Re: [PATCH v2 2/2] mmc: sdhci-of-k1: add support for SpacemiT K1 SoC

Ulf Hansson
2025-05-19T11:34:50Z

On Thu, 1 May 2025 at 10:51, Yixun Lan <dlan@gentoo.org> wrote:
>
> The SDHCI controller found in SpacemiT K1 SoC features SD,
> SDIO, eMMC support, such as:
>
> - Compatible for 4-bit SDIO 3.0 UHS-I protocol, up to SDR104
> - Compatible for 4-bit SD 3.0 UHS-I protocol, up to SDR104
> - Compatible for 8bit eMMC5.1, up to HS400
>
> Signed-off-by: Yixun Lan <dlan@gentoo.org>
> ---
> drivers/mmc/host/Kconfig | 14 ++
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-of-k1.c | 306 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 321 insertions(+)
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 6824131b69b188cae58c8f48076715ca647ca28c..0ce78f22c33cfff916a2d4d680c79e9d19637e0e 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -250,6 +250,20 @@ config MMC_SDHCI_OF_DWCMSHC
> If you have a controller with this interface, say Y or M here.
> If unsure, say N.
>
> +config MMC_SDHCI_OF_K1
> + tristate "SDHCI OF support for the SpacemiT K1 SoC"
> + depends on ARCH_SPACEMIT || COMPILE_TEST
> + depends on MMC_SDHCI_PLTFM
> + depends on OF
> + depends on COMMON_CLK
> + help
> + This selects the Secure Digital Host Controller Interface (SDHCI)
> + found in the SpacemiT K1 SoC.
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_SDHCI_OF_SPARX5
> tristate "SDHCI OF support for the MCHP Sparx5 SoC"
> depends on MMC_SDHCI_PLTFM
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 5147467ec825ffaef3a7bd812fad80545e52b180..75bafc7b162b9e1d4c6c050f5d28b9d7cb582447 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -88,6 +88,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_AT91) += sdhci-of-at91.o
> obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
> obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
> obj-$(CONFIG_MMC_SDHCI_OF_DWCMSHC) += sdhci-of-dwcmshc.o
> +obj-$(CONFIG_MMC_SDHCI_OF_K1) += sdhci-of-k1.o
> obj-$(CONFIG_MMC_SDHCI_OF_SPARX5) += sdhci-of-sparx5.o
> obj-$(CONFIG_MMC_SDHCI_OF_MA35D1) += sdhci-of-ma35d1.o
> obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
> diff --git a/drivers/mmc/host/sdhci-of-k1.c b/drivers/mmc/host/sdhci-of-k1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..8988053eeb33a476fa484d145579db6214b2d0b7
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-of-k1.c
> @@ -0,0 +1,306 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2025 SpacemiT (Hangzhou) Technology Co. Ltd
> + * Copyright (c) 2025 Yixun Lan <dlan@gentoo.org>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/iopoll.h>
> +#include <linux/init.h>
> +#include <linux/mmc/card.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/mmc.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +
> +#include "sdhci.h"
> +#include "sdhci-pltfm.h"
> +
> +#define SDHC_MMC_CTRL_REG 0x114
> +#define MISC_INT_EN BIT(1)
> +#define MISC_INT BIT(2)

These define-names look a bit too generic to me. Please add some
additional prefixes so it becomes more clear what they are.

This applies to all the others below too.

> +#define ENHANCE_STROBE_EN BIT(8)
> +#define MMC_HS400 BIT(9)
> +#define MMC_HS200 BIT(10)
> +#define MMC_CARD_MODE BIT(12)
> +
> +#define SDHC_TX_CFG_REG 0x11C
> +#define TX_INT_CLK_SEL BIT(30)
> +#define TX_MUX_SEL BIT(31)
> +
> +#define SDHC_PHY_CTRL_REG 0x160
> +#define PHY_FUNC_EN BIT(0)
> +#define PHY_PLL_LOCK BIT(1)
> +#define HOST_LEGACY_MODE BIT(31)
> +
> +#define SDHC_PHY_FUNC_REG 0x164
> +#define PHY_TEST_EN BIT(7)
> +#define HS200_USE_RFIFO BIT(15)
> +
> +#define SDHC_PHY_DLLCFG 0x168
> +#define DLL_PREDLY_NUM GENMASK(3, 2)
> +#define DLL_FULLDLY_RANGE GENMASK(5, 4)
> +#define DLL_VREG_CTRL GENMASK(7, 6)
> +#define DLL_ENABLE BIT(31)
> +
> +#define SDHC_PHY_DLLCFG1 0x16C
> +#define DLL_REG1_CTRL GENMASK(7, 0)
> +#define DLL_REG2_CTRL GENMASK(15, 8)
> +#define DLL_REG3_CTRL GENMASK(23, 16)
> +#define DLL_REG4_CTRL GENMASK(31, 24)
> +
> +#define SDHC_PHY_DLLSTS 0x170
> +#define DLL_LOCK_STATE BIT(0)
> +
> +#define SDHC_PHY_PADCFG_REG 0x178
> +#define PHY_DRIVE_SEL GENMASK(2, 0)
> +#define RX_BIAS_CTRL BIT(5)

[...]

> +
> +static int spacemit_sdhci_pre_select_hs400(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> +
> + spacemit_sdhci_setbits(host, MMC_HS400, SDHC_MMC_CTRL_REG);
> + host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;

At least this deserves a comment. Isn't MMC_CAP_WAIT_WHILE_BUSY
working for all cases?

> +
> + return 0;
> +}
> +
> +static void spacemit_sdhci_post_select_hs400(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> +
> + spacemit_sdhci_phy_dll_init(host);
> + host->mmc->caps &= ~MMC_CAP_WAIT_WHILE_BUSY;

Dito.

[...]

Kind regards
Uffe