From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Fri, 1 Jul 2011 18:19:43 +0200
Subject: [PATCH v2] ARM: CSR: Adding CSR SiRFprimaII board support
In-Reply-To: <BANLkTikoMu3ccUxj5KRmKzdReQcBqK4Y9Q@mail.gmail.com>
References: <1309231954-23260-1-git-send-email-bs14@csr.com>
	<201106301236.25822.arnd@arndb.de>
	<BANLkTikoMu3ccUxj5KRmKzdReQcBqK4Y9Q@mail.gmail.com>
Message-ID: <201107011819.43316.arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Friday 01 July 2011, Barry Song wrote:
> It looks like we can new a common function named as of_io_earlymap()
> or something in drivers/of/address.c. of_iomap() does ioremap,
> of_io_earlymap() does early static mapping?
> Then all SoCs can call this function to do early static mapping. if
> so, some lines can be deleted in sirfsoc_of_clk_init(). How do you
> think about newing the function in drivers/of/address.c?

I think that's a good idea, but the ARM specific implementation cannot
be in common code. Other architectures have stuff similar to iotable_init
in asm/fixmap.h. If we decide on a function prototype for this, the
implementation can be arch/*/.

How about this:

extern void of_set_fixmap(struct device_node *np, int index,
	unsigned long of_fixmap_offset, pgprot_t flags); 

> For DEBUG_LL uart, i have moved the static mapping to a new file named
> lluart.c too:
> +#include <linux/kernel.h>
> +#include <asm/page.h>
> +#include <asm/mach/map.h>
> +#include <mach/map.h>
> +#include <mach/uart.h>
> +
> +void __init sirfsoc_map_lluart(void)
> +{
> +       struct map_desc sirfsoc_lluart_map = {
> +               .virtual        = SIRFSOC_UART1_VA_BASE,
> +               .pfn            = __phys_to_pfn(SIRFSOC_UART1_PA_BASE),
> +               .length         = SIRFSOC_UART1_SIZE,
> +               .type           = MT_DEVICE,
> +       };
> +
> +       iotable_init(&sirfsoc_lluart_map, 1);
> +}
> +
> 
> only when DEBUG_LL is selected, this file will be compiled. Otherwise,
> an empty sirfsoc_map_lluart is used:

Ok, sounds good.

> +/* TODO:
> + * add APIs to control reset of every module
> + */

Hmm, how about this: You enumerate every bit in the reset registers, and
then add a device tree property to the devices where this is needed containing
the number. Then you just need a simple interface like

void sirfsoc_reset_device(struct device *dev)
{
	int len, i;
	unsigned int *reset_bits = of_get_property(dev->of_node, "reset-bit", &len);

	for (i = 0; i<len/4; i++)
		sirfsoc_reset_line(reset_bits[i]);
}


> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <asm/mach-types.h>
> +#include <asm/mach/arch.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include "common.h"
> +
> +static struct of_device_id sirfsoc_of_bus_ids[] __initdata = {
> +       { .compatible = "simple-bus", },
> +       {},
> +};
> +
> +void __init sirfsoc_mach_init(void)
> +{
> +       of_platform_bus_probe(NULL, sirfsoc_of_bus_ids, NULL);
> +}
> +
> +static const char *prima2cb_dt_match[] __initdata = {
> +       "sirf,prima2-cb",
> +       NULL
> +};
> +
> +MACHINE_START(PRIMA2_EVB, "prima2cb")
> +       .boot_params    = 0x00000100,
> +       .init_early     = sirfsoc_of_clk_init,
> +       .map_io         = sirfsoc_map_lluart,
> +       .init_irq       = sirfsoc_of_irq_init,
> +       .timer          = &sirfsoc_timer,
> +       .init_machine   = sirfsoc_mach_init,
> +       .dt_compat      = prima2cb_dt_match,
> +MACHINE_END

Very nice!

	Arnd