[PATCH v2 2/3] iio: dummy: Convert IIO dummy to configfs
From: Daniel Baluta
Date: Mon Apr 25 2016 - 09:12:39 EST
We register a new device type named "dummy", this will create a
configfs entry under:
* /config/iio/devices/dummy.
Creating dummy devices is now as simple as:
$ mkdir /config/iio/devices/dummy/my_dummy_device
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
drivers/iio/dummy/Kconfig | 1 +
drivers/iio/dummy/iio_simple_dummy.c | 102 +++++++++++++----------------------
2 files changed, 38 insertions(+), 65 deletions(-)
diff --git a/drivers/iio/dummy/Kconfig b/drivers/iio/dummy/Kconfig
index 71805ce..aa5824d 100644
--- a/drivers/iio/dummy/Kconfig
+++ b/drivers/iio/dummy/Kconfig
@@ -10,6 +10,7 @@ config IIO_DUMMY_EVGEN
config IIO_SIMPLE_DUMMY
tristate "An example driver with no hardware requirements"
+ depends on IIO_SW_DEVICE
help
Driver intended mainly as documentation for how to write
a driver. May also be useful for testing userspace code
diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c
index 43fe4ba..ad3410e 100644
--- a/drivers/iio/dummy/iio_simple_dummy.c
+++ b/drivers/iio/dummy/iio_simple_dummy.c
@@ -17,26 +17,18 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/buffer.h>
+#include <linux/iio/sw_device.h>
#include "iio_simple_dummy.h"
-/*
- * A few elements needed to fake a bus for this driver
- * Note instances parameter controls how many of these
- * dummy devices are registered.
- */
-static unsigned instances = 1;
-module_param(instances, uint, 0);
-
-/* Pointer array used to fake bus elements */
-static struct iio_dev **iio_dummy_devs;
-
-/* Fake a name for the part number, usually obtained from the id table */
-static const char *iio_dummy_part_number = "iio_dummy_part_no";
+static struct config_item_type iio_dummy_type = {
+ .ct_owner = THIS_MODULE,
+};
/**
* struct iio_dummy_accel_calibscale - realworld to register mapping
@@ -572,12 +564,18 @@ static int iio_dummy_init_device(struct iio_dev *indio_dev)
* const struct i2c_device_id *id)
* SPI: iio_dummy_probe(struct spi_device *spi)
*/
-static int iio_dummy_probe(int index)
+static struct iio_sw_device *iio_dummy_probe(const char *name)
{
int ret;
struct iio_dev *indio_dev;
struct iio_dummy_state *st;
+ struct iio_sw_device *swd;
+ swd = kzalloc(sizeof(*swd), GFP_KERNEL);
+ if (!swd) {
+ ret = -ENOMEM;
+ goto error_kzalloc;
+ }
/*
* Allocate an IIO device.
*
@@ -608,7 +606,7 @@ static int iio_dummy_probe(int index)
* i2c_set_clientdata(client, indio_dev);
* spi_set_drvdata(spi, indio_dev);
*/
- iio_dummy_devs[index] = indio_dev;
+ swd->device = indio_dev;
/*
* Set the device name.
@@ -619,7 +617,7 @@ static int iio_dummy_probe(int index)
* indio_dev->name = id->name;
* indio_dev->name = spi_get_device_id(spi)->name;
*/
- indio_dev->name = iio_dummy_part_number;
+ indio_dev->name = kstrdup(name, GFP_KERNEL);
/* Provide description of available channels */
indio_dev->channels = iio_dummy_channels;
@@ -646,7 +644,9 @@ static int iio_dummy_probe(int index)
if (ret < 0)
goto error_unconfigure_buffer;
- return 0;
+ iio_swd_group_init_type_name(swd, name, &iio_dummy_type);
+
+ return swd;
error_unconfigure_buffer:
iio_simple_dummy_unconfigure_buffer(indio_dev);
error_unregister_events:
@@ -654,16 +654,18 @@ error_unregister_events:
error_free_device:
iio_device_free(indio_dev);
error_ret:
- return ret;
+ kfree(swd);
+error_kzalloc:
+ return ERR_PTR(ret);
}
/**
* iio_dummy_remove() - device instance removal function
- * @index: device index.
+ * @swd: pointer to software IIO device abstraction
*
* Parameters follow those of iio_dummy_probe for buses.
*/
-static void iio_dummy_remove(int index)
+static int iio_dummy_remove(struct iio_sw_device *swd)
{
/*
* Get a pointer to the device instance iio_dev structure
@@ -671,7 +673,7 @@ static void iio_dummy_remove(int index)
* struct iio_dev *indio_dev = i2c_get_clientdata(client);
* struct iio_dev *indio_dev = spi_get_drvdata(spi);
*/
- struct iio_dev *indio_dev = iio_dummy_devs[index];
+ struct iio_dev *indio_dev = swd->device;
/* Unregister the device */
iio_device_unregister(indio_dev);
@@ -684,11 +686,13 @@ static void iio_dummy_remove(int index)
iio_simple_dummy_events_unregister(indio_dev);
/* Free all structures */
+ kfree(indio_dev->name);
iio_device_free(indio_dev);
-}
+ return 0;
+}
/**
- * iio_dummy_init() - device driver registration
+ * module_iio_sw_device_driver() - device driver registration
*
* Varies depending on bus type of the device. As there is no device
* here, call probe directly. For information on device registration
@@ -697,50 +701,18 @@ static void iio_dummy_remove(int index)
* spi:
* Documentation/spi/spi-summary
*/
-static __init int iio_dummy_init(void)
-{
- int i, ret;
-
- if (instances > 10) {
- instances = 1;
- return -EINVAL;
- }
-
- /* Fake a bus */
- iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs),
- GFP_KERNEL);
- /* Here we have no actual device so call probe */
- for (i = 0; i < instances; i++) {
- ret = iio_dummy_probe(i);
- if (ret < 0)
- goto error_remove_devs;
- }
- return 0;
-
-error_remove_devs:
- while (i--)
- iio_dummy_remove(i);
-
- kfree(iio_dummy_devs);
- return ret;
-}
-module_init(iio_dummy_init);
+static const struct iio_sw_device_ops iio_dummy_device_ops = {
+ .probe = iio_dummy_probe,
+ .remove = iio_dummy_remove,
+};
-/**
- * iio_dummy_exit() - device driver removal
- *
- * Varies depending on bus type of the device.
- * As there is no device here, call remove directly.
- */
-static __exit void iio_dummy_exit(void)
-{
- int i;
+static struct iio_sw_device_type iio_dummy_device = {
+ .name = "dummy",
+ .owner = THIS_MODULE,
+ .ops = &iio_dummy_device_ops,
+};
- for (i = 0; i < instances; i++)
- iio_dummy_remove(i);
- kfree(iio_dummy_devs);
-}
-module_exit(iio_dummy_exit);
+module_iio_sw_device_driver(iio_dummy_device);
MODULE_AUTHOR("Jonathan Cameron <jic23@xxxxxxxxxx>");
MODULE_DESCRIPTION("IIO dummy driver");
--
2.5.0