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Commit 6d7d7b3e authored by Stephen Warren's avatar Stephen Warren Committed by Olof Johansson
Browse files

ARM: tegra: Pass uncompress.h UART selection to DEBUG_LL 

uncompress.h now saves the selected UART's physical address in Tegra's
IRAM, along with a cookie to indicate validity.

The first time it's run, macro addruart in debug-macro.S looks for this
cookie, and if it's present, uses the UART address stored there. If not,
the static value TEGRA_DEBUG_UART_BASE is used, as was previous behaviour.
The static behaviour will thus be used when not booting using a zImage.

This work was inspired by work by Doug Anderson <dianders@chromium.org>;
see http://lkml.org/lkml/2011/9/26/284

. However, this patch relies on
the data passing describe above, rather than duplicating the UART
selection logic in debug-macro.S; the latest selection logic is more
complex due to the need to check reset/clock bits too.

Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
Tested-by: default avatarDoug Anderson <dianders@chromium.org>
Acked-by: default avatarDoug Anderson <dianders@chromium.org>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent fe263989

arch/arm/mach-tegra/common.c

+17 −0
Original line number Diff line number Diff line
@@ -33,6 +33,23 @@ 
#include "clock.h"

#include "fuse.h"



/*

 * Storage for debug-macro.S's state.

 *

 * This must be in .data not .bss so that it gets initialized each time the

 * kernel is loaded. The data is declared here rather than debug-macro.S so

 * that multiple inclusions of debug-macro.S point at the same data.

 */

#define TEGRA_DEBUG_UART_OFFSET (TEGRA_DEBUG_UART_BASE & 0xFFFF)

u32 tegra_uart_config[3] = {

	/* Debug UART initialization required */

	1,

	/* Debug UART physical address */

	(u32)(IO_APB_PHYS + TEGRA_DEBUG_UART_OFFSET),

	/* Debug UART virtual address */

	(u32)(IO_APB_VIRT + TEGRA_DEBUG_UART_OFFSET),

};



#ifdef CONFIG_OF

static const struct of_device_id tegra_dt_irq_match[] __initconst = {

	{ .compatible = "arm,cortex-a9-gic", .data = gic_of_init },

arch/arm/mach-tegra/include/mach/debug-macro.S

+77 −11
Original line number Diff line number Diff line 
/*

 * arch/arm/mach-tegra/include/mach/debug-macro.S

 *

 * Copyright (C) 2010 Google, Inc.

 * Copyright (C) 2010,2011 Google, Inc.

 * Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved.

 *

 * Author:

 *	Colin Cross <ccross@google.com>

 *	Erik Gilling <konkers@google.com>

 *	Doug Anderson <dianders@chromium.org>

 *	Stephen Warren <swarren@nvidia.com>

 *

 * Portions based on mach-omap2's debug-macro.S

 * Copyright (C) 1994-1999 Russell King

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and
@@ -18,18 +24,78 @@ 
 *

 */



#include <linux/serial_reg.h>



#include <mach/io.h>

#include <mach/iomap.h>

#include <mach/irammap.h>



		.macro  addruart, rp, rv, tmp

        ldr     \rp, =IO_APB_PHYS       @ physical

        ldr     \rv, =IO_APB_VIRT        @ virtual

	orr	\rp, \rp, #(TEGRA_DEBUG_UART_BASE & 0xFF)

	orr	\rp, \rp, #(TEGRA_DEBUG_UART_BASE & 0xFF00)

	orr	\rv, \rv, #(TEGRA_DEBUG_UART_BASE & 0xFF)

	orr	\rv, \rv, #(TEGRA_DEBUG_UART_BASE & 0xFF00)

		adr	\rp, 99f		@ actual addr of 99f

		ldr	\rv, [\rp]		@ linked addr is stored there

		sub	\rv, \rv, \rp		@ offset between the two

		ldr	\rp, [\rp, #4]		@ linked tegra_uart_config

		sub	\tmp, \rp, \rv		@ actual tegra_uart_config

		ldr	\rp, [\tmp]		@ Load tegra_uart_config

		cmp	\rp, #1			@ needs intitialization?

		bne	100f			@ no; go load the addresses

		mov	\rv, #0			@ yes; record init is done

		str	\rv, [\tmp]

		mov	\rp, #TEGRA_IRAM_BASE	@ See if cookie is in IRAM

		ldr	\rv, [\rp, #TEGRA_IRAM_DEBUG_UART_OFFSET]

		movw	\rp, #TEGRA_IRAM_DEBUG_UART_COOKIE & 0xffff

		movt	\rp, #TEGRA_IRAM_DEBUG_UART_COOKIE >> 16

		cmp	\rv, \rp		@ Cookie present?

		bne	100f			@ No, use default UART

		mov	\rp, #TEGRA_IRAM_BASE	@ Load UART address from IRAM

		ldr	\rv, [\rp, #TEGRA_IRAM_DEBUG_UART_OFFSET + 4]

		str	\rv, [\tmp, #4]		@ Store in tegra_uart_phys

		sub	\rv, \rv, #IO_APB_PHYS	@ Calculate virt address

		add	\rv, \rv, #IO_APB_VIRT

		str	\rv, [\tmp, #8]		@ Store in tegra_uart_virt

		b	100f



		.align

99:		.word	.

		.word	tegra_uart_config

		.ltorg



100:		ldr	\rp, [\tmp, #4]		@ Load tegra_uart_phys

		ldr	\rv, [\tmp, #8]		@ Load tegra_uart_virt

		.endm



#define UART_SHIFT 2

#include <asm/hardware/debug-8250.S>



/*

 * Code below is swiped from <asm/hardware/debug-8250.S>, but add an extra

 * check to make sure that we aren't in the CONFIG_TEGRA_DEBUG_UART_NONE case.

 * We use the fact that all 5 valid UART addresses all have something in the

 * 2nd-to-lowest byte.

 */



		.macro	senduart, rd, rx

		tst	\rx, #0x0000ff00

		strneb	\rd, [\rx, #UART_TX << UART_SHIFT]

1001:

		.endm



		.macro	busyuart, rd, rx

		tst	\rx, #0x0000ff00

		beq	1002f

1001:		ldrb	\rd, [\rx, #UART_LSR << UART_SHIFT]

		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE

		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE

		bne	1001b

1002:

		.endm



		.macro	waituart, rd, rx

#ifdef FLOW_CONTROL

		tst	\rx, #0x0000ff00

		beq	1002f

1001:		ldrb	\rd, [\rx, #UART_MSR << UART_SHIFT]

		tst	\rd, #UART_MSR_CTS

		beq	1001b

1002:

#endif

		.endm

arch/arm/mach-tegra/include/mach/irammap.h

0 → 100644
+35 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#ifndef __MACH_TEGRA_IRAMMAP_H

#define __MACH_TEGRA_IRAMMAP_H



#include <asm/sizes.h>



/* The first 1K of IRAM is permanently reserved for the CPU reset handler */

#define TEGRA_IRAM_RESET_HANDLER_OFFSET	0

#define TEGRA_IRAM_RESET_HANDLER_SIZE	SZ_1K



/*

 * These locations are written to by uncompress.h, and read by debug-macro.S.

 * The first word holds the cookie value if the data is valid. The second

 * word holds the UART physical address.

 */

#define TEGRA_IRAM_DEBUG_UART_OFFSET	SZ_1K

#define TEGRA_IRAM_DEBUG_UART_SIZE	8

#define TEGRA_IRAM_DEBUG_UART_COOKIE	0x55415254



#endif

arch/arm/mach-tegra/include/mach/uncompress.h

+14 −1
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ 
 *

 * Copyright (C) 2010 Google, Inc.

 * Copyright (C) 2011 Google, Inc.

 * Copyright (C) 2011 NVIDIA CORPORATION. All Rights Reserved.

 * Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved.

 *

 * Author:

 *	Colin Cross <ccross@google.com>
@@ -30,6 +30,7 @@ 
#include <linux/serial_reg.h>



#include <mach/iomap.h>

#include <mach/irammap.h>



#define DEBUG_UART_SHIFT 2
@@ -49,6 +50,17 @@ static inline void flush(void) 
{

}



static inline void save_uart_address(void)

{

	u32 *buf = (u32 *)(TEGRA_IRAM_BASE + TEGRA_IRAM_DEBUG_UART_OFFSET);



	if (uart) {

		buf[0] = TEGRA_IRAM_DEBUG_UART_COOKIE;

		buf[1] = (u32)uart;

	} else

		buf[0] = 0;

}



/*

 * Setup before decompression.  This is where we do UART selection for

 * earlyprintk and init the uart_base register.
@@ -125,6 +137,7 @@ static inline void arch_decomp_setup(void) 
	}

	if (i == ARRAY_SIZE(uarts))

		uart = (volatile u8 *)TEGRA_DEBUG_UART_BASE;

	save_uart_address();

	if (uart == NULL)

		return;