wdt: nuvoton: Add support for Nuvoton
Add watchdog controller driver for NPCM7xx/npcm8xx
the wdt design of npcm750 and npcm845 is the same.
so the driver can work on npcm750 and npcm845.
about npcm845 wdt dtsi i will followed kernel dts name
to use nuvoton,npcm750-wdt.
Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c
new file mode 100644
index 0000000..256020f
--- /dev/null
+++ b/drivers/watchdog/npcm_wdt.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Nuvoton Technology, Inc
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <log.h>
+#include <wdt.h>
+#include <asm/io.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+
+#define NPCM_WTCLK (BIT(10) | BIT(11)) /* Clock divider */
+#define NPCM_WTE BIT(7) /* Enable */
+#define NPCM_WTIE BIT(6) /* Enable irq */
+#define NPCM_WTIS (BIT(4) | BIT(5)) /* Interval selection */
+#define NPCM_WTIF BIT(3) /* Interrupt flag*/
+#define NPCM_WTRF BIT(2) /* Reset flag */
+#define NPCM_WTRE BIT(1) /* Reset enable */
+#define NPCM_WTR BIT(0) /* Reset counter */
+
+struct npcm_wdt_priv {
+ void __iomem *regs;
+};
+
+static int npcm_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
+{
+ struct npcm_wdt_priv *priv = dev_get_priv(dev);
+ u32 time_out, val;
+
+ time_out = (u32)(timeout_ms) / 1000;
+ if (time_out < 2)
+ val = 0x800;
+ else if (time_out < 3)
+ val = 0x420;
+ else if (time_out < 6)
+ val = 0x810;
+ else if (time_out < 11)
+ val = 0x430;
+ else if (time_out < 22)
+ val = 0x820;
+ else if (time_out < 44)
+ val = 0xc00;
+ else if (time_out < 87)
+ val = 0x830;
+ else if (time_out < 173)
+ val = 0xc10;
+ else if (time_out < 688)
+ val = 0xc20;
+ else
+ val = 0xc30;
+
+ val |= NPCM_WTRE | NPCM_WTE | NPCM_WTR | NPCM_WTIE;
+ writel(val, priv->regs);
+
+ return 0;
+}
+
+static int npcm_wdt_stop(struct udevice *dev)
+{
+ struct npcm_wdt_priv *priv = dev_get_priv(dev);
+
+ writel(0, priv->regs);
+
+ return 0;
+}
+
+static int npcm_wdt_reset(struct udevice *dev)
+{
+ struct npcm_wdt_priv *priv = dev_get_priv(dev);
+
+ writel(NPCM_WTR | NPCM_WTRE | NPCM_WTE, priv->regs);
+
+ return 0;
+}
+
+static int npcm_wdt_of_to_plat(struct udevice *dev)
+{
+ struct npcm_wdt_priv *priv = dev_get_priv(dev);
+
+ priv->regs = dev_read_addr_ptr(dev);
+ if (!priv->regs)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct wdt_ops npcm_wdt_ops = {
+ .start = npcm_wdt_start,
+ .reset = npcm_wdt_reset,
+ .stop = npcm_wdt_stop,
+};
+
+static const struct udevice_id npcm_wdt_ids[] = {
+ { .compatible = "nuvoton,npcm750-wdt" },
+ { }
+};
+
+static int npcm_wdt_probe(struct udevice *dev)
+{
+ debug("%s() wdt%u\n", __func__, dev_seq(dev));
+ npcm_wdt_stop(dev);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(npcm_wdt) = {
+ .name = "npcm_wdt",
+ .id = UCLASS_WDT,
+ .of_match = npcm_wdt_ids,
+ .probe = npcm_wdt_probe,
+ .priv_auto = sizeof(struct npcm_wdt_priv),
+ .of_to_plat = npcm_wdt_of_to_plat,
+ .ops = &npcm_wdt_ops,
+};