diff options
Diffstat (limited to 'drivers/char/broadcom/vcio.c')
| -rw-r--r-- | drivers/char/broadcom/vcio.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/char/broadcom/vcio.c b/drivers/char/broadcom/vcio.c new file mode 100644 index 000000000000..9db2408c781a --- /dev/null +++ b/drivers/char/broadcom/vcio.c @@ -0,0 +1,187 @@ +/* + * Copyright (C) 2010 Broadcom + * Copyright (C) 2015 Noralf Trønnes + * Copyright (C) 2021 Raspberry Pi (Trading) Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/ioctl.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/compat.h> +#include <linux/miscdevice.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <soc/bcm2835/raspberrypi-firmware.h> + +#define MODULE_NAME "vcio" +#define VCIO_IOC_MAGIC 100 +#define IOCTL_MBOX_PROPERTY _IOWR(VCIO_IOC_MAGIC, 0, char *) +#ifdef CONFIG_COMPAT +#define IOCTL_MBOX_PROPERTY32 _IOWR(VCIO_IOC_MAGIC, 0, compat_uptr_t) +#endif + +struct vcio_data { + struct rpi_firmware *fw; + struct miscdevice misc_dev; +}; + +static int vcio_user_property_list(struct vcio_data *vcio, void *user) +{ + u32 *buf, size; + int ret; + + /* The first 32-bit is the size of the buffer */ + if (copy_from_user(&size, user, sizeof(size))) + return -EFAULT; + + buf = kmalloc(size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (copy_from_user(buf, user, size)) { + kfree(buf); + return -EFAULT; + } + + /* Strip off protocol encapsulation */ + ret = rpi_firmware_property_list(vcio->fw, &buf[2], size - 12); + if (ret) { + kfree(buf); + return ret; + } + + buf[1] = RPI_FIRMWARE_STATUS_SUCCESS; + if (copy_to_user(user, buf, size)) + ret = -EFAULT; + + kfree(buf); + + return ret; +} + +static int vcio_device_open(struct inode *inode, struct file *file) +{ + try_module_get(THIS_MODULE); + + return 0; +} + +static int vcio_device_release(struct inode *inode, struct file *file) +{ + module_put(THIS_MODULE); + + return 0; +} + +static long vcio_device_ioctl(struct file *file, unsigned int ioctl_num, + unsigned long ioctl_param) +{ + struct vcio_data *vcio = container_of(file->private_data, + struct vcio_data, misc_dev); + + switch (ioctl_num) { + case IOCTL_MBOX_PROPERTY: + return vcio_user_property_list(vcio, (void *)ioctl_param); + default: + pr_err("unknown ioctl: %x\n", ioctl_num); + return -EINVAL; + } +} + +#ifdef CONFIG_COMPAT +static long vcio_device_compat_ioctl(struct file *file, unsigned int ioctl_num, + unsigned long ioctl_param) +{ + struct vcio_data *vcio = container_of(file->private_data, + struct vcio_data, misc_dev); + + switch (ioctl_num) { + case IOCTL_MBOX_PROPERTY32: + return vcio_user_property_list(vcio, compat_ptr(ioctl_param)); + default: + pr_err("unknown ioctl: %x\n", ioctl_num); + return -EINVAL; + } +} +#endif + +const struct file_operations vcio_fops = { + .unlocked_ioctl = vcio_device_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = vcio_device_compat_ioctl, +#endif + .open = vcio_device_open, + .release = vcio_device_release, +}; + +static int vcio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct device_node *fw_node; + struct rpi_firmware *fw; + struct vcio_data *vcio; + + fw_node = of_get_parent(np); + if (!fw_node) { + dev_err(dev, "Missing firmware node\n"); + return -ENOENT; + } + + fw = rpi_firmware_get(fw_node); + of_node_put(fw_node); + if (!fw) + return -EPROBE_DEFER; + + vcio = devm_kzalloc(dev, sizeof(struct vcio_data), GFP_KERNEL); + if (!vcio) + return -ENOMEM; + + vcio->fw = fw; + vcio->misc_dev.fops = &vcio_fops; + vcio->misc_dev.minor = MISC_DYNAMIC_MINOR; + vcio->misc_dev.name = "vcio"; + vcio->misc_dev.parent = dev; + + return misc_register(&vcio->misc_dev); +} + +static void vcio_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + + misc_deregister(dev_get_drvdata(dev)); +} + +static const struct of_device_id vcio_ids[] = { + { .compatible = "raspberrypi,vcio" }, + { } +}; +MODULE_DEVICE_TABLE(of, vcio_ids); + +static struct platform_driver vcio_driver = { + .driver = { + .name = MODULE_NAME, + .of_match_table = of_match_ptr(vcio_ids), + }, + .probe = vcio_probe, + .remove = vcio_remove, +}; + +module_platform_driver(vcio_driver); + +MODULE_AUTHOR("Gray Girling"); +MODULE_AUTHOR("Noralf Trønnes"); +MODULE_DESCRIPTION("Mailbox userspace access"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:rpi-vcio"); |