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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/mips/pmc-sierra/yosemite/py-console.c
15118 views
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/*

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 * This file is subject to the terms and conditions of the GNU General Public

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 * License.  See the file "COPYING" in the main directory of this archive

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 * for more details.

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 *

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 * Copyright (C) 2001, 2002, 2004 Ralf Baechle

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 */

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#include <linux/init.h>

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#include <linux/console.h>

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#include <linux/kdev_t.h>

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#include <linux/major.h>

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#include <linux/termios.h>

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#include <linux/sched.h>

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#include <linux/tty.h>

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#include <linux/serial.h>

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#include <linux/serial_core.h>

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#include <asm/serial.h>

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#include <asm/io.h>

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/* SUPERIO uart register map */

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struct yo_uartregs {

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	union {

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		volatile u8	rbr;	/* read only, DLAB == 0 */

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		volatile u8	thr;	/* write only, DLAB == 0 */

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		volatile u8	dll;	/* DLAB == 1 */

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	} u1;

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	union {

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		volatile u8	ier;	/* DLAB == 0 */

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		volatile u8	dlm;	/* DLAB == 1 */

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	} u2;

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	union {

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		volatile u8	iir;	/* read only */

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		volatile u8	fcr;	/* write only */

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	} u3;

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	volatile u8	iu_lcr;

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	volatile u8	iu_mcr;

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	volatile u8	iu_lsr;

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	volatile u8	iu_msr;

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	volatile u8	iu_scr;

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} yo_uregs_t;

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#define iu_rbr u1.rbr

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#define iu_thr u1.thr

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#define iu_dll u1.dll

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#define iu_ier u2.ier

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#define iu_dlm u2.dlm

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#define iu_iir u3.iir

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#define iu_fcr u3.fcr

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#define ssnop()		__asm__ __volatile__("sll	$0, $0, 1\n");

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#define ssnop_4()	do { ssnop(); ssnop(); ssnop(); ssnop(); } while (0)

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#define IO_BASE_64	0x9000000000000000ULL

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static unsigned char readb_outer_space(unsigned long long phys)

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{

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	unsigned long long vaddr = IO_BASE_64 | phys;

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	unsigned char res;

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	unsigned int sr;

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	sr = read_c0_status();

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	write_c0_status((sr | ST0_KX) & ~ ST0_IE);

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	ssnop_4();

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	__asm__ __volatile__ (

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	"	.set	mips3		\n"

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	"	.set	push		\n"

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	"	.set	noreorder	\n"

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	"	.set	nomacro		\n"

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	"	ld	%0, %1		\n"

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	"	.set	pop		\n"

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	"	lbu	%0, (%0)	\n"

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	"	.set	mips0		\n"

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	: "=r" (res)

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	: "R" (vaddr));

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	write_c0_status(sr);

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	ssnop_4();

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	return res;

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}

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static void writeb_outer_space(unsigned long long phys, unsigned char c)

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{

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	unsigned long long vaddr = IO_BASE_64 | phys;

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	unsigned long tmp;

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	unsigned int sr;

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	sr = read_c0_status();

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	write_c0_status((sr | ST0_KX) & ~ ST0_IE);

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	ssnop_4();

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	__asm__ __volatile__ (

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	"	.set	mips3		\n"

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	"	.set	push		\n"

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	"	.set	noreorder	\n"

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	"	.set	nomacro		\n"

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	"	ld	%0, %1		\n"

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	"	.set	pop		\n"

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	"	sb	%2, (%0)	\n"

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	"	.set	mips0		\n"

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	: "=&r" (tmp)

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	: "R" (vaddr), "r" (c));

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	write_c0_status(sr);

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	ssnop_4();

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}

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void prom_putchar(char c)

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{

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	unsigned long lsr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_lsr);

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	unsigned long thr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_thr);

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	while ((readb_outer_space(lsr) & 0x20) == 0);

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	writeb_outer_space(thr, c);

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}

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