target/linux/brcm2708/patches-4.19/950-0054-char-broadcom-Add-vcio-module.patch

   1 From 9fc71e9f5ee71c3f91b43c8c94a0db17349b938c 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 054/703] 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 @@ -15,6 +15,12 @@ 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 @@ -1,4 +1,5 @@
  38  obj-$(CONFIG_BCM2708_VCMEM)    += vc_mem.o
  39 +obj-$(CONFIG_BCM_VCIO)         += vcio.o
  40  obj-$(CONFIG_BCM_VC_SM)         += vc_sm/
  41
  42  obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
  43 --- /dev/null
  44 +++ b/drivers/char/broadcom/vcio.c
  45 @@ -0,0 +1,175 @@
  46 +/*
  47 + *  Copyright (C) 2010 Broadcom
  48 + *  Copyright (C) 2015 Noralf Trønnes
  49 + *
  50 + * This program is free software; you can redistribute it and/or modify
  51 + * it under the terms of the GNU General Public License version 2 as
  52 + * published by the Free Software Foundation.
  53 + *
  54 + */
  55 +
  56 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  57 +
  58 +#include <linux/cdev.h>
  59 +#include <linux/device.h>
  60 +#include <linux/fs.h>
  61 +#include <linux/init.h>
  62 +#include <linux/ioctl.h>
  63 +#include <linux/module.h>
  64 +#include <linux/slab.h>
  65 +#include <linux/uaccess.h>
  66 +#include <soc/bcm2835/raspberrypi-firmware.h>
  67 +
  68 +#define MBOX_CHAN_PROPERTY 8
  69 +
  70 +#define VCIO_IOC_MAGIC 100
  71 +#define IOCTL_MBOX_PROPERTY _IOWR(VCIO_IOC_MAGIC, 0, char *)
  72 +
  73 +static struct {
  74 +       dev_t devt;
  75 +       struct cdev cdev;
  76 +       struct class *class;
  77 +       struct rpi_firmware *fw;
  78 +} vcio;
  79 +
  80 +static int vcio_user_property_list(void *user)
  81 +{
  82 +       u32 *buf, size;
  83 +       int ret;
  84 +
  85 +       /* The first 32-bit is the size of the buffer */
  86 +       if (copy_from_user(&size, user, sizeof(size)))
  87 +               return -EFAULT;
  88 +
  89 +       buf = kmalloc(size, GFP_KERNEL);
  90 +       if (!buf)
  91 +               return -ENOMEM;
  92 +
  93 +       if (copy_from_user(buf, user, size)) {
  94 +               kfree(buf);
  95 +               return -EFAULT;
  96 +       }
  97 +
  98 +       /* Strip off protocol encapsulation */
  99 +       ret = rpi_firmware_property_list(vcio.fw, &buf[2], size - 12);
 100 +       if (ret) {
 101 +               kfree(buf);
 102 +               return ret;
 103 +       }
 104 +
 105 +       buf[1] = RPI_FIRMWARE_STATUS_SUCCESS;
 106 +       if (copy_to_user(user, buf, size))
 107 +               ret = -EFAULT;
 108 +
 109 +       kfree(buf);
 110 +
 111 +       return ret;
 112 +}
 113 +
 114 +static int vcio_device_open(struct inode *inode, struct file *file)
 115 +{
 116 +       try_module_get(THIS_MODULE);
 117 +
 118 +       return 0;
 119 +}
 120 +
 121 +static int vcio_device_release(struct inode *inode, struct file *file)
 122 +{
 123 +       module_put(THIS_MODULE);
 124 +
 125 +       return 0;
 126 +}
 127 +
 128 +static long vcio_device_ioctl(struct file *file, unsigned int ioctl_num,
 129 +                             unsigned long ioctl_param)
 130 +{
 131 +       switch (ioctl_num) {
 132 +       case IOCTL_MBOX_PROPERTY:
 133 +               return vcio_user_property_list((void *)ioctl_param);
 134 +       default:
 135 +               pr_err("unknown ioctl: %d\n", ioctl_num);
 136 +               return -EINVAL;
 137 +       }
 138 +}
 139 +
 140 +const struct file_operations vcio_fops = {
 141 +       .unlocked_ioctl = vcio_device_ioctl,
 142 +       .open = vcio_device_open,
 143 +       .release = vcio_device_release,
 144 +};
 145 +
 146 +static int __init vcio_init(void)
 147 +{
 148 +       struct device_node *np;
 149 +       static struct device *dev;
 150 +       int ret;
 151 +
 152 +       np = of_find_compatible_node(NULL, NULL,
 153 +                                    "raspberrypi,bcm2835-firmware");
 154 +/* Uncomment this when we only boot with Device Tree
 155 +       if (!of_device_is_available(np))
 156 +               return -ENODEV;
 157 +*/
 158 +       vcio.fw = rpi_firmware_get(np);
 159 +       if (!vcio.fw)
 160 +               return -ENODEV;
 161 +
 162 +       ret = alloc_chrdev_region(&vcio.devt, 0, 1, "vcio");
 163 +       if (ret) {
 164 +               pr_err("failed to allocate device number\n");
 165 +               return ret;
 166 +       }
 167 +
 168 +       cdev_init(&vcio.cdev, &vcio_fops);
 169 +       vcio.cdev.owner = THIS_MODULE;
 170 +       ret = cdev_add(&vcio.cdev, vcio.devt, 1);
 171 +       if (ret) {
 172 +               pr_err("failed to register device\n");
 173 +               goto err_unregister_chardev;
 174 +       }
 175 +
 176 +       /*
 177 +        * Create sysfs entries
 178 +        * 'bcm2708_vcio' is used for backwards compatibility so we don't break
 179 +        * userspace. Raspian has a udev rule that changes the permissions.
 180 +        */
 181 +       vcio.class = class_create(THIS_MODULE, "bcm2708_vcio");
 182 +       if (IS_ERR(vcio.class)) {
 183 +               ret = PTR_ERR(vcio.class);
 184 +               pr_err("failed to create class\n");
 185 +               goto err_cdev_del;
 186 +       }
 187 +
 188 +       dev = device_create(vcio.class, NULL, vcio.devt, NULL, "vcio");
 189 +       if (IS_ERR(dev)) {
 190 +               ret = PTR_ERR(dev);
 191 +               pr_err("failed to create device\n");
 192 +               goto err_class_destroy;
 193 +       }
 194 +
 195 +       return 0;
 196 +
 197 +err_class_destroy:
 198 +       class_destroy(vcio.class);
 199 +err_cdev_del:
 200 +       cdev_del(&vcio.cdev);
 201 +err_unregister_chardev:
 202 +       unregister_chrdev_region(vcio.devt, 1);
 203 +
 204 +       return ret;
 205 +}
 206 +module_init(vcio_init);
 207 +
 208 +static void __exit vcio_exit(void)
 209 +{
 210 +       device_destroy(vcio.class, vcio.devt);
 211 +       class_destroy(vcio.class);
 212 +       cdev_del(&vcio.cdev);
 213 +       unregister_chrdev_region(vcio.devt, 1);
 214 +}
 215 +module_exit(vcio_exit);
 216 +
 217 +MODULE_AUTHOR("Gray Girling");
 218 +MODULE_AUTHOR("Noralf Trønnes");
 219 +MODULE_DESCRIPTION("Mailbox userspace access");
 220 +MODULE_LICENSE("GPL");