[PATCH v2 2/2] platform: make platform_get_irq_byname_optional() optional

[Sergey Shtylyov <s.shtylyov@xxxxxx>]

Currently platform_get_irq_byname_optional() returns an error code even
if IRQ resource simply has not been found.  It prevents the callers from
being error code agnostic in their error handling:

	ret = platform_get_irq_byname_optional(...);
	if (ret < 0 && ret != -ENXIO)
		return ret; // respect deferred probe
	if (ret > 0)
		...we get an IRQ...

All other *_optional() APIs seem to return 0 or NULL in case an optional
resource is not available.  Let's follow this good example, so that the
callers would look like:

	ret = platform_get_irq_byname_optional(...);
	if (ret < 0)
		return ret;
	if (ret > 0)
		...we get an IRQ...

Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
---
Changes in version 2:
- added the error check using dev_err_probe() to
  platform_get_irq_byname_optional();
- reformatted the patch description.

 drivers/base/platform.c                         | 17 ++++++++++++++---
 drivers/gpu/drm/lima/lima_device.c              |  2 +-
 drivers/mailbox/tegra-hsp.c                     |  4 ++--
 drivers/net/can/rcar/rcar_canfd.c               |  4 ++--
 drivers/net/dsa/b53/b53_srab.c                  |  2 +-
 drivers/net/ethernet/freescale/fec_main.c       |  2 +-
 drivers/net/ethernet/freescale/fec_ptp.c        |  2 +-
 .../net/ethernet/stmicro/stmmac/dwmac-stm32.c   |  4 ++--
 .../ethernet/stmicro/stmmac/stmmac_platform.c   |  4 ++--
 .../pci/controller/dwc/pcie-designware-host.c   |  2 +-
 drivers/spi/spi-bcm-qspi.c                      |  2 +-
 drivers/spi/spi-rspi.c                          |  8 ++++----
 drivers/usb/cdns3/cdns3-plat.c                  |  5 +----
 drivers/usb/host/xhci-mtk.c                     |  2 +-
 drivers/usb/mtu3/mtu3_core.c                    |  2 +-
 15 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 52a8356f8261..c704d51a6dd5 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -500,14 +500,25 @@ EXPORT_SYMBOL_GPL(platform_get_irq_byname);
  * @name: IRQ name
  *
  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
- * does not print an error message if an IRQ can not be obtained.
+ * does not print an error message if an IRQ can not be obtained and returns
+ * 0 when IRQ resource has not been found.
  *
- * Return: non-zero IRQ number on success, negative error number on failure.
+ * Return: non-zero IRQ number on success, 0 if IRQ wasn't found, negative error
+ * number on failure.
  */
 int platform_get_irq_byname_optional(struct platform_device *dev,
 				     const char *name)
 {
-	return __platform_get_irq_byname(dev, name);
+	int ret;
+
+	ret = __platform_get_irq_byname(dev, name);
+	if (ret == -ENXIO)
+		return 0;
+	if (ret < 0)
+		return dev_err_probe(&dev->dev, ret, "IRQ %s not found\n",
+				     name);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
 
diff --git a/drivers/gpu/drm/lima/lima_device.c b/drivers/gpu/drm/lima/lima_device.c
index 02cef0cea657..08a86484ce6f 100644
--- a/drivers/gpu/drm/lima/lima_device.c
+++ b/drivers/gpu/drm/lima/lima_device.c
@@ -224,7 +224,7 @@ static int lima_init_ip(struct lima_device *dev, int index)
 	if (irq_name) {
 		err = must ? platform_get_irq_byname(pdev, irq_name) :
 			     platform_get_irq_byname_optional(pdev, irq_name);
-		if (err < 0)
+		if (err <= 0)
 			goto out;
 		ip->irq = err;
 	}
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index acd0675da681..17aa88e31445 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -667,7 +667,7 @@ static int tegra_hsp_probe(struct platform_device *pdev)
 	hsp->num_si = (value >> HSP_nSI_SHIFT) & HSP_nINT_MASK;
 
 	err = platform_get_irq_byname_optional(pdev, "doorbell");
-	if (err >= 0)
+	if (err > 0)
 		hsp->doorbell_irq = err;
 
 	if (hsp->num_si > 0) {
@@ -687,7 +687,7 @@ static int tegra_hsp_probe(struct platform_device *pdev)
 				return -ENOMEM;
 
 			err = platform_get_irq_byname_optional(pdev, name);
-			if (err >= 0) {
+			if (err > 0) {
 				hsp->shared_irqs[i] = err;
 				count++;
 			}
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index b7dc1c32875f..fa163ec0db80 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1772,7 +1772,7 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 
 	if (chip_id == RENESAS_RCAR_GEN3) {
 		ch_irq = platform_get_irq_byname_optional(pdev, "ch_int");
-		if (ch_irq < 0) {
+		if (ch_irq <= 0) {
 			/* For backward compatibility get irq by index */
 			ch_irq = platform_get_irq(pdev, 0);
 			if (ch_irq < 0)
@@ -1780,7 +1780,7 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 		}
 
 		g_irq = platform_get_irq_byname_optional(pdev, "g_int");
-		if (g_irq < 0) {
+		if (g_irq <= 0) {
 			/* For backward compatibility get irq by index */
 			g_irq = platform_get_irq(pdev, 1);
 			if (g_irq < 0)
diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index 4591bb1c05d2..80b7c8f053ad 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -420,7 +420,7 @@ static int b53_srab_irq_enable(struct b53_device *dev, int port)
 	/* Interrupt is optional and was not specified, do not make
 	 * this fatal
 	 */
-	if (p->irq == -ENXIO)
+	if (!p->irq)
 		return ret;
 
 	ret = request_threaded_irq(p->irq, b53_srab_port_isr,
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 796133de527e..93d1cca831dd 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3941,7 +3941,7 @@ fec_probe(struct platform_device *pdev)
 	for (i = 0; i < irq_cnt; i++) {
 		snprintf(irq_name, sizeof(irq_name), "int%d", i);
 		irq = platform_get_irq_byname_optional(pdev, irq_name);
-		if (irq < 0)
+		if (irq <= 0)
 			irq = platform_get_irq(pdev, i);
 		if (irq < 0) {
 			ret = irq;
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index de1d23808b6c..a7ef0aaaf2be 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -611,7 +611,7 @@ void fec_ptp_init(struct platform_device *pdev, int irq_idx)
 	INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
 
 	irq = platform_get_irq_byname_optional(pdev, "pps");
-	if (irq < 0)
+	if (irq <= 0)
 		irq = platform_get_irq_optional(pdev, irq_idx);
 	/* Failure to get an irq is not fatal,
 	 * only the PTP_CLOCK_PPS clock events should stop
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index 2b38a499a404..5519b5b35365 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -342,7 +342,7 @@ static int stm32mp1_parse_data(struct stm32_dwmac *dwmac,
 	if (dwmac->irq_pwr_wakeup == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
 
-	if (!dwmac->clk_eth_ck && dwmac->irq_pwr_wakeup >= 0) {
+	if (!dwmac->clk_eth_ck && dwmac->irq_pwr_wakeup > 0) {
 		err = device_init_wakeup(&pdev->dev, true);
 		if (err) {
 			dev_err(&pdev->dev, "Failed to init wake up irq\n");
@@ -426,7 +426,7 @@ static int stm32_dwmac_remove(struct platform_device *pdev)
 
 	stm32_dwmac_clk_disable(priv->plat->bsp_priv);
 
-	if (dwmac->irq_pwr_wakeup >= 0) {
+	if (dwmac->irq_pwr_wakeup > 0) {
 		dev_pm_clear_wake_irq(&pdev->dev);
 		device_init_wakeup(&pdev->dev, false);
 	}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 5d29f336315b..33fdfab93aa6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -679,7 +679,7 @@ int stmmac_get_platform_resources(struct platform_device *pdev,
 	 */
 	stmmac_res->wol_irq =
 		platform_get_irq_byname_optional(pdev, "eth_wake_irq");
-	if (stmmac_res->wol_irq < 0) {
+	if (stmmac_res->wol_irq <= 0) {
 		if (stmmac_res->wol_irq == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		dev_info(&pdev->dev, "IRQ eth_wake_irq not found\n");
@@ -688,7 +688,7 @@ int stmmac_get_platform_resources(struct platform_device *pdev,
 
 	stmmac_res->lpi_irq =
 		platform_get_irq_byname_optional(pdev, "eth_lpi");
-	if (stmmac_res->lpi_irq < 0) {
+	if (stmmac_res->lpi_irq <= 0) {
 		if (stmmac_res->lpi_irq == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		dev_info(&pdev->dev, "IRQ eth_lpi not found\n");
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index f4755f3a03be..00e1a33fd06d 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -364,7 +364,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		} else if (pp->has_msi_ctrl) {
 			if (!pp->msi_irq) {
 				pp->msi_irq = platform_get_irq_byname_optional(pdev, "msi");
-				if (pp->msi_irq < 0) {
+				if (pp->msi_irq <= 0) {
 					pp->msi_irq = platform_get_irq(pdev, 0);
 					if (pp->msi_irq < 0)
 						return pp->msi_irq;
diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index c9a769b8594b..21fb80291d03 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -1627,7 +1627,7 @@ int bcm_qspi_probe(struct platform_device *pdev,
 			irq = platform_get_irq(pdev, 0);
 		}
 
-		if (irq  >= 0) {
+		if (irq > 0) {
 			ret = devm_request_irq(&pdev->dev, irq,
 					       qspi_irq_tab[val].irq_handler, 0,
 					       name,
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index bd5708d7e5a1..1ddbd30e68d5 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -1355,16 +1355,16 @@ static int rspi_probe(struct platform_device *pdev)
 	ctlr->max_native_cs = rspi->ops->num_hw_ss;
 
 	ret = platform_get_irq_byname_optional(pdev, "rx");
-	if (ret < 0) {
+	if (ret <= 0) {
 		ret = platform_get_irq_byname_optional(pdev, "mux");
-		if (ret < 0)
+		if (ret <= 0)
 			ret = platform_get_irq(pdev, 0);
-		if (ret >= 0)
+		if (ret > 0)
 			rspi->rx_irq = rspi->tx_irq = ret;
 	} else {
 		rspi->rx_irq = ret;
 		ret = platform_get_irq_byname(pdev, "tx");
-		if (ret >= 0)
+		if (ret > 0)
 			rspi->tx_irq = ret;
 	}
 
diff --git a/drivers/usb/cdns3/cdns3-plat.c b/drivers/usb/cdns3/cdns3-plat.c
index dc068e940ed5..3a0bdf726af2 100644
--- a/drivers/usb/cdns3/cdns3-plat.c
+++ b/drivers/usb/cdns3/cdns3-plat.c
@@ -110,10 +110,7 @@ static int cdns3_plat_probe(struct platform_device *pdev)
 	cdns->wakeup_irq = platform_get_irq_byname_optional(pdev, "wakeup");
 	if (cdns->wakeup_irq == -EPROBE_DEFER)
 		return cdns->wakeup_irq;
-	else if (cdns->wakeup_irq == 0)
-		return -EINVAL;
-
-	if (cdns->wakeup_irq < 0) {
+	if (cdns->wakeup_irq <= 0) {
 		dev_dbg(dev, "couldn't get wakeup irq\n");
 		cdns->wakeup_irq = 0x0;
 	}
diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 91738af0ab14..19c742bf3ce0 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -493,7 +493,7 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 		return ret;
 
 	irq = platform_get_irq_byname_optional(pdev, "host");
-	if (irq < 0) {
+	if (irq <= 0) {
 		if (irq == -EPROBE_DEFER)
 			return irq;
 
diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
index c4a2c37abf62..08173c05a1d6 100644
--- a/drivers/usb/mtu3/mtu3_core.c
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -925,7 +925,7 @@ int ssusb_gadget_init(struct ssusb_mtk *ssusb)
 		return -ENOMEM;
 
 	mtu->irq = platform_get_irq_byname_optional(pdev, "device");
-	if (mtu->irq < 0) {
+	if (mtu->irq <= 0) {
 		if (mtu->irq == -EPROBE_DEFER)
 			return mtu->irq;
 
-- 
2.26.3