target/linux/brcm2708/patches-4.9/0049-char-broadcom-Add-vcio-module.patch

   1 From 2e8101a5e6228109d2cd5b965b6077e63e643d6b Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
   3 Date: Fri, 26 Jun 2015 14:27:06 +0200
   4 Subject: [PATCH] char: broadcom: Add vcio module
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Add module for accessing the mailbox property channel through
  10 /dev/vcio. Was previously in bcm2708-vcio.
  11
  12 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  13 ---
  14  drivers/char/broadcom/Kconfig  |   6 ++
  15  drivers/char/broadcom/Makefile |   1 +
  16  drivers/char/broadcom/vcio.c   | 175 +++++++++++++++++++++++++++++++++++++++++
  17  3 files changed, 182 insertions(+)
  18  create mode 100644 drivers/char/broadcom/vcio.c
  19
  20 --- a/drivers/char/broadcom/Kconfig
  21 +++ b/drivers/char/broadcom/Kconfig
  22 @@ -22,6 +22,12 @@ config BCM2708_VCMEM
  23          help
  24            Helper for videocore memory access and total size allocation.
  25
  26 +config BCM_VCIO
  27 +       tristate "Mailbox userspace access"
  28 +       depends on BCM2835_MBOX
  29 +       help
  30 +         Gives access to the mailbox property channel from userspace.
  31 +
  32  endif
  33
  34  config BCM_VC_SM
  35 --- a/drivers/char/broadcom/Makefile
  36 +++ b/drivers/char/broadcom/Makefile
  37 @@ -1,5 +1,6 @@
  38  obj-$(CONFIG_BCM_VC_CMA)       += vc_cma/
  39  obj-$(CONFIG_BCM2708_VCMEM)    += vc_mem.o
  40 +obj-$(CONFIG_BCM_VCIO)         += vcio.o
  41  obj-$(CONFIG_BCM_VC_SM)         += vc_sm/
  42
  43  obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
  44 --- /dev/null
  45 +++ b/drivers/char/broadcom/vcio.c
  46 @@ -0,0 +1,175 @@
  47 +/*
  48 + *  Copyright (C) 2010 Broadcom
  49 + *  Copyright (C) 2015 Noralf Trønnes
  50 + *
  51 + * This program is free software; you can redistribute it and/or modify
  52 + * it under the terms of the GNU General Public License version 2 as
  53 + * published by the Free Software Foundation.
  54 + *
  55 + */
  56 +
  57 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  58 +
  59 +#include <linux/cdev.h>
  60 +#include <linux/device.h>
  61 +#include <linux/fs.h>
  62 +#include <linux/init.h>
  63 +#include <linux/ioctl.h>
  64 +#include <linux/module.h>
  65 +#include <linux/slab.h>
  66 +#include <linux/uaccess.h>
  67 +#include <soc/bcm2835/raspberrypi-firmware.h>
  68 +
  69 +#define MBOX_CHAN_PROPERTY 8
  70 +
  71 +#define VCIO_IOC_MAGIC 100
  72 +#define IOCTL_MBOX_PROPERTY _IOWR(VCIO_IOC_MAGIC, 0, char *)
  73 +
  74 +static struct {
  75 +       dev_t devt;
  76 +       struct cdev cdev;
  77 +       struct class *class;
  78 +       struct rpi_firmware *fw;
  79 +} vcio;
  80 +
  81 +static int vcio_user_property_list(void *user)
  82 +{
  83 +       u32 *buf, size;
  84 +       int ret;
  85 +
  86 +       /* The first 32-bit is the size of the buffer */
  87 +       if (copy_from_user(&size, user, sizeof(size)))
  88 +               return -EFAULT;
  89 +
  90 +       buf = kmalloc(size, GFP_KERNEL);
  91 +       if (!buf)
  92 +               return -ENOMEM;
  93 +
  94 +       if (copy_from_user(buf, user, size)) {
  95 +               kfree(buf);
  96 +               return -EFAULT;
  97 +       }
  98 +
  99 +       /* Strip off protocol encapsulation */
 100 +       ret = rpi_firmware_property_list(vcio.fw, &buf[2], size - 12);
 101 +       if (ret) {
 102 +               kfree(buf);
 103 +               return ret;
 104 +       }
 105 +
 106 +       buf[1] = RPI_FIRMWARE_STATUS_SUCCESS;
 107 +       if (copy_to_user(user, buf, size))
 108 +               ret = -EFAULT;
 109 +
 110 +       kfree(buf);
 111 +
 112 +       return ret;
 113 +}
 114 +
 115 +static int vcio_device_open(struct inode *inode, struct file *file)
 116 +{
 117 +       try_module_get(THIS_MODULE);
 118 +
 119 +       return 0;
 120 +}
 121 +
 122 +static int vcio_device_release(struct inode *inode, struct file *file)
 123 +{
 124 +       module_put(THIS_MODULE);
 125 +
 126 +       return 0;
 127 +}
 128 +
 129 +static long vcio_device_ioctl(struct file *file, unsigned int ioctl_num,
 130 +                             unsigned long ioctl_param)
 131 +{
 132 +       switch (ioctl_num) {
 133 +       case IOCTL_MBOX_PROPERTY:
 134 +               return vcio_user_property_list((void *)ioctl_param);
 135 +       default:
 136 +               pr_err("unknown ioctl: %d\n", ioctl_num);
 137 +               return -EINVAL;
 138 +       }
 139 +}
 140 +
 141 +const struct file_operations vcio_fops = {
 142 +       .unlocked_ioctl = vcio_device_ioctl,
 143 +       .open = vcio_device_open,
 144 +       .release = vcio_device_release,
 145 +};
 146 +
 147 +static int __init vcio_init(void)
 148 +{
 149 +       struct device_node *np;
 150 +       static struct device *dev;
 151 +       int ret;
 152 +
 153 +       np = of_find_compatible_node(NULL, NULL,
 154 +                                    "raspberrypi,bcm2835-firmware");
 155 +/* Uncomment this when we only boot with Device Tree
 156 +       if (!of_device_is_available(np))
 157 +               return -ENODEV;
 158 +*/
 159 +       vcio.fw = rpi_firmware_get(np);
 160 +       if (!vcio.fw)
 161 +               return -ENODEV;
 162 +
 163 +       ret = alloc_chrdev_region(&vcio.devt, 0, 1, "vcio");
 164 +       if (ret) {
 165 +               pr_err("failed to allocate device number\n");
 166 +               return ret;
 167 +       }
 168 +
 169 +       cdev_init(&vcio.cdev, &vcio_fops);
 170 +       vcio.cdev.owner = THIS_MODULE;
 171 +       ret = cdev_add(&vcio.cdev, vcio.devt, 1);
 172 +       if (ret) {
 173 +               pr_err("failed to register device\n");
 174 +               goto err_unregister_chardev;
 175 +       }
 176 +
 177 +       /*
 178 +        * Create sysfs entries
 179 +        * 'bcm2708_vcio' is used for backwards compatibility so we don't break
 180 +        * userspace. Raspian has a udev rule that changes the permissions.
 181 +        */
 182 +       vcio.class = class_create(THIS_MODULE, "bcm2708_vcio");
 183 +       if (IS_ERR(vcio.class)) {
 184 +               ret = PTR_ERR(vcio.class);
 185 +               pr_err("failed to create class\n");
 186 +               goto err_cdev_del;
 187 +       }
 188 +
 189 +       dev = device_create(vcio.class, NULL, vcio.devt, NULL, "vcio");
 190 +       if (IS_ERR(dev)) {
 191 +               ret = PTR_ERR(dev);
 192 +               pr_err("failed to create device\n");
 193 +               goto err_class_destroy;
 194 +       }
 195 +
 196 +       return 0;
 197 +
 198 +err_class_destroy:
 199 +       class_destroy(vcio.class);
 200 +err_cdev_del:
 201 +       cdev_del(&vcio.cdev);
 202 +err_unregister_chardev:
 203 +       unregister_chrdev_region(vcio.devt, 1);
 204 +
 205 +       return ret;
 206 +}
 207 +module_init(vcio_init);
 208 +
 209 +static void __exit vcio_exit(void)
 210 +{
 211 +       device_destroy(vcio.class, vcio.devt);
 212 +       class_destroy(vcio.class);
 213 +       cdev_del(&vcio.cdev);
 214 +       unregister_chrdev_region(vcio.devt, 1);
 215 +}
 216 +module_exit(vcio_exit);
 217 +
 218 +MODULE_AUTHOR("Gray Girling");
 219 +MODULE_AUTHOR("Noralf Trønnes");
 220 +MODULE_DESCRIPTION("Mailbox userspace access");
 221 +MODULE_LICENSE("GPL");