watchdog: Add support for Xilinx Microblaze watchdog

Watchdog can be used on Microblaze, PPC and Zynq hw designs.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@ti.com>

arch/microblaze/include/asm/processor.h

@@ -31,4 +31,8 @@ extern char __text_start[];
 /* Microblaze board initialization function */
 void board_init(void);
 
+/* Watchdog functions */
+extern int hw_watchdog_init(void);
+extern void hw_watchdog_disable(void);
+
 #endif /* __ASM_MICROBLAZE_PROCESSOR_H */

arch/microblaze/lib/board.c

@@ -61,6 +61,9 @@ init_fnc_t *init_sequence[] = {
 	serial_init,
 	console_init_f,
 	interrupts_init,
+#ifdef CONFIG_XILINX_TB_WATCHDOG
+	hw_watchdog_init,
+#endif
 	timer_init,
 	NULL,
 };

board/xilinx/microblaze-generic/microblaze-generic.c

@@ -39,6 +39,10 @@ int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	    ++(*((unsigned long *)(CONFIG_SYS_GPIO_0_ADDR)));
 #endif
 
+#ifdef CONFIG_XILINX_TB_WATCHDOG
+	hw_watchdog_disable();
+#endif
+
 	puts ("Reseting board\n");
 	__asm__ __volatile__ ("	mts rmsr, r0;" \
 				"bra r0");

board/xilinx/microblaze-generic/xparameters.h

@@ -77,3 +77,7 @@
 #define XILINX_LLTEMAC_SDMA_CTRL_BASEADDR	0x42000180
 #define XILINX_LLTEMAC_BASEADDR1		0x44200000
 #define XILINX_LLTEMAC_FIFO_BASEADDR1		0x42100000
+
+/* Watchdog IP is wxi_timebase_wdt_0 */
+#define XILINX_WATCHDOG_BASEADDR	0x50000000
+#define XILINX_WATCHDOG_IRQ		1

doc/README.watchdog

@@ -27,3 +27,6 @@ CONFIG_IMX_WATCHDOG
 	Available for i.mx31/35/5x/6x to service the watchdog. This is not
 	automatically set because some boards (vision2) still need to define
 	their own hw_watchdog_reset routine.
+
+CONFIG_XILINX_TB_WATCHDOG
+	Available for Xilinx Axi platforms to service timebase watchdog timer.

drivers/watchdog/Makefile

@@ -32,6 +32,7 @@ COBJS-y += imx_watchdog.o
 endif
 COBJS-$(CONFIG_TNETV107X_WATCHDOG) += tnetv107x_wdt.o
 COBJS-$(CONFIG_S5P)               += s5p_wdt.o
+COBJS-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)

drivers/watchdog/xilinx_tb_wdt.c

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2011-2013 Xilinx Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/microblaze_intc.h>
+#include <asm/processor.h>
+#include <watchdog.h>
+
+#define XWT_CSR0_WRS_MASK	0x00000008 /* Reset status Mask */
+#define XWT_CSR0_WDS_MASK	0x00000004 /* Timer state Mask */
+#define XWT_CSR0_EWDT1_MASK	0x00000002 /* Enable bit 1 Mask*/
+#define XWT_CSRX_EWDT2_MASK	0x00000001 /* Enable bit 2 Mask */
+
+struct watchdog_regs {
+	u32 twcsr0; /* 0x0 */
+	u32 twcsr1; /* 0x4 */
+	u32 tbr; /* 0x8 */
+};
+
+static struct watchdog_regs *watchdog_base =
+			(struct watchdog_regs *)CONFIG_WATCHDOG_BASEADDR;
+
+void hw_watchdog_reset(void)
+{
+	u32 reg;
+
+	/* Read the current contents of TCSR0 */
+	reg = readl(&watchdog_base->twcsr0);
+
+	/* Clear the watchdog WDS bit */
+	if (reg & (XWT_CSR0_EWDT1_MASK | XWT_CSRX_EWDT2_MASK))
+		writel(reg | XWT_CSR0_WDS_MASK, &watchdog_base->twcsr0);
+}
+
+void hw_watchdog_disable(void)
+{
+	u32 reg;
+
+	/* Read the current contents of TCSR0 */
+	reg = readl(&watchdog_base->twcsr0);
+
+	writel(reg & ~XWT_CSR0_EWDT1_MASK, &watchdog_base->twcsr0);
+	writel(~XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
+
+	puts("Watchdog disabled!\n");
+}
+
+static void hw_watchdog_isr(void *arg)
+{
+	hw_watchdog_reset();
+}
+
+int hw_watchdog_init(void)
+{
+	int ret;
+
+	writel((XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK | XWT_CSR0_EWDT1_MASK),
+	       &watchdog_base->twcsr0);
+	writel(XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
+
+	ret = install_interrupt_handler(CONFIG_WATCHDOG_IRQ,
+						hw_watchdog_isr, NULL);
+	if (ret)
+		return 1;
+
+	return 0;
+}

include/configs/microblaze-generic.h

@@ -120,6 +120,14 @@
 #  define CONFIG_SYS_TIMER_0_IRQ	XILINX_TIMER_IRQ
 #endif
 
+/* watchdog */
+#if defined(XILINX_WATCHDOG_BASEADDR) && defined(XILINX_WATCHDOG_IRQ)
+# define CONFIG_WATCHDOG_BASEADDR	XILINX_WATCHDOG_BASEADDR
+# define CONFIG_WATCHDOG_IRQ		XILINX_WATCHDOG_IRQ
+# define CONFIG_HW_WATCHDOG
+# define CONFIG_XILINX_TB_WATCHDOG
+#endif
+
 /*
  * memory layout - Example
  * CONFIG_SYS_TEXT_BASE = 0x1200_0000;	defined in config.mk