watchdog: Add support for ADI SC5XX-family watchdog peripheral

Co-developed-by: Greg Malysa <malysagreg@gmail.com>
Signed-off-by: Greg Malysa <malysagreg@gmail.com>
Co-developed-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Vasileios Bimpikas <vasileios.bimpikas@analog.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>
Signed-off-by: Arturs Artamonovs <arturs.artamonovs@analog.com>
Signed-off-by: Oliver Gaskell <Oliver.Gaskell@analog.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
Reviewed-by: Stefan Roese <sr@denx.de>

MAINTAINERS

@@ -640,6 +640,7 @@ F:	drivers/pinctrl/pinctrl-adi-adsp.c
 F:	drivers/serial/serial_adi_uart4.c
 F:	drivers/timer/adi_sc5xx_timer.c
 F:	drivers/usb/musb-new/sc5xx.c
+F:	drivers/watchdog/adi_wdt.c
 F:	include/configs/sc5*
 F:	include/dt-bindings/pinctrl/adi-adsp.h
 F:	include/env/adi/

drivers/watchdog/Kconfig

@@ -95,6 +95,15 @@ config WDT_APPLE
 	  The watchdog will perform a full SoC reset resulting in a
 	  reboot of the entire system.
 
+config WDT_ADI
+	bool "Analog Devices watchdog timer support"
+	select WDT
+	select SPL_WDT if SPL
+	depends on ARCH_SC5XX
+	help
+	  Enable this to support Watchdog Timer on ADI SC57X, SC58X, SC59X,
+	  and SC59X_64 processors
+
 config WDT_ARMADA_37XX
 	bool "Marvell Armada 37xx watchdog timer support"
 	depends on WDT && ARMADA_3700

drivers/watchdog/Makefile

@@ -53,3 +53,4 @@ obj-$(CONFIG_WDT_STM32MP) += stm32mp_wdt.o
 obj-$(CONFIG_WDT_SUNXI) += sunxi_wdt.o
 obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o
 obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o
+obj-$(CONFIG_WDT_ADI) += adi_wdt.o

drivers/watchdog/adi_wdt.c

@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (C) Copyright 2022 - Analog Devices, Inc.
+ *
+ * Written and/or maintained by Timesys Corporation
+ *
+ * Converted to driver model by Nathan Barrett-Morrison
+ *
+ * Contact: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
+ * Contact: Greg Malysa <greg.malysa@timesys.com>
+ *
+ * adi_wtd.c - driver for ADI on-chip watchdog
+ *
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <wdt.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+
+#define WDOG_CTL  0x0
+#define WDOG_CNT  0x4
+#define WDOG_STAT 0x8
+
+#define RCU_CTL   0x0
+#define RCU_STAT  0x4
+
+#define SEC_GCTL  0x0
+#define SEC_FCTL  0x10
+#define SEC_SCTL0 0x800
+
+#define WDEN      0x0010
+#define WDDIS     0x0AD0
+
+struct adi_wdt_priv {
+	void __iomem *rcu_base;
+	void __iomem *sec_base;
+	void __iomem *wdt_base;
+	struct clk clock;
+};
+
+static int adi_wdt_reset(struct udevice *dev)
+{
+	struct adi_wdt_priv *priv = dev_get_priv(dev);
+
+	iowrite32(0, priv->wdt_base + WDOG_STAT);
+
+	return 0;
+}
+
+static int adi_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
+{
+	struct adi_wdt_priv *priv = dev_get_priv(dev);
+
+	/* Disable SYSCD_RESETb input and clear the RCU0 reset status */
+	iowrite32(0xf, priv->rcu_base + RCU_STAT);
+	iowrite32(0x0, priv->rcu_base + RCU_CTL);
+
+	/* reset the SEC controller */
+	iowrite32(0x2, priv->sec_base + SEC_GCTL);
+	iowrite32(0x2, priv->sec_base + SEC_FCTL);
+
+	udelay(50);
+
+	/* enable SEC fault event */
+	iowrite32(0x1, priv->sec_base + SEC_GCTL);
+
+	/* ANOMALY 36100004 Spurious External Fault event occurs when FCTL
+	 * is re-programmed when currently active fault is not cleared
+	 */
+	iowrite32(0xc0, priv->sec_base + SEC_FCTL);
+	iowrite32(0xc1, priv->sec_base + SEC_FCTL);
+
+	/* enable SEC fault source for watchdog0 */
+	setbits_32(priv->sec_base + SEC_SCTL0 + (3*8), 0x6);
+
+	/* Enable SYSCD_RESETb input */
+	iowrite32(0x100, priv->rcu_base + RCU_CTL);
+
+	/* enable watchdog0 */
+	iowrite32(WDDIS, priv->wdt_base + WDOG_CTL);
+
+	iowrite32(timeout_ms / 1000 *
+	       (clk_get_rate(&priv->clock) / (IS_ENABLED(CONFIG_SC58X) ? 2 : 1)),
+	       priv->wdt_base + WDOG_CNT);
+
+	iowrite32(0, priv->wdt_base + WDOG_STAT);
+	iowrite32(WDEN, priv->wdt_base + WDOG_CTL);
+
+	return 0;
+}
+
+static int adi_wdt_probe(struct udevice *dev)
+{
+	struct adi_wdt_priv *priv = dev_get_priv(dev);
+	int ret;
+	struct resource res;
+
+	ret = dev_read_resource_byname(dev, "rcu", &res);
+	if (ret)
+		return ret;
+	priv->rcu_base = devm_ioremap(dev, res.start, resource_size(&res));
+
+	ret = dev_read_resource_byname(dev, "sec", &res);
+	if (ret)
+		return ret;
+	priv->sec_base = devm_ioremap(dev, res.start, resource_size(&res));
+
+	ret = dev_read_resource_byname(dev, "wdt", &res);
+	if (ret)
+		return ret;
+	priv->wdt_base = devm_ioremap(dev, res.start, resource_size(&res));
+
+	ret = clk_get_by_name(dev, "sclk0", &priv->clock);
+	if (ret < 0) {
+		printf("Can't get WDT clk: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct wdt_ops adi_wdt_ops = {
+	.start		= adi_wdt_start,
+	.reset		= adi_wdt_reset,
+};
+
+static const struct udevice_id adi_wdt_ids[] = {
+	{ .compatible = "adi,wdt" },
+	{}
+};
+
+U_BOOT_DRIVER(adi_wdt) = {
+	.name		= "adi_wdt",
+	.id		= UCLASS_WDT,
+	.of_match	= adi_wdt_ids,
+	.probe		= adi_wdt_probe,
+	.ops		= &adi_wdt_ops,
+	.priv_auto = sizeof(struct adi_wdt_priv),
+	.flags		= DM_FLAG_PRE_RELOC,
+};