1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
new file mode 100644
index 000000000..1c569be72
--- /dev/null
+++ b/drivers/watchdog/mpc8xxx_wdt.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
+ *
+ * Authors: Dave Updegraff <dave@cray.org>
+ *	    Kumar Gala <galak@kernel.crashing.org>
+ *		Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
+ *				..and from sc520_wdt
+ * Copyright (c) 2008  MontaVista Software, Inc.
+ *                     Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * Note: it appears that you can only actually ENABLE or DISABLE the thing
+ * once after POR. Once enabled, you cannot disable, and vice versa.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <sysdev/fsl_soc.h>
+
+#define WATCHDOG_TIMEOUT 10
+
+struct mpc8xxx_wdt {
+	__be32 res0;
+	__be32 swcrr; /* System watchdog control register */
+#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
+#define SWCRR_SWF  0x00000008 /* Software Watchdog Freeze (mpc8xx). */
+#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
+#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
+#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
+	__be32 swcnr; /* System watchdog count register */
+	u8 res1[2];
+	__be16 swsrr; /* System watchdog service register */
+	u8 res2[0xF0];
+};
+
+struct mpc8xxx_wdt_type {
+	int prescaler;
+	bool hw_enabled;
+	u32 rsr_mask;
+};
+
+struct mpc8xxx_wdt_ddata {
+	struct mpc8xxx_wdt __iomem *base;
+	struct watchdog_device wdd;
+	spinlock_t lock;
+	u16 swtc;
+};
+
+static u16 timeout;
+module_param(timeout, ushort, 0);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout in seconds. (1<timeout<65535, default="
+	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static bool reset = 1;
+module_param(reset, bool, 0);
+MODULE_PARM_DESC(reset,
+	"Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+		 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void mpc8xxx_wdt_keepalive(struct mpc8xxx_wdt_ddata *ddata)
+{
+	/* Ping the WDT */
+	spin_lock(&ddata->lock);
+	out_be16(&ddata->base->swsrr, 0x556c);
+	out_be16(&ddata->base->swsrr, 0xaa39);
+	spin_unlock(&ddata->lock);
+}
+
+static int mpc8xxx_wdt_start(struct watchdog_device *w)
+{
+	struct mpc8xxx_wdt_ddata *ddata =
+		container_of(w, struct mpc8xxx_wdt_ddata, wdd);
+	u32 tmp = in_be32(&ddata->base->swcrr);
+
+	/* Good, fire up the show */
+	tmp &= ~(SWCRR_SWTC | SWCRR_SWF | SWCRR_SWEN | SWCRR_SWRI | SWCRR_SWPR);
+	tmp |= SWCRR_SWEN | SWCRR_SWPR | (ddata->swtc << 16);
+
+	if (reset)
+		tmp |= SWCRR_SWRI;
+
+	out_be32(&ddata->base->swcrr, tmp);
+
+	tmp = in_be32(&ddata->base->swcrr);
+	if (!(tmp & SWCRR_SWEN))
+		return -EOPNOTSUPP;
+
+	ddata->swtc = tmp >> 16;
+	set_bit(WDOG_HW_RUNNING, &ddata->wdd.status);
+
+	return 0;
+}
+
+static int mpc8xxx_wdt_ping(struct watchdog_device *w)
+{
+	struct mpc8xxx_wdt_ddata *ddata =
+		container_of(w, struct mpc8xxx_wdt_ddata, wdd);
+
+	mpc8xxx_wdt_keepalive(ddata);
+	return 0;
+}
+
+static struct watchdog_info mpc8xxx_wdt_info = {
+	.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT,
+	.firmware_version = 1,
+	.identity = "MPC8xxx",
+};
+
+static const struct watchdog_ops mpc8xxx_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = mpc8xxx_wdt_start,
+	.ping = mpc8xxx_wdt_ping,
+};
+
+static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
+{
+	int ret;
+	struct resource *res;
+	const struct mpc8xxx_wdt_type *wdt_type;
+	struct mpc8xxx_wdt_ddata *ddata;
+	u32 freq = fsl_get_sys_freq();
+	bool enabled;
+	struct device *dev = &ofdev->dev;
+
+	wdt_type = of_device_get_match_data(dev);
+	if (!wdt_type)
+		return -EINVAL;
+
+	if (!freq || freq == -1)
+		return -EINVAL;
+
+	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	ddata->base = devm_platform_ioremap_resource(ofdev, 0);
+	if (IS_ERR(ddata->base))
+		return PTR_ERR(ddata->base);
+
+	enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN;
+	if (!enabled && wdt_type->hw_enabled) {
+		dev_info(dev, "could not be enabled in software\n");
+		return -ENODEV;
+	}
+
+	res = platform_get_resource(ofdev, IORESOURCE_MEM, 1);
+	if (res) {
+		bool status;
+		u32 __iomem *rsr = ioremap(res->start, resource_size(res));
+
+		if (!rsr)
+			return -ENOMEM;
+
+		status = in_be32(rsr) & wdt_type->rsr_mask;
+		ddata->wdd.bootstatus = status ? WDIOF_CARDRESET : 0;
+		 /* clear reset status bits related to watchdog timer */
+		out_be32(rsr, wdt_type->rsr_mask);
+		iounmap(rsr);
+
+		dev_info(dev, "Last boot was %scaused by watchdog\n",
+			 status ? "" : "not ");
+	}
+
+	spin_lock_init(&ddata->lock);
+
+	ddata->wdd.info = &mpc8xxx_wdt_info;
+	ddata->wdd.ops = &mpc8xxx_wdt_ops;
+
+	ddata->wdd.timeout = WATCHDOG_TIMEOUT;
+	watchdog_init_timeout(&ddata->wdd, timeout, dev);
+
+	watchdog_set_nowayout(&ddata->wdd, nowayout);
+
+	ddata->swtc = min(ddata->wdd.timeout * freq / wdt_type->prescaler,
+			  0xffffU);
+
+	/*
+	 * If the watchdog was previously enabled or we're running on
+	 * MPC8xxx, we should ping the wdt from the kernel until the
+	 * userspace handles it.
+	 */
+	if (enabled)
+		mpc8xxx_wdt_start(&ddata->wdd);
+
+	ddata->wdd.max_hw_heartbeat_ms = (ddata->swtc * wdt_type->prescaler) /
+					 (freq / 1000);
+	ddata->wdd.min_timeout = ddata->wdd.max_hw_heartbeat_ms / 1000;
+	if (ddata->wdd.timeout < ddata->wdd.min_timeout)
+		ddata->wdd.timeout = ddata->wdd.min_timeout;
+
+	ret = devm_watchdog_register_device(dev, &ddata->wdd);
+	if (ret)
+		return ret;
+
+	dev_info(dev,
+		 "WDT driver for MPC8xxx initialized. mode:%s timeout=%d sec\n",
+		 reset ? "reset" : "interrupt", ddata->wdd.timeout);
+
+	platform_set_drvdata(ofdev, ddata);
+	return 0;
+}
+
+static const struct of_device_id mpc8xxx_wdt_match[] = {
+	{
+		.compatible = "mpc83xx_wdt",
+		.data = &(struct mpc8xxx_wdt_type) {
+			.prescaler = 0x10000,
+			.rsr_mask = BIT(3), /* RSR Bit SWRS */
+		},
+	},
+	{
+		.compatible = "fsl,mpc8610-wdt",
+		.data = &(struct mpc8xxx_wdt_type) {
+			.prescaler = 0x10000,
+			.hw_enabled = true,
+			.rsr_mask = BIT(20), /* RSTRSCR Bit WDT_RR */
+		},
+	},
+	{
+		.compatible = "fsl,mpc823-wdt",
+		.data = &(struct mpc8xxx_wdt_type) {
+			.prescaler = 0x800,
+			.hw_enabled = true,
+			.rsr_mask = BIT(28), /* RSR Bit SWRS */
+		},
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
+
+static struct platform_driver mpc8xxx_wdt_driver = {
+	.probe		= mpc8xxx_wdt_probe,
+	.driver = {
+		.name = "mpc8xxx_wdt",
+		.of_match_table = mpc8xxx_wdt_match,
+	},
+};
+
+static int __init mpc8xxx_wdt_init(void)
+{
+	return platform_driver_register(&mpc8xxx_wdt_driver);
+}
+arch_initcall(mpc8xxx_wdt_init);
+
+static void __exit mpc8xxx_wdt_exit(void)
+{
+	platform_driver_unregister(&mpc8xxx_wdt_driver);
+}
+module_exit(mpc8xxx_wdt_exit);
+
+MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
+MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
+		   "uProcessors");
+MODULE_LICENSE("GPL");