[v3,2/2] mmc: sdhci-of-k1: add support for SpacemiT K1 SoC

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 | 304 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 319 insertions(+)

On 09/05/2025 16:22, Yixun Lan 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>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/Kconfig       |  14 ++
>  drivers/mmc/host/Makefile      |   1 +
>  drivers/mmc/host/sdhci-of-k1.c | 304 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 319 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..6880d3e9ab620dab5e5fea239cf1a78e1afe0d7c
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-of-k1.c
> @@ -0,0 +1,304 @@
> +// 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)
> +#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)
> +
> +struct spacemit_sdhci_host {
> +	struct clk *clk_core;
> +	struct clk *clk_io;
> +};
> +
> +/* All helper functions will update clr/set while preserve rest bits */
> +static inline void spacemit_sdhci_setbits(struct sdhci_host *host, u32 val, int reg)
> +{
> +	sdhci_writel(host, sdhci_readl(host, reg) | val, reg);
> +}
> +
> +static inline void spacemit_sdhci_clrbits(struct sdhci_host *host, u32 val, int reg)
> +{
> +	sdhci_writel(host, sdhci_readl(host, reg) & ~val, reg);
> +}
> +
> +static inline void spacemit_sdhci_clrsetbits(struct sdhci_host *host, u32 clr, u32 set, int reg)
> +{
> +	u32 val = sdhci_readl(host, reg);
> +
> +	val = (val & ~clr) | set;
> +	sdhci_writel(host, val, reg);
> +}
> +
> +static void spacemit_sdhci_reset(struct sdhci_host *host, u8 mask)
> +{
> +	sdhci_reset(host, mask);
> +
> +	if (mask != SDHCI_RESET_ALL)
> +		return;
> +
> +	spacemit_sdhci_setbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
> +
> +	spacemit_sdhci_clrsetbits(host, PHY_DRIVE_SEL,
> +				  RX_BIAS_CTRL | FIELD_PREP(PHY_DRIVE_SEL, 4),
> +				  SDHC_PHY_PADCFG_REG);
> +
> +	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC))
> +		spacemit_sdhci_setbits(host, MMC_CARD_MODE, SDHC_MMC_CTRL_REG);
> +}
> +
> +static void spacemit_sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
> +{
> +	if (timing == MMC_TIMING_MMC_HS200)
> +		spacemit_sdhci_setbits(host, MMC_HS200, SDHC_MMC_CTRL_REG);
> +
> +	if (timing == MMC_TIMING_MMC_HS400)
> +		spacemit_sdhci_setbits(host, MMC_HS400, SDHC_MMC_CTRL_REG);
> +
> +	sdhci_set_uhs_signaling(host, timing);
> +
> +	if (!(host->mmc->caps2 & MMC_CAP2_NO_SDIO))
> +		spacemit_sdhci_setbits(host, SDHCI_CTRL_VDD_180, SDHCI_HOST_CONTROL2);
> +}
> +
> +static void spacemit_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> +	struct mmc_host *mmc = host->mmc;
> +
> +	if (mmc->ios.timing <= MMC_TIMING_UHS_SDR50)
> +		spacemit_sdhci_setbits(host, TX_INT_CLK_SEL, SDHC_TX_CFG_REG);
> +	else
> +		spacemit_sdhci_clrbits(host, TX_INT_CLK_SEL, SDHC_TX_CFG_REG);
> +
> +	sdhci_set_clock(host, clock);
> +};
> +
> +static void spacemit_sdhci_phy_dll_init(struct sdhci_host *host)
> +{
> +	u32 state;
> +	int ret;
> +
> +	spacemit_sdhci_clrsetbits(host, DLL_PREDLY_NUM | DLL_FULLDLY_RANGE | DLL_VREG_CTRL,
> +				  FIELD_PREP(DLL_PREDLY_NUM, 1) |
> +				  FIELD_PREP(DLL_FULLDLY_RANGE, 1) |
> +				  FIELD_PREP(DLL_VREG_CTRL, 1),
> +				  SDHC_PHY_DLLCFG);
> +
> +	spacemit_sdhci_clrsetbits(host, DLL_REG1_CTRL,
> +				  FIELD_PREP(DLL_REG1_CTRL, 0x92),
> +				  SDHC_PHY_DLLCFG1);
> +
> +	spacemit_sdhci_setbits(host, DLL_ENABLE, SDHC_PHY_DLLCFG);
> +
> +	ret = readl_poll_timeout(host->ioaddr + SDHC_PHY_DLLSTS, state,
> +				 state & DLL_LOCK_STATE, 2, 100);
> +	if (ret == -ETIMEDOUT)
> +		dev_warn(mmc_dev(host->mmc), "fail to lock phy dll in 100us!\n");
> +}
> +
> +static void spacemit_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +
> +	if (!ios->enhanced_strobe) {
> +		spacemit_sdhci_clrbits(host, ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
> +		return;
> +	}
> +
> +	spacemit_sdhci_setbits(host, ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
> +	spacemit_sdhci_phy_dll_init(host);
> +}
> +
> +static unsigned int spacemit_sdhci_clk_get_max_clock(struct sdhci_host *host)
> +{
> +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +
> +	return clk_get_rate(pltfm_host->clk);
> +}
> +
> +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;
> +
> +	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;
> +}
> +
> +static void spacemit_sdhci_pre_hs400_to_hs200(struct mmc_host *mmc)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +
> +	spacemit_sdhci_clrbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
> +	spacemit_sdhci_clrbits(host, MMC_HS400 | MMC_HS200 | ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
> +	spacemit_sdhci_clrbits(host, HS200_USE_RFIFO, SDHC_PHY_FUNC_REG);
> +
> +	udelay(5);
> +
> +	spacemit_sdhci_setbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
> +}
> +
> +static inline int spacemit_sdhci_get_clocks(struct device *dev,
> +					    struct sdhci_pltfm_host *pltfm_host)
> +{
> +	struct spacemit_sdhci_host *sdhst = sdhci_pltfm_priv(pltfm_host);
> +
> +	sdhst->clk_core = devm_clk_get_enabled(dev, "core");
> +	if (IS_ERR(sdhst->clk_core))
> +		return -EINVAL;
> +
> +	sdhst->clk_io = devm_clk_get_enabled(dev, "io");
> +	if (IS_ERR(sdhst->clk_io))
> +		return -EINVAL;
> +
> +	pltfm_host->clk = sdhst->clk_io;
> +
> +	return 0;
> +}
> +
> +static const struct sdhci_ops spacemit_sdhci_ops = {
> +	.get_max_clock		= spacemit_sdhci_clk_get_max_clock,
> +	.reset			= spacemit_sdhci_reset,
> +	.set_bus_width		= sdhci_set_bus_width,
> +	.set_clock		= spacemit_sdhci_set_clock,
> +	.set_uhs_signaling	= spacemit_sdhci_set_uhs_signaling,
> +};
> +
> +static const struct sdhci_pltfm_data spacemit_sdhci_k1_pdata = {
> +	.ops = &spacemit_sdhci_ops,
> +	.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
> +		  SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
> +		  SDHCI_QUIRK_32BIT_ADMA_SIZE |
> +		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
> +		  SDHCI_QUIRK_BROKEN_CARD_DETECTION |
> +		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
> +	.quirks2 = SDHCI_QUIRK2_BROKEN_64_BIT_DMA |
> +		   SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> +};
> +
> +static const struct of_device_id spacemit_sdhci_of_match[] = {
> +	{ .compatible = "spacemit,k1-sdhci" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, spacemit_sdhci_of_match);
> +
> +static int spacemit_sdhci_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct spacemit_sdhci_host *sdhst;
> +	struct sdhci_pltfm_host *pltfm_host;
> +	struct sdhci_host *host;
> +	struct mmc_host_ops *mops;
> +	int ret;
> +
> +	host = sdhci_pltfm_init(pdev, &spacemit_sdhci_k1_pdata, sizeof(*sdhst));
> +	if (IS_ERR(host))
> +		return PTR_ERR(host);
> +
> +	pltfm_host = sdhci_priv(host);
> +
> +	ret = mmc_of_parse(host->mmc);
> +	if (ret)
> +		goto err_pltfm;
> +
> +	sdhci_get_of_property(pdev);
> +
> +	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC)) {
> +		mops = &host->mmc_host_ops;
> +		mops->hs400_prepare_ddr	= spacemit_sdhci_pre_select_hs400;
> +		mops->hs400_complete	= spacemit_sdhci_post_select_hs400;
> +		mops->hs400_downgrade	= spacemit_sdhci_pre_hs400_to_hs200;
> +		mops->hs400_enhanced_strobe = spacemit_sdhci_hs400_enhanced_strobe;
> +	}
> +
> +	host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
> +
> +	if (spacemit_sdhci_get_clocks(dev, pltfm_host))
> +		goto err_pltfm;
> +
> +	ret = sdhci_add_host(host);
> +	if (ret)
> +		goto err_pltfm;
> +
> +	return 0;
> +
> +err_pltfm:
> +	sdhci_pltfm_free(pdev);
> +	return ret;
> +}
> +
> +static struct platform_driver spacemit_sdhci_driver = {
> +	.driver		= {
> +		.name	= "sdhci-spacemit",
> +		.of_match_table = spacemit_sdhci_of_match,
> +	},
> +	.probe		= spacemit_sdhci_probe,
> +	.remove		= sdhci_pltfm_remove,
> +};
> +module_platform_driver(spacemit_sdhci_driver);
> +
> +MODULE_DESCRIPTION("SpacemiT SDHCI platform driver");
> +MODULE_LICENSE("GPL");
>

Hi Ulf,

On 09:04 Mon 12 May     , Adrian Hunter wrote:
> On 09/05/2025 16:22, Yixun Lan 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>
> 
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> 

If this isn't too late (as v6.15-rc6 is tagged), I'd like to seek
the opportunity to queue for v6.16 as no big changes during these
two review cycles..

I also know people who would expect to have a full rootfs support,
and this driver is sufficient to bring eMMC up and will make their
life of development easy..

But if you have different opinion, then I'm totally fine to delay
it to next merge window, thanks