1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
new file mode 100644
index 00000000000..ebe29c74091
--- /dev/null
+++ b/drivers/watchdog/rti_wdt.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) Siemens AG, 2020
+ *
+ * Authors:
+ *   Jan Kiszka <jan.kiszka@siemens.com>
+ *
+ * Derived from linux/drivers/watchdog/rti_wdt.c
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <power-domain.h>
+#include <wdt.h>
+#include <asm/io.h>
+
+/* Timer register set definition */
+#define RTIDWDCTRL		0x90
+#define RTIDWDPRLD		0x94
+#define RTIWDSTATUS		0x98
+#define RTIWDKEY		0x9c
+#define RTIDWDCNTR		0xa0
+#define RTIWWDRXCTRL		0xa4
+#define RTIWWDSIZECTRL		0xa8
+
+#define RTIWWDRX_NMI		0xa
+
+#define RTIWWDSIZE_50P		0x50
+
+#define WDENABLE_KEY		0xa98559da
+
+#define WDKEY_SEQ0		0xe51a
+#define WDKEY_SEQ1		0xa35c
+
+#define WDT_PRELOAD_SHIFT	13
+
+#define WDT_PRELOAD_MAX		0xfff
+
+struct rti_wdt_priv {
+	phys_addr_t regs;
+	unsigned int clk_khz;
+};
+
+static int rti_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
+{
+	struct rti_wdt_priv *priv = dev_get_priv(dev);
+	u32 timer_margin;
+	int ret;
+
+	if (readl(priv->regs + RTIDWDCTRL) == WDENABLE_KEY)
+		return -EBUSY;
+
+	timer_margin = timeout_ms * priv->clk_khz / 1000;
+	timer_margin >>= WDT_PRELOAD_SHIFT;
+	if (timer_margin > WDT_PRELOAD_MAX)
+		timer_margin = WDT_PRELOAD_MAX;
+
+	writel(timer_margin, priv->regs + RTIDWDPRLD);
+	writel(RTIWWDRX_NMI, priv->regs + RTIWWDRXCTRL);
+	writel(RTIWWDSIZE_50P, priv->regs + RTIWWDSIZECTRL);
+
+	readl(priv->regs + RTIWWDSIZECTRL);
+
+	writel(WDENABLE_KEY, priv->regs + RTIDWDCTRL);
+
+	return 0;
+}
+
+static int rti_wdt_reset(struct udevice *dev)
+{
+	struct rti_wdt_priv *priv = dev_get_priv(dev);
+	u32 prld;
+
+	/* Make sure we do not reset too early */
+	prld = readl(priv->regs + RTIDWDPRLD) << WDT_PRELOAD_SHIFT;
+	if (readl(priv->regs + RTIDWDCNTR) >= prld / 2)
+		return -EPERM;
+
+	writel(WDKEY_SEQ0, priv->regs + RTIWDKEY);
+	writel(WDKEY_SEQ1, priv->regs + RTIWDKEY);
+
+	return 0;
+}
+
+static int rti_wdt_probe(struct udevice *dev)
+{
+	struct rti_wdt_priv *priv = dev_get_priv(dev);
+	struct clk clk;
+	int ret;
+
+	priv->regs = devfdt_get_addr(dev);
+	if (!priv->regs)
+		return -EINVAL;
+
+	ret = clk_get_by_index(dev, 0, &clk);
+	if (ret)
+		return ret;
+
+	priv->clk_khz = clk_get_rate(&clk);
+
+	return 0;
+}
+
+static const struct wdt_ops rti_wdt_ops = {
+	.start = rti_wdt_start,
+	.reset = rti_wdt_reset,
+};
+
+static const struct udevice_id rti_wdt_ids[] = {
+	{ .compatible = "ti,j7-rti-wdt" },
+	{ }
+};
+
+U_BOOT_DRIVER(rti_wdt) = {
+	.name = "rti_wdt",
+	.id = UCLASS_WDT,
+	.of_match = rti_wdt_ids,
+	.ops = &rti_wdt_ops,
+	.probe = rti_wdt_probe,
+	.priv_auto_alloc_size = sizeof(struct rti_wdt_priv),
+	.flags = DM_FLAG_REMOVE_WITH_PD_ON,
+};