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Commit e553f182 authored by Michael Hennerich's avatar Michael Hennerich Committed by Greg Kroah-Hartman
Browse files

staging: iio: core: Introduce debugfs support, add support for direct register access 



Changes since V1:

Exclude iio debugfs code in case CONFIG_DEBUG_FS isn't enabled.
	Introduce helper function iio_get_debugfs_dentry.
	Document additions to struct iio_dev

iio_debugfs_read_reg:
	Use snprintf.
	Use a shorter fixed length.
	Introduce len instead of pointer math.

iio_debugfs_write_reg:
	Fix return value use PT_ERR.

Changes since V2:

Use debugfs_remove.
Fix whitespace damage.

Signed-off-by: default avatarMichael Hennerich <michael.hennerich@analog.com>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4abf6f8b

drivers/staging/iio/iio.h

+26 −1
Original line number Diff line number Diff line
@@ -286,6 +286,9 @@ 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);

};



/**
@@ -332,7 +335,9 @@ struct iio_buffer_setup_ops { 
 * @groups:		[INTERN] attribute groups

 * @groupcounter:	[INTERN] index of next attribute group

 * @flags:		[INTERN] file ops related flags including busy flag.

 **/

 * @debugfs_dentry:	[INTERN] device specific debugfs dentry.

 * @cached_reg_addr:	[INTERN] cached register address for debugfs reads.

 */

struct iio_dev {

	int				id;
@@ -366,6 +371,10 @@ struct iio_dev { 
	int				groupcounter;



	unsigned long			flags;

#if defined(CONFIG_DEBUG_FS)

	struct dentry			*debugfs_dentry;

	unsigned			cached_reg_addr;

#endif

};



/**
@@ -443,4 +452,20 @@ static inline bool iio_buffer_enabled(struct iio_dev *indio_dev) 
		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);

};



/**

 * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry

 * @indio_dev:		IIO device info structure for device

 **/

#if defined(CONFIG_DEBUG_FS)

static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)

{

	return indio_dev->debugfs_dentry;

};

#else

static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)

{

	return NULL;

};

#endif



#endif /* _INDUSTRIAL_IO_H_ */

drivers/staging/iio/industrialio-core.c

+136 −1
Original line number Diff line number Diff line
@@ -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 +147,84 @@ static void __exit iio_exit(void) 
	if (iio_devt)

		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);

	bus_unregister(&iio_bus_type);

	debugfs_remove(iio_debugfs_dentry);

}



#if defined(CONFIG_DEBUG_FS)

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[20];

	unsigned val = 0;

	ssize_t len;

	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__);



	len = snprintf(buf, sizeof(buf), "0x%X\n", val);



	return simple_read_from_buffer(userbuf, count, ppos, buf, len);

}



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];

	int ret;



	count = min_t(size_t, count, (sizeof(buf)-1));

	if (copy_from_user(buf, userbuf, count))

		return -EFAULT;



	buf[count] = 0;



	ret = sscanf(buf, "%i %i", &reg, &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 ssize_t iio_read_channel_ext_info(struct device *dev,
@@ -171,6 +254,49 @@ static ssize_t iio_write_channel_ext_info(struct device *dev, 
	return ext_info->write(indio_dev, this_attr->c, buf, len);

}



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 PTR_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;

	}



	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;

}

#else

static int iio_device_register_debugfs(struct iio_dev *indio_dev)

{

	return 0;

}



static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)

{

}

#endif /* CONFIG_DEBUG_FS */



static ssize_t iio_read_channel_info(struct device *dev,

				     struct device_attribute *attr,

				     char *buf)
@@ -618,6 +744,7 @@ 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 = {
@@ -734,11 +861,17 @@ 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) {
@@ -765,6 +898,8 @@ int iio_device_register(struct iio_dev *indio_dev) 
	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;

}