On 2/17/2012 12:46 PM, michael.hennerich@xxxxxxxxxx wrote:
From: Michael Hennerich<michael.hennerich@xxxxxxxxxx>
Please can we have some documentation for this. We may not 'have'
to keep debugfs interfaces the same, but they are a type of userspace
abi.
Worth having the code disappear if debugfs isn't actually being built?
Otherwise all fine with me.
Signed-off-by: Michael Hennerich<michael.hennerich@xxxxxxxxxx>
---
drivers/staging/iio/iio.h | 5 +
drivers/staging/iio/industrialio-core.c | 124 ++++++++++++++++++++++++++++++-
2 files changed, 128 insertions(+), 1 deletions(-)
diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
index 42a362c..d0cf71f 100644
--- a/drivers/staging/iio/iio.h
+++ b/drivers/staging/iio/iio.h
@@ -269,6 +269,9 @@ struct iio_info {
struct iio_trigger *trig);
int (*update_scan_mode)(struct iio_dev *indio_dev,
const unsigned long *scan_mask);
+ int (*debugfs_reg_access)(struct iio_dev *indio_dev,
+ unsigned reg, unsigned writeval,
+ unsigned *readval);
};
/**
@@ -347,6 +350,8 @@ struct iio_dev {
int groupcounter;
unsigned long flags;
+ struct dentry *debugfs_dentry;
+ unsigned cached_reg_addr;
};
/**
diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
index e4824fe..cf48489 100644
--- a/drivers/staging/iio/industrialio-core.c
+++ b/drivers/staging/iio/industrialio-core.c
@@ -22,6 +22,7 @@
#include<linux/cdev.h>
#include<linux/slab.h>
#include<linux/anon_inodes.h>
+#include<linux/debugfs.h>
#include "iio.h"
#include "iio_core.h"
#include "iio_core_trigger.h"
@@ -39,6 +40,8 @@ struct bus_type iio_bus_type = {
};
EXPORT_SYMBOL(iio_bus_type);
+static struct dentry *iio_debugfs_dentry;
+
static const char * const iio_data_type_name[] = {
[IIO_RAW] = "raw",
[IIO_PROCESSED] = "input",
@@ -129,6 +132,8 @@ static int __init iio_init(void)
goto error_unregister_bus_type;
}
+ iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
+
return 0;
error_unregister_bus_type:
@@ -142,6 +147,114 @@ static void __exit iio_exit(void)
if (iio_devt)
unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
bus_unregister(&iio_bus_type);
+ debugfs_remove_recursive(iio_debugfs_dentry);
+}
+
+static int iio_debugfs_open(struct inode *inode, struct file *file)
+{
+ if (inode->i_private)
+ file->private_data = inode->i_private;
+
+ return 0;
+}
+
+static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ struct iio_dev *indio_dev = file->private_data;
+ char buf[80], *p = buf;
+ unsigned val;
+ int ret;
+
+ ret = indio_dev->info->debugfs_reg_access(indio_dev,
+ indio_dev->cached_reg_addr,
+ 0,&val);
+ if (ret)
+ dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
+
I'd prefer a length parameter and using &buf. A little easier to read
to my mind.
+ p += sprintf(p, "0x%X\n", val);
snprintf. 80 chars seems excessive but it is fixed length.
+
+ return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+}
+
+static ssize_t iio_debugfs_write_reg(struct file *file,
+ const char __user *userbuf, size_t count, loff_t *ppos)
+{
+ struct iio_dev *indio_dev = file->private_data;
+ unsigned reg, val;
+ char buf[80], *p = buf;
+ int ret;
+
+ count = min_t(size_t, count, (sizeof(buf)-1));
+ if (copy_from_user(p, userbuf, count))
+ return -EFAULT;
+
+ ret = sscanf(p, "%x %x",®,&val);
+
+ switch (ret) {
+ case 1:
+ indio_dev->cached_reg_addr = reg;
+ break;
+ case 2:
+ indio_dev->cached_reg_addr = reg;
+ ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
+ val, NULL);
+ if (ret) {
+ dev_err(indio_dev->dev.parent, "%s: write failed\n",
+ __func__);
+ return ret;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return count;
+}
+
+static const struct file_operations iio_debugfs_reg_fops = {
+ .open = iio_debugfs_open,
+ .read = iio_debugfs_read_reg,
+ .write = iio_debugfs_write_reg,
+};
+
+static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
+{
+ debugfs_remove_recursive(indio_dev->debugfs_dentry);
+}
+
+static int iio_device_register_debugfs(struct iio_dev *indio_dev)
+{
+ struct dentry *d;
+
+ if (indio_dev->info->debugfs_reg_access == NULL)
+ return 0;
+
+ if (IS_ERR(iio_debugfs_dentry))
+ return 0;
+
+ indio_dev->debugfs_dentry =
+ debugfs_create_dir(dev_name(&indio_dev->dev),
+ iio_debugfs_dentry);
+ if (IS_ERR(indio_dev->debugfs_dentry))
+ return IS_ERR(indio_dev->debugfs_dentry);
+
+ if (indio_dev->debugfs_dentry == NULL) {
+ dev_warn(indio_dev->dev.parent,
+ "Failed to create debugfs directory\n");
+ return -EFAULT;
excess blank line.
+
+ }
+
+ d = debugfs_create_file("direct_reg_access", 0644,
+ indio_dev->debugfs_dentry,
+ indio_dev,&iio_debugfs_reg_fops);
+ if (!d) {
+ iio_device_unregister_debugfs(indio_dev);
+ return -ENOMEM;
+ }
+
+ return 0;
}
static ssize_t iio_read_channel_info(struct device *dev,
@@ -565,6 +678,7 @@ static void iio_dev_release(struct device *device)
iio_device_unregister_trigger_consumer(indio_dev);
iio_device_unregister_eventset(indio_dev);
iio_device_unregister_sysfs(indio_dev);
+ iio_device_unregister_debugfs(indio_dev);
}
static struct device_type iio_dev_type = {
@@ -680,11 +794,17 @@ int iio_device_register(struct iio_dev *indio_dev)
/* configure elements for the chrdev */
indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
+ ret = iio_device_register_debugfs(indio_dev);
+ if (ret) {
+ dev_err(indio_dev->dev.parent,
+ "Failed to register debugfs interfaces\n");
+ goto error_ret;
+ }
ret = iio_device_register_sysfs(indio_dev);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to register sysfs interfaces\n");
- goto error_ret;
+ goto error_unreg_debugfs;
}
ret = iio_device_register_eventset(indio_dev);
if (ret) {
@@ -711,6 +831,8 @@ error_unreg_eventset:
iio_device_unregister_eventset(indio_dev);
error_free_sysfs:
iio_device_unregister_sysfs(indio_dev);
+error_unreg_debugfs:
+ iio_device_unregister_debugfs(indio_dev);
error_ret:
return ret;
}
--
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