mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 17:18:59 +00:00
7d7aa2fd92
This change makes the names of Broadcom targets consistent by using the common notation based on SoC/CPU ID (which is used internally anyway), bcmXXXX instead of brcmXXXX. This is even used for target TITLE in make menuconfig already, only the short target name used brcm so far. Despite, since subtargets range from bcm2708 to bcm2711, it seems appropriate to use bcm27xx instead of bcm2708 (again, as already done for BOARDNAME). This also renames the packages brcm2708-userland and brcm2708-gpu-fw. Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de> Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
304 lines
9.1 KiB
Diff
304 lines
9.1 KiB
Diff
From cff179ff275e8f7849384ad2876c9a3237eeac79 Mon Sep 17 00:00:00 2001
|
|
From: Luke Wren <luke@raspberrypi.org>
|
|
Date: Fri, 21 Aug 2015 23:14:48 +0100
|
|
Subject: [PATCH] Add /dev/gpiomem device for rootless user GPIO access
|
|
|
|
Signed-off-by: Luke Wren <luke@raspberrypi.org>
|
|
|
|
bcm2835-gpiomem: Fix for ARCH_BCM2835 builds
|
|
|
|
Build on ARCH_BCM2835, and fail to probe if no IO resource.
|
|
|
|
See: https://github.com/raspberrypi/linux/issues/1154
|
|
---
|
|
drivers/char/broadcom/Kconfig | 9 +
|
|
drivers/char/broadcom/Makefile | 3 +
|
|
drivers/char/broadcom/bcm2835-gpiomem.c | 258 ++++++++++++++++++++++++
|
|
3 files changed, 270 insertions(+)
|
|
create mode 100644 drivers/char/broadcom/bcm2835-gpiomem.c
|
|
|
|
--- a/drivers/char/broadcom/Kconfig
|
|
+++ b/drivers/char/broadcom/Kconfig
|
|
@@ -26,3 +26,12 @@ config BCM_VC_SM
|
|
help
|
|
Support for the VC shared memory on the Broadcom reference
|
|
design. Uses the VCHIQ stack.
|
|
+
|
|
+config BCM2835_DEVGPIOMEM
|
|
+ tristate "/dev/gpiomem rootless GPIO access via mmap() on the BCM2835"
|
|
+ default m
|
|
+ help
|
|
+ Provides users with root-free access to the GPIO registers
|
|
+ on the 2835. Calling mmap(/dev/gpiomem) will map the GPIO
|
|
+ register page to the user's pointer.
|
|
+
|
|
--- a/drivers/char/broadcom/Makefile
|
|
+++ b/drivers/char/broadcom/Makefile
|
|
@@ -1,2 +1,5 @@
|
|
obj-$(CONFIG_BCM2708_VCMEM) += vc_mem.o
|
|
obj-$(CONFIG_BCM_VC_SM) += vc_sm/
|
|
+
|
|
+obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
|
|
+
|
|
--- /dev/null
|
|
+++ b/drivers/char/broadcom/bcm2835-gpiomem.c
|
|
@@ -0,0 +1,258 @@
|
|
+/**
|
|
+ * GPIO memory device driver
|
|
+ *
|
|
+ * Creates a chardev /dev/gpiomem which will provide user access to
|
|
+ * the BCM2835's GPIO registers when it is mmap()'d.
|
|
+ * No longer need root for user GPIO access, but without relaxing permissions
|
|
+ * on /dev/mem.
|
|
+ *
|
|
+ * Written by Luke Wren <luke@raspberrypi.org>
|
|
+ * Copyright (c) 2015, Raspberry Pi (Trading) Ltd.
|
|
+ *
|
|
+ * Redistribution and use in source and binary forms, with or without
|
|
+ * modification, are permitted provided that the following conditions
|
|
+ * are met:
|
|
+ * 1. Redistributions of source code must retain the above copyright
|
|
+ * notice, this list of conditions, and the following disclaimer,
|
|
+ * without modification.
|
|
+ * 2. Redistributions in binary form must reproduce the above copyright
|
|
+ * notice, this list of conditions and the following disclaimer in the
|
|
+ * documentation and/or other materials provided with the distribution.
|
|
+ * 3. The names of the above-listed copyright holders may not be used
|
|
+ * to endorse or promote products derived from this software without
|
|
+ * specific prior written permission.
|
|
+ *
|
|
+ * ALTERNATIVELY, this software may be distributed under the terms of the
|
|
+ * GNU General Public License ("GPL") version 2, as published by the Free
|
|
+ * Software Foundation.
|
|
+ *
|
|
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
|
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
|
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
|
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
+ */
|
|
+
|
|
+#include <linux/kernel.h>
|
|
+#include <linux/module.h>
|
|
+#include <linux/of.h>
|
|
+#include <linux/platform_device.h>
|
|
+#include <linux/mm.h>
|
|
+#include <linux/slab.h>
|
|
+#include <linux/cdev.h>
|
|
+#include <linux/pagemap.h>
|
|
+#include <linux/io.h>
|
|
+
|
|
+#define DEVICE_NAME "bcm2835-gpiomem"
|
|
+#define DRIVER_NAME "gpiomem-bcm2835"
|
|
+#define DEVICE_MINOR 0
|
|
+
|
|
+struct bcm2835_gpiomem_instance {
|
|
+ unsigned long gpio_regs_phys;
|
|
+ struct device *dev;
|
|
+};
|
|
+
|
|
+static struct cdev bcm2835_gpiomem_cdev;
|
|
+static dev_t bcm2835_gpiomem_devid;
|
|
+static struct class *bcm2835_gpiomem_class;
|
|
+static struct device *bcm2835_gpiomem_dev;
|
|
+static struct bcm2835_gpiomem_instance *inst;
|
|
+
|
|
+
|
|
+/****************************************************************************
|
|
+*
|
|
+* GPIO mem chardev file ops
|
|
+*
|
|
+***************************************************************************/
|
|
+
|
|
+static int bcm2835_gpiomem_open(struct inode *inode, struct file *file)
|
|
+{
|
|
+ int dev = iminor(inode);
|
|
+ int ret = 0;
|
|
+
|
|
+ if (dev != DEVICE_MINOR) {
|
|
+ dev_err(inst->dev, "Unknown minor device: %d", dev);
|
|
+ ret = -ENXIO;
|
|
+ }
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+static int bcm2835_gpiomem_release(struct inode *inode, struct file *file)
|
|
+{
|
|
+ int dev = iminor(inode);
|
|
+ int ret = 0;
|
|
+
|
|
+ if (dev != DEVICE_MINOR) {
|
|
+ dev_err(inst->dev, "Unknown minor device %d", dev);
|
|
+ ret = -ENXIO;
|
|
+ }
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+static const struct vm_operations_struct bcm2835_gpiomem_vm_ops = {
|
|
+#ifdef CONFIG_HAVE_IOREMAP_PROT
|
|
+ .access = generic_access_phys
|
|
+#endif
|
|
+};
|
|
+
|
|
+static int bcm2835_gpiomem_mmap(struct file *file, struct vm_area_struct *vma)
|
|
+{
|
|
+ /* Ignore what the user says - they're getting the GPIO regs
|
|
+ whether they like it or not! */
|
|
+ unsigned long gpio_page = inst->gpio_regs_phys >> PAGE_SHIFT;
|
|
+
|
|
+ vma->vm_page_prot = phys_mem_access_prot(file, gpio_page,
|
|
+ PAGE_SIZE,
|
|
+ vma->vm_page_prot);
|
|
+ vma->vm_ops = &bcm2835_gpiomem_vm_ops;
|
|
+ if (remap_pfn_range(vma, vma->vm_start,
|
|
+ gpio_page,
|
|
+ PAGE_SIZE,
|
|
+ vma->vm_page_prot)) {
|
|
+ return -EAGAIN;
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static const struct file_operations
|
|
+bcm2835_gpiomem_fops = {
|
|
+ .owner = THIS_MODULE,
|
|
+ .open = bcm2835_gpiomem_open,
|
|
+ .release = bcm2835_gpiomem_release,
|
|
+ .mmap = bcm2835_gpiomem_mmap,
|
|
+};
|
|
+
|
|
+
|
|
+ /****************************************************************************
|
|
+*
|
|
+* Probe and remove functions
|
|
+*
|
|
+***************************************************************************/
|
|
+
|
|
+
|
|
+static int bcm2835_gpiomem_probe(struct platform_device *pdev)
|
|
+{
|
|
+ int err;
|
|
+ void *ptr_err;
|
|
+ struct device *dev = &pdev->dev;
|
|
+ struct resource *ioresource;
|
|
+
|
|
+ /* Allocate buffers and instance data */
|
|
+
|
|
+ inst = kzalloc(sizeof(struct bcm2835_gpiomem_instance), GFP_KERNEL);
|
|
+
|
|
+ if (!inst) {
|
|
+ err = -ENOMEM;
|
|
+ goto failed_inst_alloc;
|
|
+ }
|
|
+
|
|
+ inst->dev = dev;
|
|
+
|
|
+ ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
+ if (ioresource) {
|
|
+ inst->gpio_regs_phys = ioresource->start;
|
|
+ } else {
|
|
+ dev_err(inst->dev, "failed to get IO resource");
|
|
+ err = -ENOENT;
|
|
+ goto failed_get_resource;
|
|
+ }
|
|
+
|
|
+ /* Create character device entries */
|
|
+
|
|
+ err = alloc_chrdev_region(&bcm2835_gpiomem_devid,
|
|
+ DEVICE_MINOR, 1, DEVICE_NAME);
|
|
+ if (err != 0) {
|
|
+ dev_err(inst->dev, "unable to allocate device number");
|
|
+ goto failed_alloc_chrdev;
|
|
+ }
|
|
+ cdev_init(&bcm2835_gpiomem_cdev, &bcm2835_gpiomem_fops);
|
|
+ bcm2835_gpiomem_cdev.owner = THIS_MODULE;
|
|
+ err = cdev_add(&bcm2835_gpiomem_cdev, bcm2835_gpiomem_devid, 1);
|
|
+ if (err != 0) {
|
|
+ dev_err(inst->dev, "unable to register device");
|
|
+ goto failed_cdev_add;
|
|
+ }
|
|
+
|
|
+ /* Create sysfs entries */
|
|
+
|
|
+ bcm2835_gpiomem_class = class_create(THIS_MODULE, DEVICE_NAME);
|
|
+ ptr_err = bcm2835_gpiomem_class;
|
|
+ if (IS_ERR(ptr_err))
|
|
+ goto failed_class_create;
|
|
+
|
|
+ bcm2835_gpiomem_dev = device_create(bcm2835_gpiomem_class, NULL,
|
|
+ bcm2835_gpiomem_devid, NULL,
|
|
+ "gpiomem");
|
|
+ ptr_err = bcm2835_gpiomem_dev;
|
|
+ if (IS_ERR(ptr_err))
|
|
+ goto failed_device_create;
|
|
+
|
|
+ dev_info(inst->dev, "Initialised: Registers at 0x%08lx",
|
|
+ inst->gpio_regs_phys);
|
|
+
|
|
+ return 0;
|
|
+
|
|
+failed_device_create:
|
|
+ class_destroy(bcm2835_gpiomem_class);
|
|
+failed_class_create:
|
|
+ cdev_del(&bcm2835_gpiomem_cdev);
|
|
+ err = PTR_ERR(ptr_err);
|
|
+failed_cdev_add:
|
|
+ unregister_chrdev_region(bcm2835_gpiomem_devid, 1);
|
|
+failed_alloc_chrdev:
|
|
+failed_get_resource:
|
|
+ kfree(inst);
|
|
+failed_inst_alloc:
|
|
+ dev_err(inst->dev, "could not load bcm2835_gpiomem");
|
|
+ return err;
|
|
+}
|
|
+
|
|
+static int bcm2835_gpiomem_remove(struct platform_device *pdev)
|
|
+{
|
|
+ struct device *dev = inst->dev;
|
|
+
|
|
+ kfree(inst);
|
|
+ device_destroy(bcm2835_gpiomem_class, bcm2835_gpiomem_devid);
|
|
+ class_destroy(bcm2835_gpiomem_class);
|
|
+ cdev_del(&bcm2835_gpiomem_cdev);
|
|
+ unregister_chrdev_region(bcm2835_gpiomem_devid, 1);
|
|
+
|
|
+ dev_info(dev, "GPIO mem driver removed - OK");
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+ /****************************************************************************
|
|
+*
|
|
+* Register the driver with device tree
|
|
+*
|
|
+***************************************************************************/
|
|
+
|
|
+static const struct of_device_id bcm2835_gpiomem_of_match[] = {
|
|
+ {.compatible = "brcm,bcm2835-gpiomem",},
|
|
+ { /* sentinel */ },
|
|
+};
|
|
+
|
|
+MODULE_DEVICE_TABLE(of, bcm2835_gpiomem_of_match);
|
|
+
|
|
+static struct platform_driver bcm2835_gpiomem_driver = {
|
|
+ .probe = bcm2835_gpiomem_probe,
|
|
+ .remove = bcm2835_gpiomem_remove,
|
|
+ .driver = {
|
|
+ .name = DRIVER_NAME,
|
|
+ .owner = THIS_MODULE,
|
|
+ .of_match_table = bcm2835_gpiomem_of_match,
|
|
+ },
|
|
+};
|
|
+
|
|
+module_platform_driver(bcm2835_gpiomem_driver);
|
|
+
|
|
+MODULE_ALIAS("platform:gpiomem-bcm2835");
|
|
+MODULE_LICENSE("GPL");
|
|
+MODULE_DESCRIPTION("gpiomem driver for accessing GPIO from userspace");
|
|
+MODULE_AUTHOR("Luke Wren <luke@raspberrypi.org>");
|