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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/clk.h>
#include <linux/miscdevice.h>
static unsigned long iim_reg_base, iim_reg_end, iim_reg_size;
static struct clk *iim_clk;
static struct device *iim_dev;
/*!
* MXC IIM interface - memory map function
* This function maps 4KB IIM registers from IIM base address.
*
* @param file struct file *
* @param vma structure vm_area_struct *
*
* @return Return 0 on success or negative error code on error
*/
static int mxc_iim_mmap(struct file *file, struct vm_area_struct *vma)
{
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_base >> PAGE_SHIFT,
iim_reg_size,
vma->vm_page_prot))
return -EAGAIN;
return 0;
}
/*!
* MXC 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 mxc_iim_open(struct inode *inode, struct file *filp)
{
iim_clk = clk_get(NULL, "iim_clk");
if (IS_ERR(iim_clk)) {
dev_err(iim_dev, "No IIM clock defined\n");
return -ENODEV;
}
clk_enable(iim_clk);
return 0;
}
/*!
* MXC 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 mxc_iim_release(struct inode *inode, struct file *filp)
{
clk_disable(iim_clk);
clk_put(iim_clk);
return 0;
}
static const struct file_operations mxc_iim_fops = {
.mmap = mxc_iim_mmap,
.open = mxc_iim_open,
.release = mxc_iim_release,
};
static struct miscdevice mxc_iim_miscdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "mxc_iim",
.fops = &mxc_iim_fops,
};
/*!
* This function is called by the driver framework to get iim base/end address
* and register iim misc device.
*
* @param dev The device structure for IIM passed in by the driver
* framework.
*
* @return Returns 0 on success or negative error code on error
*/
static int mxc_iim_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 IIM resource\n");
return -ENODEV;
}
iim_reg_base = res->start;
iim_reg_end = res->end;
iim_reg_size = iim_reg_end - iim_reg_base + 1;
ret = misc_register(&mxc_iim_miscdev);
if (ret)
return ret;
return 0;
}
static int mxc_iim_remove(struct platform_device *pdev)
{
misc_deregister(&mxc_iim_miscdev);
return 0;
}
static struct platform_driver mxc_iim_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "mxc_iim",
},
.probe = mxc_iim_probe,
.remove = mxc_iim_remove,
};
static int __init mxc_iim_dev_init(void)
{
return platform_driver_register(&mxc_iim_driver);
}
static void __exit mxc_iim_dev_cleanup(void)
{
platform_driver_unregister(&mxc_iim_driver);
}
module_init(mxc_iim_dev_init);
module_exit(mxc_iim_dev_cleanup);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MXC IIM driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
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