[PATCH 15/23] gpio: mockup: use dynamic device IDs

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

We're currently creating chips at module init time only so using a
static index for dummy devices is fine. We want to support dynamically
created chips however so we need to switch to dynamic device IDs.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
 drivers/gpio/gpio-mockup.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 96976ba66598..995e37fef9c5 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -9,6 +9,7 @@
 
 #include <linux/debugfs.h>
 #include <linux/gpio/driver.h>
+#include <linux/idr.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irq_sim.h>
@@ -70,6 +71,8 @@ module_param_named(gpio_mockup_named_lines,
 
 static struct dentry *gpio_mockup_dbg_dir;
 
+static DEFINE_IDA(gpio_mockup_ida);
+
 static int gpio_mockup_range_base(unsigned int index)
 {
 	return gpio_mockup_ranges[index * 2];
@@ -480,8 +483,12 @@ static LIST_HEAD(gpio_mockup_devices);
 
 static void gpio_mockup_unregister_one_device(struct gpio_mockup_device *dev)
 {
+	int id;
+
 	list_del(&dev->list);
+	id = dev->pdev->id;
 	platform_device_unregister(dev->pdev);
+	ida_free(&gpio_mockup_ida, id);
 	kfree(dev);
 }
 
@@ -587,12 +594,19 @@ static int __init gpio_mockup_init(void)
 		}
 
 		pdevinfo.name = "gpio-mockup";
-		pdevinfo.id = i;
 		pdevinfo.properties = properties;
 
+		pdevinfo.id = ida_alloc(&gpio_mockup_ida, GFP_KERNEL);
+		if (pdevinfo.id < 0) {
+			kfree_strarray(line_names, ngpio);
+			err = pdevinfo.id;
+			goto err_out;
+		}
+
 		mockup_dev = kzalloc(sizeof(*mockup_dev), GFP_KERNEL);
 		if (!mockup_dev) {
 			kfree_strarray(line_names, ngpio);
+			ida_free(&gpio_mockup_ida, pdevinfo.id);
 			err = -ENOMEM;
 			goto err_out;
 		}
@@ -601,6 +615,7 @@ static int __init gpio_mockup_init(void)
 		kfree_strarray(line_names, ngpio);
 		if (IS_ERR(mockup_dev->pdev)) {
 			pr_err("error registering device");
+			ida_free(&gpio_mockup_ida, pdevinfo.id);
 			kfree(mockup_dev);
 			err = PTR_ERR(mockup_dev->pdev);
 			goto err_out;
-- 
2.26.1