mmc: sdhci: add UHS-II module and add a kernel configuration

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>
Message-ID: <20241018105333.4569-4-victorshihgli@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 0ba5a9f..45df8dd 100644 (file)
--- 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 3ccffeb..5147467 100644 (file)
--- 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 (file)
index 0000000..9ec1d6a
--- /dev/null
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -0,0 +1,41 @@
+// 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 __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");