Re: [PATCH v5 2/2] mmc: sdhci-of-ma35d1: Add Nuvoton MA35D1 SDHCI driver

From: Adrian Hunter
Date: Tue Jul 16 2024 - 03:03:58 EST


On 16/07/24 03:45, Shan-Chun Hung wrote:
> Add the SDHCI driver for the MA35D1 platform. It is based upon the
> SDHCI interface, but requires some extra initialization.
>
> Signed-off-by: Shan-Chun Hung <shanchun1218@xxxxxxxxx>

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

> ---
> drivers/mmc/host/Kconfig | 12 ++
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-of-ma35d1.c | 314 +++++++++++++++++++++++++++++
> 3 files changed, 327 insertions(+)
> create mode 100644 drivers/mmc/host/sdhci-of-ma35d1.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index bb0d4fb0892a..aa6922ff4210 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -252,6 +252,18 @@ config MMC_SDHCI_OF_SPARX5
>
> If unsure, say N.
>
> +config MMC_SDHCI_OF_MA35D1
> + tristate "SDHCI OF support for the MA35D1 SDHCI controller"
> + depends on ARCH_MA35 || COMPILE_TEST
> + depends on MMC_SDHCI_PLTFM
> + help
> + This selects the MA35D1 Secure Digital Host Controller Interface.
> + The controller supports SD/MMC/SDIO devices.
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_SDHCI_CADENCE
> tristate "SDHCI support for the Cadence SD/SDIO/eMMC controller"
> depends on MMC_SDHCI_PLTFM
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index f53f86d200ac..3ccffebbe59b 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -88,6 +88,7 @@ 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_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
> obj-$(CONFIG_MMC_SDHCI_IPROC) += sdhci-iproc.o
> obj-$(CONFIG_MMC_SDHCI_NPCM) += sdhci-npcm.o
> diff --git a/drivers/mmc/host/sdhci-of-ma35d1.c b/drivers/mmc/host/sdhci-of-ma35d1.c
> new file mode 100644
> index 000000000000..b84c2927bd4a
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-of-ma35d1.c
> @@ -0,0 +1,314 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + *
> + * Author: Shan-Chun Hung <shanchun1218@xxxxxxxxx>
> + */
> +
> +#include <linux/align.h>
> +#include <linux/array_size.h>
> +#include <linux/bits.h>
> +#include <linux/build_bug.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dev_printk.h>
> +#include <linux/device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/math.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/minmax.h>
> +#include <linux/mmc/card.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include <linux/sizes.h>
> +#include <linux/types.h>
> +
> +#include "sdhci-pltfm.h"
> +#include "sdhci.h"
> +
> +#define MA35_SYS_MISCFCR0 0x070
> +#define MA35_SDHCI_MSHCCTL 0x508
> +#define MA35_SDHCI_MBIUCTL 0x510
> +
> +#define MA35_SDHCI_CMD_CONFLICT_CHK BIT(0)
> +#define MA35_SDHCI_INCR_MSK GENMASK(3, 0)
> +#define MA35_SDHCI_INCR16 BIT(3)
> +#define MA35_SDHCI_INCR8 BIT(2)
> +
> +struct ma35_priv {
> + struct reset_control *rst;
> + struct pinctrl *pinctrl;
> + struct pinctrl_state *pins_uhs;
> + struct pinctrl_state *pins_default;
> +};
> +
> +struct ma35_restore_data {
> + u32 reg;
> + u32 width;
> +};
> +
> +static const struct ma35_restore_data restore_data[] = {
> + { SDHCI_CLOCK_CONTROL, sizeof(u32)},
> + { SDHCI_BLOCK_SIZE, sizeof(u32)},
> + { SDHCI_INT_ENABLE, sizeof(u32)},
> + { SDHCI_SIGNAL_ENABLE, sizeof(u32)},
> + { SDHCI_AUTO_CMD_STATUS, sizeof(u32)},
> + { SDHCI_HOST_CONTROL, sizeof(u32)},
> + { SDHCI_TIMEOUT_CONTROL, sizeof(u8) },
> + { MA35_SDHCI_MSHCCTL, sizeof(u16)},
> + { MA35_SDHCI_MBIUCTL, sizeof(u16)},
> +};
> +
> +/*
> + * If DMA addr spans 128MB boundary, we split the DMA transfer into two
> + * so that each DMA transfer doesn't exceed the boundary.
> + */
> +static void ma35_adma_write_desc(struct sdhci_host *host, void **desc, dma_addr_t addr, int len,
> + unsigned int cmd)
> +{
> + int tmplen, offset;
> +
> + if (likely(!len || (ALIGN(addr, SZ_128M) == ALIGN(addr + len - 1, SZ_128M)))) {
> + sdhci_adma_write_desc(host, desc, addr, len, cmd);
> + return;
> + }
> +
> + offset = addr & (SZ_128M - 1);
> + tmplen = SZ_128M - offset;
> + sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
> +
> + addr += tmplen;
> + len -= tmplen;
> + sdhci_adma_write_desc(host, desc, addr, len, cmd);
> +}
> +
> +static void ma35_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + u32 ctl;
> +
> + /*
> + * If the clock frequency exceeds MMC_HIGH_52_MAX_DTR,
> + * disable command conflict check.
> + */
> + ctl = sdhci_readw(host, MA35_SDHCI_MSHCCTL);
> + if (clock > MMC_HIGH_52_MAX_DTR)
> + ctl &= ~MA35_SDHCI_CMD_CONFLICT_CHK;
> + else
> + ctl |= MA35_SDHCI_CMD_CONFLICT_CHK;
> + sdhci_writew(host, ctl, MA35_SDHCI_MSHCCTL);
> +
> + sdhci_set_clock(host, clock);
> +}
> +
> +static int ma35_start_signal_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
> +
> + switch (ios->signal_voltage) {
> + case MMC_SIGNAL_VOLTAGE_180:
> + if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_uhs))
> + pinctrl_select_state(priv->pinctrl, priv->pins_uhs);
> + break;
> + case MMC_SIGNAL_VOLTAGE_330:
> + if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_default))
> + pinctrl_select_state(priv->pinctrl, priv->pins_default);
> + break;
> + default:
> + dev_err(mmc_dev(host->mmc), "Unsupported signal voltage!\n");
> + return -EINVAL;
> + }
> +
> + return sdhci_start_signal_voltage_switch(mmc, ios);
> +}
> +
> +static void ma35_voltage_switch(struct sdhci_host *host)
> +{
> + /* Wait for 5ms after set 1.8V signal enable bit */
> + fsleep(5000);
> +}
> +
> +static int ma35_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
> + int idx;
> + u32 regs[ARRAY_SIZE(restore_data)] = {};
> +
> + /*
> + * Limitations require a reset of SD/eMMC before tuning and
> + * saving the registers before resetting, then restoring
> + * after the reset.
> + */
> + for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
> + if (restore_data[idx].width == sizeof(u32))
> + regs[idx] = sdhci_readl(host, restore_data[idx].reg);
> + else if (restore_data[idx].width == sizeof(u16))
> + regs[idx] = sdhci_readw(host, restore_data[idx].reg);
> + else if (restore_data[idx].width == sizeof(u8))
> + regs[idx] = sdhci_readb(host, restore_data[idx].reg);
> + }
> +
> + reset_control_assert(priv->rst);
> + reset_control_deassert(priv->rst);
> +
> + for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
> + if (restore_data[idx].width == sizeof(u32))
> + sdhci_writel(host, regs[idx], restore_data[idx].reg);
> + else if (restore_data[idx].width == sizeof(u16))
> + sdhci_writew(host, regs[idx], restore_data[idx].reg);
> + else if (restore_data[idx].width == sizeof(u8))
> + sdhci_writeb(host, regs[idx], restore_data[idx].reg);
> + }
> +
> + return sdhci_execute_tuning(mmc, opcode);
> +}
> +
> +static const struct sdhci_ops sdhci_ma35_ops = {
> + .set_clock = ma35_set_clock,
> + .set_bus_width = sdhci_set_bus_width,
> + .set_uhs_signaling = sdhci_set_uhs_signaling,
> + .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> + .reset = sdhci_reset,
> + .adma_write_desc = ma35_adma_write_desc,
> + .voltage_switch = ma35_voltage_switch,
> +};
> +
> +static const struct sdhci_pltfm_data sdhci_ma35_pdata = {
> + .ops = &sdhci_ma35_ops,
> + .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
> + .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN | SDHCI_QUIRK2_BROKEN_DDR50 |
> + SDHCI_QUIRK2_ACMD23_BROKEN,
> +};
> +
> +static int ma35_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct sdhci_pltfm_host *pltfm_host;
> + struct sdhci_host *host;
> + struct ma35_priv *priv;
> + int err;
> + u32 extra, ctl;
> +
> + host = sdhci_pltfm_init(pdev, &sdhci_ma35_pdata, sizeof(struct ma35_priv));
> + if (IS_ERR(host))
> + return PTR_ERR(host);
> +
> + /* Extra adma table cnt for cross 128M boundary handling. */
> + extra = DIV_ROUND_UP_ULL(dma_get_required_mask(dev), SZ_128M);
> + extra = min(extra, SDHCI_MAX_SEGS);
> +
> + host->adma_table_cnt += extra;
> + pltfm_host = sdhci_priv(host);
> + priv = sdhci_pltfm_priv(pltfm_host);
> +
> + pltfm_host->clk = devm_clk_get_optional_enabled(dev, NULL);
> + if (IS_ERR(pltfm_host->clk)) {
> + err = dev_err_probe(dev, PTR_ERR(pltfm_host->clk), "failed to get clk\n");
> + goto err_sdhci;
> + }
> +
> + err = mmc_of_parse(host->mmc);
> + if (err)
> + goto err_sdhci;
> +
> + priv->rst = devm_reset_control_get_exclusive(dev, NULL);
> + if (IS_ERR(priv->rst)) {
> + err = dev_err_probe(dev, PTR_ERR(priv->rst), "failed to get reset control\n");
> + goto err_sdhci;
> + }
> +
> + sdhci_get_of_property(pdev);
> +
> + priv->pinctrl = devm_pinctrl_get(dev);
> + if (!IS_ERR(priv->pinctrl)) {
> + priv->pins_default = pinctrl_lookup_state(priv->pinctrl, "default");
> + priv->pins_uhs = pinctrl_lookup_state(priv->pinctrl, "state_uhs");
> + pinctrl_select_state(priv->pinctrl, priv->pins_default);
> + }
> +
> + if (!(host->quirks2 & SDHCI_QUIRK2_NO_1_8_V)) {
> + struct regmap *regmap;
> + u32 reg;
> +
> + regmap = syscon_regmap_lookup_by_phandle(dev_of_node(dev), "nuvoton,sys");
> + if (!IS_ERR(regmap)) {
> + /* Enable SDHCI voltage stable for 1.8V */
> + regmap_read(regmap, MA35_SYS_MISCFCR0, &reg);
> + reg |= BIT(17);
> + regmap_write(regmap, MA35_SYS_MISCFCR0, reg);
> + }
> +
> + host->mmc_host_ops.start_signal_voltage_switch =
> + ma35_start_signal_voltage_switch;
> + }
> +
> + host->mmc_host_ops.execute_tuning = ma35_execute_tuning;
> +
> + err = sdhci_add_host(host);
> + if (err)
> + goto err_sdhci;
> +
> + /*
> + * Split data into chunks of 16 or 8 bytes for transmission.
> + * Each chunk transfer is guaranteed to be uninterrupted on the bus.
> + * This likely corresponds to the AHB bus DMA burst size.
> + */
> + ctl = sdhci_readw(host, MA35_SDHCI_MBIUCTL);
> + ctl &= ~MA35_SDHCI_INCR_MSK;
> + ctl |= MA35_SDHCI_INCR16 | MA35_SDHCI_INCR8;
> + sdhci_writew(host, ctl, MA35_SDHCI_MBIUCTL);
> +
> + return 0;
> +
> +err_sdhci:
> + sdhci_pltfm_free(pdev);
> + return err;
> +}
> +
> +static void ma35_disable_card_clk(struct sdhci_host *host)
> +{
> + u16 ctrl;
> +
> + ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> + if (ctrl & SDHCI_CLOCK_CARD_EN) {
> + ctrl &= ~SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> + }
> +}
> +
> +static void ma35_remove(struct platform_device *pdev)
> +{
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> +
> + sdhci_remove_host(host, 0);
> + ma35_disable_card_clk(host);
> + sdhci_pltfm_free(pdev);
> +}
> +
> +static const struct of_device_id sdhci_ma35_dt_ids[] = {
> + { .compatible = "nuvoton,ma35d1-sdhci" },
> + {}
> +};
> +
> +static struct platform_driver sdhci_ma35_driver = {
> + .driver = {
> + .name = "sdhci-ma35",
> + .of_match_table = sdhci_ma35_dt_ids,
> + },
> + .probe = ma35_probe,
> + .remove_new = ma35_remove,
> +};
> +module_platform_driver(sdhci_ma35_driver);
> +
> +MODULE_DESCRIPTION("SDHCI platform driver for Nuvoton MA35");
> +MODULE_AUTHOR("Shan-Chun Hung <shanchun1218@xxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>