Re: [PATCH 22/24] ARM: at91: sama7: introduce sama7 SoC family

[Nicolas Ferre]

On 01/04/2021 at 12:24, Claudiu Beznea - M18063 wrote:
> On 01.04.2021 12:38, Claudiu Beznea - M18063 wrote:
> > On 31.03.2021 19:01, Alexandre Belloni wrote:
> > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > >
> > > On 31/03/2021 13:59:06+0300, Claudiu Beznea wrote:
> > > > From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> > > >
> > > > Introduce new family of SoCs, sama7, and first SoC, sama7g5.
> > > >
> > > > Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> > > > Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
> > > > ---
> > > >   arch/arm/mach-at91/Makefile |  1 +
> > > >   arch/arm/mach-at91/sama7.c  | 48 +++++++++++++++++++++++++++++++++++++
> > > >   2 files changed, 49 insertions(+)
> > > >   create mode 100644 arch/arm/mach-at91/sama7.c
> > > >
> > > > diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
> > > > index f565490f1b70..6cc6624cddac 100644
> > > > --- a/arch/arm/mach-at91/Makefile
> > > > +++ b/arch/arm/mach-at91/Makefile
> > > > @@ -9,6 +9,7 @@ obj-$(CONFIG_SOC_AT91SAM9)    += at91sam9.o
> > > >   obj-$(CONFIG_SOC_SAM9X60)    += sam9x60.o
> > > >   obj-$(CONFIG_SOC_SAMA5)              += sama5.o
> > > >   obj-$(CONFIG_SOC_SAMV7)              += samv7.o
> > > > +obj-$(CONFIG_SOC_SAMA7)              += sama7.o
> > > >
> > > >   # Power Management
> > > >   obj-$(CONFIG_ATMEL_PM)               += pm.o pm_suspend.o
> > > > diff --git a/arch/arm/mach-at91/sama7.c b/arch/arm/mach-at91/sama7.c
> > > > new file mode 100644
> > > > index 000000000000..e04cadb569ad
> > > > --- /dev/null
> > > > +++ b/arch/arm/mach-at91/sama7.c
> > > > @@ -0,0 +1,48 @@
> > > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > > +/*
> > > > + * Setup code for SAMA7
> > > > + *
> > > > + * Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries
> > > > + *
> > > > + */
> > > > +
> > > > +#include <linux/of.h>
> > > > +#include <linux/of_platform.h>
> > > > +
> > > > +#include <asm/mach/arch.h>
> > > > +#include <asm/system_misc.h>
> > > > +
> > > > +#include "generic.h"
> > > > +
> > > > +static void __init sama7_common_init(void)
> > > > +{
> > > > +     of_platform_default_populate(NULL, NULL, NULL);
> > >
> > > Is this necessary? This is left as a workaround for the old SoCs using
> > > pinctrl-at91. I guess this will be using pio4 so this has to be removed.
> >
> > OK, I'll have a look. BTW, SAMA5D2 which is also using PIO4 calls
> > of_platform_default_populate(NULL, NULL, NULL);
>
> Without this call the PM code (arch/arm/mach-at/pm.c) is not able to locate
> proper DT nodes:
>
> [    0.194615] at91_pm_backup_init: failed to find securam device!
> [    0.201393] at91_pm_sram_init: failed to find sram device!
> [    0.207449] AT91: PM not supported, due to no SRAM allocated

Okay, so we can't afford removing these calls to sama5d2 and upcoming 
sama7g5 right now.

Is it a common pattern to have to reach DT content in the early stages 
that explicit call to of_platform_default_populate() tries to solve?

Best regards,
  Nicolas


> > > > +}
> > > > +
> > > > +static void __init sama7_dt_device_init(void)
> > > > +{
> > > > +     sama7_common_init();
> > > > +}
> > > > +
> > > > +static const char *const sama7_dt_board_compat[] __initconst = {
> > > > +     "microchip,sama7",
> > > > +     NULL
> > > > +};
> > > > +
> > > > +DT_MACHINE_START(sama7_dt, "Microchip SAMA7")
> > > > +     /* Maintainer: Microchip */
> > > > +     .init_machine   = sama7_dt_device_init,
> > > > +     .dt_compat      = sama7_dt_board_compat,
> > > > +MACHINE_END
> > > > +
> > > > +static const char *const sama7g5_dt_board_compat[] __initconst = {
> > > > +     "microchip,sama7g5",
> > > > +     NULL
> > > > +};
> > > > +
> > > > +DT_MACHINE_START(sama7g5_dt, "Microchip SAMA7G5")
> > > > +     /* Maintainer: Microchip */
> > > > +     .init_machine   = sama7_dt_device_init,
> > > > +     .dt_compat      = sama7g5_dt_board_compat,
> > > > +MACHINE_END
> > > > +
> > > > --
> > > > 2.25.1
> > >
> > > --
> > > Alexandre Belloni, co-owner and COO, Bootlin
> > > Embedded Linux and Kernel engineering
> > > https://bootlin.com


--
Nicolas Ferre