[PATCH 1/8] bcm2835-gpio-exp: Driver for GPIO expander via mailbox service
Kleber Souza
kleber.souza at canonical.com
Fri Jan 11 16:29:36 UTC 2019
On 1/11/19 3:17 PM, Paolo Pisati wrote:
> From: Dave Stevenson <dave.stevenson at raspberrypi.org>
>
> BugLink: http://bugs.launchpad.net/bugs/1808366
We are now using https for the BugLink's, that can be fixed when
applying though.
Kleber
>
> 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.
>
> Pwr_led node added to device-tree for Pi3.
>
> Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.org>
> (cherry picked from commit 5d1da107bc619c1cc091ee5301f85cd89a6d92fb
> https://github.com/raspberrypi/linux rpi-4.9.y)
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
> arch/arm/boot/dts/bcm2710-rpi-3-b.dts | 22 +++
> arch/arm/boot/dts/bcm2710-rpi-cm3.dts | 10 +-
> arch/arm/configs/bcm2709_defconfig | 1 +
> drivers/gpio/Kconfig | 7 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-bcm-exp.c | 256 +++++++++++++++++++++++++++++
> include/soc/bcm2835/raspberrypi-firmware.h | 4 +
> 7 files changed, 300 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpio/gpio-bcm-exp.c
>
> diff --git a/arch/arm/boot/dts/bcm2710-rpi-3-b.dts b/arch/arm/boot/dts/bcm2710-rpi-3-b.dts
> index 98352b5..193e08e 100644
> --- a/arch/arm/boot/dts/bcm2710-rpi-3-b.dts
> +++ b/arch/arm/boot/dts/bcm2710-rpi-3-b.dts
> @@ -92,6 +92,14 @@
> firmware = <&firmware>;
> status = "okay";
> };
> +
> + expgpio: expgpio {
> + compatible = "brcm,bcm2835-expgpio";
> + gpio-controller;
> + #gpio-cells = <2>;
> + firmware = <&firmware>;
> + status = "okay";
> + };
> };
>
> &fb {
> @@ -164,6 +172,16 @@
> linux,default-trigger = "mmc0";
> gpios = <&virtgpio 0 0>;
> };
> +
> + pwr_led: pwr {
> + label = "led1";
> + linux,default-trigger = "input";
> + gpios = <&expgpio 7 GPIO_ACTIVE_LOW>;
> + };
> +};
> +
> +&hdmi {
> + hpd-gpios = <&expgpio 4 GPIO_ACTIVE_LOW>;
> };
>
> &audio {
> @@ -196,6 +214,10 @@
> act_led_activelow = <&act_led>,"gpios:8";
> act_led_trigger = <&act_led>,"linux,default-trigger";
>
> + pwr_led_gpio = <&pwr_led>,"gpios:4";
> + pwr_led_activelow = <&pwr_led>,"gpios:8";
> + pwr_led_trigger = <&pwr_led>,"linux,default-trigger";
> +
> audio = <&audio>,"status";
> watchdog = <&watchdog>,"status";
> random = <&random>,"status";
> diff --git a/arch/arm/boot/dts/bcm2710-rpi-cm3.dts b/arch/arm/boot/dts/bcm2710-rpi-cm3.dts
> index 7ceb16b..40f6066 100644
> --- a/arch/arm/boot/dts/bcm2710-rpi-cm3.dts
> +++ b/arch/arm/boot/dts/bcm2710-rpi-cm3.dts
> @@ -66,6 +66,14 @@
> firmware = <&firmware>;
> status = "okay";
> };
> +
> + expgpio: expgpio {
> + compatible = "brcm,bcm2835-expgpio";
> + gpio-controller;
> + #gpio-cells = <2>;
> + firmware = <&firmware>;
> + status = "okay";
> + };
> };
>
> &fb {
> @@ -129,7 +137,7 @@
> };
>
> &hdmi {
> - hpd-gpios = <&gpio 46 GPIO_ACTIVE_LOW>;
> + hpd-gpios = <&expgpio 0 GPIO_ACTIVE_LOW>;
> };
>
> &audio {
> diff --git a/arch/arm/configs/bcm2709_defconfig b/arch/arm/configs/bcm2709_defconfig
> index 783d2c2..6e7f1e6 100644
> --- a/arch/arm/configs/bcm2709_defconfig
> +++ b/arch/arm/configs/bcm2709_defconfig
> @@ -624,6 +624,7 @@ CONFIG_PPS=m
> CONFIG_PPS_CLIENT_LDISC=m
> CONFIG_PPS_CLIENT_GPIO=m
> CONFIG_GPIO_SYSFS=y
> +CONFIG_GPIO_BCM_EXP=y
> CONFIG_GPIO_BCM_VIRT=y
> CONFIG_GPIO_ARIZONA=m
> CONFIG_GPIO_STMPE=y
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 45e6729..f2eaf8b 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -127,6 +127,13 @@ config GPIO_AMDPT
> driver for GPIO functionality on Promontory IOHub
> Require ACPI ASL code to enumerate as a platform device.
>
> +config GPIO_BCM_EXP
> + bool "Broadcom Exp GPIO"
> + depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
> + help
> + Turn on GPIO support for Broadcom chips 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 b2ccc9f..1270487 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
> obj-$(CONFIG_GPIO_AMDPT) += gpio-amdpt.o
> obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o
> obj-$(CONFIG_ATH79) += gpio-ath79.o
> +obj-$(CONFIG_GPIO_BCM_EXP) += gpio-bcm-exp.o
> obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
> obj-$(CONFIG_GPIO_BCM_VIRT) += gpio-bcm-virt.o
> obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
> diff --git a/drivers/gpio/gpio-bcm-exp.c b/drivers/gpio/gpio-bcm-exp.c
> new file mode 100644
> index 0000000..681a914
> --- /dev/null
> +++ b/drivers/gpio/gpio-bcm-exp.c
> @@ -0,0 +1,256 @@
> +/*
> + * Broadcom expander GPIO driver
> + *
> + * Uses the firmware mailbox service to communicate with the
> + * GPIO expander on the VPU.
> + *
> + * Copyright (C) 2017 Raspberry Pi Trading Ltd.
> + *
> + * Author: Dave Stevenson <dave.stevenson at raspberrypi.org>
> + * Based on gpio-bcm-virt.c by Dom Cobley <popcornmix at gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/gpio.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <soc/bcm2835/raspberrypi-firmware.h>
> +
> +#define MODULE_NAME "brcmexp-gpio"
> +#define NUM_GPIO 8
> +
> +struct brcmexp_gpio {
> + struct gpio_chip gc;
> + struct device *dev;
> + struct rpi_firmware *fw;
> +};
> +
> +struct gpio_set_config {
> + u32 gpio, direction, polarity, term_en, term_pull_up, state;
> +};
> +
> +struct gpio_get_config {
> + u32 gpio, direction, polarity, term_en, term_pull_up;
> +};
> +
> +struct gpio_get_set_state {
> + u32 gpio, state;
> +};
> +
> +static int brcmexp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_get_config get;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + get.gpio = off + gpio->gc.base; /* GPIO to update */
> +
> + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
> + &get, sizeof(get));
> + if (ret) {
> + dev_err(gpio->dev,
> + "Failed to get GPIO %u config (%d)\n", off, ret);
> + return ret;
> + }
> + return get.polarity;
> +}
> +
> +static int brcmexp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_set_config set_in;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + set_in.gpio = off + gpio->gc.base; /* GPIO to update */
> + set_in.direction = 0; /* Input */
> + set_in.polarity = brcmexp_gpio_get_polarity(gc, off);
> + /* Retain existing setting */
> + 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_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
> + &set_in, sizeof(set_in));
> + if (ret) {
> + dev_err(gpio->dev,
> + "Failed to set GPIO %u to input (%d)\n",
> + off, ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int brcmexp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_set_config set_out;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + set_out.gpio = off + gpio->gc.base; /* GPIO to update */
> + set_out.direction = 1; /* Output */
> + set_out.polarity = brcmexp_gpio_get_polarity(gc, off);
> + /* Retain existing setting */
> + 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_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
> + &set_out, sizeof(set_out));
> + if (ret) {
> + dev_err(gpio->dev,
> + "Failed to set GPIO %u to output (%d)\n", off, ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int brcmexp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_get_config get;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + get.gpio = off + gpio->gc.base; /* GPIO to update */
> +
> + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
> + &get, sizeof(get));
> + if (ret) {
> + dev_err(gpio->dev,
> + "Failed to get GPIO %u config (%d)\n", off, ret);
> + return ret;
> + }
> + return get.direction ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
> +}
> +
> +static int brcmexp_gpio_get(struct gpio_chip *gc, unsigned int off)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_get_set_state get;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + get.gpio = off + gpio->gc.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) {
> + dev_err(gpio->dev,
> + "Failed to get GPIO %u state (%d)\n", off, ret);
> + return ret;
> + }
> + return !!get.state;
> +}
> +
> +static void brcmexp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
> +{
> + struct brcmexp_gpio *gpio;
> + struct gpio_get_set_state set;
> + int ret;
> +
> + gpio = container_of(gc, struct brcmexp_gpio, gc);
> +
> + off += gpio->gc.base;
> +
> + set.gpio = off + gpio->gc.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)
> + dev_err(gpio->dev,
> + "Failed to set GPIO %u state (%d)\n", off, ret);
> +}
> +
> +static int brcmexp_gpio_probe(struct platform_device *pdev)
> +{
> + int err = 0;
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + struct device_node *fw_node;
> + struct rpi_firmware *fw;
> + struct brcmexp_gpio *ucb;
> +
> + fw_node = of_parse_phandle(np, "firmware", 0);
> + if (!fw_node) {
> + dev_err(dev, "Missing firmware node\n");
> + return -ENOENT;
> + }
> +
> + fw = rpi_firmware_get(fw_node);
> + if (!fw)
> + return -EPROBE_DEFER;
> +
> + ucb = devm_kzalloc(dev, sizeof(*ucb), GFP_KERNEL);
> + if (!ucb)
> + return -EINVAL;
> +
> + ucb->fw = fw;
> + ucb->dev = dev;
> + ucb->gc.label = MODULE_NAME;
> + ucb->gc.owner = THIS_MODULE;
> + ucb->gc.of_node = np;
> + ucb->gc.base = 128;
> + ucb->gc.ngpio = NUM_GPIO;
> +
> + ucb->gc.direction_input = brcmexp_gpio_dir_in;
> + ucb->gc.direction_output = brcmexp_gpio_dir_out;
> + ucb->gc.get_direction = brcmexp_gpio_get_direction;
> + ucb->gc.get = brcmexp_gpio_get;
> + ucb->gc.set = brcmexp_gpio_set;
> + ucb->gc.can_sleep = true;
> +
> + err = gpiochip_add(&ucb->gc);
> + if (err)
> + return err;
> +
> + platform_set_drvdata(pdev, ucb);
> +
> + return 0;
> +}
> +
> +static int brcmexp_gpio_remove(struct platform_device *pdev)
> +{
> + struct brcmexp_gpio *ucb = platform_get_drvdata(pdev);
> +
> + gpiochip_remove(&ucb->gc);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id __maybe_unused brcmexp_gpio_ids[] = {
> + { .compatible = "brcm,bcm2835-expgpio" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, brcmexp_gpio_ids);
> +
> +static struct platform_driver brcmexp_gpio_driver = {
> + .driver = {
> + .name = MODULE_NAME,
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(brcmexp_gpio_ids),
> + },
> + .probe = brcmexp_gpio_probe,
> + .remove = brcmexp_gpio_remove,
> +};
> +module_platform_driver(brcmexp_gpio_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Dave Stevenson <dave.stevenson at raspberrypi.org>");
> +MODULE_DESCRIPTION("brcm-exp GPIO driver");
> +MODULE_ALIAS("platform:brcmexp-gpio");
> diff --git a/include/soc/bcm2835/raspberrypi-firmware.h b/include/soc/bcm2835/raspberrypi-firmware.h
> index 2859db0..56b3f0f 100644
> --- a/include/soc/bcm2835/raspberrypi-firmware.h
> +++ b/include/soc/bcm2835/raspberrypi-firmware.h
> @@ -83,7 +83,11 @@ enum rpi_firmware_property_tag {
> 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,
>
> /* Dispmanx TAGS */
> RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE = 0x00040001,
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