watchdog/denali: Adding DesignWare watchdog driver support

To add the DesignWare watchdog driver support. It required
information such as register base address and clock info from
configuration header file  within include/configs folder.

Signed-off-by: Chin Liang See <clsee@altera.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@ti.com>

drivers/watchdog/Makefile

@@ -15,3 +15,4 @@ obj-$(CONFIG_S5P)               += s5p_wdt.o
 obj-$(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

drivers/watchdog/designware_wdt.c

+/*
+ * Copyright (C) 2013 Altera Corporation <www.altera.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <watchdog.h>
+#include <asm/io.h>
+#include <asm/utils.h>
+
+#define DW_WDT_CR	0x00
+#define DW_WDT_TORR	0x04
+#define DW_WDT_CRR	0x0C
+
+#define DW_WDT_CR_EN_OFFSET	0x00
+#define DW_WDT_CR_RMOD_OFFSET	0x01
+#define DW_WDT_CR_RMOD_VAL	0x00
+#define DW_WDT_CRR_RESTART_VAL	0x76
+
+/*
+ * Set the watchdog time interval.
+ * Counter is 32 bit.
+ */
+static int designware_wdt_settimeout(unsigned int timeout)
+{
+	signed int i;
+
+	/* calculate the timeout range value */
+	i = (log_2_n_round_up(timeout * CONFIG_DW_WDT_CLOCK_KHZ)) - 16;
+	if (i > 15)
+		i = 15;
+	if (i < 0)
+		i = 0;
+
+	writel((i | (i << 4)), (CONFIG_DW_WDT_BASE + DW_WDT_TORR));
+	return 0;
+}
+
+static void designware_wdt_enable(void)
+{
+	writel(((DW_WDT_CR_RMOD_VAL << DW_WDT_CR_RMOD_OFFSET) |
+	      (0x1 << DW_WDT_CR_EN_OFFSET)),
+	      (CONFIG_DW_WDT_BASE + DW_WDT_CR));
+}
+
+static unsigned int designware_wdt_is_enabled(void)
+{
+	unsigned long val;
+	val = readl((CONFIG_DW_WDT_BASE + DW_WDT_CR));
+	return val & 0x1;
+}
+
+#if defined(CONFIG_HW_WATCHDOG)
+void hw_watchdog_reset(void)
+{
+	if (designware_wdt_is_enabled())
+		/* restart the watchdog counter */
+		writel(DW_WDT_CRR_RESTART_VAL,
+		       (CONFIG_DW_WDT_BASE + DW_WDT_CRR));
+}
+
+void hw_watchdog_init(void)
+{
+	/* reset to disable the watchdog */
+	hw_watchdog_reset();
+	/* set timer in miliseconds */
+	designware_wdt_settimeout(CONFIG_HW_WATCHDOG_TIMEOUT_MS);
+	/* enable the watchdog */
+	designware_wdt_enable();
+	/* reset the watchdog */
+	hw_watchdog_reset();
+}
+#endif