1 files changed, 122 insertions, 84 deletions

diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
index cc9d328086ed..21935f9620e4 100644
--- a/drivers/watchdog/max63xx_wdt.c
+++ b/drivers/watchdog/max63xx_wdt.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * drivers/char/watchdog/max63xx_wdt.c
  *
@@ -5,10 +6,6 @@
  *
  * Copyright (C) 2009 Marc Zyngier <maz@misterjones.org>
  *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
- *
  * This driver assumes the watchdog pins are memory mapped (as it is
  * the case for the Arcom Zeus). Should it be connected over GPIOs or
  * another interface, some abstraction will have to be introduced.
@@ -17,16 +14,16 @@
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/mod_devicetable.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/miscdevice.h>
 #include <linux/watchdog.h>
-#include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/property.h>
 
 #define DEFAULT_HEARTBEAT 60
 #define MAX_HEARTBEAT     60
@@ -41,10 +38,22 @@ static bool nowayout  = WATCHDOG_NOWAYOUT;
 #define MAX6369_WDSET	(7 << 0)
 #define MAX6369_WDI	(1 << 3)
 
-static DEFINE_SPINLOCK(io_lock);
+#define MAX6369_WDSET_DISABLED	3
 
 static int nodelay;
-static void __iomem	*wdt_base;
+
+struct max63xx_wdt {
+	struct watchdog_device wdd;
+	const struct max63xx_timeout *timeout;
+
+	/* memory mapping */
+	void __iomem *base;
+	spinlock_t lock;
+
+	/* WDI and WSET bits write access routines */
+	void (*ping)(struct max63xx_wdt *wdt);
+	void (*set)(struct max63xx_wdt *wdt, u8 set);
+};
 
 /*
  * The timeout values used are actually the absolute minimum the chip
@@ -61,25 +70,25 @@ static void __iomem	*wdt_base;
 
 /* Timeouts in second */
 struct max63xx_timeout {
-	u8 wdset;
-	u8 tdelay;
-	u8 twd;
+	const u8 wdset;
+	const u8 tdelay;
+	const u8 twd;
 };
 
-static struct max63xx_timeout max6369_table[] = {
+static const struct max63xx_timeout max6369_table[] = {
 	{ 5,  1,  1 },
 	{ 6, 10, 10 },
 	{ 7, 60, 60 },
 	{ },
 };
 
-static struct max63xx_timeout max6371_table[] = {
+static const struct max63xx_timeout max6371_table[] = {
 	{ 6, 60,  3 },
 	{ 7, 60, 60 },
 	{ },
 };
 
-static struct max63xx_timeout max6373_table[] = {
+static const struct max63xx_timeout max6373_table[] = {
 	{ 2, 60,  1 },
 	{ 5,  0,  1 },
 	{ 1,  3,  3 },
@@ -88,10 +97,8 @@ static struct max63xx_timeout max6373_table[] = {
 	{ },
 };
 
-static struct max63xx_timeout *current_timeout;
-
-static struct max63xx_timeout *
-max63xx_select_timeout(struct max63xx_timeout *table, int value)
+static const struct max63xx_timeout *
+max63xx_select_timeout(const struct max63xx_timeout *table, int value)
 {
 	while (table->twd) {
 		if (value <= table->twd) {
@@ -110,59 +117,32 @@ max63xx_select_timeout(struct max63xx_timeout *table, int value)
 
 static int max63xx_wdt_ping(struct watchdog_device *wdd)
 {
-	u8 val;
+	struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	spin_lock(&io_lock);
-
-	val = __raw_readb(wdt_base);
-
-	__raw_writeb(val | MAX6369_WDI, wdt_base);
-	__raw_writeb(val & ~MAX6369_WDI, wdt_base);
-
-	spin_unlock(&io_lock);
+	wdt->ping(wdt);
 	return 0;
 }
 
 static int max63xx_wdt_start(struct watchdog_device *wdd)
 {
-	struct max63xx_timeout *entry = watchdog_get_drvdata(wdd);
-	u8 val;
-
-	spin_lock(&io_lock);
-
-	val = __raw_readb(wdt_base);
-	val &= ~MAX6369_WDSET;
-	val |= entry->wdset;
-	__raw_writeb(val, wdt_base);
+	struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	spin_unlock(&io_lock);
+	wdt->set(wdt, wdt->timeout->wdset);
 
 	/* check for a edge triggered startup */
-	if (entry->tdelay == 0)
-		max63xx_wdt_ping(wdd);
+	if (wdt->timeout->tdelay == 0)
+		wdt->ping(wdt);
 	return 0;
 }
 
 static int max63xx_wdt_stop(struct watchdog_device *wdd)
 {
-	u8 val;
-
-	spin_lock(&io_lock);
-
-	val = __raw_readb(wdt_base);
-	val &= ~MAX6369_WDSET;
-	val |= 3;
-	__raw_writeb(val, wdt_base);
+	struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	spin_unlock(&io_lock);
+	wdt->set(wdt, MAX6369_WDSET_DISABLED);
 	return 0;
 }
 
-static const struct watchdog_info max63xx_wdt_info = {
-	.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
-	.identity = "max63xx Watchdog",
-};
-
 static const struct watchdog_ops max63xx_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = max63xx_wdt_start,
@@ -170,53 +150,102 @@ static const struct watchdog_ops max63xx_wdt_ops = {
 	.ping = max63xx_wdt_ping,
 };
 
-static struct watchdog_device max63xx_wdt_dev = {
-	.info = &max63xx_wdt_info,
-	.ops = &max63xx_wdt_ops,
+static const struct watchdog_info max63xx_wdt_info = {
+	.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "max63xx Watchdog",
 };
 
+static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
+{
+	u8 val;
+
+	spin_lock(&wdt->lock);
+
+	val = __raw_readb(wdt->base);
+
+	__raw_writeb(val | MAX6369_WDI, wdt->base);
+	__raw_writeb(val & ~MAX6369_WDI, wdt->base);
+
+	spin_unlock(&wdt->lock);
+}
+
+static void max63xx_mmap_set(struct max63xx_wdt *wdt, u8 set)
+{
+	u8 val;
+
+	spin_lock(&wdt->lock);
+
+	val = __raw_readb(wdt->base);
+	val &= ~MAX6369_WDSET;
+	val |= set & MAX6369_WDSET;
+	__raw_writeb(val, wdt->base);
+
+	spin_unlock(&wdt->lock);
+}
+
+static int max63xx_mmap_init(struct platform_device *p, struct max63xx_wdt *wdt)
+{
+	wdt->base = devm_platform_ioremap_resource(p, 0);
+	if (IS_ERR(wdt->base))
+		return PTR_ERR(wdt->base);
+
+	spin_lock_init(&wdt->lock);
+
+	wdt->ping = max63xx_mmap_ping;
+	wdt->set = max63xx_mmap_set;
+	return 0;
+}
+
 static int max63xx_wdt_probe(struct platform_device *pdev)
 {
-	struct resource	*wdt_mem;
-	struct max63xx_timeout *table;
+	struct device *dev = &pdev->dev;
+	struct max63xx_wdt *wdt;
+	const struct max63xx_timeout *table;
+	int err;
 
-	table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	/* Attempt to use fwnode first */
+	table = device_get_match_data(dev);
+	if (!table)
+		table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
 
 	if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
 		heartbeat = DEFAULT_HEARTBEAT;
 
-	dev_info(&pdev->dev, "requesting %ds heartbeat\n", heartbeat);
-	current_timeout = max63xx_select_timeout(table, heartbeat);
-
-	if (!current_timeout) {
-		dev_err(&pdev->dev, "unable to satisfy heartbeat request\n");
+	wdt->timeout = max63xx_select_timeout(table, heartbeat);
+	if (!wdt->timeout) {
+		dev_err(dev, "unable to satisfy %ds heartbeat request\n",
+			heartbeat);
 		return -EINVAL;
 	}
 
-	dev_info(&pdev->dev, "using %ds heartbeat with %ds initial delay\n",
-		 current_timeout->twd, current_timeout->tdelay);
+	err = max63xx_mmap_init(pdev, wdt);
+	if (err)
+		return err;
 
-	heartbeat = current_timeout->twd;
+	platform_set_drvdata(pdev, &wdt->wdd);
+	watchdog_set_drvdata(&wdt->wdd, wdt);
 
-	wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	wdt_base = devm_ioremap_resource(&pdev->dev, wdt_mem);
-	if (IS_ERR(wdt_base))
-		return PTR_ERR(wdt_base);
+	wdt->wdd.parent = dev;
+	wdt->wdd.timeout = wdt->timeout->twd;
+	wdt->wdd.info = &max63xx_wdt_info;
+	wdt->wdd.ops = &max63xx_wdt_ops;
 
-	max63xx_wdt_dev.timeout = heartbeat;
-	watchdog_set_nowayout(&max63xx_wdt_dev, nowayout);
-	watchdog_set_drvdata(&max63xx_wdt_dev, current_timeout);
+	watchdog_set_nowayout(&wdt->wdd, nowayout);
 
-	return watchdog_register_device(&max63xx_wdt_dev);
-}
+	err = devm_watchdog_register_device(dev, &wdt->wdd);
+	if (err)
+		return err;
 
-static int max63xx_wdt_remove(struct platform_device *pdev)
-{
-	watchdog_unregister_device(&max63xx_wdt_dev);
+	dev_info(dev, "using %ds heartbeat with %ds initial delay\n",
+		 wdt->timeout->twd, wdt->timeout->tdelay);
 	return 0;
 }
 
-static struct platform_device_id max63xx_id_table[] = {
+static const struct platform_device_id max63xx_id_table[] = {
 	{ "max6369_wdt", (kernel_ulong_t)max6369_table, },
 	{ "max6370_wdt", (kernel_ulong_t)max6369_table, },
 	{ "max6371_wdt", (kernel_ulong_t)max6371_table, },
@@ -227,13 +256,23 @@ static struct platform_device_id max63xx_id_table[] = {
 };
 MODULE_DEVICE_TABLE(platform, max63xx_id_table);
 
+static const struct of_device_id max63xx_dt_id_table[] = {
+	{ .compatible = "maxim,max6369", .data = max6369_table, },
+	{ .compatible = "maxim,max6370", .data = max6369_table, },
+	{ .compatible = "maxim,max6371", .data = max6371_table, },
+	{ .compatible = "maxim,max6372", .data = max6371_table, },
+	{ .compatible = "maxim,max6373", .data = max6373_table, },
+	{ .compatible = "maxim,max6374", .data = max6373_table, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max63xx_dt_id_table);
+
 static struct platform_driver max63xx_wdt_driver = {
 	.probe		= max63xx_wdt_probe,
-	.remove		= max63xx_wdt_remove,
 	.id_table	= max63xx_id_table,
 	.driver		= {
 		.name	= "max63xx_wdt",
-		.owner	= THIS_MODULE,
+		.of_match_table = max63xx_dt_id_table,
 	},
 };
 
@@ -257,5 +296,4 @@ MODULE_PARM_DESC(nodelay,
 		 "Force selection of a timeout setting without initial delay "
 		 "(max6373/74 only, default=0)");
 
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_LICENSE("GPL v2");