Add RPi3 GPIO expander, RPi fixes, OMAP serial update, general ARM fixes

1 files changed, 638 insertions, 0 deletions

diff --git a/bcm283x-gpio-expander.patch b/bcm283x-gpio-expander.patch
new file mode 100644
index 000000000..55b7ec4d7
--- /dev/null
+++ b/bcm283x-gpio-expander.patch
@@ -0,0 +1,638 @@
+From patchwork Tue Feb 20 12:19:31 2018
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v5,1/5] ARM: bcm2835: sync firmware properties with downstream
+From: Baruch Siach <baruch@tkos.co.il>
+X-Patchwork-Id: 10229963
+Message-Id: <e7d1f1d0789f11d37957a8998bee23d035115aeb.1519128054.git.baruch@tkos.co.il>
+To: Linus Walleij <linus.walleij@linaro.org>,
+ Dave Stevenson <dave.stevenson@raspberrypi.org>,
+ Eric Anholt <eric@anholt.net>, Stefan Wahren <stefan.wahren@i2se.com>
+Cc: devicetree@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
+ linux-gpio@vger.kernel.org, Michael Zoran <mzoran@crowfest.net>,
+ Rob Herring <robh+dt@kernel.org>, linux-rpi-kernel@lists.infradead.org,
+ Frank Rowand <frowand.list@gmail.com>, linux-arm-kernel@lists.infradead.org
+Date: Tue, 20 Feb 2018 14:19:31 +0200
+
+Add latest firmware property tags from the latest Raspberry Pi downstream
+kernel. This is needed for the GPIO tags, so we can control the GPIO
+multiplexor lines.
+
+Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+---
+v4: No change
+
+v3: Add Stefan's ack
+
+v2: No change
+---
+ include/soc/bcm2835/raspberrypi-firmware.h | 18 ++++++++++++++++++
+ 1 file changed, 18 insertions(+)
+
+diff --git a/include/soc/bcm2835/raspberrypi-firmware.h b/include/soc/bcm2835/raspberrypi-firmware.h
+index cb979ad90401..50df5b28d2c9 100644
+--- a/include/soc/bcm2835/raspberrypi-firmware.h
++++ b/include/soc/bcm2835/raspberrypi-firmware.h
+@@ -63,6 +63,7 @@ enum rpi_firmware_property_tag {
+ 	RPI_FIRMWARE_GET_MIN_VOLTAGE =                        0x00030008,
+ 	RPI_FIRMWARE_GET_TURBO =                              0x00030009,
+ 	RPI_FIRMWARE_GET_MAX_TEMPERATURE =                    0x0003000a,
++	RPI_FIRMWARE_GET_STC =                                0x0003000b,
+ 	RPI_FIRMWARE_ALLOCATE_MEMORY =                        0x0003000c,
+ 	RPI_FIRMWARE_LOCK_MEMORY =                            0x0003000d,
+ 	RPI_FIRMWARE_UNLOCK_MEMORY =                          0x0003000e,
+@@ -72,12 +73,22 @@ enum rpi_firmware_property_tag {
+ 	RPI_FIRMWARE_SET_ENABLE_QPU =                         0x00030012,
+ 	RPI_FIRMWARE_GET_DISPMANX_RESOURCE_MEM_HANDLE =       0x00030014,
+ 	RPI_FIRMWARE_GET_EDID_BLOCK =                         0x00030020,
++	RPI_FIRMWARE_GET_CUSTOMER_OTP =                       0x00030021,
+ 	RPI_FIRMWARE_GET_DOMAIN_STATE =                       0x00030030,
+ 	RPI_FIRMWARE_SET_CLOCK_STATE =                        0x00038001,
+ 	RPI_FIRMWARE_SET_CLOCK_RATE =                         0x00038002,
+ 	RPI_FIRMWARE_SET_VOLTAGE =                            0x00038003,
+ 	RPI_FIRMWARE_SET_TURBO =                              0x00038009,
++	RPI_FIRMWARE_SET_CUSTOMER_OTP =                       0x00038021,
+ 	RPI_FIRMWARE_SET_DOMAIN_STATE =                       0x00038030,
++	RPI_FIRMWARE_GET_GPIO_STATE =                         0x00030041,
++	RPI_FIRMWARE_SET_GPIO_STATE =                         0x00038041,
++	RPI_FIRMWARE_SET_SDHOST_CLOCK =                       0x00038042,
++	RPI_FIRMWARE_GET_GPIO_CONFIG =                        0x00030043,
++	RPI_FIRMWARE_SET_GPIO_CONFIG =                        0x00038043,
++	RPI_FIRMWARE_GET_PERIPH_REG =                         0x00030045,
++	RPI_FIRMWARE_SET_PERIPH_REG =                         0x00038045,
++
+ 
+ 	/* Dispmanx TAGS */
+ 	RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE =                   0x00040001,
+@@ -91,6 +102,8 @@ enum rpi_firmware_property_tag {
+ 	RPI_FIRMWARE_FRAMEBUFFER_GET_VIRTUAL_OFFSET =         0x00040009,
+ 	RPI_FIRMWARE_FRAMEBUFFER_GET_OVERSCAN =               0x0004000a,
+ 	RPI_FIRMWARE_FRAMEBUFFER_GET_PALETTE =                0x0004000b,
++	RPI_FIRMWARE_FRAMEBUFFER_GET_TOUCHBUF =               0x0004000f,
++	RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF =            0x00040010,
+ 	RPI_FIRMWARE_FRAMEBUFFER_RELEASE =                    0x00048001,
+ 	RPI_FIRMWARE_FRAMEBUFFER_TEST_PHYSICAL_WIDTH_HEIGHT = 0x00044003,
+ 	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_WIDTH_HEIGHT =  0x00044004,
+@@ -100,6 +113,7 @@ enum rpi_firmware_property_tag {
+ 	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_OFFSET =        0x00044009,
+ 	RPI_FIRMWARE_FRAMEBUFFER_TEST_OVERSCAN =              0x0004400a,
+ 	RPI_FIRMWARE_FRAMEBUFFER_TEST_PALETTE =               0x0004400b,
++	RPI_FIRMWARE_FRAMEBUFFER_TEST_VSYNC =                 0x0004400e,
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_PHYSICAL_WIDTH_HEIGHT =  0x00048003,
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_WIDTH_HEIGHT =   0x00048004,
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_DEPTH =                  0x00048005,
+@@ -108,6 +122,10 @@ enum rpi_firmware_property_tag {
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_OFFSET =         0x00048009,
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,
+ 	RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,
++	RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF =               0x0004801f,
++	RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF =            0x00048020,
++	RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC =                  0x0004800e,
++	RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT =              0x0004800f,
+ 
+ 	RPI_FIRMWARE_VCHIQ_INIT =                             0x00048010,
+ 
+From patchwork Tue Feb 20 12:19:32 2018
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v5,2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding
+From: Baruch Siach <baruch@tkos.co.il>
+X-Patchwork-Id: 10229965
+Message-Id: <f400b48cbcd8a138c39d4e8f63d6c1f569090dcc.1519128054.git.baruch@tkos.co.il>
+To: Linus Walleij <linus.walleij@linaro.org>,
+ Dave Stevenson <dave.stevenson@raspberrypi.org>,
+ Eric Anholt <eric@anholt.net>, Stefan Wahren <stefan.wahren@i2se.com>
+Cc: devicetree@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
+ linux-gpio@vger.kernel.org, Michael Zoran <mzoran@crowfest.net>,
+ Rob Herring <robh+dt@kernel.org>, linux-rpi-kernel@lists.infradead.org,
+ Frank Rowand <frowand.list@gmail.com>, linux-arm-kernel@lists.infradead.org
+Date: Tue, 20 Feb 2018 14:19:32 +0200
+
+The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over
+I2C. The firmware mailbox interface allows the ARM core to control the
+GPIO lines.
+
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+Reviewed-by: Rob Herring <robh@kernel.org>
+---
+v5:
+  * Remove the 'firmware' property
+  * Note that the gpio node is a child of the firmware node
+
+v4:
+  * Move the example gpio node under the firmware node
+  * Rename gpio node name to plain 'gpio'
+
+v3:
+  * Rename node name.
+
+v2:
+  * Rename compatible string to raspberrypi,firmware-gpio
+---
+ .../bindings/gpio/raspberrypi,firmware-gpio.txt    | 30 ++++++++++++++++++++++
+ 1 file changed, 30 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt
+
+diff --git a/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt
+new file mode 100644
+index 000000000000..ce97265e23ba
+--- /dev/null
++++ b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt
+@@ -0,0 +1,30 @@
++Raspberry Pi GPIO expander
++
++The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The
++firmware exposes a mailbox interface that allows the ARM core to control the
++GPIO lines on the expander.
++
++The Raspberry Pi GPIO expander node must be a child node of the Raspberry Pi
++firmware node.
++
++Required properties:
++
++- compatible : Should be "raspberrypi,firmware-gpio"
++- gpio-controller : Marks the device node as a gpio controller
++- #gpio-cells : Should be two.  The first cell is the pin number, and
++  the second cell is used to specify the gpio polarity:
++  0 = active high
++  1 = active low
++
++Example:
++
++firmware: firmware-rpi {
++	compatible = "raspberrypi,bcm2835-firmware";
++	mboxes = <&mailbox>;
++
++	expgpio: gpio {
++		 compatible = "raspberrypi,firmware-gpio";
++		 gpio-controller;
++		 #gpio-cells = <2>;
++	 };
++};
+From patchwork Tue Feb 20 12:19:33 2018
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v5,
+ 3/5] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox
+ service
+From: Baruch Siach <baruch@tkos.co.il>
+X-Patchwork-Id: 10229967
+Message-Id: <8c34f287ee72b340fa9d693aa0e304b25541c74c.1519128054.git.baruch@tkos.co.il>
+To: Linus Walleij <linus.walleij@linaro.org>,
+ Dave Stevenson <dave.stevenson@raspberrypi.org>,
+ Eric Anholt <eric@anholt.net>, Stefan Wahren <stefan.wahren@i2se.com>
+Cc: devicetree@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
+ linux-gpio@vger.kernel.org, Michael Zoran <mzoran@crowfest.net>,
+ Rob Herring <robh+dt@kernel.org>, linux-rpi-kernel@lists.infradead.org,
+ Frank Rowand <frowand.list@gmail.com>, linux-arm-kernel@lists.infradead.org
+Date: Tue, 20 Feb 2018 14:19:33 +0200
+
+From: Dave Stevenson <dave.stevenson@raspberrypi.org>
+
+Pi3 and Compute Module 3 have a GPIO expander that the
+VPU communicates with.
+There is a mailbox service that now allows control of this
+expander, so add a kernel driver that can make use of it.
+
+Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
+Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+---
+v5:
+  * Use the parent node to find the firmware
+
+v4:
+  * Don't set the .owner driver field
+  * Add Stefan's review tag
+
+v3:
+  * Tweak Kconfig driver prompt
+  * Make GPIO_RASPBERRYPI_EXP tristate
+  * Make COMPILE_TEST independent of RASPBERRYPI_FIRMWARE
+  * Remove redundant DMA header
+  * Use less code lines for dev_err()
+  * Check rpi_exp_gpio_get_polarity() return value
+  * Remove redundant platform_set_drvdata() call
+
+v2:
+  * Rename driver to gpio-raspberrypi-exp
+  * Populate the gpiochip parent device pointer
+  * Use macro for the mailbox base GPIO number
+  * Drop linux/gpio.h and GPIOF_DIR_*
+  * Check and print firmware error value
+  * Use devm_gpiochip_add_data(); drop .remove
+  * A few more minor tweaks
+---
+ drivers/gpio/Kconfig                |   9 ++
+ drivers/gpio/Makefile               |   1 +
+ drivers/gpio/gpio-raspberrypi-exp.c | 252 ++++++++++++++++++++++++++++++++++++
+ 3 files changed, 262 insertions(+)
+ create mode 100644 drivers/gpio/gpio-raspberrypi-exp.c
+
+diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
+index 8dbb2280538d..fd0562a37f68 100644
+--- a/drivers/gpio/Kconfig
++++ b/drivers/gpio/Kconfig
+@@ -122,6 +122,15 @@ config GPIO_ATH79
+ 	  Select this option to enable GPIO driver for
+ 	  Atheros AR71XX/AR724X/AR913X SoC devices.
+ 
++config GPIO_RASPBERRYPI_EXP
++	tristate "Raspberry Pi 3 GPIO Expander"
++	default RASPBERRYPI_FIRMWARE
++	depends on OF_GPIO
++	depends on (ARCH_BCM2835 && RASPBERRYPI_FIRMWARE) || COMPILE_TEST
++	help
++	  Turn on GPIO support for the expander on Raspberry Pi 3 boards, using
++	  the firmware mailbox to communicate with VideoCore on BCM283x chips.
++
+ config GPIO_BCM_KONA
+ 	bool "Broadcom Kona GPIO"
+ 	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
+diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
+index cccb0d40846c..76dc0a02bd56 100644
+--- a/drivers/gpio/Makefile
++++ b/drivers/gpio/Makefile
+@@ -32,6 +32,7 @@ obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o
+ obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
+ obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o
+ obj-$(CONFIG_GPIO_ASPEED)	+= gpio-aspeed.o
++obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)	+= gpio-raspberrypi-exp.o
+ obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
+ obj-$(CONFIG_GPIO_BD9571MWV)	+= gpio-bd9571mwv.o
+ obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o
+diff --git a/drivers/gpio/gpio-raspberrypi-exp.c b/drivers/gpio/gpio-raspberrypi-exp.c
+new file mode 100644
+index 000000000000..d6d36d537e37
+--- /dev/null
++++ b/drivers/gpio/gpio-raspberrypi-exp.c
+@@ -0,0 +1,252 @@
++// SPDX-License-Identifier: GPL-2.0+
++/*
++ *  Raspberry Pi 3 expander GPIO driver
++ *
++ *  Uses the firmware mailbox service to communicate with the
++ *  GPIO expander on the VPU.
++ *
++ *  Copyright (C) 2017 Raspberry Pi Trading Ltd.
++ */
++
++#include <linux/err.h>
++#include <linux/gpio/driver.h>
++#include <linux/module.h>
++#include <linux/platform_device.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
++
++#define MODULE_NAME "raspberrypi-exp-gpio"
++#define NUM_GPIO 8
++
++#define RPI_EXP_GPIO_BASE	128
++
++#define RPI_EXP_GPIO_DIR_IN	0
++#define RPI_EXP_GPIO_DIR_OUT	1
++
++struct rpi_exp_gpio {
++	struct gpio_chip gc;
++	struct rpi_firmware *fw;
++};
++
++/* VC4 firmware mailbox interface data structures */
++
++struct gpio_set_config {
++	u32 gpio;
++	u32 direction;
++	u32 polarity;
++	u32 term_en;
++	u32 term_pull_up;
++	u32 state;
++};
++
++struct gpio_get_config {
++	u32 gpio;
++	u32 direction;
++	u32 polarity;
++	u32 term_en;
++	u32 term_pull_up;
++};
++
++struct gpio_get_set_state {
++	u32 gpio;
++	u32 state;
++};
++
++static int rpi_exp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_get_config get;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
++				    &get, sizeof(get));
++	if (ret || get.gpio != 0) {
++		dev_err(gc->parent, "Failed to get GPIO %u config (%d %x)\n",
++			off, ret, get.gpio);
++		return ret ? ret : -EIO;
++	}
++	return get.polarity;
++}
++
++static int rpi_exp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_set_config set_in;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	set_in.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++	set_in.direction = RPI_EXP_GPIO_DIR_IN;
++	set_in.term_en = 0;		/* termination disabled */
++	set_in.term_pull_up = 0;	/* n/a as termination disabled */
++	set_in.state = 0;		/* n/a as configured as an input */
++
++	ret = rpi_exp_gpio_get_polarity(gc, off);
++	if (ret < 0)
++		return ret;
++	set_in.polarity = ret;		/* Retain existing setting */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
++				    &set_in, sizeof(set_in));
++	if (ret || set_in.gpio != 0) {
++		dev_err(gc->parent, "Failed to set GPIO %u to input (%d %x)\n",
++			off, ret, set_in.gpio);
++		return ret ? ret : -EIO;
++	}
++	return 0;
++}
++
++static int rpi_exp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_set_config set_out;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	set_out.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++	set_out.direction = RPI_EXP_GPIO_DIR_OUT;
++	set_out.term_en = 0;		/* n/a as an output */
++	set_out.term_pull_up = 0;	/* n/a as termination disabled */
++	set_out.state = val;		/* Output state */
++
++	ret = rpi_exp_gpio_get_polarity(gc, off);
++	if (ret < 0)
++		return ret;
++	set_out.polarity = ret;		/* Retain existing setting */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
++				    &set_out, sizeof(set_out));
++	if (ret || set_out.gpio != 0) {
++		dev_err(gc->parent, "Failed to set GPIO %u to output (%d %x)\n",
++			off, ret, set_out.gpio);
++		return ret ? ret : -EIO;
++	}
++	return 0;
++}
++
++static int rpi_exp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_get_config get;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
++				    &get, sizeof(get));
++	if (ret || get.gpio != 0) {
++		dev_err(gc->parent,
++			"Failed to get GPIO %u config (%d %x)\n", off, ret,
++			get.gpio);
++		return ret ? ret : -EIO;
++	}
++	return !get.direction;
++}
++
++static int rpi_exp_gpio_get(struct gpio_chip *gc, unsigned int off)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_get_set_state get;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++	get.state = 0;		/* storage for returned value */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE,
++					 &get, sizeof(get));
++	if (ret || get.gpio != 0) {
++		dev_err(gc->parent,
++			"Failed to get GPIO %u state (%d %x)\n", off, ret,
++			get.gpio);
++		return ret ? ret : -EIO;
++	}
++	return !!get.state;
++}
++
++static void rpi_exp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
++{
++	struct rpi_exp_gpio *gpio;
++	struct gpio_get_set_state set;
++	int ret;
++
++	gpio = gpiochip_get_data(gc);
++
++	set.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
++	set.state = val;	/* Output state */
++
++	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE,
++					 &set, sizeof(set));
++	if (ret || set.gpio != 0)
++		dev_err(gc->parent,
++			"Failed to set GPIO %u state (%d %x)\n", off, ret,
++			set.gpio);
++}
++
++static int rpi_exp_gpio_probe(struct platform_device *pdev)
++{
++	struct device *dev = &pdev->dev;
++	struct device_node *np = dev->of_node;
++	struct device_node *fw_node;
++	struct rpi_firmware *fw;
++	struct rpi_exp_gpio *rpi_gpio;
++
++	fw_node = of_get_parent(np);
++	if (!fw_node) {
++		dev_err(dev, "Missing firmware node\n");
++		return -ENOENT;
++	}
++
++	fw = rpi_firmware_get(fw_node);
++	if (!fw)
++		return -EPROBE_DEFER;
++
++	rpi_gpio = devm_kzalloc(dev, sizeof(*rpi_gpio), GFP_KERNEL);
++	if (!rpi_gpio)
++		return -ENOMEM;
++
++	rpi_gpio->fw = fw;
++	rpi_gpio->gc.parent = dev;
++	rpi_gpio->gc.label = MODULE_NAME;
++	rpi_gpio->gc.owner = THIS_MODULE;
++	rpi_gpio->gc.of_node = np;
++	rpi_gpio->gc.base = -1;
++	rpi_gpio->gc.ngpio = NUM_GPIO;
++
++	rpi_gpio->gc.direction_input = rpi_exp_gpio_dir_in;
++	rpi_gpio->gc.direction_output = rpi_exp_gpio_dir_out;
++	rpi_gpio->gc.get_direction = rpi_exp_gpio_get_direction;
++	rpi_gpio->gc.get = rpi_exp_gpio_get;
++	rpi_gpio->gc.set = rpi_exp_gpio_set;
++	rpi_gpio->gc.can_sleep = true;
++
++	return devm_gpiochip_add_data(dev, &rpi_gpio->gc, rpi_gpio);
++}
++
++static const struct of_device_id rpi_exp_gpio_ids[] = {
++	{ .compatible = "raspberrypi,firmware-gpio" },
++	{ }
++};
++MODULE_DEVICE_TABLE(of, rpi_exp_gpio_ids);
++
++static struct platform_driver rpi_exp_gpio_driver = {
++	.driver	= {
++		.name		= MODULE_NAME,
++		.of_match_table	= of_match_ptr(rpi_exp_gpio_ids),
++	},
++	.probe	= rpi_exp_gpio_probe,
++};
++module_platform_driver(rpi_exp_gpio_driver);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.org>");
++MODULE_DESCRIPTION("Raspberry Pi 3 expander GPIO driver");
++MODULE_ALIAS("platform:rpi-exp-gpio");
+From patchwork Tue Feb 20 12:19:34 2018
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v5,4/5] ARM: dts: bcm2835: make the firmware node into a bus
+From: Baruch Siach <baruch@tkos.co.il>
+X-Patchwork-Id: 10229961
+Message-Id: <43f9082a6835df6d7bcd3e16d79db687c52826d2.1519128054.git.baruch@tkos.co.il>
+To: Linus Walleij <linus.walleij@linaro.org>,
+ Dave Stevenson <dave.stevenson@raspberrypi.org>,
+ Eric Anholt <eric@anholt.net>, Stefan Wahren <stefan.wahren@i2se.com>
+Cc: devicetree@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
+ linux-gpio@vger.kernel.org, Michael Zoran <mzoran@crowfest.net>,
+ Rob Herring <robh+dt@kernel.org>, linux-rpi-kernel@lists.infradead.org,
+ Frank Rowand <frowand.list@gmail.com>, linux-arm-kernel@lists.infradead.org
+Date: Tue, 20 Feb 2018 14:19:34 +0200
+
+This allows adding devices for which the firmware exposes control interface
+via the mailbox. An example of such device is the GPIO expander.
+
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
+---
+v4: New patch in this series
+---
+ arch/arm/boot/dts/bcm2835-rpi.dtsi | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
+index e36c392a2b8f..0198bd46ef7c 100644
+--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
++++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
+@@ -18,7 +18,9 @@
+ 
+ 	soc {
+ 		firmware: firmware {
+-			compatible = "raspberrypi,bcm2835-firmware";
++			compatible = "raspberrypi,bcm2835-firmware", "simple-bus";
++			#address-cells = <0>;
++			#size-cells = <0>;
+ 			mboxes = <&mailbox>;
+ 		};
+ 
+From patchwork Tue Feb 20 12:19:35 2018
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v5,5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander
+From: Baruch Siach <baruch@tkos.co.il>
+X-Patchwork-Id: 10229995
+Message-Id: <a6d59692dc4847e0b1639a26542e28c95ad5240f.1519128054.git.baruch@tkos.co.il>
+To: Linus Walleij <linus.walleij@linaro.org>,
+ Dave Stevenson <dave.stevenson@raspberrypi.org>,
+ Eric Anholt <eric@anholt.net>, Stefan Wahren <stefan.wahren@i2se.com>
+Cc: devicetree@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
+ linux-gpio@vger.kernel.org, Michael Zoran <mzoran@crowfest.net>,
+ Rob Herring <robh+dt@kernel.org>, linux-rpi-kernel@lists.infradead.org,
+ Frank Rowand <frowand.list@gmail.com>, linux-arm-kernel@lists.infradead.org
+Date: Tue, 20 Feb 2018 14:19:35 +0200
+
+Add a description of the RPi3 GPIO expander that the VC4 firmware controls.
+
+Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
+Signed-off-by: Baruch Siach <baruch@tkos.co.il>
+Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
+---
+v5:
+  * Drop the 'firmware' property
+
+v4:
+  * Move the gpio node under the firmware node
+  * Rename the gpio node to plain 'gpio'
+  * Add Stefan's ack
+
+v3:
+  * List GPIO names one per line.
+
+v2:
+  * Move GPIO expander node out of the soc container
+  * Rename compatible string
+  * Add gpio-line-names property
+---
+ arch/arm/boot/dts/bcm2837-rpi-3-b.dts | 17 +++++++++++++++++
+ 1 file changed, 17 insertions(+)
+
+diff --git a/arch/arm/boot/dts/bcm2837-rpi-3-b.dts b/arch/arm/boot/dts/bcm2837-rpi-3-b.dts
+index 3e4ed7c5b0b3..0b31d995a066 100644
+--- a/arch/arm/boot/dts/bcm2837-rpi-3-b.dts
++++ b/arch/arm/boot/dts/bcm2837-rpi-3-b.dts
+@@ -25,6 +25,23 @@
+ 	};
+ };
+ 
++&firmware {
++	expgpio: gpio {
++		compatible = "raspberrypi,firmware-gpio";
++		gpio-controller;
++		#gpio-cells = <2>;
++		gpio-line-names = "BT_ON",
++				  "WL_ON",
++				  "STATUS_LED",
++				  "LAN_RUN",
++				  "HPD_N",
++				  "CAM_GPIO0",
++				  "CAM_GPIO1",
++				  "PWR_LOW_N";
++		status = "okay";
++	};
++};
++
+ /* uart0 communicates with the BT module */
+ &uart0 {
+ 	pinctrl-names = "default";