[V21,09/22] mmc: sdhci: add UHS-II module and add a kernel configuration

From: Victor Shih <victor.shih@genesyslogic.com.tw>

This patch adds sdhci-uhs2.c as a module for UHS-II support.
This is a skeleton for further development in this patch series.

This kernel configuration, CONFIG_MMC_SDHCI_UHS2, will be used
in the following commits to indicate UHS-II specific code in sdhci
controllers.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---

Updates in V9:
 - Modify the commit message.

Updates in V8:
 - Modify MODULE_LICENSE from "GPL v2" to "GPL".

Updates in V6:
 - Merage V5 of patch[7] and patch[9] in to V6 of patch[8].

---

 drivers/mmc/host/Kconfig      |  9 +++++++
 drivers/mmc/host/Makefile     |  1 +
 drivers/mmc/host/sdhci-uhs2.c | 46 +++++++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-uhs2.c

On 6/09/24 13:20, Victor Shih wrote:
> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> 
> This patch adds sdhci-uhs2.c as a module for UHS-II support.
> This is a skeleton for further development in this patch series.
> 
> This kernel configuration, CONFIG_MMC_SDHCI_UHS2, will be used
> in the following commits to indicate UHS-II specific code in sdhci
> controllers.
> 
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>

Doesn't compile:

drivers/mmc/host/sdhci-uhs2.c:28:12: error: ‘sdhci_uhs2_host_ops_init’ defined but not used [-Werror=unused-function]
   28 | static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
      |            ^~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[5]: *** [scripts/Makefile.build:244: drivers/mmc/host/sdhci-uhs2.o] Error 1
make[4]: *** [scripts/Makefile.build:485: drivers/mmc/host] Error 2
make[3]: *** [scripts/Makefile.build:485: drivers/mmc] Error 2
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [scripts/Makefile.build:485: drivers] Error 2
make[1]: *** [/home/ahunter/git/review/Makefile:1925: .] Error 2
make: *** [Makefile:224: __sub-make] Error 2

> ---
> 
> Updates in V9:
>  - Modify the commit message.
> 
> Updates in V8:
>  - Modify MODULE_LICENSE from "GPL v2" to "GPL".
> 
> Updates in V6:
>  - Merage V5 of patch[7] and patch[9] in to V6 of patch[8].
> 
> ---
> 
>  drivers/mmc/host/Kconfig      |  9 +++++++
>  drivers/mmc/host/Makefile     |  1 +
>  drivers/mmc/host/sdhci-uhs2.c | 46 +++++++++++++++++++++++++++++++++++
>  3 files changed, 56 insertions(+)
>  create mode 100644 drivers/mmc/host/sdhci-uhs2.c
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 7199cb0bd0b9..f636af8a98df 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -98,6 +98,15 @@ config MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
>  
>  	  This is the case for the Nintendo Wii SDHCI.
>  
> +config MMC_SDHCI_UHS2
> +	tristate "UHS2 support on SDHCI controller"
> +	depends on MMC_SDHCI
> +	help
> +	  This option is selected by SDHCI controller drivers that want to
> +	  support UHS2-capable devices.
> +
> +	  If you have a controller with this feature, say Y or M here.
> +
>  config MMC_SDHCI_PCI
>  	tristate "SDHCI support on PCI bus"
>  	depends on MMC_SDHCI && PCI
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 3ccffebbe59b..5147467ec825 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_MMC_PXA)		+= pxamci.o
>  obj-$(CONFIG_MMC_MXC)		+= mxcmmc.o
>  obj-$(CONFIG_MMC_MXS)		+= mxs-mmc.o
>  obj-$(CONFIG_MMC_SDHCI)		+= sdhci.o
> +obj-$(CONFIG_MMC_SDHCI_UHS2)	+= sdhci-uhs2.o
>  obj-$(CONFIG_MMC_SDHCI_PCI)	+= sdhci-pci.o
>  sdhci-pci-y			+= sdhci-pci-core.o sdhci-pci-o2micro.o sdhci-pci-arasan.o \
>  				   sdhci-pci-dwc-mshc.o sdhci-pci-gli.o
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> new file mode 100644
> index 000000000000..608f8ad5aaed
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *  linux/drivers/mmc/host/sdhci_uhs2.c - Secure Digital Host Controller
> + *  Interface driver
> + *
> + *  Copyright (C) 2014 Intel Corp, All Rights Reserved.
> + *  Copyright (C) 2020 Genesys Logic, Inc.
> + *  Authors: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> + *  Copyright (C) 2020 Linaro Limited
> + *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> + */
> +
> +#include <linux/module.h>
> +
> +#include "sdhci.h"
> +#include "sdhci-uhs2.h"
> +
> +#define DRIVER_NAME "sdhci_uhs2"
> +#define DBG(f, x...) \
> +	pr_debug(DRIVER_NAME " [%s()]: " f, __func__, ## x)
> +
> +/*****************************************************************************\
> + *                                                                           *
> + * Driver init/exit                                                          *
> + *                                                                           *
> +\*****************************************************************************/
> +
> +static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
> +{
> +	return 0;
> +}
> +
> +static int __init sdhci_uhs2_mod_init(void)
> +{
> +	return 0;
> +}
> +module_init(sdhci_uhs2_mod_init);
> +
> +static void __exit sdhci_uhs2_mod_exit(void)
> +{
> +}
> +module_exit(sdhci_uhs2_mod_exit);
> +
> +MODULE_AUTHOR("Intel, Genesys Logic, Linaro");
> +MODULE_DESCRIPTION("MMC UHS-II Support");
> +MODULE_LICENSE("GPL");