart_port *port)
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{
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}
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/* port->lock is not held. */
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static void sunhv_break_ctl(struct uart_port *port, int break_state)
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{
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if (break_state) {
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unsigned long flags;
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int limit = 1000000;
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spin_lock_irqsave(&port->lock, flags);
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while (limit-- > 0) {
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long status = hypervisor_con_putchar(CON_BREAK);
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if (status == HV_EOK)
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break;
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udelay(2);
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}
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spin_unlock_irqrestore(&port->lock, flags);
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}
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}
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/* port->lock is not held. */
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static int sunhv_startup(struct uart_port *port)
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{
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return 0;
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}
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/* port->lock is not held. */
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static void sunhv_shutdown(struct uart_port *port)
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{
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}
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/* port->lock is not held. */
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static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
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struct ktermios *old)
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{
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unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
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unsigned int quot = uart_get_divisor(port, baud);
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unsigned int iflag, cflag;
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unsigned long flags;
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spin_lock_irqsave(&port->lock, flags);
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iflag = termios->c_iflag;
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cflag = termios->c_cflag;
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port->ignore_status_mask = 0;
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if (iflag & IGNBRK)
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port->ignore_status_mask |= IGNORE_BREAK;
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if ((cflag & CREAD) == 0)
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port->ignore_status_mask |= IGNORE_ALL;
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/* XXX */
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uart_update_timeout(port, cflag,
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(port->uartclk / (16 * quot)));
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static const char *sunhv_type(struct uart_port *port)
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{
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return "SUN4V HCONS";
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}
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static void sunhv_release_port(struct uart_port *port)
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{
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}
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static int sunhv_request_port(struct uart_port *port)
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{
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return 0;
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}
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static void sunhv_config_port(struct uart_port *port, int flags)
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{
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}
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static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser)
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{
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return -EINVAL;
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}
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static struct uart_ops sunhv_pops = {
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.tx_empty = sunhv_tx_empty,
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.set_mctrl = sunhv_set_mctrl,
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.get_mctrl = sunhv_get_mctrl,
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.stop_tx = sunhv_stop_tx,
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.start_tx = sunhv_start_tx,
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.send_xchar = sunhv_send_xchar,
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.stop_rx = sunhv_stop_rx,
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.enable_ms = sunhv_enable_ms,
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.break_ctl = sunhv_break_ctl,
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.startup = sunhv_startup,
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.shutdown = sunhv_shutdown,
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.set_termios = sunhv_set_termios,
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.type = sunhv_type,
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.release_port = sunhv_release_port,
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.request_port = sunhv_request_port,
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.config_port = sunhv_config_port,
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.verify_port = sunhv_verify_port,
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};
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static struct uart_driver sunhv_reg = {
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.owner = THIS_MODULE,
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.driver_name = "serial",
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.dev_name = "ttyS",
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.major = TTY_MAJOR,
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};
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static struct uart_port *sunhv_port;
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static inline void sunhv_console_putchar(struct uart_port *port, char c)
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{
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unsigned long flags;
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int limit = 1000000;
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spin_lock_irqsave(&port->lock, flags);
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while (limit-- > 0) {
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long status = hypervisor_con_putchar(c);
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if (status == HV_EOK)
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break;
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udelay(2);
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}
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spin_unlock_irqrestore(&port->lock, flags);
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}
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static void sunhv_console_write(struct console *con, const char *s, unsigned n)
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{
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struct uart_port *port = sunhv_port;
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int i;
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for (i = 0; i < n; i++) {
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if (*s == '\n')
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sunhv_console_putchar(port, '\r');
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sunhv_console_putchar(port, *s++);
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}
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}
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static struct console sunhv_console = {
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.name = "ttyHV",
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.write = sunhv_console_write,
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.device = uart_console_device,
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.flags = CON_PRINTBUFFER,
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.index = -1,
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.data = &sunhv_reg,
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};
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static inline struct console *SUNHV_CONSOLE(void)
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{
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if (con_is_present())
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return NULL;
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sunhv_console.index = 0;
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return &sunhv_console;
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}
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static int __devinit hv_probe(struct of_device *op, const struct of_device_id *match)
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{
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struct uart_port *port;
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int err;
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if (op->irqs[0] == 0xffffffff)
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return -ENODEV;
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port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
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if (unlikely(!port))
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return -ENOMEM;
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sunhv_port = port;
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port->line = 0;
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port->ops = &sunhv_pops;
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port->type = PORT_SUNHV;
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port->uartclk = ( 29491200 / 16 ); /* arbitrary */
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port->membase = (unsigned char __iomem *) __pa(port);
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port->irq = op->irqs[0];
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port->dev = &op->dev;
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sunhv_reg.minor = sunserial_current_minor;
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sunhv_reg.nr = 1;
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err = uart_register_driver(&sunhv_reg);
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if (err)
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goto out_free_port;
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sunhv_reg.tty_driver->name_base = sunhv_reg.minor - 64;
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sunserial_current_minor += 1;
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sunhv_reg.cons = SUNHV_CONSOLE();
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err = uart_add_one_port(&sunhv_reg, port);
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if (err)
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goto out_unregister_driver;
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err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
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if (err)
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goto out_remove_port;
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dev_set_drvdata(&op->dev, port);
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return 0;
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out_remove_port:
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uart_remove_one_port(&sunhv_reg, port);
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out_unregister_driver:
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sunserial_current_minor -= 1;
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uart_unregister_driver(&sunhv_reg);
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out_free_port:
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kfree(port);
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sunhv_port = NULL;
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return err;
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}
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static int __devexit hv_remove(struct of_device *dev)
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{
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struct uart_port *port = dev_get_drvdata(&dev->dev);
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free_irq(port->irq, port);
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uart_remove_one_port(&sunhv_reg, port);
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sunserial_current_minor -= 1;
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uart_unregister_driver(&sunhv_reg);
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kfree(port);
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sunhv_port = NULL;
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dev_set_drvdata(&dev->dev, NULL);
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return 0;
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}
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static struct of_device_id hv_match[] = {
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{
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.name = "console",
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.compatible = "qcn",
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, hv_match);
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static struct of_platform_driver hv_driver = {
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.name = "hv",
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.match_table = hv_match,
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.probe = hv_probe,
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.remove = __devexit_p(hv_remove),
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};
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static int __init sunhv_init(void)
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{
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if (tlb_type != hypervisor)
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return -ENODEV;
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return of_register_driver(&hv_driver, &of_bus_type);
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}
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static void __exit sunhv_exit(void)
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{
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of_unregister_driver(&hv_driver);
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}
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module_init(sunhv_init);
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module_exit(sunhv_exit);
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MODULE_AUTHOR("David S. Miller");
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MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
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MODULE_VERSION("2.0");
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MODULE_LICENSE("GPL");
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