From 2f8f62fbd42a55825da437faba4b6164f2e0bee9 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Mon, 20 Feb 2017 17:01:21 +0000
Subject: [PATCH] bcm2835-gpio-exp: Driver for GPIO expander via mailbox
service
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@raspberrypi.org>
---
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
--- a/arch/arm/boot/dts/bcm2710-rpi-3-b.dts
+++ b/arch/arm/boot/dts/bcm2710-rpi-3-b.dts
@@ -96,6 +96,14 @@
firmware = <&firmware>;
status = "okay";
};
+
+ expgpio: expgpio {
+ compatible = "brcm,bcm2835-expgpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ firmware = <&firmware>;
+ status = "okay";
+ };
};
&fb {
@@ -163,6 +171,16 @@
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 {
@@ -193,6 +211,10 @@
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";
--- a/arch/arm/boot/dts/bcm2710-rpi-cm3.dts
+++ b/arch/arm/boot/dts/bcm2710-rpi-cm3.dts
@@ -65,6 +65,14 @@
firmware = <&firmware>;
status = "okay";
};
+
+ expgpio: expgpio {
+ compatible = "brcm,bcm2835-expgpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ firmware = <&firmware>;
+ status = "okay";
+ };
};
&fb {
@@ -123,7 +131,7 @@
};
&hdmi {
- hpd-gpios = <&gpio 46 GPIO_ACTIVE_LOW>;
+ hpd-gpios = <&expgpio 0 GPIO_ACTIVE_LOW>;
};
&audio {
--- a/arch/arm/configs/bcm2709_defconfig
+++ b/arch/arm/configs/bcm2709_defconfig
@@ -625,6 +625,7 @@ 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
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -128,6 +128,13 @@ config GPIO_AXP209
help
Say yes to enable GPIO support for the AXP209 PMIC
+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)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizo
obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o
obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed.o
obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.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
--- /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@raspberrypi.org>
+ * Based on gpio-bcm-virt.c by Dom Cobley <popcornmix@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@raspberrypi.org>");
+MODULE_DESCRIPTION("brcm-exp GPIO driver");
+MODULE_ALIAS("platform:brcmexp-gpio");
--- 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,