[PATCH 1/5] drivers: watchdog: add mcf watchdog support

Angelo Dureghello
2023-06-25T19:36:12Z

This watchdog driver applies to the following
mcf families:

- mcf52x2 (5271 5275 5282)
- mcf532x (5329 5373)
- mcf523x (5235)

Cpu's not listed for each family does not have WDT module.

Note, after some attempts testing by qemu on 5208 i
finally abandoned, watchdog seems not implemented properly.

The driver has been tested in a real M5282EVM.

Signed-off-by: Angelo Dureghello <angelo@kernel-space.org>
---
drivers/watchdog/Kconfig | 7 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mcf_wdt.c | 162 +++++++++++++++++++++++++++++++++++++
3 files changed, 170 insertions(+)
create mode 100644 drivers/watchdog/mcf_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 646663528a..07fc4940e9 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -178,6 +178,13 @@ config WDT_MAX6370
help
Select this to enable max6370 watchdog timer.

+config WDT_MCF
+ bool "ColdFire family watchdog timer support"
+ depends on WDT
+ help
+ Select this to enable ColdFire watchdog timer,
+ which supports mcf52x2 mcf532x mcf523x families.
+
config WDT_MESON_GXBB
bool "Amlogic watchdog timer support"
depends on WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index fd5d9c7376..eef786f5e7 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
obj-$(CONFIG_WDT_FTWDT010) += ftwdt010_wdt.o
obj-$(CONFIG_WDT_GPIO) += gpio_wdt.o
obj-$(CONFIG_WDT_MAX6370) += max6370_wdt.o
+obj-$(CONFIG_WDT_MCF) += mcf_wdt.o
obj-$(CONFIG_WDT_MESON_GXBB) += meson_gxbb_wdt.o
obj-$(CONFIG_WDT_MPC8xxx) += mpc8xxx_wdt.o
obj-$(CONFIG_WDT_MT7620) += mt7620_wdt.o
diff --git a/drivers/watchdog/mcf_wdt.c b/drivers/watchdog/mcf_wdt.c
new file mode 100644
index 0000000000..03842135c5
--- /dev/null
+++ b/drivers/watchdog/mcf_wdt.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mcf_wdt.c - driver for ColdFire on-chip watchdog
+ *
+ * Author: Angelo Dureghello <angelo@kernel-space.org>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <hang.h>
+#include <asm/io.h>
+#include <wdt.h>
+#include <linux/bitops.h>
+
+#define TIMEOUT_MAX 3360
+#define TIMEOUT_MIN 500
+
+#define DIVIDER_5XXX 4096
+#define DIVIDER_5282 8192
+
+#define WCR_EN BIT(0)
+#define WCR_HALTED BIT(1)
+#define WCR_DOZE BIT(2)
+#define WCR_WAIT BIT(3)
+
+struct watchdog_regs {
+ u16 wcr; /* Control */
+ u16 wmr; /* Service */
+ u16 wcntr; /* Counter */
+ u16 wsr; /* Reset Status */
+};
+
+#if defined(CONFIG_WDT_MCF)
+static void mcf_watchdog_reset(struct watchdog_regs *wdog)
+{
+#ifndef CONFIG_WATCHDOG_RESET_DISABLE
+ writew(0x5555, &wdog->wsr);
+ writew(0xaaaa, &wdog->wsr);
+#endif /* CONFIG_WATCHDOG_RESET_DISABLE*/
+}
+
+static void mcf_watchdog_init(struct watchdog_regs *wdog, u32 fixed_divider,
+ u64 timeout_msecs)
+{
+ u32 wdog_module;
+
+ /*
+ * The timer watchdog can be set between
+ * 0.5 and 128 Seconds.
+ */
+
+ /* set timeout and enable watchdog */
+ wdog_module = ((CFG_SYS_CLK / 1000) * timeout_msecs);
+
+ writew((u16)(wdog_module / fixed_divider), &wdog->wmr);
+ writew(WCR_EN, &wdog->wcr);
+
+ mcf_watchdog_reset(wdog);
+}
+
+#if !CONFIG_IS_ENABLED(WDT)
+void hw_watchdog_reset(void)
+{
+ struct watchdog_regs *wdog = (struct watchdog_regs *)MMAP_WDOG;
+
+ mcf_watchdog_reset(wdog);
+}
+
+void hw_watchdog_init(void)
+{
+ struct watchdog_regs *wdog = (struct watchdog_regs *)MMAP_WDOG;
+
+ if (IS_ENABLED(CONFIG_MCF5282))
+ writew(&wdog->wmr, wdog_module / DIVIDER_5282);
+ else
+ writew(&wdog->wmr, wdog_module / DIVIDER_5XXX);
+
+ mcf_watchdog_init(wdog, CONFIG_WATCHDOG_TIMEOUT_MSECS);
+}
+
+#else /* CONFIG_WDT */
+
+struct mcf_wdt_priv {
+ void __iomem *base;
+ u32 fixed_divider;
+};
+
+static int mcf_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ hang();
+
+ return 0;
+}
+
+static int mcf_wdt_reset(struct udevice *dev)
+{
+ struct mcf_wdt_priv *priv = dev_get_priv(dev);
+
+ mcf_watchdog_reset(priv->base);
+
+ return 0;
+}
+
+static int mcf_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ struct mcf_wdt_priv *priv = dev_get_priv(dev);
+
+ /* Timeout from fdt is in second, driver works in msecs */
+ mcf_watchdog_init(priv->base, priv->fixed_divider,
+ timeout * 1000);
+
+ return 0;
+}
+
+static int mcf_wdt_stop(struct udevice *dev)
+{
+ struct mcf_wdt_priv *priv = dev_get_priv(dev);
+ struct watchdog_regs *wdog = (struct watchdog_regs *)priv->base;
+
+ setbits_be16(&wdog->wcr, WCR_HALTED);
+
+ return 0;
+}
+
+static int mcf_wdt_probe(struct udevice *dev)
+{
+ struct mcf_wdt_priv *priv = dev_get_priv(dev);
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -ENOENT;
+
+ priv->fixed_divider = (u32)dev_get_driver_data(dev);
+
+ return 0;
+}
+
+static const struct wdt_ops mcf_wdt_ops = {
+ .start = mcf_wdt_start,
+ .stop = mcf_wdt_stop,
+ .reset = mcf_wdt_reset,
+ .expire_now = mcf_wdt_expire_now,
+};
+
+static const struct udevice_id mcf_wdt_ids[] = {
+ { .compatible = "fsl,mcf5208-wdt", .data = DIVIDER_5XXX },
+ { .compatible = "fsl,mcf5282-wdt", .data = DIVIDER_5282 },
+ {}
+};
+
+U_BOOT_DRIVER(mcf_wdt) = {
+ .name = "mcf_wdt",
+ .id = UCLASS_WDT,
+ .of_match = mcf_wdt_ids,
+ .probe = mcf_wdt_probe,
+ .ops = &mcf_wdt_ops,
+ .priv_auto = sizeof(struct mcf_wdt_priv),
+ .flags = DM_FLAG_PRE_RELOC,
+};
+#endif
+#endif
--
2.41.0