[PATCH v10 07/15] FWU: STM32MP1: Add support to read boot index from backup register

[Etienne Carriere]

On Thu, 15 Sept 2022 at 10:15, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>
> The FWU Multi Bank Update feature allows the platform to boot the
> firmware images from one of the partitions(banks). The first stage
> bootloader(fsbl) passes the value of the boot index, i.e. the bank
> from which the firmware images were booted from to U-Boot. On the
> STM32MP157C-DK2 board, this value is passed through one of the SoC's
> backup register. Add a function to read the boot index value from the
> backup register.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
> Changes since V9:
> * Change the fwu_plat_get_bootidx() function to take an uint * as the
>   function parameter instead of the void * as suggested by Etienne.
>
>  arch/arm/mach-stm32mp/include/mach/stm32.h |  5 +++++
>  board/st/stm32mp1/stm32mp1.c               | 23 ++++++++++++++++++++++
>  include/fwu.h                              | 12 +++++++++++
>  3 files changed, 40 insertions(+)
>
> diff --git a/arch/arm/mach-stm32mp/include/mach/stm32.h b/arch/arm/mach-stm32mp/include/mach/stm32.h
> index c70375a723..c85ae6a34e 100644
> --- a/arch/arm/mach-stm32mp/include/mach/stm32.h
> +++ b/arch/arm/mach-stm32mp/include/mach/stm32.h
> @@ -112,11 +112,16 @@ enum boot_device {
>  #ifdef CONFIG_STM32MP15x
>  #define TAMP_BACKUP_MAGIC_NUMBER       TAMP_BACKUP_REGISTER(4)
>  #define TAMP_BACKUP_BRANCH_ADDRESS     TAMP_BACKUP_REGISTER(5)
> +#define TAMP_FWU_BOOT_INFO_REG         TAMP_BACKUP_REGISTER(10)
>  #define TAMP_COPRO_RSC_TBL_ADDRESS     TAMP_BACKUP_REGISTER(17)
>  #define TAMP_COPRO_STATE               TAMP_BACKUP_REGISTER(18)
>  #define TAMP_BOOT_CONTEXT              TAMP_BACKUP_REGISTER(20)
>  #define TAMP_BOOTCOUNT                 TAMP_BACKUP_REGISTER(21)
>
> +#define TAMP_FWU_BOOT_IDX_MASK         GENMASK(3, 0)
> +
> +#define TAMP_FWU_BOOT_IDX_OFFSET       0
> +
>  #define TAMP_COPRO_STATE_OFF           0
>  #define TAMP_COPRO_STATE_INIT          1
>  #define TAMP_COPRO_STATE_CRUN          2
> diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
> index 6562bcf95b..54b9535405 100644
> --- a/board/st/stm32mp1/stm32mp1.c
> +++ b/board/st/stm32mp1/stm32mp1.c
> @@ -960,3 +960,26 @@ static void board_copro_image_process(ulong fw_image, size_t fw_size)
>  }
>
>  U_BOOT_FIT_LOADABLE_HANDLER(IH_TYPE_COPRO, board_copro_image_process);
> +
> +#if defined(CONFIG_FWU_MULTI_BANK_UPDATE)
> +
> +#include <fwu.h>
> +
> +/**
> + * fwu_plat_get_bootidx() - Get the value of the boot index
> + * @boot_idx: Boot index value
> + *
> + * Get the value of the bank(partition) from which the platform
> + * has booted. This value is passed to U-Boot from the earlier
> + * stage bootloader which loads and boots all the relevant
> + * firmware images
> + *
> + */
> +void fwu_plat_get_bootidx(uint *boot_idx)
> +{
> +       u32 *bootidx = boot_idx;
> +
> +       *bootidx = (readl(TAMP_FWU_BOOT_INFO_REG) >>
> +                   TAMP_FWU_BOOT_IDX_OFFSET) & TAMP_FWU_BOOT_IDX_MASK;
> +}

I may be nitpicking but despite this is fine in this source file build
only for 32bit, I think the cast is not that clean.
Would prefer:

void fwu_plat_get_bootidx(uint *boot_idx)
{
        *boot_idx = (readl(TAMP_FWU_BOOT_INFO_REG) >>
                     TAMP_FWU_BOOT_IDX_OFFSET) & TAMP_FWU_BOOT_IDX_MASK;
}

br,
etienne

> +#endif /* CONFIG_FWU_MULTI_BANK_UPDATE */
> diff --git a/include/fwu.h b/include/fwu.h
> index 3ff37c628b..484289ed4f 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -244,4 +244,16 @@ int fwu_plat_get_alt_num(struct udevice *dev, efi_guid_t *image_guid,
>   *
>   */
>  int fwu_plat_get_update_index(uint *update_idx);
> +
> +/**
> + * fwu_plat_get_bootidx() - Get the value of the boot index
> + * @boot_idx: Boot index value
> + *
> + * Get the value of the bank(partition) from which the platform
> + * has booted. This value is passed to U-Boot from the earlier
> + * stage bootloader which loads and boots all the relevant
> + * firmware images
> + *
> + */
> +void fwu_plat_get_bootidx(uint *boot_idx);
>  #endif /* _FWU_H_ */
> --
> 2.34.1
>