counter: intel-qep: Convert to new counter registration

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

Fixes: b711f68 ("counter: Add support for Intel Quadrature Encoder Peripheral")
Tested-by: Jarkko Nikula <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Acked-by: William Breathitt Gray <[email protected]>
Acked-by: Jarkko Nikula <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Uwe Kleine-König

drivers/counter/intel-qep.c

@@ -63,7 +63,6 @@
 #define INTEL_QEP_CLK_PERIOD_NS		10
 
 struct intel_qep {
-	struct counter_device counter;
 	struct mutex lock;
 	struct device *dev;
 	void __iomem *regs;
@@ -392,14 +391,16 @@ static struct counter_count intel_qep_counter_count[] = {
 
 static int intel_qep_probe(struct pci_dev *pci, const struct pci_device_id *id)
 {
+	struct counter_device *counter;
 	struct intel_qep *qep;
 	struct device *dev = &pci->dev;
 	void __iomem *regs;
 	int ret;
 
-	qep = devm_kzalloc(dev, sizeof(*qep), GFP_KERNEL);
-	if (!qep)
+	counter = devm_counter_alloc(dev, sizeof(*qep));
+	if (!counter)
 		return -ENOMEM;
+	qep = counter_priv(counter);
 
 	ret = pcim_enable_device(pci);
 	if (ret)
@@ -422,20 +423,23 @@ static int intel_qep_probe(struct pci_dev *pci, const struct pci_device_id *id)
 	intel_qep_init(qep);
 	pci_set_drvdata(pci, qep);
 
-	qep->counter.name = pci_name(pci);
-	qep->counter.parent = dev;
-	qep->counter.ops = &intel_qep_counter_ops;
-	qep->counter.counts = intel_qep_counter_count;
-	qep->counter.num_counts = ARRAY_SIZE(intel_qep_counter_count);
-	qep->counter.signals = intel_qep_signals;
-	qep->counter.num_signals = ARRAY_SIZE(intel_qep_signals);
-	qep->counter.priv = qep;
+	counter->name = pci_name(pci);
+	counter->parent = dev;
+	counter->ops = &intel_qep_counter_ops;
+	counter->counts = intel_qep_counter_count;
+	counter->num_counts = ARRAY_SIZE(intel_qep_counter_count);
+	counter->signals = intel_qep_signals;
+	counter->num_signals = ARRAY_SIZE(intel_qep_signals);
 	qep->enabled = false;
 
 	pm_runtime_put(dev);
 	pm_runtime_allow(dev);
 
-	return devm_counter_register(&pci->dev, &qep->counter);
+	ret = devm_counter_add(&pci->dev, counter);
+	if (ret < 0)
+		return dev_err_probe(&pci->dev, ret, "Failed to add counter\n");
+
+	return 0;
 }
 
 static void intel_qep_remove(struct pci_dev *pci)