[U-Boot] [PATCH 02/12] aspeed: Add support for Watchdot Timer

[Maxim Sloyko]

The driver is compatible with AST2400 and AST2500 watchdogs.
There is no uclass for Watchdog yet, so the driver does not follow
the driver model. It also uses fixed clock, so no clock driver
is needed.

# Conflicts:
#	arch/arm/mach-aspeed/Makefile

Signed-off-by: Maxim Sloyko <maxims at google.com>
---

 arch/arm/include/asm/arch-aspeed/wdt.h | 89 ++++++++++++++++++++++++++++++++++
 arch/arm/mach-aspeed/Makefile          |  3 +-
 arch/arm/mach-aspeed/ast_wdt.c         | 44 +++++++++++++++++
 3 files changed, 134 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/include/asm/arch-aspeed/wdt.h
 create mode 100644 arch/arm/mach-aspeed/ast_wdt.c

diff --git a/arch/arm/include/asm/arch-aspeed/wdt.h b/arch/arm/include/asm/arch-aspeed/wdt.h
new file mode 100644
index 0000000000..32774b1a70
--- /dev/null
+++ b/arch/arm/include/asm/arch-aspeed/wdt.h
@@ -0,0 +1,89 @@
+/*
+ * (C) Copyright 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#ifndef _ASM_ARCH_WDT_H
+#define _ASM_ARCH_WDT_H
+
+#define WDT_BASE			0x1e785000
+
+/*
+ * Special value that needs to be written to counter_restart register to
+ * (re)start the timer
+ */
+#define WDT_COUNTER_RESTART_VAL		0x4755
+
+/* Control register */
+#define WDT_CTRL_RESET_MODE_SHIFT	5
+#define WDT_CTRL_RESET_MODE_MASK	3
+
+#define WDT_CTRL_EN			(1 << 0)
+#define WDT_CTRL_RESET			(1 << 1)
+#define WDT_CTRL_CLK1MHZ		(1 << 4)
+#define WDT_CTRL_2ND_BOOT		(1 << 7)
+
+/* Values for Reset Mode */
+#define WDT_CTRL_RESET_SOC		0
+#define WDT_CTRL_RESET_CHIP		1
+#define WDT_CTRL_RESET_CPU		2
+#define WDT_CTRL_RESET_MASK		3
+
+/* Reset Mask register */
+#define WDT_RESET_ARM			(1 << 0)
+#define WDT_RESET_COPROC		(1 << 1)
+#define WDT_RESET_SDRAM			(1 << 2)
+#define WDT_RESET_AHB			(1 << 3)
+#define WDT_RESET_I2C			(1 << 4)
+#define WDT_RESET_MAC1			(1 << 5)
+#define WDT_RESET_MAC2			(1 << 6)
+#define WDT_RESET_GCRT			(1 << 7)
+#define WDT_RESET_USB20			(1 << 8)
+#define WDT_RESET_USB11_HOST		(1 << 9)
+#define WDT_RESET_USB11_EHCI2		(1 << 10)
+#define WDT_RESET_VIDEO			(1 << 11)
+#define WDT_RESET_HAC			(1 << 12)
+#define WDT_RESET_LPC			(1 << 13)
+#define WDT_RESET_SDSDIO		(1 << 14)
+#define WDT_RESET_MIC			(1 << 15)
+#define WDT_RESET_CRT2C			(1 << 16)
+#define WDT_RESET_PWM			(1 << 17)
+#define WDT_RESET_PECI			(1 << 18)
+#define WDT_RESET_JTAG			(1 << 19)
+#define WDT_RESET_ADC			(1 << 20)
+#define WDT_RESET_GPIO			(1 << 21)
+#define WDT_RESET_MCTP			(1 << 22)
+#define WDT_RESET_XDMA			(1 << 23)
+#define WDT_RESET_SPI			(1 << 24)
+#define WDT_RESET_MISC			(1 << 25)
+
+#ifndef __ASSEMBLY__
+struct ast_wdt {
+	u32 counter_status;
+	u32 counter_reload_val;
+	u32 counter_restart;
+	u32 ctrl;
+	u32 timeout_status;
+	u32 clr_timeout_status;
+	u32 reset_width;
+#ifdef CONFIG_ASPEED_AST2500
+	u32 reset_mask;
+#else
+	u32 reserved0;
+#endif
+};
+
+void wdt_stop(struct ast_wdt *wdt);
+void wdt_start(struct ast_wdt *wdt, u32 timeout);
+
+/**
+ * ast_get_wdt() - get a pointer to watchdog registers
+ *
+ * @wdt_number: 0-based WDT peripheral number
+ * @return pointer to registers or -ve error on error
+ */
+struct ast_wdt *ast_get_wdt(u8 wdt_number);
+#endif  /* __ASSEMBLY__ */
+
+#endif /* _ASM_ARCH_WDT_H */
diff --git a/arch/arm/mach-aspeed/Makefile b/arch/arm/mach-aspeed/Makefile
index 8e276b4a9f..a14b8f751d 100644
--- a/arch/arm/mach-aspeed/Makefile
+++ b/arch/arm/mach-aspeed/Makefile
@@ -1,8 +1,7 @@
 #
-# Copyright (c) 2014 Google, Inc
+# Copyright (c) 2016 Google, Inc
 #
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
 obj-$(CONFIG_ARCH_ASPEED) += ast_wdt.o
-obj-$(CONFIG_ASPEED_AST2500) += ast2500/ ast2500-board.o
diff --git a/arch/arm/mach-aspeed/ast_wdt.c b/arch/arm/mach-aspeed/ast_wdt.c
new file mode 100644
index 0000000000..0b62abc455
--- /dev/null
+++ b/arch/arm/mach-aspeed/ast_wdt.c
@@ -0,0 +1,44 @@
+/*
+ * (C) Copyright 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/wdt.h>
+#include <asm/io.h>
+#include <linux/err.h>
+
+/* Number of available watchdog timers */
+#ifdef CONFIG_ASPEED_AST2500
+#define WDT_MAX_NUM			2
+#else
+#define WDT_MAX_NUM			1
+#endif
+
+void wdt_stop(struct ast_wdt *wdt)
+{
+	clrbits_le32(&wdt->ctrl, WDT_CTRL_EN);
+}
+
+void wdt_start(struct ast_wdt *wdt, u32 timeout)
+{
+	writel(timeout, &wdt->counter_reload_val);
+	writel(WDT_COUNTER_RESTART_VAL, &wdt->counter_restart);
+	/*
+	 * Setting CLK1MHZ bit is just for compatibility with ast2400 part.
+	 * On ast2500 watchdog timer clock is fixed at 1MHz and the bit is
+	 * read-only
+	 */
+	setbits_le32(&wdt->ctrl,
+		     WDT_CTRL_EN | WDT_CTRL_RESET | WDT_CTRL_CLK1MHZ);
+}
+
+struct ast_wdt *ast_get_wdt(u8 wdt_number)
+{
+	if (wdt_number > WDT_MAX_NUM)
+		return ERR_PTR(-EINVAL);
+
+	return (struct ast_wdt *)(WDT_BASE +
+				  sizeof(struct ast_wdt) * wdt_number);
+}
-- 
2.11.0.390.gc69c2f50cf-goog