The RP1 is an MFD supporting a gpio controller and /pinmux/pinctrl.
Add minimum support for the gpio only portion. The driver is in
pinctrl folder since upcoming patches will add the pinmux/pinctrl
support where the gpio part can be seen as an addition.

Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
---
 MAINTAINERS                   |   1 +
 drivers/pinctrl/Kconfig       |  10 +
 drivers/pinctrl/Makefile      |   1 +
 drivers/pinctrl/pinctrl-rp1.c | 719 ++++++++++++++++++++++++++++++++++
 4 files changed, 731 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-rp1.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4ce7b049d67e..67f460c36ea1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -19122,6 +19122,7 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/clock/raspberrypi,rp1-clocks.yaml
 F:	Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml
 F:	drivers/clk/clk-rp1.c
+F:	drivers/pinctrl/pinctrl-rp1.c
 F:	include/dt-bindings/clock/rp1.h
 F:	include/dt-bindings/misc/rp1.h
 

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 7e4f93a3bc7a..18bb1a8bd102 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig

@@ -565,6 +565,16 @@ config PINCTRL_MLXBF3
 	  each pin. This driver can also be built as a module called
 	  pinctrl-mlxbf3.
 
+config PINCTRL_RP1
+	bool "Pinctrl driver for RP1"
+	select PINMUX
+	select PINCONF
+	select GENERIC_PINCONF
+	select GPIOLIB_IRQCHIP
+	help
+	  Enable the gpio and pinctrl/mux  driver for RaspberryPi RP1
+	  multi function device. 
+
 source "drivers/pinctrl/actions/Kconfig"
 source "drivers/pinctrl/aspeed/Kconfig"
 source "drivers/pinctrl/bcm/Kconfig"

diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index cc809669405a..f1ca23b563f6 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_PINCTRL_PIC32)	+= pinctrl-pic32.o
 obj-$(CONFIG_PINCTRL_PISTACHIO)	+= pinctrl-pistachio.o
 obj-$(CONFIG_PINCTRL_RK805)	+= pinctrl-rk805.o
 obj-$(CONFIG_PINCTRL_ROCKCHIP)	+= pinctrl-rockchip.o
+obj-$(CONFIG_PINCTRL_RP1)       += pinctrl-rp1.o
 obj-$(CONFIG_PINCTRL_SCMI)	+= pinctrl-scmi.o
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_ST) 	+= pinctrl-st.o

diff --git a/drivers/pinctrl/pinctrl-rp1.c b/drivers/pinctrl/pinctrl-rp1.c
new file mode 100644
index 000000000000..c035d2014505
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-rp1.c

@@ -0,0 +1,719 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Raspberry Pi RP1 GPIO unit
+ *
+ * Copyright (C) 2023 Raspberry Pi Ltd.
+ *
+ * This driver is inspired by:
+ * pinctrl-bcm2835.c, please see original file for copyright information
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>