Use minor number for device node
Allocate a range of minor numbers and use the minor number as index
when creating the /dev/ethosu<nr> device node.
Change-Id: I76c2a3995ff5087e42a4e95945eb884a4bfb58f6
diff --git a/kernel/ethosu_device.c b/kernel/ethosu_device.c
index 40b214c..13c30f6 100644
--- a/kernel/ethosu_device.c
+++ b/kernel/ethosu_device.c
@@ -44,8 +44,6 @@
* Defines
****************************************************************************/
-#define MINOR_VERSION 0 /* Minor version starts at 0 */
-#define MINOR_COUNT 1 /* Allocate 1 minor version */
#define DMA_ADDR_BITS 32 /* Number of address bits */
#define CAPABILITIES_RESP_TIMEOUT_MS 100
@@ -397,6 +395,7 @@
int ethosu_dev_init(struct ethosu_device *edev,
struct device *dev,
struct class *class,
+ dev_t devt,
struct resource *in_queue,
struct resource *out_queue)
{
@@ -413,6 +412,7 @@
edev->dev = dev;
edev->class = class;
+ edev->devt = devt;
mutex_init(&edev->mutex);
INIT_LIST_HEAD(&edev->capabilities_list);
INIT_LIST_HEAD(&edev->inference_list);
@@ -428,24 +428,17 @@
if (ret)
goto release_reserved_mem;
- ret = alloc_chrdev_region(&edev->devt, MINOR_VERSION, MINOR_COUNT,
- "ethosu");
- if (ret) {
- dev_err(edev->dev, "Failed to allocate chrdev region.\n");
- goto deinit_mailbox;
- }
-
cdev_init(&edev->cdev, &fops);
edev->cdev.owner = THIS_MODULE;
- ret = cdev_add(&edev->cdev, edev->devt, MINOR_COUNT);
+ ret = cdev_add(&edev->cdev, edev->devt, 1);
if (ret) {
dev_err(edev->dev, "Failed to add character device.\n");
- goto region_unregister;
+ goto deinit_mailbox;
}
sysdev = device_create(edev->class, NULL, edev->devt, edev,
- "ethosu%d", MAJOR(edev->devt));
+ "ethosu%d", MINOR(edev->devt));
if (IS_ERR(sysdev)) {
dev_err(edev->dev, "Failed to create device.\n");
ret = PTR_ERR(sysdev);
@@ -461,9 +454,6 @@
del_cdev:
cdev_del(&edev->cdev);
-region_unregister:
- unregister_chrdev_region(edev->devt, 1);
-
deinit_mailbox:
ethosu_mailbox_deinit(&edev->mailbox);
@@ -478,7 +468,6 @@
ethosu_mailbox_deinit(&edev->mailbox);
device_destroy(edev->class, edev->cdev.dev);
cdev_del(&edev->cdev);
- unregister_chrdev_region(edev->devt, MINOR_COUNT);
of_reserved_mem_device_release(edev->dev);
dev_info(edev->dev, "%s\n", __FUNCTION__);
diff --git a/kernel/ethosu_device.h b/kernel/ethosu_device.h
index 0722814..3afdda8 100644
--- a/kernel/ethosu_device.h
+++ b/kernel/ethosu_device.h
@@ -76,6 +76,7 @@
int ethosu_dev_init(struct ethosu_device *edev,
struct device *dev,
struct class *class,
+ dev_t devt,
struct resource *in_queue,
struct resource *out_queue);
diff --git a/kernel/ethosu_driver.c b/kernel/ethosu_driver.c
index 3fc752b..9d02431 100644
--- a/kernel/ethosu_driver.c
+++ b/kernel/ethosu_driver.c
@@ -18,6 +18,8 @@
* SPDX-License-Identifier: GPL-2.0-only
*/
+#include <linux/bitmap.h>
+#include <linux/fs.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/of.h>
@@ -33,11 +35,18 @@
#define ETHOSU_DRIVER_VERSION "1.0"
#define ETHOSU_DRIVER_NAME "ethosu"
+#define MINOR_BASE 0 /* Minor version starts at 0 */
+#define MINOR_COUNT 64 /* Allocate minor versions */
+
/****************************************************************************
* Variables
****************************************************************************/
-struct class *ethosu_class;
+static struct class *ethosu_class;
+
+static dev_t devt;
+
+static DECLARE_BITMAP(minors, MINOR_COUNT);
/****************************************************************************
* Arm Ethos-U
@@ -48,10 +57,18 @@
struct ethosu_device *edev;
struct resource *in_queue_res;
struct resource *out_queue_res;
+ int minor;
int ret;
dev_info(&pdev->dev, "Probe\n");
+ minor = find_first_zero_bit(minors, MINOR_COUNT);
+ if (minor >= MINOR_COUNT) {
+ dev_err(&pdev->dev, "No more minor numbers.\n");
+
+ return -ENOMEM;
+ }
+
/* Get path to TCM memory */
in_queue_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
"in_queue");
@@ -77,11 +94,14 @@
platform_set_drvdata(pdev, edev);
/* Initialize device */
- ret = ethosu_dev_init(edev, &pdev->dev, ethosu_class, in_queue_res,
+ ret = ethosu_dev_init(edev, &pdev->dev, ethosu_class,
+ MKDEV(MAJOR(devt), minor), in_queue_res,
out_queue_res);
if (ret)
goto free_dev;
+ set_bit(minor, minors);
+
return 0;
free_dev:
@@ -94,8 +114,7 @@
{
struct ethosu_device *edev = platform_get_drvdata(pdev);
- dev_info(&pdev->dev, "Remove\n");
-
+ clear_bit(MINOR(edev->devt), minors);
ethosu_dev_deinit(edev);
return 0;
@@ -133,14 +152,24 @@
return PTR_ERR(ethosu_class);
}
- ret = platform_driver_register(ðosu_pdev_driver);
+ ret = alloc_chrdev_region(&devt, MINOR_BASE, MINOR_COUNT,
+ ETHOSU_DRIVER_NAME);
if (ret) {
- printk("Failed to register Arm Ethos-U platform driver.\n");
+ printk("Failed to allocate chrdev region.\n");
goto destroy_class;
}
+ ret = platform_driver_register(ðosu_pdev_driver);
+ if (ret) {
+ printk("Failed to register Arm Ethos-U platform driver.\n");
+ goto region_unregister;
+ }
+
return 0;
+region_unregister:
+ unregister_chrdev_region(devt, MINOR_COUNT);
+
destroy_class:
class_destroy(ethosu_class);
@@ -150,6 +179,7 @@
static void __exit ethosu_exit(void)
{
platform_driver_unregister(ðosu_pdev_driver);
+ unregister_chrdev_region(devt, MINOR_COUNT);
class_destroy(ethosu_class);
}