ptp: vmclock: Clean up miscdev and ptp clock through devres

Most resources owned by the vmclock device are managed through devres.
Only the miscdev and ptp clock are managed manually.
This makes the code slightly harder to understand than necessary.

Switch them over to devres and remove the now unnecessary drvdata.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: t-8ch

drivers/ptp/ptp_vmclock.c

@@ -421,10 +421,9 @@ static const struct file_operations vmclock_miscdev_fops = {
 
 /* module operations */
 
-static void vmclock_remove(struct platform_device *pdev)
+static void vmclock_remove(void *data)
 {
-	struct device *dev = &pdev->dev;
-	struct vmclock_state *st = dev_get_drvdata(dev);
+	struct vmclock_state *st = data;
 
 	if (st->ptp_clock)
 		ptp_clock_unregister(st->ptp_clock);
@@ -525,8 +524,6 @@ static int vmclock_probe(struct platform_device *pdev)
 		goto out;
 	}
 
-	dev_set_drvdata(dev, st);
-
 	if (le32_to_cpu(st->clk->magic) != VMCLOCK_MAGIC ||
 	    le32_to_cpu(st->clk->size) > resource_size(&st->res) ||
 	    le16_to_cpu(st->clk->version) != 1) {
@@ -552,6 +549,10 @@ static int vmclock_probe(struct platform_device *pdev)
 
 	st->miscdev.minor = MISC_DYNAMIC_MINOR;
 
+	ret = devm_add_action_or_reset(&pdev->dev, vmclock_remove, st);
+	if (ret)
+		goto out;
+
 	/*
 	 * If the structure is big enough, it can be mapped to userspace.
 	 * Theoretically a guest OS even using larger pages could still
@@ -574,7 +575,6 @@ static int vmclock_probe(struct platform_device *pdev)
 		if (IS_ERR(st->ptp_clock)) {
 			ret = PTR_ERR(st->ptp_clock);
 			st->ptp_clock = NULL;
-			vmclock_remove(pdev);
 			goto out;
 		}
 	}
@@ -603,7 +603,6 @@ MODULE_DEVICE_TABLE(acpi, vmclock_acpi_ids);
 
 static struct platform_driver vmclock_platform_driver = {
 	.probe		= vmclock_probe,
-	.remove		= vmclock_remove,
 	.driver	= {
 		.name	= "vmclock",
 		.acpi_match_table = vmclock_acpi_ids,