pwm: dwc: Move memory allocation to own function

In preparation for adding other bus support, move the allocation
of the PWM structure out of the main driver code.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-dwc.c

@@ -198,13 +198,29 @@ static const struct pwm_ops dwc_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
+static struct dwc_pwm *dwc_pwm_alloc(struct device *dev)
+{
+	struct dwc_pwm *dwc;
+
+	dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
+	if (!dwc)
+		return NULL;
+
+	dwc->chip.dev = dev;
+	dwc->chip.ops = &dwc_pwm_ops;
+	dwc->chip.npwm = DWC_TIMERS_TOTAL;
+
+	dev_set_drvdata(dev, dwc);
+	return dwc;
+}
+
 static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
 {
 	struct device *dev = &pci->dev;
 	struct dwc_pwm *dwc;
 	int ret;
 
-	dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
+	dwc = dwc_pwm_alloc(dev);
 	if (!dwc)
 		return -ENOMEM;
 
@@ -228,12 +244,6 @@ static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
 		return -ENOMEM;
 	}
 
-	pci_set_drvdata(pci, dwc);
-
-	dwc->chip.dev = dev;
-	dwc->chip.ops = &dwc_pwm_ops;
-	dwc->chip.npwm = DWC_TIMERS_TOTAL;
-
 	ret = pwmchip_add(&dwc->chip);
 	if (ret)
 		return ret;