[PATCH 4/4] ARM: at91: introduce SAMA5 support

[Joachim Eastwood]

On 8 March 2013 19:56, Jean-Christophe PLAGNIOL-VILLARD
<plagnioj at jcrosoft.com> wrote:
> On 18:18 Fri 08 Mar     , Joachim Eastwood wrote:
>> On 8 March 2013 17:52, Ludovic Desroches <ludovic.desroches at atmel.com> wrote:

<snip>

>> >>
>> >> > diff --git a/arch/arm/mach-at91/board-dt-sama5.c b/arch/arm/mach-at91/board-dt-sama5.c
>> >> > new file mode 100644
>> >> > index 0000000..705305e
>> >> > --- /dev/null
>> >> > +++ b/arch/arm/mach-at91/board-dt-sama5.c
>> >> > @@ -0,0 +1,86 @@
>> >> > +/*
>> >> > + *  Setup code for SAMA5 Evaluation Kits with Device Tree support
>> >> > + *
>> >> > + *  Copyright (C) 2013 Atmel,
>> >> > + *                2013 Ludovic Desroches <ludovic.desroches at atmel.com>
>> >> > + *
>> >> > + * Licensed under GPLv2 or later.
>> >> > + */
>> >> > +
>> >> > +#include <linux/types.h>
>> >> > +#include <linux/init.h>
>> >> > +#include <linux/module.h>
>> >> > +#include <linux/gpio.h>
>> >> > +#include <linux/micrel_phy.h>
>> >> > +#include <linux/of.h>
>> >> > +#include <linux/of_irq.h>
>> >> > +#include <linux/of_platform.h>
>> >> > +#include <linux/phy.h>
>> >> > +
>> >> > +#include <asm/setup.h>
>> >> > +#include <asm/irq.h>
>> >> > +#include <asm/mach/arch.h>
>> >> > +#include <asm/mach/map.h>
>> >> > +#include <asm/mach/irq.h>
>> >> > +
>> >> > +#include "at91_aic.h"
>> >> > +#include "generic.h"
>> >> > +
>> >> > +
>> >> > +static const struct of_device_id irq_of_match[] __initconst = {
>> >> > +
>> >> > +       { .compatible = "atmel,sama5d3-aic", .data = at91_aic5_of_init },
>> >> > +       { /*sentinel*/ }
>> >> > +};
>> >> > +
>> >> > +static void __init at91_dt_init_irq(void)
>> >> > +{
>> >> > +       of_irq_init(irq_of_match);
>> >> > +}
>> >> > +
>> >> > +static int ksz9021rn_phy_fixup(struct phy_device *phy)
>> >> > +{
>> >> > +       int value;
>> >> > +
>> >> > +#define GMII_RCCPSR    260
>> >> > +#define GMII_RRDPSR    261
>> >> > +#define GMII_ERCR      11
>> >> > +#define GMII_ERDWR     12
>> >> > +
>> >> > +       /* Set delay values */
>> >> > +       value = GMII_RCCPSR | 0x8000;
>> >> > +       phy_write(phy, GMII_ERCR, value);
>> >> > +       value = 0xF2F4;
>> >> > +       phy_write(phy, GMII_ERDWR, value);
>> >> > +       value = GMII_RRDPSR | 0x8000;
>> >> > +       phy_write(phy, GMII_ERCR, value);
>> >> > +       value = 0x2222;
>> >> > +       phy_write(phy, GMII_ERDWR, value);
>> >> > +
>> >> > +       return 0;
>> >> > +}
>> >> > +
>> >> > +static void __init sama5_dt_device_init(void)
>> >> > +{
>> >> > +       if (of_machine_is_compatible("atmel,sama5d3xcm"))
>> >> > +               phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
>> >> > +                       ksz9021rn_phy_fixup);
>> >> > +
>> >> > +       of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
>> >> > +}
>> >> > +
>> >> > +static const char *sama5_dt_board_compat[] __initdata = {
>> >> > +       "atmel,sama5",
>> >> > +       NULL
>> >> > +};
>> >> > +
>> >> > +DT_MACHINE_START(sama5_dt, "Atmel SAMA5 (Device Tree)")
>> >> > +       /* Maintainer: Atmel */
>> >> > +       .init_time      = at91sam926x_pit_init,
>> >> > +       .map_io         = at91_map_io,
>> >> > +       .handle_irq     = at91_aic5_handle_irq,
>> >> > +       .init_early     = at91_dt_initialize,
>> >> > +       .init_irq       = at91_dt_init_irq,
>> >> > +       .init_machine   = sama5_dt_device_init,
>> >> > +       .dt_compat      = sama5_dt_board_compat,
>> >> > +MACHINE_END
>> >>
>> >> Do we really need board-dt-sama5.c?
>> >> Now that we have both irqchip_init and clocksource_of_init it
>> >> shouldn't be necessary with more than one board-dt.c.
>> >>
>> >
>> > At the beginning, I had the same point of view but we have a new
>> > architecture, we can't build a single kernel image for both AT91SAM9 and
>> > SAMA5. So why not splitting it?
>>
>> It does add more lines to mach-at91 and I don't see a reason to have
>> two near identical board-dt files. board-dt could be used for SAMA5
>> even without irqchip_init and clocksource_of_init so what's the point
>> in splitting it?
>>
>> When the at91 clocksource and irqchip driver are converted/moved we
>> could support all AT91 SoC from RM9200 to SAMA5 in one board-dt. I
>> don't see the reason for 3 board-dt files or even 2.
>>
>> That we can't build a kernel that supports both ARMv4-5 and ARMv7
>> doesn't make a difference.
> my answer is no I do not want to if compatible_is on the c code so no
> different files

But you have this already on the above code:
>> >> > +       if (of_machine_is_compatible("atmel,sama5d3xcm"))

I don't see the point to have different board-dt files.
If a board turns out to need lots of specific C code to work I think
it's fine to have it in its own board file. But right now you are just
duplicating code unnecessary.

regards
Joachim Eastwood