mailbox: stm32-ipcc: check invalid irq

On failure of_irq_get() returns a negative value or zero, which is
not handled as an error in the existing implementation.
Instead of using this API, use platform_get_irq() that returns
exclusively a negative value on failure.
Also, do not output an error log in case of defer probe error.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/stm32-ipcc.c

@@ -8,9 +8,9 @@
 #include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
 #include <linux/mailbox_controller.h>
 #include <linux/module.h>
-#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/pm_wakeirq.h>
 
@@ -240,9 +240,11 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 
 	/* irq */
 	for (i = 0; i < IPCC_IRQ_NUM; i++) {
-		ipcc->irqs[i] = of_irq_get_byname(dev->of_node, irq_name[i]);
+		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
 		if (ipcc->irqs[i] < 0) {
-			dev_err(dev, "no IRQ specified %s\n", irq_name[i]);
+			if (ipcc->irqs[i] != -EPROBE_DEFER)
+				dev_err(dev, "no IRQ specified %s\n",
+					irq_name[i]);
 			ret = ipcc->irqs[i];
 			goto err_clk;
 		}
@@ -263,8 +265,9 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 
 	/* wakeup */
 	if (of_property_read_bool(np, "wakeup-source")) {
-		ipcc->wkp = of_irq_get_byname(dev->of_node, "wakeup");
+		ipcc->wkp = platform_get_irq_byname(pdev, "wakeup");
 		if (ipcc->wkp < 0) {
+			if (ipcc->wkp != -EPROBE_DEFER)
 				dev_err(dev, "could not get wakeup IRQ\n");
 			ret = ipcc->wkp;
 			goto err_clk;