--- /dev/null
+From 0f05af4c96c0272bb431ace33dd284a891e4fe41 Mon Sep 17 00:00:00 2001
+From: popcornmix <popcornmix@gmail.com>
+Date: Tue, 23 Feb 2016 19:56:04 +0000
+Subject: [PATCH] bcm2835-virtgpio: Virtual GPIO driver
+
+Add a virtual GPIO driver that uses the firmware mailbox interface to
+request that the VPU toggles LEDs.
+---
+ drivers/gpio/Kconfig | 6 +
+ drivers/gpio/Makefile | 1 +
+ drivers/gpio/gpio-bcm-virt.c | 214 +++++++++++++++++++++++++++++++++++
+ 3 files changed, 221 insertions(+)
+ create mode 100644 drivers/gpio/gpio-bcm-virt.c
+
+--- a/drivers/gpio/Kconfig
++++ b/drivers/gpio/Kconfig
+@@ -151,6 +151,12 @@ config GPIO_BCM_KONA
+ help
+ Turn on GPIO support for Broadcom "Kona" chips.
+
++config GPIO_BCM_VIRT
++ bool "Broadcom Virt GPIO"
++ depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
++ help
++ Turn on virtual GPIO support for Broadcom BCM283X chips.
++
+ config GPIO_BRCMSTB
+ tristate "BRCMSTB GPIO support"
+ default y if (ARCH_BRCMSTB || BMIPS_GENERIC)
+--- a/drivers/gpio/Makefile
++++ b/drivers/gpio/Makefile
+@@ -35,6 +35,7 @@ obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed
+ obj-$(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-$(CONFIG_GPIO_BCM_VIRT) += gpio-bcm-virt.o
+ obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
+ obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
+ obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o
+--- /dev/null
++++ b/drivers/gpio/gpio-bcm-virt.c
+@@ -0,0 +1,214 @@
++/*
++ * brcmvirt GPIO driver
++ *
++ * Copyright (C) 2012,2013 Dom Cobley <popcornmix@gmail.com>
++ * Based on gpio-clps711x.c by Alexander Shiyan <shc_work@mail.ru>
++ *
++ * 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 "brcmvirt-gpio"
++#define NUM_GPIO 2
++
++struct brcmvirt_gpio {
++ struct gpio_chip gc;
++ u32 __iomem *ts_base;
++ /* two packed 16-bit counts of enabled and disables
++ Allows host to detect a brief enable that was missed */
++ u32 enables_disables[NUM_GPIO];
++ dma_addr_t bus_addr;
++};
++
++static int brcmvirt_gpio_dir_in(struct gpio_chip *gc, unsigned off)
++{
++ struct brcmvirt_gpio *gpio;
++ gpio = container_of(gc, struct brcmvirt_gpio, gc);
++ return -EINVAL;
++}
++
++static int brcmvirt_gpio_dir_out(struct gpio_chip *gc, unsigned off, int val)
++{
++ struct brcmvirt_gpio *gpio;
++ gpio = container_of(gc, struct brcmvirt_gpio, gc);
++ return 0;
++}
++
++static int brcmvirt_gpio_get(struct gpio_chip *gc, unsigned off)
++{
++ struct brcmvirt_gpio *gpio;
++ unsigned v;
++ gpio = container_of(gc, struct brcmvirt_gpio, gc);
++ v = readl(gpio->ts_base + off);
++ return (v >> off) & 1;
++}
++
++static void brcmvirt_gpio_set(struct gpio_chip *gc, unsigned off, int val)
++{
++ struct brcmvirt_gpio *gpio;
++ u16 enables, disables;
++ s16 diff;
++ bool lit;
++ gpio = container_of(gc, struct brcmvirt_gpio, gc);
++ enables = gpio->enables_disables[off] >> 16;
++ disables = gpio->enables_disables[off] >> 0;
++ diff = (s16)(enables - disables);
++ lit = diff > 0;
++ if ((val && lit) || (!val && !lit))
++ return;
++ if (val)
++ enables++;
++ else
++ disables++;
++ diff = (s16)(enables - disables);
++ BUG_ON(diff != 0 && diff != 1);
++ gpio->enables_disables[off] = (enables << 16) | (disables << 0);
++ writel(gpio->enables_disables[off], gpio->ts_base + off);
++}
++
++static int brcmvirt_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 brcmvirt_gpio *ucb;
++ u32 gpiovirtbuf;
++
++ 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) {
++ err = -EINVAL;
++ goto out;
++ }
++
++ ucb->ts_base = dma_zalloc_coherent(dev, PAGE_SIZE, &ucb->bus_addr, GFP_KERNEL);
++ if (!ucb->ts_base) {
++ pr_err("[%s]: failed to dma_alloc_coherent(%ld)\n",
++ __func__, PAGE_SIZE);
++ err = -ENOMEM;
++ goto out;
++ }
++
++ gpiovirtbuf = (u32)ucb->bus_addr;
++ err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF,
++ &gpiovirtbuf, sizeof(gpiovirtbuf));
++
++ if (err || gpiovirtbuf != 0) {
++ dev_warn(dev, "Failed to set gpiovirtbuf, trying to get err:%x\n", err);
++ dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
++ ucb->ts_base = 0;
++ ucb->bus_addr = 0;
++ }
++
++ if (!ucb->ts_base) {
++ err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
++ &gpiovirtbuf, sizeof(gpiovirtbuf));
++
++ if (err) {
++ dev_err(dev, "Failed to get gpiovirtbuf\n");
++ goto out;
++ }
++
++ if (!gpiovirtbuf) {
++ dev_err(dev, "No virtgpio buffer\n");
++ err = -ENOENT;
++ goto out;
++ }
++
++ // mmap the physical memory
++ gpiovirtbuf &= ~0xc0000000;
++ ucb->ts_base = ioremap(gpiovirtbuf, 4096);
++ if (ucb->ts_base == NULL) {
++ dev_err(dev, "Failed to map physical address\n");
++ err = -ENOENT;
++ goto out;
++ }
++ ucb->bus_addr = 0;
++ }
++ ucb->gc.label = MODULE_NAME;
++ ucb->gc.owner = THIS_MODULE;
++ //ucb->gc.dev = dev;
++ ucb->gc.of_node = np;
++ ucb->gc.base = 100;
++ ucb->gc.ngpio = NUM_GPIO;
++
++ ucb->gc.direction_input = brcmvirt_gpio_dir_in;
++ ucb->gc.direction_output = brcmvirt_gpio_dir_out;
++ ucb->gc.get = brcmvirt_gpio_get;
++ ucb->gc.set = brcmvirt_gpio_set;
++ ucb->gc.can_sleep = true;
++
++ err = gpiochip_add(&ucb->gc);
++ if (err)
++ goto out;
++
++ platform_set_drvdata(pdev, ucb);
++
++ return 0;
++out:
++ if (ucb->bus_addr) {
++ dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
++ ucb->bus_addr = 0;
++ ucb->ts_base = NULL;
++ } else if (ucb->ts_base) {
++ iounmap(ucb->ts_base);
++ ucb->ts_base = NULL;
++ }
++ return err;
++}
++
++static int brcmvirt_gpio_remove(struct platform_device *pdev)
++{
++ struct device *dev = &pdev->dev;
++ int err = 0;
++ struct brcmvirt_gpio *ucb = platform_get_drvdata(pdev);
++
++ gpiochip_remove(&ucb->gc);
++ if (ucb->bus_addr)
++ dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
++ else if (ucb->ts_base)
++ iounmap(ucb->ts_base);
++ return err;
++}
++
++static const struct of_device_id __maybe_unused brcmvirt_gpio_ids[] = {
++ { .compatible = "brcm,bcm2835-virtgpio" },
++ { }
++};
++MODULE_DEVICE_TABLE(of, brcmvirt_gpio_ids);
++
++static struct platform_driver brcmvirt_gpio_driver = {
++ .driver = {
++ .name = MODULE_NAME,
++ .owner = THIS_MODULE,
++ .of_match_table = of_match_ptr(brcmvirt_gpio_ids),
++ },
++ .probe = brcmvirt_gpio_probe,
++ .remove = brcmvirt_gpio_remove,
++};
++module_platform_driver(brcmvirt_gpio_driver);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Dom Cobley <popcornmix@gmail.com>");
++MODULE_DESCRIPTION("brcmvirt GPIO driver");
++MODULE_ALIAS("platform:brcmvirt-gpio");
projects / openwrt / openwrt.git / blobdiff