target/linux/bcm27xx/patches-5.4/950-0051-char-broadcom-Add-vcio-module.patch

   1 From 665ddd6b1e4bad3473ef5f4834c04db3e8968867 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 char: vcio: Add compat ioctl handling
  15
  16 There was no compat ioctl handler, so 32 bit userspace on a
  17 64 bit kernel failed as IOCTL_MBOX_PROPERTY used the size
  18 of char*.
  19
  20 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
  21
  22 char: vcio: Fail probe if rpi_firmware is not found.
  23
  24 Device Tree is now the only supported config mechanism, therefore
  25 uncomment the block of code that fails the probe if the
  26 firmware node can't be found.
  27
  28 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
  29 ---
  30  drivers/char/broadcom/Kconfig  |   6 +
  31  drivers/char/broadcom/Makefile |   1 +
  32  drivers/char/broadcom/vcio.c   | 194 +++++++++++++++++++++++++++++++++
  33  3 files changed, 201 insertions(+)
  34  create mode 100644 drivers/char/broadcom/vcio.c
  35
  36 --- a/drivers/char/broadcom/Kconfig
  37 +++ b/drivers/char/broadcom/Kconfig
  38 @@ -15,6 +15,12 @@ config BCM2708_VCMEM
  39          help
  40            Helper for videocore memory access and total size allocation.
  41
  42 +config BCM_VCIO
  43 +       tristate "Mailbox userspace access"
  44 +       depends on BCM2835_MBOX
  45 +       help
  46 +         Gives access to the mailbox property channel from userspace.
  47 +
  48  endif
  49
  50  config BCM_VC_SM
  51 --- a/drivers/char/broadcom/Makefile
  52 +++ b/drivers/char/broadcom/Makefile
  53 @@ -1,4 +1,5 @@
  54  obj-$(CONFIG_BCM2708_VCMEM)    += vc_mem.o
  55 +obj-$(CONFIG_BCM_VCIO)         += vcio.o
  56  obj-$(CONFIG_BCM_VC_SM)         += vc_sm/
  57
  58  obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
  59 --- /dev/null
  60 +++ b/drivers/char/broadcom/vcio.c
  61 @@ -0,0 +1,194 @@
  62 +/*
  63 + *  Copyright (C) 2010 Broadcom
  64 + *  Copyright (C) 2015 Noralf Trønnes
  65 + *
  66 + * This program is free software; you can redistribute it and/or modify
  67 + * it under the terms of the GNU General Public License version 2 as
  68 + * published by the Free Software Foundation.
  69 + *
  70 + */
  71 +
  72 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  73 +
  74 +#include <linux/cdev.h>
  75 +#include <linux/device.h>
  76 +#include <linux/fs.h>
  77 +#include <linux/init.h>
  78 +#include <linux/ioctl.h>
  79 +#include <linux/module.h>
  80 +#include <linux/slab.h>
  81 +#include <linux/uaccess.h>
  82 +#include <soc/bcm2835/raspberrypi-firmware.h>
  83 +
  84 +#define MBOX_CHAN_PROPERTY 8
  85 +
  86 +#define VCIO_IOC_MAGIC 100
  87 +#define IOCTL_MBOX_PROPERTY _IOWR(VCIO_IOC_MAGIC, 0, char *)
  88 +#ifdef CONFIG_COMPAT
  89 +#define IOCTL_MBOX_PROPERTY32 _IOWR(VCIO_IOC_MAGIC, 0, compat_uptr_t)
  90 +#endif
  91 +
  92 +static struct {
  93 +       dev_t devt;
  94 +       struct cdev cdev;
  95 +       struct class *class;
  96 +       struct rpi_firmware *fw;
  97 +} vcio;
  98 +
  99 +static int vcio_user_property_list(void *user)
 100 +{
 101 +       u32 *buf, size;
 102 +       int ret;
 103 +
 104 +       /* The first 32-bit is the size of the buffer */
 105 +       if (copy_from_user(&size, user, sizeof(size)))
 106 +               return -EFAULT;
 107 +
 108 +       buf = kmalloc(size, GFP_KERNEL);
 109 +       if (!buf)
 110 +               return -ENOMEM;
 111 +
 112 +       if (copy_from_user(buf, user, size)) {
 113 +               kfree(buf);
 114 +               return -EFAULT;
 115 +       }
 116 +
 117 +       /* Strip off protocol encapsulation */
 118 +       ret = rpi_firmware_property_list(vcio.fw, &buf[2], size - 12);
 119 +       if (ret) {
 120 +               kfree(buf);
 121 +               return ret;
 122 +       }
 123 +
 124 +       buf[1] = RPI_FIRMWARE_STATUS_SUCCESS;
 125 +       if (copy_to_user(user, buf, size))
 126 +               ret = -EFAULT;
 127 +
 128 +       kfree(buf);
 129 +
 130 +       return ret;
 131 +}
 132 +
 133 +static int vcio_device_open(struct inode *inode, struct file *file)
 134 +{
 135 +       try_module_get(THIS_MODULE);
 136 +
 137 +       return 0;
 138 +}
 139 +
 140 +static int vcio_device_release(struct inode *inode, struct file *file)
 141 +{
 142 +       module_put(THIS_MODULE);
 143 +
 144 +       return 0;
 145 +}
 146 +
 147 +static long vcio_device_ioctl(struct file *file, unsigned int ioctl_num,
 148 +                             unsigned long ioctl_param)
 149 +{
 150 +       switch (ioctl_num) {
 151 +       case IOCTL_MBOX_PROPERTY:
 152 +               return vcio_user_property_list((void *)ioctl_param);
 153 +       default:
 154 +               pr_err("unknown ioctl: %x\n", ioctl_num);
 155 +               return -EINVAL;
 156 +       }
 157 +}
 158 +
 159 +#ifdef CONFIG_COMPAT
 160 +static long vcio_device_compat_ioctl(struct file *file, unsigned int ioctl_num,
 161 +                                    unsigned long ioctl_param)
 162 +{
 163 +       switch (ioctl_num) {
 164 +       case IOCTL_MBOX_PROPERTY32:
 165 +               return vcio_user_property_list(compat_ptr(ioctl_param));
 166 +       default:
 167 +               pr_err("unknown ioctl: %x\n", ioctl_num);
 168 +               return -EINVAL;
 169 +       }
 170 +}
 171 +#endif
 172 +
 173 +const struct file_operations vcio_fops = {
 174 +       .unlocked_ioctl = vcio_device_ioctl,
 175 +#ifdef CONFIG_COMPAT
 176 +       .compat_ioctl = vcio_device_compat_ioctl,
 177 +#endif
 178 +       .open = vcio_device_open,
 179 +       .release = vcio_device_release,
 180 +};
 181 +
 182 +static int __init vcio_init(void)
 183 +{
 184 +       struct device_node *np;
 185 +       static struct device *dev;
 186 +       int ret;
 187 +
 188 +       np = of_find_compatible_node(NULL, NULL,
 189 +                                    "raspberrypi,bcm2835-firmware");
 190 +       if (!of_device_is_available(np))
 191 +               return -ENODEV;
 192 +
 193 +       vcio.fw = rpi_firmware_get(np);
 194 +       if (!vcio.fw)
 195 +               return -ENODEV;
 196 +
 197 +       ret = alloc_chrdev_region(&vcio.devt, 0, 1, "vcio");
 198 +       if (ret) {
 199 +               pr_err("failed to allocate device number\n");
 200 +               return ret;
 201 +       }
 202 +
 203 +       cdev_init(&vcio.cdev, &vcio_fops);
 204 +       vcio.cdev.owner = THIS_MODULE;
 205 +       ret = cdev_add(&vcio.cdev, vcio.devt, 1);
 206 +       if (ret) {
 207 +               pr_err("failed to register device\n");
 208 +               goto err_unregister_chardev;
 209 +       }
 210 +
 211 +       /*
 212 +        * Create sysfs entries
 213 +        * 'bcm2708_vcio' is used for backwards compatibility so we don't break
 214 +        * userspace. Raspian has a udev rule that changes the permissions.
 215 +        */
 216 +       vcio.class = class_create(THIS_MODULE, "bcm2708_vcio");
 217 +       if (IS_ERR(vcio.class)) {
 218 +               ret = PTR_ERR(vcio.class);
 219 +               pr_err("failed to create class\n");
 220 +               goto err_cdev_del;
 221 +       }
 222 +
 223 +       dev = device_create(vcio.class, NULL, vcio.devt, NULL, "vcio");
 224 +       if (IS_ERR(dev)) {
 225 +               ret = PTR_ERR(dev);
 226 +               pr_err("failed to create device\n");
 227 +               goto err_class_destroy;
 228 +       }
 229 +
 230 +       return 0;
 231 +
 232 +err_class_destroy:
 233 +       class_destroy(vcio.class);
 234 +err_cdev_del:
 235 +       cdev_del(&vcio.cdev);
 236 +err_unregister_chardev:
 237 +       unregister_chrdev_region(vcio.devt, 1);
 238 +
 239 +       return ret;
 240 +}
 241 +module_init(vcio_init);
 242 +
 243 +static void __exit vcio_exit(void)
 244 +{
 245 +       device_destroy(vcio.class, vcio.devt);
 246 +       class_destroy(vcio.class);
 247 +       cdev_del(&vcio.cdev);
 248 +       unregister_chrdev_region(vcio.devt, 1);
 249 +}
 250 +module_exit(vcio_exit);
 251 +
 252 +MODULE_AUTHOR("Gray Girling");
 253 +MODULE_AUTHOR("Noralf Trønnes");
 254 +MODULE_DESCRIPTION("Mailbox userspace access");
 255 +MODULE_LICENSE("GPL");