Subject: [RFC PATCH 5/7] ARM: s3c64xx: Add board file for boot using Device Tree

From: [email-masked] (Kukjin Kim)
Date: Wed, 09 Jan 2013 16:24:42 -0800

Tomasz Figa wrote:
> 
> This patch adds board file that will be used to boot S3C64xx-based boards
> using Device Tree.
> 
> Signed-off-by: Tomasz Figa <[email-masked]>
> ---
>  arch/arm/mach-s3c64xx/Kconfig           | 13 +++++
>  arch/arm/mach-s3c64xx/Makefile          |  1 +
>  arch/arm/mach-s3c64xx/mach-s3c64xx-dt.c | 93
> +++++++++++++++++++++++++++++++++
>  3 files changed, 107 insertions(+)
>  create mode 100644 arch/arm/mach-s3c64xx/mach-s3c64xx-dt.c
> 
> diff --git a/arch/arm/mach-s3c64xx/Kconfig b/arch/arm/mach-
> s3c64xx/Kconfig
> index 131c862..a43b3f7 100644
> --- a/arch/arm/mach-s3c64xx/Kconfig
> +++ b/arch/arm/mach-s3c64xx/Kconfig
> @@ -309,3 +309,16 @@ config MACH_WLF_CRAGG_6410
>  	select SAMSUNG_GPIO_EXTRA128
>  	help
>  	  Machine support for the Wolfson Cragganmore S3C6410 variant.
> +
> +config MACH_S3C64XX_DT
> +	bool "Samsung S3C6400/S3C6410 machine using Device Tree"
> +	select CPU_S3C6400
> +	select CPU_S3C6410
> +	select USE_OF
> +	help
> +	  Machine support for Samsung S3C6400/S3C6410 machines with
> Device Tree
> +	  enabled.
> +	  Select this if a fdt blob is available for your S3C64XX SoC based
> +	  board.
> +	  Note: This is under development and not all peripherals can be
> +	  supported with this machine file.
> diff --git a/arch/arm/mach-s3c64xx/Makefile b/arch/arm/mach-
> s3c64xx/Makefile
> index f9ce1dc..59b3d06 100644
> --- a/arch/arm/mach-s3c64xx/Makefile
> +++ b/arch/arm/mach-s3c64xx/Makefile
> @@ -58,3 +58,4 @@ obj-$(CONFIG_MACH_SMARTQ7)		+= mach-
> smartq7.o
>  obj-$(CONFIG_MACH_SMDK6400)		+= mach-smdk6400.o
>  obj-$(CONFIG_MACH_SMDK6410)		+= mach-smdk6410.o
>  obj-$(CONFIG_MACH_WLF_CRAGG_6410)	+= mach-crag6410.o mach-
> crag6410-module.o
> +obj-$(CONFIG_MACH_S3C64XX_DT)		+= mach-s3c64xx-dt.o
> diff --git a/arch/arm/mach-s3c64xx/mach-s3c64xx-dt.c b/arch/arm/mach-
> s3c64xx/mach-s3c64xx-dt.c
> new file mode 100644
> index 0000000..f5725ce
> --- /dev/null
> +++ b/arch/arm/mach-s3c64xx/mach-s3c64xx-dt.c
> @@ -0,0 +1,93 @@
> +/*
> + * Samsung's S3C64XX flattened device tree enabled machine
> + *
> + * Copyright (c) 2012 Tomasz Figa <[email-masked]>
> + *
> + * 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 <linux/of_platform.h>
> +#include <linux/serial_core.h>
> +
> +#include <asm/mach/arch.h>
> +#include <asm/hardware/vic.h>
> +#include <mach/map.h>
> +
> +#include <plat/cpu.h>
> +#include <plat/regs-serial.h>
> +#include <plat/s5p-time.h>
> +
> +#include "common.h"
> +
> +/*
> + * The following lookup table is used to override device names when
> devices
> + * are registered from device tree. This is temporarily added to enable
> + * device tree support addition for the Exynos4 architecture.
> + *
> + * For drivers that require platform data to be provided from the machine
> + * file, a platform data pointer can also be supplied along with the
> + * devices names. Usually, the platform data elements that cannot be
> parsed
> + * from the device tree by the drivers (example: function pointers) are
> + * supplied. But it should be noted that this is a temporary mechanism
and
> + * at some point, the drivers should be capable of parsing all the
platform
> + * data from the device tree.
> + */
> +static const struct of_dev_auxdata s3c64xx_auxdata_lookup[] __initconst =
> {
> +	OF_DEV_AUXDATA("samsung,s3c6400-uart", S3C_PA_UART0,
> +				"s3c6400-uart.0", NULL),
> +	OF_DEV_AUXDATA("samsung,s3c6400-uart", S3C_PA_UART1,
> +				"s3c6400-uart.1", NULL),
> +	OF_DEV_AUXDATA("samsung,s3c6400-uart", S3C_PA_UART2,
> +				"s3c6400-uart.2", NULL),
> +	OF_DEV_AUXDATA("samsung,s3c6400-uart", S3C_PA_UART3,
> +				"s3c6400-uart.3", NULL),

I'd prefer to use 0x7F005000 instead of S3C_PA_UART0 so that we can remove
the static definitions at the map.h

> +	{},
> +};
> +
> +static void __init s3c64xx_dt_map_io(void)
> +{
> +	s3c64xx_init_io(NULL, 0);
> +	s3c24xx_init_clocks(12000000);

The value of xtal clock for s3c24xx_init_clocks() should be defined via dt
according to board condition _next_time_  because it can be different on
each board, it's same on current s3c64xx boards though.

> +}
> +
> +static void __init s3c64xx_dt_machine_init(void)
> +{
> +	of_platform_populate(NULL, of_default_bus_match_table,
> +				s3c64xx_auxdata_lookup, NULL);
> +}
> +
> +static char const *s3c6400_dt_compat[] __initdata = {
> +	"samsung,s3c6400",
> +	NULL
> +};
> +
> +DT_MACHINE_START(S3C6400_DT, "Samsung S3C6400 (Flattened Device
> Tree)")
> +	/* Maintainer: Tomasz Figa <[email-masked]> */
> +	.init_irq	= s3c6400_init_irq,
> +	.map_io		= s3c64xx_dt_map_io,
> +	.handle_irq	= vic_handle_irq,
> +	.init_machine	= s3c64xx_dt_machine_init,
> +	.init_late	= s3c64xx_init_late,
> +	.timer		= &s3c24xx_timer,
> +	.dt_compat	= s3c6400_dt_compat,
> +	.restart        = s3c64xx_restart,
> +MACHINE_END
> +
> +static char const *s3c6410_dt_compat[] __initdata = {
> +	"samsung,s3c6410",
> +	NULL
> +};

I think, we don't need separation.

+static char const *s3c64xx_dt_compat[] __initdata = {
+	"samsung,s3c6400",
+	"samsung,s3c6410",
+	NULL
+};

> +
> +DT_MACHINE_START(S3C6410_DT, "Samsung S3C6410 (Flattened Device
> Tree)")
> +	/* Maintainer: Tomasz Figa <[email-masked]> */
> +	.init_irq	= s3c6410_init_irq,
> +	.map_io		= s3c64xx_dt_map_io,
> +	.handle_irq	= vic_handle_irq,
> +	.init_machine	= s3c64xx_dt_machine_init,
> +	.init_late	= s3c64xx_init_late,
> +	.timer		= &s3c24xx_timer,
> +	.dt_compat	= s3c6410_dt_compat,

+	.dt_compat	= s3c64xx_dt_compat,

> +	.restart        = s3c64xx_restart,
> +MACHINE_END
> --
> 1.8.1