[PATCH v5 0/5] gpio: driver for the RPi3 GPIO expander

[PATCH v5 0/5] gpio: driver for the RPi3 GPIO expander

[Baruch Siach]

The Raspberry Pi 3 has a GPIO expander that controls, among others, the 
activity LED, and the camera connector GPIOs. The GPIO expander on an I2C bus 
that is not directly controlled from the ARM core. The VC4 firmware controls 
the I2C bus, and allows the ARM core to set/get GPIO settings over its mailbox 
interface.

This series adds support for the RPi3 expander.

The driver is ported from the downstream kernel at 
https://github.com/raspberrypi/linux/, branch rpi-4.9.y.

This series is based on commit v4.16-rc2.

Changes in v5:

  * Remove the 'firmware' property from the binding as suggested by Rob
    Herring. The firmware node is the parent of the gpio node, so use
    of_get_parent() instead of a phandle.

Changes in v4:

  * Move the gpio expander node under the firmware node; this requires an
    addtional patch that makes the firmware node into a bus
  * Rename the gpio node to just 'gpio'
  * Drop the platform driver .owner set

Changes in v3:

  * Kconfig tweaks
  * Check rpi_exp_gpio_get_polarity() return value
  * Redundant header removal
  * Redundant platform_set_drvdata() call removal
  * Small coding style changes

Changes in v2:

  * Driver renamed to gpio-raspberrypi-exp
  * Compatible string renamed to "raspberrypi,firmware-gpio"
  * Firmware error check
  * Smaller tweaks listed in individual patches

Baruch Siach (4):
  ARM: bcm2835: sync firmware properties with downstream
  dt-bindings: gpio: add raspberry pi GPIO expander binding
  ARM: dts: bcm2835: make the firmware node into a bus
  ARM: dts: bcm2837-rpi-3-b: add GPIO expander

Dave Stevenson (1):
  gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox
    service

 .../bindings/gpio/raspberrypi,firmware-gpio.txt    |  30 +++
 arch/arm/boot/dts/bcm2835-rpi.dtsi                 |   4 +-
 arch/arm/boot/dts/bcm2837-rpi-3-b.dts              |  17 ++
 drivers/gpio/Kconfig                               |   9 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-raspberrypi-exp.c                | 252 +++++++++++++++++++++
 include/soc/bcm2835/raspberrypi-firmware.h         |  18 ++
 7 files changed, 330 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt
 create mode 100644 drivers/gpio/gpio-raspberrypi-exp.c

-- 
2.16.1

[PATCH v5 0/5] gpio: driver for the RPi3 GPIO expander

[Baruch Siach]

The Raspberry Pi 3 has a GPIO expander that controls, among others, the 
activity LED, and the camera connector GPIOs. The GPIO expander on an I2C bus 
that is not directly controlled from the ARM core. The VC4 firmware controls 
the I2C bus, and allows the ARM core to set/get GPIO settings over its mailbox 
interface.

This series adds support for the RPi3 expander.

The driver is ported from the downstream kernel at 
https://github.com/raspberrypi/linux/, branch rpi-4.9.y.

This series is based on commit v4.16-rc2.

Changes in v5:

  * Remove the 'firmware' property from the binding as suggested by Rob
    Herring. The firmware node is the parent of the gpio node, so use
    of_get_parent() instead of a phandle.

Changes in v4:

  * Move the gpio expander node under the firmware node; this requires an
    addtional patch that makes the firmware node into a bus
  * Rename the gpio node to just 'gpio'
  * Drop the platform driver .owner set

Changes in v3:

  * Kconfig tweaks
  * Check rpi_exp_gpio_get_polarity() return value
  * Redundant header removal
  * Redundant platform_set_drvdata() call removal
  * Small coding style changes

Changes in v2:

  * Driver renamed to gpio-raspberrypi-exp
  * Compatible string renamed to "raspberrypi,firmware-gpio"
  * Firmware error check
  * Smaller tweaks listed in individual patches

Baruch Siach (4):
  ARM: bcm2835: sync firmware properties with downstream
  dt-bindings: gpio: add raspberry pi GPIO expander binding
  ARM: dts: bcm2835: make the firmware node into a bus
  ARM: dts: bcm2837-rpi-3-b: add GPIO expander

Dave Stevenson (1):
  gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox
    service

 .../bindings/gpio/raspberrypi,firmware-gpio.txt    |  30 +++
 arch/arm/boot/dts/bcm2835-rpi.dtsi                 |   4 +-
 arch/arm/boot/dts/bcm2837-rpi-3-b.dts              |  17 ++
 drivers/gpio/Kconfig                               |   9 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-raspberrypi-exp.c                | 252 +++++++++++++++++++++
 include/soc/bcm2835/raspberrypi-firmware.h         |  18 ++
 7 files changed, 330 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt
 create mode 100644 drivers/gpio/gpio-raspberrypi-exp.c

-- 
2.16.1

[PATCH v5 1/5] ARM: bcm2835: sync firmware properties with downstream

[Baruch Siach]

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,
 
-- 
2.16.1

[PATCH v5 1/5] ARM: bcm2835: sync firmware properties with downstream

[Baruch Siach]

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,
 
-- 
2.16.1

[PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Baruch Siach]

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>
---
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>;
+	 };
+};
-- 
2.16.1

[PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Baruch Siach]

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>
---
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>;
+	 };
+};
-- 
2.16.1

[PATCH v5 3/5] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service

[Baruch Siach]

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");
-- 
2.16.1

[PATCH v5 3/5] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service

[Baruch Siach]

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");
-- 
2.16.1

[PATCH v5 4/5] ARM: dts: bcm2835: make the firmware node into a bus

[Baruch Siach]

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>
---
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>;
 		};
 
-- 
2.16.1

[PATCH v5 4/5] ARM: dts: bcm2835: make the firmware node into a bus

[Baruch Siach]

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>
---
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>;
 		};
 
-- 
2.16.1

[PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Baruch Siach]

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>
---
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";
-- 
2.16.1

[PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Baruch Siach]

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>
---
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";
-- 
2.16.1

Re: [PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Rob Herring]

On Tue, Feb 20, 2018 at 6:19 AM, Baruch Siach <baruch@tkos.co.il> wrote:
> 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>
> ---
> 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

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Rob Herring]

On Tue, Feb 20, 2018 at 6:19 AM, Baruch Siach <baruch@tkos.co.il> wrote:
> 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>
> ---
> 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

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 1/5] ARM: bcm2835: sync firmware properties with downstream

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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

Patch applied to the GPIO tree for v4.17.

But I changed the subject from ARM: to soc:

Yours,
Linus Walleij

[PATCH v5 1/5] ARM: bcm2835: sync firmware properties with downstream

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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

Patch applied to the GPIO tree for v4.17.

But I changed the subject from ARM: to soc:

Yours,
Linus Walleij

Re: [PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v5:
>   * Remove the 'firmware' property
>   * Note that the gpio node is a child of the firmware node

This v5 patch applied to the GPIO tree for v4.17 with Rob's ACK.

Yours,
Linus Walleij

[PATCH v5 2/5] dt-bindings: gpio: add raspberry pi GPIO expander binding

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v5:
>   * Remove the 'firmware' property
>   * Note that the gpio node is a child of the firmware node

This v5 patch applied to the GPIO tree for v4.17 with Rob's ACK.

Yours,
Linus Walleij

Re: [PATCH v5 3/5] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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

This v5 version applied to the GPIO tree for v4.17.

Yours,
Linus Walleij

[PATCH v5 3/5] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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

This v5 version applied to the GPIO tree for v4.17.

Yours,
Linus Walleij

Re: [PATCH v5 4/5] ARM: dts: bcm2835: make the firmware node into a bus

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v4: New patch in this series

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Please funnel this patch through the ARM SoC tree.

Yours,
Linus Walleij

[PATCH v5 4/5] ARM: dts: bcm2835: make the firmware node into a bus

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v4: New patch in this series

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Please funnel this patch through the ARM SoC tree.

Yours,
Linus Walleij

Re: [PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v5:
>   * Drop the 'firmware' property

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Please funnel this patch through the ARM SoC tree.

Yours,
Linus Walleij

[PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Linus Walleij]

On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:

> 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>
> ---
> v5:
>   * Drop the 'firmware' property

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Please funnel this patch through the ARM SoC tree.

Yours,
Linus Walleij

Re: [PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Eric Anholt]

[-- Attachment #1.1: Type: text/plain, Size: 846 bytes --]

Linus Walleij <linus.walleij@linaro.org> writes:

> On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:
>
>> 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>
>> ---
>> v5:
>>   * Drop the 'firmware' property
>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>
> Please funnel this patch through the ARM SoC tree.

Picked up the reviews and applied these last 2 to bcm2835-dt-next.  I
didn't see the gpio tree's for-next updated, so I didn't integration
test it personally, but hopefully our branches can come together in
-next soon.

(FWIW, I was looking at
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for
gpio)

Thanks for pushing this to completion, Baruch!

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[PATCH v5 5/5] ARM: dts: bcm2837-rpi-3-b: add GPIO expander

[Eric Anholt]

Linus Walleij <linus.walleij@linaro.org> writes:

> On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach <baruch@tkos.co.il> wrote:
>
>> 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>
>> ---
>> v5:
>>   * Drop the 'firmware' property
>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>
> Please funnel this patch through the ARM SoC tree.

Picked up the reviews and applied these last 2 to bcm2835-dt-next.  I
didn't see the gpio tree's for-next updated, so I didn't integration
test it personally, but hopefully our branches can come together in
-next soon.

(FWIW, I was looking at
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for
gpio)

Thanks for pushing this to completion, Baruch!
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