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/*
* Copyright 2009 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
static unsigned long iim_reg_base0, iim_reg_end0, iim_reg_size0;
static unsigned long iim_reg_base1, iim_reg_end1, iim_reg_size1;
static struct device *iim_dev;
/*!
* MXS Virtual IIM interface - memory map function
* This function maps one page size VIIM registers from VIIM base address0
* if the size of the required virtual memory space is less than or equal to
* one page size, otherwise this function will also map one page size VIIM
* registers from VIIM base address1.
*
* @param file struct file *
* @param vma structure vm_area_struct *
*
* @return Return 0 on success or negative error code on error
*/
static int mxs_viim_mmap(struct file *file, struct vm_area_struct *vma)
{
size_t size = vma->vm_end - vma->vm_start;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
iim_reg_base0 >> PAGE_SHIFT,
iim_reg_size0,
vma->vm_page_prot))
return -EAGAIN;
if (size > iim_reg_size0) {
if (remap_pfn_range(vma,
vma->vm_start + iim_reg_size0,
iim_reg_base1 >> PAGE_SHIFT,
iim_reg_size1,
vma->vm_page_prot))
return -EAGAIN;
}
return 0;
}
/*!
* MXS Virtual IIM interface - open function
*
* @param inode struct inode *
* @param filp struct file *
*
* @return Return 0 on success or negative error code on error
*/
static int mxs_viim_open(struct inode *inode, struct file *filp)
{
return 0;
}
/*!
* MXS Virtual IIM interface - release function
*
* @param inode struct inode *
* @param filp struct file *
*
* @return Return 0 on success or negative error code on error
*/
static int mxs_viim_release(struct inode *inode, struct file *filp)
{
return 0;
}
static const struct file_operations mxs_viim_fops = {
.mmap = mxs_viim_mmap,
.open = mxs_viim_open,
.release = mxs_viim_release,
};
static struct miscdevice mxs_viim_miscdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "mxs_viim",
.fops = &mxs_viim_fops,
};
/*!
* This function is called by the driver framework to get virtual iim base/end
* address and register iim misc device.
*
* @param dev The device structure for Virtual IIM passed in by the
* driver framework.
*
* @return Returns 0 on success or negative error code on error
*/
static int mxs_viim_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
iim_dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (IS_ERR(res)) {
dev_err(iim_dev, "Unable to get Virtual IIM resource 0\n");
return -ENODEV;
}
iim_reg_base0 = res->start;
iim_reg_end0 = res->end;
iim_reg_size0 = iim_reg_end0 - iim_reg_base0 + 1;
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (IS_ERR(res)) {
dev_err(iim_dev, "Unable to get Virtual IIM resource 1\n");
return -ENODEV;
}
iim_reg_base1 = res->start;
iim_reg_end1 = res->end;
iim_reg_size1 = iim_reg_end1 - iim_reg_base1 + 1;
ret = misc_register(&mxs_viim_miscdev);
if (ret)
return ret;
return 0;
}
static int mxs_viim_remove(struct platform_device *pdev)
{
misc_deregister(&mxs_viim_miscdev);
return 0;
}
static struct platform_driver mxs_viim_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "mxs_viim",
},
.probe = mxs_viim_probe,
.remove = mxs_viim_remove,
};
static int __init mxs_viim_dev_init(void)
{
return platform_driver_register(&mxs_viim_driver);
}
static void __exit mxs_viim_dev_cleanup(void)
{
platform_driver_unregister(&mxs_viim_driver);
}
module_init(mxs_viim_dev_init);
module_exit(mxs_viim_dev_cleanup);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MXS Virtual IIM driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
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