summaryrefslogtreecommitdiff
path: root/drivers/char/mxs_viim.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/mxs_viim.c')
-rw-r--r--drivers/char/mxs_viim.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/char/mxs_viim.c b/drivers/char/mxs_viim.c
new file mode 100644
index 000000000000..302d967d12e2
--- /dev/null
+++ b/drivers/char/mxs_viim.c
@@ -0,0 +1,175 @@
+/*
+ * Copyright 2009-2010 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);