[U-Boot] [PATCH v1] watchdog: Introduce watchdog driver for Intel Tangier

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

From: Felipe Balbi <felipe.balbi@linux.intel.com>

Add watchdog driver for Intel Tangier based platforms.

Signed-off-by: Vincent Tinelli <vincent.tinelli@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 common/board_f.c               |  1 +
 drivers/watchdog/Kconfig       |  8 ++++++
 drivers/watchdog/Makefile      |  1 +
 drivers/watchdog/tangier_wdt.c | 63 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+)
 create mode 100644 drivers/watchdog/tangier_wdt.c

diff --git a/common/board_f.c b/common/board_f.c
index d9431ee79a..ad1eae98a5 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -91,6 +91,7 @@ static int init_func_watchdog_init(void)
 	(defined(CONFIG_M68K) || defined(CONFIG_MICROBLAZE) || \
 	defined(CONFIG_SH) || defined(CONFIG_AT91SAM9_WATCHDOG) || \
 	defined(CONFIG_DESIGNWARE_WATCHDOG) || \
+	defined(CONFIG_TANGIER_WATCHDOG) || \
 	defined(CONFIG_IMX_WATCHDOG))
 	hw_watchdog_init();
 	puts("       Watchdog enabled\n");
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index dbdaafc149..66fe70dba1 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1,5 +1,13 @@
 menu "WATCHDOG support"
 
+config TANGIER_WATCHDOG
+	bool "Intel Tangier watchdog"
+	depends on INTEL_MID
+	help
+	  This enables support for watchdog controller available on
+	  Intel Tangier SoC. If you're using a board with Intel Tangier
+	  SoC, say Y here.
+
 config ULP_WATCHDOG
 	bool "i.MX7ULP watchdog"
 	help
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index dea18363ca..7b77d8379f 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -15,4 +15,5 @@ obj-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o
 obj-$(CONFIG_BFIN_WATCHDOG)  += bfin_wdt.o
 obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
 obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o
+obj-$(CONFIG_TANGIER_WATCHDOG) += tangier_wdt.o
 obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o
diff --git a/drivers/watchdog/tangier_wdt.c b/drivers/watchdog/tangier_wdt.c
new file mode 100644
index 0000000000..23be71a42f
--- /dev/null
+++ b/drivers/watchdog/tangier_wdt.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2017 Intel Corporation
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <watchdog.h>
+#include <asm/scu.h>
+
+/* Hardware timeout in seconds */
+#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
+#define WATCHDOG_HEARTBEAT 60000
+#else
+#define WATCHDOG_HEARTBEAT CONFIG_WATCHDOG_TIMEOUT_MSECS
+#endif
+
+enum {
+	SCU_WATCHDOG_START			= 0,
+	SCU_WATCHDOG_STOP			= 1,
+	SCU_WATCHDOG_KEEPALIVE			= 2,
+	SCU_WATCHDOG_SET_ACTION_ON_TIMEOUT	= 3,
+};
+
+void hw_watchdog_reset(void)
+{
+	static unsigned long prev;
+	unsigned long now;
+
+	if (gd->timer)
+		now = timer_get_us();
+	else
+		now = rdtsc() / 1000000;
+
+	/* Do not flood SCU */
+	if (unlikely((now - prev) > (WATCHDOG_HEARTBEAT * 1000))) {
+		prev = now;
+		scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_KEEPALIVE);
+	}
+}
+
+int hw_watchdog_disable(void)
+{
+	return scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_STOP);
+}
+
+void hw_watchdog_init(void)
+{
+	u32 timeout = WATCHDOG_HEARTBEAT / 1000;
+	int in_size;
+	struct ipc_wd_start {
+		u32 pretimeout;
+		u32 timeout;
+	} ipc_wd_start = { timeout, timeout };
+
+	/*
+	 * SCU expects the input size for watchdog IPC
+	 * to be based on 4 bytes
+	 */
+	in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
+
+	scu_ipc_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_START,
+			(u32 *)&ipc_wd_start, in_size, NULL, 0);
+}
-- 
2.11.0