diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0047-Add-dev-gpiomem-device-for-rootless-user-GPIO-access.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0047-Add-dev-gpiomem-device-for-rootless-user-GPIO-access.patch | 303 |
1 files changed, 0 insertions, 303 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0047-Add-dev-gpiomem-device-for-rootless-user-GPIO-access.patch b/target/linux/brcm2708/patches-4.19/950-0047-Add-dev-gpiomem-device-for-rootless-user-GPIO-access.patch deleted file mode 100644 index 6afffd2a16..0000000000 --- a/target/linux/brcm2708/patches-4.19/950-0047-Add-dev-gpiomem-device-for-rootless-user-GPIO-access.patch +++ /dev/null @@ -1,303 +0,0 @@ -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>"); |