[PATCH 3/8] mikrobus: Add mikrobus driver

[Ayush Singh <ayush@beagleboard.org>]

A simple platform driver for now that does nothing. This is required
because without a platform driver, the mikrobus_gpio0 nexus node cannot
be used.

In future, this driver will also allow for dynamic board detection using
1-wire eeprom in new mikrobus boards.

Signed-off-by: Ayush Singh <ayush@beagleboard.org>
---
 MAINTAINERS              |  1 +
 drivers/misc/Kconfig     | 17 +++++++++++++++++
 drivers/misc/Makefile    |  1 +
 drivers/misc/mikrobus.rs | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 51 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0cc27446b18a..d0c18bd7b558 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15433,6 +15433,7 @@ MIKROBUS CONNECTOR
 M:	Ayush Singh <ayush@beagleboard.org>
 S:	Maintained
 F:	Documentation/devicetree/bindings/connector/mikrobus-connector.yaml
+F:	drivers/misc/mikrobus.rs
 
 MIKROTIK CRS3XX 98DX3236 BOARD SUPPORT
 M:	Luka Kovacic <luka.kovacic@sartura.hr>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3fe7e2a9bd29..30defb522e98 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -610,6 +610,23 @@ config MARVELL_CN10K_DPI
 	  To compile this driver as a module, choose M here: the module
 	  will be called mrvl_cn10k_dpi.
 
+menuconfig MIKROBUS
+	tristate "Module for instantiating devices on mikroBUS ports"
+	help
+	  This option enables the mikroBUS driver. mikroBUS is an add-on
+	  board socket standard that offers maximum expandability with
+	  the smallest number of pins. The mikroBUS driver instantiates
+	  devices on a mikroBUS port described by identifying data present
+	  in an add-on board resident EEPROM, more details on the mikroBUS
+	  driver support and discussion can be found in this eLinux wiki :
+	  elinux.org/Mikrobus
+
+
+	  Say Y here to enable support for this driver.
+
+	  To compile this code as a module, chose M here: the module
+	  will be called mikrobus.ko
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index a9f94525e181..86ea188e3cf9 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -72,3 +72,4 @@ obj-$(CONFIG_TPS6594_PFSM)	+= tps6594-pfsm.o
 obj-$(CONFIG_NSM)		+= nsm.o
 obj-$(CONFIG_MARVELL_CN10K_DPI)	+= mrvl_cn10k_dpi.o
 obj-y				+= keba/
+obj-$(CONFIG_MIKROBUS)		+= mikrobus.o
diff --git a/drivers/misc/mikrobus.rs b/drivers/misc/mikrobus.rs
new file mode 100644
index 000000000000..a52268efd71b
--- /dev/null
+++ b/drivers/misc/mikrobus.rs
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! MikroBUS driver
+
+use kernel::c_str;
+use kernel::platform::{self, DeviceId};
+use kernel::prelude::*;
+
+kernel::module_platform_driver! {
+    driver: MikrobusDriver,
+    of_table: [DeviceId::new(c_str!("mikrobus-connector"))],
+    name: "mikrobus",
+    author: "Ayush Singh <ayush@beagleboard.org>",
+    description: "MikroBUS connector Driver",
+    license: "GPL",
+}
+
+struct MikrobusDriver;
+
+#[vtable]
+impl platform::Driver for MikrobusDriver {
+    const NAME: &'static CStr = c_str!("MikroBUS");
+
+    fn probe(_dev: &mut platform::Device) -> Result {
+        pr_debug!("Mikrobus Driver (probe)\n");
+        Ok(())
+    }
+
+    fn remove(_dev: &mut platform::Device) {
+        pr_debug!("Mikrobus Driver (remove)\n");
+    }
+}

-- 
2.46.0