On Mon, Dec 05, 2022 at 10:53:51AM +0200, Tomer Maimon wrote:
> Add Nuvoton NPCM BMC sdhci-pltfm controller driver.
>
> Signed-off-by: Tomer Maimon <tmaimon77@xxxxxxxxx>
I still don't see this driver in the upstream kernel, or in linux-next.
Couple of comments:
- devm ordering does not really matter here. The devm resource
is the clock, it does not depend on local data, and it will be
released last, so that is ok.
- sdhci_pltfm_unregister() calls clk_disable_unprepare(),
so there is no enabled clock floating around on driver removal.
Unfortunately, that also means that the more convenient
devm_clk_get_optional_enabled() can not be used.
Real problem inline below.
Guenter
> ---
> drivers/mmc/host/Kconfig | 8 ++++
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-npcm.c | 84 +++++++++++++++++++++++++++++++++++
> 3 files changed, 93 insertions(+)
> create mode 100644 drivers/mmc/host/sdhci-npcm.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index fb1062a6394c..82ab6fc25dca 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -415,6 +415,14 @@ config MMC_SDHCI_MILBEAUT
>
> If unsure, say N.
>
> +config MMC_SDHCI_NPCM
> + tristate "Secure Digital Host Controller Interface support for NPCM"
> + depends on ARCH_NPCM || COMPILE_TEST
> + depends on MMC_SDHCI_PLTFM
> + help
> + This provides support for the SD/eMMC controller found in
> + NPCM BMC family SoCs.
> +
> config MMC_SDHCI_IPROC
> tristate "SDHCI support for the BCM2835 & iProc SD/MMC Controller"
> depends on ARCH_BCM2835 || ARCH_BCM_IPROC || ARCH_BRCMSTB || COMPILE_TEST
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 4e4ceb32c4b4..a101f87a5f19 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -97,6 +97,7 @@ obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32) += sdhci-pic32.o
> obj-$(CONFIG_MMC_SDHCI_BRCMSTB) += sdhci-brcmstb.o
> obj-$(CONFIG_MMC_SDHCI_OMAP) += sdhci-omap.o
> obj-$(CONFIG_MMC_SDHCI_SPRD) += sdhci-sprd.o
> +obj-$(CONFIG_MMC_SDHCI_NPCM) += sdhci-npcm.o
> obj-$(CONFIG_MMC_CQHCI) += cqhci.o
> cqhci-y += cqhci-core.o
> cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o
> diff --git a/drivers/mmc/host/sdhci-npcm.c b/drivers/mmc/host/sdhci-npcm.c
> new file mode 100644
> index 000000000000..beace15b6c00
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-npcm.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * NPCM SDHC MMC host controller driver.
> + *
> + * Copyright (c) 2020 Nuvoton Technology corporation.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/mmc.h>
> +#include <linux/module.h>
> +
> +#include "sdhci-pltfm.h"
> +
> +static const struct sdhci_pltfm_data npcm_sdhci_pdata = {
> + .quirks = SDHCI_QUIRK_DELAY_AFTER_POWER,
> + .quirks2 = SDHCI_QUIRK2_STOP_WITH_TC |
> + SDHCI_QUIRK2_NO_1_8_V,
> +};
> +
> +static int npcm_sdhci_probe(struct platform_device *pdev)
> +{
> + struct sdhci_pltfm_host *pltfm_host;
> + struct sdhci_host *host;
> + u32 caps;
> + int ret;
> +
> + host = sdhci_pltfm_init(pdev, &npcm_sdhci_pdata, 0);
> + if (IS_ERR(host))
> + return PTR_ERR(host);
> +
> + pltfm_host = sdhci_priv(host);
> +
> + pltfm_host->clk = devm_clk_get_optional(&pdev->dev, NULL);
> + if (IS_ERR(pltfm_host->clk))
> + return PTR_ERR(pltfm_host->clk);
> +
> + ret = clk_prepare_enable(pltfm_host->clk);
> + if (ret)
> + return ret;
> +
The two functions above should not return but goto the call
to sdhci_pltfm_free() to avoid a memory leak on error.
> + caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> + if (caps & SDHCI_CAN_DO_8BIT)
> + host->mmc->caps |= MMC_CAP_8_BIT_DATA;
> +
> + ret = mmc_of_parse(host->mmc);
> + if (ret)
> + goto err_sdhci_add;
> +
> + ret = sdhci_add_host(host);
> + if (ret)
> + goto err_sdhci_add;
> +
> + return 0;
> +
> +err_sdhci_add:
> + clk_disable_unprepare(pltfm_host->clk);
> + sdhci_pltfm_free(pdev);
> + return ret;
> +}
> +
> +static const struct of_device_id npcm_sdhci_of_match[] = {
> + { .compatible = "nuvoton,npcm750-sdhci" },
> + { .compatible = "nuvoton,npcm845-sdhci" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, npcm_sdhci_of_match);
> +
> +static struct platform_driver npcm_sdhci_driver = {
> + .driver = {
> + .name = "npcm-sdhci",
> + .of_match_table = npcm_sdhci_of_match,
> + .pm = &sdhci_pltfm_pmops,
> + },
> + .probe = npcm_sdhci_probe,
> + .remove = sdhci_pltfm_unregister,
> +};
> +module_platform_driver(npcm_sdhci_driver);
> +
> +MODULE_DESCRIPTION("NPCM Secure Digital Host Controller Interface driver");
> +MODULE_AUTHOR("Tomer Maimon <tomer.maimon@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 2.33.0
>
