[PATCH v1 01/22] wdt: imx8qxp: add option to control external PMIC wdt via IMX8 SCU

[Heiko Schocher <hs@denx.de>]

control the watchdog in the PMIC through SCU.

Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
Signed-off-by: Heiko Schocher <hs@denx.de>
---

 drivers/misc/imx8/scu_api.c    | 21 ++++++++++++++
 drivers/watchdog/Kconfig       |  7 +++++
 drivers/watchdog/Makefile      |  1 +
 drivers/watchdog/scu_wdt.c     | 52 ++++++++++++++++++++++++++++++++++
 include/firmware/imx/sci/rpc.h |  1 +
 include/firmware/imx/sci/sci.h |  1 +
 6 files changed, 83 insertions(+)
 create mode 100644 drivers/watchdog/scu_wdt.c

diff --git a/drivers/misc/imx8/scu_api.c b/drivers/misc/imx8/scu_api.c
index 591d71b096a..edb6923151a 100644
--- a/drivers/misc/imx8/scu_api.c
+++ b/drivers/misc/imx8/scu_api.c
@@ -951,6 +951,27 @@ int sc_timer_set_wdog_window(sc_ipc_t ipc, sc_timer_wdog_time_t window)
 	return ret;
 }
 
+int sc_timer_control_pmic_wdog(sc_ipc_t ipc, u8 cmd)
+{
+	struct udevice *dev = gd->arch.scu_dev;
+	struct sc_rpc_msg_s msg;
+	int size = sizeof(struct sc_rpc_msg_s);
+	int ret;
+
+	RPC_VER(&msg) = SC_RPC_VERSION;
+	RPC_SVC(&msg) = (u8)SC_RPC_SVC_TIMER;
+	RPC_FUNC(&msg) = (u8)TIMER_FUNC_CTRL_PMIC_WDOG;
+	RPC_U8(&msg, 0U) = (u8)cmd;
+	RPC_SIZE(&msg) = 2U;
+
+	ret = misc_call(dev, SC_FALSE, &msg, size, &msg, size);
+	if (ret)
+		printf("%s: res:%d\n",
+		       __func__, RPC_R8(&msg));
+
+	return ret;
+}
+
 int sc_seco_authenticate(sc_ipc_t ipc, sc_seco_auth_cmd_t cmd,
 			 sc_faddr_t addr)
 {
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0e45f0a0922..eb9e75abe48 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -428,6 +428,13 @@ config WDT_ARM_SMC
 	  Select this to enable Arm SMC watchdog timer. This watchdog will manage
 	  a watchdog based on ARM SMCCC communication.
 
+config WDT_IMX_SCU
+	bool "Enable external Watchdog Timer support for IMX"
+	depends on IMX8 && WDT
+	help
+	  Select this to enable the external IMX watchdog driver
+	  controlled via IMX8 SCU.
+
 config SPL_WDT
 	bool "Enable driver model for watchdog timer drivers in SPL"
 	depends on SPL_DM
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 0b107c008f7..e943b904bae 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_WDT_DA9063) += da9063-wdt.o
 obj-$(CONFIG_WDT_DAVINCI) += davinci_wdt.o
 obj-$(CONFIG_WDT_FTWDT010) += ftwdt010_wdt.o
 obj-$(CONFIG_$(SPL_TPL_)WDT_GPIO) += gpio_wdt.o
+obj-$(CONFIG_WDT_IMX_SCU) += scu_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
diff --git a/drivers/watchdog/scu_wdt.c b/drivers/watchdog/scu_wdt.c
new file mode 100644
index 00000000000..ad8766dc132
--- /dev/null
+++ b/drivers/watchdog/scu_wdt.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <dm.h>
+#include <wdt.h>
+#include <firmware/imx/sci/sci.h>
+
+/* watchdog commands */
+#define CMD_START_WDT 0x55
+#define CMD_STOP_WDT  0x45
+#define CMD_PING_WDT  0x35
+
+static int scu_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
+{
+	/* start external watchdog via Timer API */
+	return sc_timer_control_pmic_wdog(-1, CMD_START_WDT);
+}
+
+static int scu_wdt_stop(struct udevice *dev)
+{
+	/* stop external watchdog via Timer API */
+	return sc_timer_control_pmic_wdog(-1, CMD_STOP_WDT);
+}
+
+static int scu_wdt_reset(struct udevice *dev)
+{
+	return sc_timer_control_pmic_wdog(-1, CMD_PING_WDT);
+}
+
+static int scu_wdt_probe(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+	return 0;
+}
+
+static const struct wdt_ops scu_wdt_ops = {
+	.reset		= scu_wdt_reset,
+	.start		= scu_wdt_start,
+	.stop		= scu_wdt_stop,
+};
+
+static const struct udevice_id scu_wdt_ids[] = {
+	{ .compatible = "siemens,scu-wdt" },
+	{ }
+};
+
+U_BOOT_DRIVER(scu_wdt) = {
+	.name		= "scu_wdt",
+	.id		= UCLASS_WDT,
+	.of_match	= scu_wdt_ids,
+	.probe		= scu_wdt_probe,
+	.ops		= &scu_wdt_ops,
+};
diff --git a/include/firmware/imx/sci/rpc.h b/include/firmware/imx/sci/rpc.h
index 28adec2a8e1..9470f9e7178 100644
--- a/include/firmware/imx/sci/rpc.h
+++ b/include/firmware/imx/sci/rpc.h
@@ -230,5 +230,6 @@ struct sc_rpc_msg_s {
 #define TIMER_FUNC_SET_SYSCTR_ALARM 16U /* Index for sc_timer_set_sysctr_alarm() RPC call */
 #define TIMER_FUNC_SET_SYSCTR_PERIODIC_ALARM 17U /* Index for sc_timer_set_sysctr_periodic_alarm() RPC call */
 #define TIMER_FUNC_CANCEL_SYSCTR_ALARM 18U /* Index for sc_timer_cancel_sysctr_alarm() RPC call */
+#define TIMER_FUNC_CTRL_PMIC_WDOG 20U  /*!< Index for sc_timer_ctrl_pmic_wdog() RPC call */
 
 #endif /* SC_RPC_H */
diff --git a/include/firmware/imx/sci/sci.h b/include/firmware/imx/sci/sci.h
index 7d8499f070a..b971b62836d 100644
--- a/include/firmware/imx/sci/sci.h
+++ b/include/firmware/imx/sci/sci.h
@@ -123,6 +123,7 @@ int sc_rm_set_master_sid(sc_ipc_t ipc, sc_rsrc_t resource, sc_rm_sid_t sid);
 
 /* Timer API */
 int sc_timer_set_wdog_window(sc_ipc_t ipc, sc_timer_wdog_time_t window);
+int sc_timer_control_pmic_wdog(sc_ipc_t ipc, u8 cmd);
 
 /* SECO API */
 int sc_seco_authenticate(sc_ipc_t ipc, sc_seco_auth_cmd_t cmd,
-- 
2.20.1