[PATCH 4/4] arm: mvebu: clearfog: Detect MMC vs SDHC and fixup fdt

[Pali Rohár]

On Sunday 05 March 2023 21:31:00 Martin Rowe wrote:
> [upstream of vendor commit 19a96f7c40a8fc1d0a6546ac2418d966e5840a99]
> 
> The Clearfog devices have only one SDHC device. This is either eMMC if
> it is populated on the SOM or SDHC if not. The Linux device tree assumes
> the SDHC case. Detect if the device is an eMMC and fixup the device-tree
> so it will be detected by Linux.
> 
> Ported from vendor repo at https://github.com/SolidRun/u-boot
> 
> Signed-off-by: Martin Rowe <martin.p.rowe at gmail.com>
> ---
>  board/solidrun/clearfog/clearfog.c | 42 ++++++++++++++++++++++++++++++
>  configs/clearfog_defconfig         |  1 +
>  configs/clearfog_sata_defconfig    |  1 +
>  configs/clearfog_spi_defconfig     |  1 +
>  4 files changed, 45 insertions(+)
> 
> diff --git a/board/solidrun/clearfog/clearfog.c b/board/solidrun/clearfog/clearfog.c
> index 03adb591d8..cafead3a1a 100644
> --- a/board/solidrun/clearfog/clearfog.c
> +++ b/board/solidrun/clearfog/clearfog.c
> @@ -10,6 +10,7 @@
>  #include <miiphy.h>
>  #include <net.h>
>  #include <netdev.h>
> +#include <mmc.h>
>  #include <asm/global_data.h>
>  #include <asm/io.h>
>  #include <asm/arch/cpu.h>
> @@ -261,3 +262,44 @@ int board_late_init(void)
>  
>  	return 0;
>  }
> +
> +static bool has_emmc(void)
> +{
> +	struct mmc *mmc;
> +	mmc = find_mmc_device(0);
> +	if (!mmc)
> +		return 0;
> +	return (!mmc_init(mmc) && IS_MMC(mmc)) ? true : false;
> +}
> +
> +/*
> + * The Clearfog devices have only one SDHC device. This is either eMMC
> + * if it is populated on the SOM or SDHC if not. The Linux device tree
> + * assumes the SDHC case. Detect if the device is an eMMC and fixup the
> + * device-tree so it will be detected by Linux.
> + */
> +int ft_board_setup(void *blob, struct bd_info *bd)
> +{
> +	__maybe_unused int offset, rc;
> +
> +	if (has_emmc()) {
> +		puts("Patching FDT so that eMMC is detected by kernel\n");
> +		offset = fdt_path_offset(blob, "/soc/internal-regs/sdhci at d8000");

Do not use fixed DT paths when parsing Linux kernel DT files. Linux
developers often changes DT node names in their DTS files which cause
changing of DT paths and hence this code in bootloader stops working.

I would suggest to find node offset by compatible string
("marvell,armada-380-sdhci"). Look for inspiration what I done in past:
https://source.denx.de/u-boot/u-boot/-/commit/7cd67018dd7f754c66cf08a76397bbee254b32aa

> +		if (offset >= 0) {
> +			rc = fdt_delprop(blob, offset, "cd-gpios");
> +			if (rc == -FDT_ERR_NOTFOUND)
> +				return 0; /* Assume that the device tree is already customized for eMMC */

I would suggest to always add "non-removable" property when it does not
exist.

> +			if (rc) {
> +				printf("Unable to remove cd-gpios for eMMC, err=%s\n", fdt_strerror(rc));
> +				return rc;

Normally it is not a good idea to return non-zero value from
ft_board_setup() function because it "crashes" u-boot and stops booting
kernel.

> +			}
> +			rc = fdt_setprop_empty(blob, offset, "non-removable");
> +			if (rc) {
> +				printf("Unable to add non-removable for eMMC, err=%s\n", fdt_strerror(rc));
> +				return rc;
> +			}
> +		}
> +	}
> +
> +	return 0;
> +}
> diff --git a/configs/clearfog_defconfig b/configs/clearfog_defconfig
> index f9cfa94e77..45b093c6d8 100644
> --- a/configs/clearfog_defconfig
> +++ b/configs/clearfog_defconfig
> @@ -21,6 +21,7 @@ CONFIG_SYS_LOAD_ADDR=0x800000
>  CONFIG_DEBUG_UART=y
>  CONFIG_AHCI=y
>  CONFIG_DISTRO_DEFAULTS=y
> +CONFIG_OF_BOARD_SETUP=y

Hint: To avoid having CONFIG_OF_BOARD_SETUP=y in every defconfig file,
you can add "select OF_BOARD_SETUP" into "config TARGET_CLEARFOG"
section in arch/arm/mach-mvebu/Kconfig file.

>  CONFIG_BOOTDELAY=3
>  CONFIG_USE_PREBOOT=y
>  CONFIG_SYS_CONSOLE_INFO_QUIET=y
> diff --git a/configs/clearfog_sata_defconfig b/configs/clearfog_sata_defconfig
> index b11d8746b0..081ebd7e7a 100644
> --- a/configs/clearfog_sata_defconfig
> +++ b/configs/clearfog_sata_defconfig
> @@ -23,6 +23,7 @@ CONFIG_SYS_LOAD_ADDR=0x800000
>  CONFIG_DEBUG_UART=y
>  CONFIG_AHCI=y
>  CONFIG_DISTRO_DEFAULTS=y
> +CONFIG_OF_BOARD_SETUP=y
>  CONFIG_BOOTDELAY=3
>  CONFIG_USE_PREBOOT=y
>  CONFIG_SYS_CONSOLE_INFO_QUIET=y
> diff --git a/configs/clearfog_spi_defconfig b/configs/clearfog_spi_defconfig
> index d6695f31e6..6b9e817f68 100644
> --- a/configs/clearfog_spi_defconfig
> +++ b/configs/clearfog_spi_defconfig
> @@ -24,6 +24,7 @@ CONFIG_SYS_LOAD_ADDR=0x800000
>  CONFIG_DEBUG_UART=y
>  CONFIG_AHCI=y
>  CONFIG_DISTRO_DEFAULTS=y
> +CONFIG_OF_BOARD_SETUP=y
>  CONFIG_BOOTDELAY=3
>  CONFIG_USE_PREBOOT=y
>  CONFIG_SYS_CONSOLE_INFO_QUIET=y
> -- 
> 2.39.2
>