linux-kernel - [PATCH 2/4] watchdog: iTCO_wdt: Use device managed resources

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Date:   Tue,  3 Jan 2017 06:39:22 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Wim Van Sebroeck <wim@...ana.be>
Cc:     linux-watchdog@...r.kernel.org, linux-kernel@...r.kernel.org,
        Matt Fleming <matt.fleming@...el.com>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 2/4] watchdog: iTCO_wdt: Use device managed resources

Using device managed resources simplifies error handling and cleanup,
and to reduce the likelyhood of errors.

Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/watchdog/iTCO_wdt.c | 80 ++++++++++-----------------------------------
 1 file changed, 17 insertions(+), 63 deletions(-)

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index a35a9164ccd0..eed1dee6de19 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -401,27 +401,6 @@ static const struct watchdog_ops iTCO_wdt_ops = {
  *	Init & exit routines
  */
 
-static void iTCO_wdt_cleanup(struct iTCO_wdt_private *p)
-{
-	/* Stop the timer before we leave */
-	if (!nowayout)
-		iTCO_wdt_stop(&p->wddev);
-
-	/* Deregister */
-	watchdog_unregister_device(&p->wddev);
-
-	/* release resources */
-	release_region(p->tco_res->start,
-			resource_size(p->tco_res));
-	release_region(p->smi_res->start,
-			resource_size(p->smi_res));
-	if (p->iTCO_version >= 2) {
-		iounmap(p->gcs_pmc);
-		release_mem_region(p->gcs_pmc_res->start,
-				resource_size(p->gcs_pmc_res));
-	}
-}
-
 static int iTCO_wdt_probe(struct platform_device *dev)
 {
 	struct itco_wdt_platform_data *pdata = dev_get_platdata(&dev->dev);
@@ -458,41 +437,28 @@ static int iTCO_wdt_probe(struct platform_device *dev)
 		p->gcs_pmc_res = platform_get_resource(dev,
 						       IORESOURCE_MEM,
 						       ICH_RES_MEM_GCS_PMC);
-
-		if (!p->gcs_pmc_res)
-			return -ENODEV;
-
-		if (!request_mem_region(p->gcs_pmc_res->start,
-					resource_size(p->gcs_pmc_res),
-					dev->name))
-			return -EBUSY;
-
-		p->gcs_pmc = ioremap(p->gcs_pmc_res->start,
-				     resource_size(p->gcs_pmc_res));
-		if (!p->gcs_pmc) {
-			ret = -EIO;
-			goto unreg_gcs_pmc;
-		}
+		p->gcs_pmc = devm_ioremap_resource(&dev->dev, p->gcs_pmc_res);
+		if (IS_ERR(p->gcs_pmc))
+			return PTR_ERR(p->gcs_pmc);
 	}
 
 	/* Check chipset's NO_REBOOT bit */
 	if (iTCO_wdt_unset_NO_REBOOT_bit(p) &&
 	    iTCO_vendor_check_noreboot_on()) {
 		pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
-		ret = -ENODEV;	/* Cannot reset NO_REBOOT bit */
-		goto unmap_gcs_pmc;
+		return -ENODEV;	/* Cannot reset NO_REBOOT bit */
 	}
 
 	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
 	iTCO_wdt_set_NO_REBOOT_bit(p);
 
 	/* The TCO logic uses the TCO_EN bit in the SMI_EN register */
-	if (!request_region(p->smi_res->start,
-			    resource_size(p->smi_res), dev->name)) {
+	if (!devm_request_region(&dev->dev, p->smi_res->start,
+				 resource_size(p->smi_res),
+				 dev->name)) {
 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
 		       (u64)SMI_EN(p));
-		ret = -EBUSY;
-		goto unmap_gcs_pmc;
+		return -EBUSY;
 	}
 	if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
 		/*
@@ -504,12 +470,12 @@ static int iTCO_wdt_probe(struct platform_device *dev)
 		outl(val32, SMI_EN(p));
 	}
 
-	if (!request_region(p->tco_res->start,
-			    resource_size(p->tco_res), dev->name)) {
+	if (!devm_request_region(&dev->dev, p->tco_res->start,
+				 resource_size(p->tco_res),
+				 dev->name)) {
 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
 		       (u64)TCOBASE(p));
-		ret = -EBUSY;
-		goto unreg_smi;
+		return -EBUSY;
 	}
 
 	pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
@@ -555,37 +521,25 @@ static int iTCO_wdt_probe(struct platform_device *dev)
 			WATCHDOG_TIMEOUT);
 	}
 
-	ret = watchdog_register_device(&p->wddev);
+	ret = devm_watchdog_register_device(&dev->dev, &p->wddev);
 	if (ret != 0) {
 		pr_err("cannot register watchdog device (err=%d)\n", ret);
-		goto unreg_tco;
+		return ret;
 	}
 
 	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 		heartbeat, nowayout);
 
 	return 0;
-
-unreg_tco:
-	release_region(p->tco_res->start, resource_size(p->tco_res));
-unreg_smi:
-	release_region(p->smi_res->start, resource_size(p->smi_res));
-unmap_gcs_pmc:
-	if (p->iTCO_version >= 2)
-		iounmap(p->gcs_pmc);
-unreg_gcs_pmc:
-	if (p->iTCO_version >= 2)
-		release_mem_region(p->gcs_pmc_res->start,
-				   resource_size(p->gcs_pmc_res));
-	return ret;
 }
 
 static int iTCO_wdt_remove(struct platform_device *dev)
 {
 	struct iTCO_wdt_private *p = platform_get_drvdata(dev);
 
-	if (p->tco_res || p->smi_res)
-		iTCO_wdt_cleanup(p);
+	/* Stop the timer before we leave */
+	if (!nowayout)
+		iTCO_wdt_stop(&p->wddev);
 
 	return 0;
 }
-- 
2.7.4