[PATCH 08/10] bus: uniphier-system-bus: add UniPhier System Bus driver

[Masahiro Yamada]

Since commit 1517126fdac2 ("ARM: uniphier: select DM_ETH"), DM-based
drivers/net/smc911x.c is compiled, but it is never probed because the
parent node lacks the DM-based driver.

I need a skeleton driver to populate child devices (but the next commit
will move more hardware settings to the this driver).

I put this to drivers/bus/uniphier-system-bus.c because this is the
same path as the driver in Linux kernel.

Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
---

 arch/arm/mach-uniphier/Kconfig    |  1 +
 drivers/Kconfig                   |  2 ++
 drivers/Makefile                  |  1 +
 drivers/bus/Kconfig               | 16 ++++++++++++++++
 drivers/bus/Makefile              |  6 ++++++
 drivers/bus/uniphier-system-bus.c | 14 ++++++++++++++
 6 files changed, 40 insertions(+)
 create mode 100644 drivers/bus/Kconfig
 create mode 100644 drivers/bus/Makefile
 create mode 100644 drivers/bus/uniphier-system-bus.c

diff --git a/arch/arm/mach-uniphier/Kconfig b/arch/arm/mach-uniphier/Kconfig
index e125f50fa6..3a8eee7b84 100644
--- a/arch/arm/mach-uniphier/Kconfig
+++ b/arch/arm/mach-uniphier/Kconfig
@@ -83,6 +83,7 @@ config CACHE_UNIPHIER
 
 config MICRO_SUPPORT_CARD
 	bool "Use Micro Support Card"
+	depends on UNIPHIER_SYSTEM_BUS
 	help
 	  This option provides support for the expansion board, available
 	  on some UniPhier reference boards.
diff --git a/drivers/Kconfig b/drivers/Kconfig
index e34a22708c..7a839fa1aa 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -10,6 +10,8 @@ source "drivers/ata/Kconfig"
 
 source "drivers/axi/Kconfig"
 
+source "drivers/bus/Kconfig"
+
 source "drivers/block/Kconfig"
 
 source "drivers/bootcount/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 94e8c5da17..afd159e903 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -74,6 +74,7 @@ ifeq ($(CONFIG_SPL_BUILD)$(CONFIG_TPL_BUILD),)
 
 obj-y += adc/
 obj-y += ata/
+obj-y += bus/
 obj-$(CONFIG_DM_DEMO) += demo/
 obj-$(CONFIG_BIOSEMU) += bios_emulator/
 obj-y += block/
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
new file mode 100644
index 0000000000..07a33c6287
--- /dev/null
+++ b/drivers/bus/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Bus Devices
+#
+
+menu "Bus devices"
+
+config UNIPHIER_SYSTEM_BUS
+	bool "UniPhier System Bus driver"
+	depends on ARCH_UNIPHIER
+	default y
+	help
+	  Support for UniPhier System Bus, a simple external bus.  This is
+	  needed to use on-board devices connected to UniPhier SoCs.
+
+endmenu
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
new file mode 100644
index 0000000000..0b97fc1f8b
--- /dev/null
+++ b/drivers/bus/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the bus drivers.
+#
+
+obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
diff --git a/drivers/bus/uniphier-system-bus.c b/drivers/bus/uniphier-system-bus.c
new file mode 100644
index 0000000000..c61d795bac
--- /dev/null
+++ b/drivers/bus/uniphier-system-bus.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <dm.h>
+
+static const struct udevice_id uniphier_system_bus_match[] = {
+	{ .compatible = "socionext,uniphier-system-bus" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(uniphier_system_bus_driver) = {
+	.name	= "uniphier-system-bus",
+	.id	= UCLASS_SIMPLE_BUS,
+	.of_match = uniphier_system_bus_match,
+};
-- 
2.25.1