On Thu, 13 Jun 2024 at 00:53, Liming Sun <limings@xxxxxxxxxx> wrote:
>
> The eMMC RST_N register is implemented as secure register on
> BlueField SoC and controlled by ATF. This commit sends SMC call
> to ATF for the eMMC HW reset.
Just to make sure I get this correctly. Asserting the eMMC reset line
is managed through a secure register? Or is this about resetting the
eMMC controller?
No matter what, it looks to me that it should be implemented as a
reset provider.
Kind regards
Uffe
>
> Reviewed-by: David Thompson <davthompson@xxxxxxxxxx>
> Signed-off-by: Liming Sun <limings@xxxxxxxxxx>
> ---
> drivers/mmc/host/dw_mmc-bluefield.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-bluefield.c b/drivers/mmc/host/dw_mmc-bluefield.c
> index 4747e5698f48..24e0b604b405 100644
> --- a/drivers/mmc/host/dw_mmc-bluefield.c
> +++ b/drivers/mmc/host/dw_mmc-bluefield.c
> @@ -3,6 +3,7 @@
> * Copyright (C) 2018 Mellanox Technologies.
> */
>
> +#include <linux/arm-smccc.h>
> #include <linux/bitfield.h>
> #include <linux/bitops.h>
> #include <linux/mmc/host.h>
> @@ -20,6 +21,9 @@
> #define BLUEFIELD_UHS_REG_EXT_SAMPLE 2
> #define BLUEFIELD_UHS_REG_EXT_DRIVE 4
>
> +/* SMC call for RST_N */
> +#define BLUEFIELD_SMC_SET_EMMC_RST_N 0x82000007
> +
> static void dw_mci_bluefield_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> {
> u32 reg;
> @@ -34,8 +38,20 @@ static void dw_mci_bluefield_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> mci_writel(host, UHS_REG_EXT, reg);
> }
>
> +static void dw_mci_bluefield_hw_reset(struct dw_mci *host)
> +{
> + struct arm_smccc_res res = { 0 };
> +
> + arm_smccc_smc(BLUEFIELD_SMC_SET_EMMC_RST_N, 0, 0, 0, 0, 0, 0, 0,
> + &res);
> +
> + if (res.a0)
> + pr_err("RST_N failed.\n");
> +}
> +
> static const struct dw_mci_drv_data bluefield_drv_data = {
> - .set_ios = dw_mci_bluefield_set_ios
> + .set_ios = dw_mci_bluefield_set_ios,
> + .hw_reset = dw_mci_bluefield_hw_reset
> };
>
> static const struct of_device_id dw_mci_bluefield_match[] = {
> --
> 2.30.1
>
