Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 289 insertions, 0 deletions

diff --git a/drivers/watchdog/lantiq_wdt.c b/drivers/watchdog/lantiq_wdt.c
new file mode 100644
index 0000000000..a273b97ebc
--- /dev/null
+++ b/drivers/watchdog/lantiq_wdt.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ *  Copyright (C) 2010 John Crispin <john@phrozen.org>
+ *  Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
+ *  Based on EP93xx wdt driver
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/watchdog.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include <lantiq_soc.h>
+
+#define LTQ_XRX_RCU_RST_STAT		0x0014
+#define LTQ_XRX_RCU_RST_STAT_WDT	BIT(31)
+
+/* CPU0 Reset Source Register */
+#define LTQ_FALCON_SYS1_CPU0RS		0x0060
+/* reset cause mask */
+#define LTQ_FALCON_SYS1_CPU0RS_MASK	0x0007
+#define LTQ_FALCON_SYS1_CPU0RS_WDT	0x02
+
+/*
+ * Section 3.4 of the datasheet
+ * The password sequence protects the WDT control register from unintended
+ * write actions, which might cause malfunction of the WDT.
+ *
+ * essentially the following two magic passwords need to be written to allow
+ * IO access to the WDT core
+ */
+#define LTQ_WDT_CR_PW1		0x00BE0000
+#define LTQ_WDT_CR_PW2		0x00DC0000
+
+#define LTQ_WDT_CR		0x0		/* watchdog control register */
+#define  LTQ_WDT_CR_GEN		BIT(31)		/* enable bit */
+/* Pre-warning limit set to 1/16 of max WDT period */
+#define  LTQ_WDT_CR_PWL		(0x3 << 26)
+/* set clock divider to 0x40000 */
+#define  LTQ_WDT_CR_CLKDIV	(0x3 << 24)
+#define  LTQ_WDT_CR_PW_MASK	GENMASK(23, 16)	/* Password field */
+#define  LTQ_WDT_CR_MAX_TIMEOUT	((1 << 16) - 1)	/* The reload field is 16 bit */
+#define LTQ_WDT_SR		0x8		/* watchdog status register */
+#define  LTQ_WDT_SR_EN		BIT(31)		/* Enable */
+#define  LTQ_WDT_SR_VALUE_MASK	GENMASK(15, 0)	/* Timer value */
+
+#define LTQ_WDT_DIVIDER		0x40000
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+struct ltq_wdt_hw {
+	int (*bootstatus_get)(struct device *dev);
+};
+
+struct ltq_wdt_priv {
+	struct watchdog_device wdt;
+	void __iomem *membase;
+	unsigned long clk_rate;
+};
+
+static u32 ltq_wdt_r32(struct ltq_wdt_priv *priv, u32 offset)
+{
+	return __raw_readl(priv->membase + offset);
+}
+
+static void ltq_wdt_w32(struct ltq_wdt_priv *priv, u32 val, u32 offset)
+{
+	__raw_writel(val, priv->membase + offset);
+}
+
+static void ltq_wdt_mask(struct ltq_wdt_priv *priv, u32 clear, u32 set,
+			 u32 offset)
+{
+	u32 val = ltq_wdt_r32(priv, offset);
+
+	val &= ~(clear);
+	val |= set;
+	ltq_wdt_w32(priv, val, offset);
+}
+
+static struct ltq_wdt_priv *ltq_wdt_get_priv(struct watchdog_device *wdt)
+{
+	return container_of(wdt, struct ltq_wdt_priv, wdt);
+}
+
+static struct watchdog_info ltq_wdt_info = {
+	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+		   WDIOF_CARDRESET,
+	.identity = "ltq_wdt",
+};
+
+static int ltq_wdt_start(struct watchdog_device *wdt)
+{
+	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
+	u32 timeout;
+
+	timeout = wdt->timeout * priv->clk_rate;
+
+	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
+	/* write the second magic plus the configuration and new timeout */
+	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
+		     LTQ_WDT_CR_GEN | LTQ_WDT_CR_PWL | LTQ_WDT_CR_CLKDIV |
+		     LTQ_WDT_CR_PW2 | timeout,
+		     LTQ_WDT_CR);
+
+	return 0;
+}
+
+static int ltq_wdt_stop(struct watchdog_device *wdt)
+{
+	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
+
+	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
+	ltq_wdt_mask(priv, LTQ_WDT_CR_GEN | LTQ_WDT_CR_PW_MASK,
+		     LTQ_WDT_CR_PW2, LTQ_WDT_CR);
+
+	return 0;
+}
+
+static int ltq_wdt_ping(struct watchdog_device *wdt)
+{
+	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
+	u32 timeout;
+
+	timeout = wdt->timeout * priv->clk_rate;
+
+	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
+	/* write the second magic plus the configuration and new timeout */
+	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
+		     LTQ_WDT_CR_PW2 | timeout, LTQ_WDT_CR);
+
+	return 0;
+}
+
+static unsigned int ltq_wdt_get_timeleft(struct watchdog_device *wdt)
+{
+	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
+	u64 timeout;
+
+	timeout = ltq_wdt_r32(priv, LTQ_WDT_SR) & LTQ_WDT_SR_VALUE_MASK;
+	return do_div(timeout, priv->clk_rate);
+}
+
+static const struct watchdog_ops ltq_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= ltq_wdt_start,
+	.stop		= ltq_wdt_stop,
+	.ping		= ltq_wdt_ping,
+	.get_timeleft	= ltq_wdt_get_timeleft,
+};
+
+static int ltq_wdt_xrx_bootstatus_get(struct device *dev)
+{
+	struct regmap *rcu_regmap;
+	u32 val;
+	int err;
+
+	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
+	if (IS_ERR(rcu_regmap))
+		return PTR_ERR(rcu_regmap);
+
+	err = regmap_read(rcu_regmap, LTQ_XRX_RCU_RST_STAT, &val);
+	if (err)
+		return err;
+
+	if (val & LTQ_XRX_RCU_RST_STAT_WDT)
+		return WDIOF_CARDRESET;
+
+	return 0;
+}
+
+static int ltq_wdt_falcon_bootstatus_get(struct device *dev)
+{
+	struct regmap *rcu_regmap;
+	u32 val;
+	int err;
+
+	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
+						     "lantiq,rcu");
+	if (IS_ERR(rcu_regmap))
+		return PTR_ERR(rcu_regmap);
+
+	err = regmap_read(rcu_regmap, LTQ_FALCON_SYS1_CPU0RS, &val);
+	if (err)
+		return err;
+
+	if ((val & LTQ_FALCON_SYS1_CPU0RS_MASK) == LTQ_FALCON_SYS1_CPU0RS_WDT)
+		return WDIOF_CARDRESET;
+
+	return 0;
+}
+
+static int ltq_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ltq_wdt_priv *priv;
+	struct watchdog_device *wdt;
+	struct clk *clk;
+	const struct ltq_wdt_hw *ltq_wdt_hw;
+	int ret;
+	u32 status;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->membase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->membase))
+		return PTR_ERR(priv->membase);
+
+	/* we do not need to enable the clock as it is always running */
+	clk = clk_get_io();
+	priv->clk_rate = clk_get_rate(clk) / LTQ_WDT_DIVIDER;
+	if (!priv->clk_rate) {
+		dev_err(dev, "clock rate less than divider %i\n",
+			LTQ_WDT_DIVIDER);
+		return -EINVAL;
+	}
+
+	wdt = &priv->wdt;
+	wdt->info		= &ltq_wdt_info;
+	wdt->ops		= &ltq_wdt_ops;
+	wdt->min_timeout	= 1;
+	wdt->max_timeout	= LTQ_WDT_CR_MAX_TIMEOUT / priv->clk_rate;
+	wdt->timeout		= wdt->max_timeout;
+	wdt->parent		= dev;
+
+	ltq_wdt_hw = of_device_get_match_data(dev);
+	if (ltq_wdt_hw && ltq_wdt_hw->bootstatus_get) {
+		ret = ltq_wdt_hw->bootstatus_get(dev);
+		if (ret >= 0)
+			wdt->bootstatus = ret;
+	}
+
+	watchdog_set_nowayout(wdt, nowayout);
+	watchdog_init_timeout(wdt, 0, dev);
+
+	status = ltq_wdt_r32(priv, LTQ_WDT_SR);
+	if (status & LTQ_WDT_SR_EN) {
+		/*
+		 * If the watchdog is already running overwrite it with our
+		 * new settings. Stop is not needed as the start call will
+		 * replace all settings anyway.
+		 */
+		ltq_wdt_start(wdt);
+		set_bit(WDOG_HW_RUNNING, &wdt->status);
+	}
+
+	return devm_watchdog_register_device(dev, wdt);
+}
+
+static const struct ltq_wdt_hw ltq_wdt_xrx100 = {
+	.bootstatus_get = ltq_wdt_xrx_bootstatus_get,
+};
+
+static const struct ltq_wdt_hw ltq_wdt_falcon = {
+	.bootstatus_get = ltq_wdt_falcon_bootstatus_get,
+};
+
+static const struct of_device_id ltq_wdt_match[] = {
+	{ .compatible = "lantiq,wdt", .data = NULL },
+	{ .compatible = "lantiq,xrx100-wdt", .data = &ltq_wdt_xrx100 },
+	{ .compatible = "lantiq,falcon-wdt", .data = &ltq_wdt_falcon },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ltq_wdt_match);
+
+static struct platform_driver ltq_wdt_driver = {
+	.probe = ltq_wdt_probe,
+	.driver = {
+		.name = "wdt",
+		.of_match_table = ltq_wdt_match,
+	},
+};
+
+module_platform_driver(ltq_wdt_driver);
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+MODULE_AUTHOR("John Crispin <john@phrozen.org>");
+MODULE_DESCRIPTION("Lantiq SoC Watchdog");
+MODULE_LICENSE("GPL");