[PATCH v2 05/15] ARM: mxs: Add low-level debug UART support

[Uwe Kleine-König]

On Wed, Dec 08, 2010 at 12:31:55AM +0800, Shawn Guo wrote:
>  - DEBUG_LL support, which is incompatible with single MXS image
maybe better: s/single/multi-soc/

>    because of different DUART base address on MX23 and MX28
>  - uncompress message support
> 
> Signed-off-by: Shawn Guo <shawn.guo at freescale.com>
> ---
> Changes for v2:
>  - Remove incorrect comments
> 
>  arch/arm/mach-mxs/include/mach/debug-macro.S |   51 +++++++++++++++++
>  arch/arm/mach-mxs/include/mach/uncompress.h  |   78 ++++++++++++++++++++++++++
>  2 files changed, 129 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/mach-mxs/include/mach/debug-macro.S
>  create mode 100644 arch/arm/mach-mxs/include/mach/uncompress.h
> 
> diff --git a/arch/arm/mach-mxs/include/mach/debug-macro.S b/arch/arm/mach-mxs/include/mach/debug-macro.S
> new file mode 100644
> index 0000000..efb3173
> --- /dev/null
> +++ b/arch/arm/mach-mxs/include/mach/debug-macro.S
> @@ -0,0 +1,51 @@
> +/* arch/arm/mach-mxs/include/mach/debug-macro.S
> + *
> + * Debugging macro include header
> + *
> + *  Copyright (C) 1994-1999 Russell King
> + *  Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <mach/hardware.h>
> +
> +#ifdef CONFIG_SOC_IMX23
> +#ifdef UART_PADDR
> +#error "CONFIG_DEBUG_LL is incompatible with multiple archs"
> +#endif
> +#define UART_PADDR	MX23_DUART_BASE_ADDR
> +#endif
> +
> +#ifdef CONFIG_SOC_IMX28
> +#ifdef UART_PADDR
> +#error "CONFIG_DEBUG_LL is incompatible with multiple archs"
> +#endif
> +#define UART_PADDR	MX28_DUART_BASE_ADDR
> +#endif
> +
> +#define UART_VADDR	MXS_IO_ADDRESS(UART_PADDR)
> +
> +		.macro	addruart, rp, rv
> +		ldr	\rp, =UART_PADDR	@ physical
> +		ldr	\rv, =UART_VADDR	@ virtual
> +		.endm
> +
> +		.macro	senduart, rd, rx
> +		str	\rd, [\rx, #0x0]	@ DR
> +		.endm
> +
> +		.macro	waituart, rd, rx
> +1001:		ldr	\rd, [\rx, #0x18]	@ FR
> +		tst	\rd, #1 << 5		@ FR_TXFF
> +		bne	1001b
> +		.endm
> +
> +		.macro	busyuart, rd, rx
> +1002:		ldr	\rd, [\rx, #0x18]	@ FR
> +		tst	\rd, #1 << 3		@ FR_BUSY
> +		beq	1002b
> +		.endm
> diff --git a/arch/arm/mach-mxs/include/mach/uncompress.h b/arch/arm/mach-mxs/include/mach/uncompress.h
> new file mode 100644
> index 0000000..efdacc7
> --- /dev/null
> +++ b/arch/arm/mach-mxs/include/mach/uncompress.h
> @@ -0,0 +1,78 @@
> +/*
> + *  arch/arm/mach-mxs/include/mach/uncompress.h
> + *
> + *  Copyright (C) 1999 ARM Limited
> + *  Copyright (C) Shane Nay (shane at minirl.com)
> + *  Copyright 2010 Freescale Semiconductor, Inc. All Rights Reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that 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.
> + */
> +#ifndef __MACH_MXS_UNCOMPRESS_H__
> +#define __MACH_MXS_UNCOMPRESS_H__
> +
> +#define __MXS_BOOT_UNCOMPRESS
> +
> +#include <asm/mach-types.h>
> +
> +static unsigned long uart_base;
> +
> +#define UART(x) (*(volatile unsigned long *)(uart_base + (x)))
> +
> +#define DR		0x00
> +#define FR		0x18
> +#define FR_BUSY		(1 << 3)
> +#define FR_TXFE		(1 << 7)
> +#define CR		0x30
> +#define CR_UARTEN	1
Maybe namespace these?  Maybe better define CR_UARTEN as (1 << 0) for
consistency?

> +
> +/*
> + * The following code assumes the serial port has already been
> + * initialized by the bootloader.
Maybe add:
    * If it's not, the output is simply discarded.
> + */
> +
> +static void putc(int ch)
> +{
> +	if (!uart_base)
> +		return;
> +	if (!(UART(CR) & CR_UARTEN))
> +		return;
> +
> +	while (!(UART(FR) & FR_TXFE))
> +		barrier();
> +
> +	UART(DR) = ch;
> +}
> +
> +static inline void flush(void)
> +{
> +}
> +
> +#define MX23_DUART_BASE_ADDR	0x80070000
> +#define MX28_DUART_BASE_ADDR	0x80074000
> +
> +static __inline__ void __arch_decomp_setup(unsigned long arch_id)
> +{
> +	switch (arch_id) {
> +	case MACH_TYPE_MX23EVK:
> +		uart_base = MX23_DUART_BASE_ADDR;
> +		break;
> +	case MACH_TYPE_MX28EVK:
> +		uart_base = MX28_DUART_BASE_ADDR;
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +#define arch_decomp_setup()	__arch_decomp_setup(arch_id)
> +#define arch_decomp_wdog()
> +
> +#endif /* __MACH_MXS_UNCOMPRESS_H__ */
> -- 
> 1.7.1
> 
> 
> 
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Pengutronix e.K.                           | Uwe Kleine-König            |
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