counter: interrupt-cnt: Convert to new counter registration

This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: a55ebd4 ("counter: add IRQ or GPIO based counter")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-17-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Uwe Kleine-König

drivers/counter/interrupt-cnt.c

@@ -16,7 +16,6 @@
 
 struct interrupt_cnt_priv {
 	atomic_t count;
-	struct counter_device counter;
 	struct gpio_desc *gpio;
 	int irq;
 	bool enabled;
@@ -148,12 +147,14 @@ static const struct counter_ops interrupt_cnt_ops = {
 static int interrupt_cnt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct counter_device *counter;
 	struct interrupt_cnt_priv *priv;
 	int ret;
 
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
+	counter = devm_counter_alloc(dev, sizeof(*priv));
+	if (!counter)
 		return -ENOMEM;
+	priv = counter_priv(counter);
 
 	priv->irq = platform_get_irq_optional(pdev,  0);
 	if (priv->irq == -ENXIO)
@@ -184,8 +185,8 @@ static int interrupt_cnt_probe(struct platform_device *pdev)
 	if (!priv->signals.name)
 		return -ENOMEM;
 
-	priv->counter.signals = &priv->signals;
-	priv->counter.num_signals = 1;
+	counter->signals = &priv->signals;
+	counter->num_signals = 1;
 
 	priv->synapses.actions_list = interrupt_cnt_synapse_actions;
 	priv->synapses.num_actions = ARRAY_SIZE(interrupt_cnt_synapse_actions);
@@ -199,12 +200,11 @@ static int interrupt_cnt_probe(struct platform_device *pdev)
 	priv->cnts.ext = interrupt_cnt_ext;
 	priv->cnts.num_ext = ARRAY_SIZE(interrupt_cnt_ext);
 
-	priv->counter.priv = priv;
-	priv->counter.name = dev_name(dev);
-	priv->counter.parent = dev;
-	priv->counter.ops = &interrupt_cnt_ops;
-	priv->counter.counts = &priv->cnts;
-	priv->counter.num_counts = 1;
+	counter->name = dev_name(dev);
+	counter->parent = dev;
+	counter->ops = &interrupt_cnt_ops;
+	counter->counts = &priv->cnts;
+	counter->num_counts = 1;
 
 	irq_set_status_flags(priv->irq, IRQ_NOAUTOEN);
 	ret = devm_request_irq(dev, priv->irq, interrupt_cnt_isr,
@@ -213,7 +213,11 @@ static int interrupt_cnt_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	return devm_counter_register(dev, &priv->counter);
+	ret = devm_counter_add(dev, counter);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to add counter\n");
+
+	return 0;
 }
 
 static const struct of_device_id interrupt_cnt_of_match[] = {