[PATCH v6 02/17] riscv: sifive: fu540: Use OTP DM driver for serial environment variable

[Jagan Teki]

On Tue, Apr 7, 2020 at 1:40 PM Pragnesh Patel <pragnesh.patel at sifive.com> wrote:
>
> Hi Jagan,
>
> >-----Original Message-----
> >From: Jagan Teki <jagan at amarulasolutions.com>
> >Sent: 07 April 2020 13:32
> >To: Pragnesh Patel <pragnesh.patel at sifive.com>
> >Cc: U-Boot-Denx <u-boot at lists.denx.de>; Atish Patra
> ><atish.patra at wdc.com>; palmerdabbelt at google.com; Bin Meng
> ><bmeng.cn at gmail.com>; Paul Walmsley <paul.walmsley at sifive.com>; Troy
> >Benjegerdes <troy.benjegerdes at sifive.com>; Anup Patel
> ><anup.patel at wdc.com>; Sagar Kadam <sagar.kadam at sifive.com>; Rick Chen
> ><rick at andestech.com>; Palmer Dabbelt <palmer at dabbelt.com>
> >Subject: Re: [PATCH v6 02/17] riscv: sifive: fu540: Use OTP DM driver for serial
> >environment variable
> >
> >[External Email] Do not click links or attachments unless you recognize the
> >sender and know the content is safe
> >
> >On Thu, Apr 2, 2020 at 3:47 PM Pragnesh Patel <pragnesh.patel at sifive.com>
> >wrote:
> >>
> >> Hi Jagan,
> >>
> >> >-----Original Message-----
> >> >From: Jagan Teki <jagan at amarulasolutions.com>
> >> >Sent: 02 April 2020 14:59
> >> >To: Pragnesh Patel <pragnesh.patel at sifive.com>
> >> >Cc: U-Boot-Denx <u-boot at lists.denx.de>; Atish Patra
> >> ><atish.patra at wdc.com>; palmerdabbelt at google.com; Bin Meng
> >> ><bmeng.cn at gmail.com>; Paul Walmsley <paul.walmsley at sifive.com>;
> >Troy
> >> >Benjegerdes <troy.benjegerdes at sifive.com>; Anup Patel
> >> ><anup.patel at wdc.com>; Sagar Kadam <sagar.kadam at sifive.com>; Rick
> >Chen
> >> ><rick at andestech.com>; Palmer Dabbelt <palmer at dabbelt.com>
> >> >Subject: Re: [PATCH v6 02/17] riscv: sifive: fu540: Use OTP DM driver
> >> >for serial environment variable
> >> >
> >> >[External Email] Do not click links or attachments unless you
> >> >recognize the sender and know the content is safe
> >> >
> >> >On Thu, Apr 2, 2020 at 2:54 PM Pragnesh Patel
> >> ><pragnesh.patel at sifive.com>
> >> >wrote:
> >> >>
> >> >>
> >> >> Hi Jagan,
> >> >>
> >> >> >-----Original Message-----
> >> >> >From: Jagan Teki <jagan at amarulasolutions.com>
> >> >> >Sent: 02 April 2020 14:49
> >> >> >To: Pragnesh Patel <pragnesh.patel at sifive.com>
> >> >> >Cc: U-Boot-Denx <u-boot at lists.denx.de>; Atish Patra
> >> >> ><atish.patra at wdc.com>; palmerdabbelt at google.com; Bin Meng
> >> >> ><bmeng.cn at gmail.com>; Paul Walmsley <paul.walmsley at sifive.com>;
> >> >Troy
> >> >> >Benjegerdes <troy.benjegerdes at sifive.com>; Anup Patel
> >> >> ><anup.patel at wdc.com>; Sagar Kadam <sagar.kadam at sifive.com>; Rick
> >> >Chen
> >> >> ><rick at andestech.com>; Palmer Dabbelt <palmer at dabbelt.com>
> >> >> >Subject: Re: [PATCH v6 02/17] riscv: sifive: fu540: Use OTP DM
> >> >> >driver for serial environment variable
> >> >> >
> >> >> >[External Email] Do not click links or attachments unless you
> >> >> >recognize the sender and know the content is safe
> >> >> >
> >> >> >On Sun, Mar 29, 2020 at 10:36 PM Pragnesh Patel
> >> >> ><pragnesh.patel at sifive.com> wrote:
> >> >> >>
> >> >> >> Use the OTP DM driver to set the serial environment variable.
> >> >> >>
> >> >> >> Signed-off-by: Pragnesh Patel <pragnesh.patel at sifive.com>
> >> >> >> ---
> >> >> >>  arch/riscv/dts/fu540-c000-u-boot.dtsi         |  14 +++
> >> >> >>  .../dts/hifive-unleashed-a00-u-boot.dtsi      |   6 +
> >> >> >>  board/sifive/fu540/Kconfig                    |   2 +
> >> >> >>  board/sifive/fu540/fu540.c                    | 111 ++++++------------
> >> >> >>  4 files changed, 61 insertions(+), 72 deletions(-)  create mode
> >> >> >> 100644 arch/riscv/dts/fu540-c000-u-boot.dtsi
> >> >> >>  create mode 100644
> >> >> >> arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> >> >> >>
> >> >> >> diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >> >> >> b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >> >> >> new file mode 100644
> >> >> >> index 0000000000..db55773bd2
> >> >> >> --- /dev/null
> >> >> >> +++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >> >> >> @@ -0,0 +1,14 @@
> >> >> >> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> >> >> >> +/*
> >> >> >> + * (C) Copyright 2019 SiFive, Inc  */
> >> >> >> +
> >> >> >> +/ {
> >> >> >> +       soc {
> >> >> >> +               otp: otp at 10070000 {
> >> >> >> +                       compatible = "sifive,fu540-c000-otp";
> >> >> >> +                       reg = <0x0 0x10070000 0x0 0x0FFF>;
> >> >> >> +                       fuse-count = <0x1000>;
> >> >> >> +               };
> >> >> >> +       };
> >> >> >> +};
> >> >> >> diff --git a/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> >> >> >> b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> >> >> >> new file mode 100644
> >> >> >> index 0000000000..f1735c1385
> >> >> >> --- /dev/null
> >> >> >> +++ b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> >> >> >> @@ -0,0 +1,6 @@
> >> >> >> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> >> >> >> +/*
> >> >> >> + * Copyright (C) 2019 SiFive, Inc  */
> >> >> >> +
> >> >> >> +#include "fu540-c000-u-boot.dtsi"
> >> >> >> diff --git a/board/sifive/fu540/Kconfig
> >> >> >> b/board/sifive/fu540/Kconfig index 5ca21474de..900197bbb2 100644
> >> >> >> --- a/board/sifive/fu540/Kconfig
> >> >> >> +++ b/board/sifive/fu540/Kconfig
> >> >> >> @@ -48,5 +48,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
> >> >> >>         imply SIFIVE_GPIO
> >> >> >>         imply CMD_GPIO
> >> >> >>         imply SMP
> >> >> >> +       imply MISC
> >> >> >> +       imply SIFIVE_OTP
> >> >> >
> >> >> >Mark this default y if it is SIFIVE.
> >> >>
> >> >> All other SiFive drivers (SPI_SIFIVE, SIFIVE_GPIO) are enabled by
> >> >> "imply", so I
> >> >am following the same. I think "imply" will make it default y.
> >> >
> >> >Just mark 'default y' on SIFIVE_OTP area of drivers/misc/Kconfig
> >> >depends on SIFIVE SoC would select this driver so-that you no need to
> >> >add impy SIFIVE_OTP here.
> >>
> >> I am not sure if all SiFive SoC will contain SiFive OTP controller, so it's better
> >not to make it default y.
> >>
> >> If all Sifive SoCs contain OTP controller then I need to add another
> >> Kconfig option like "RISCV_SIFIVE" as shown below, config SIFIVE_OTP
> >>         default y if RISCV_SIFIVE
> >
> >Yes, use this TARGET_SIFIVE_FU540
>
> I am okay with this but if other future SiFive SoCs support this OTP then it would be a long chain.
> What's your opinion on this ?

That is fine, these are at least SoC not boards. boards will increment
a lot but SoC may not. Having SoC dependency or select would be
meaningful.

Jagan.