aspeed: Add drivers common to all Aspeed SoCs

Add support for Watchdog Timer, which 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.

Add support for timer for Aspeed ast2400/ast2500 devices.
The driver actually controls several devices, but because all devices
share the same Control Register, it is somewhat difficult to completely
decouple them. Since only one timer is needed at the moment, this should
be OK. The timer uses fixed clock, so does not rely on a clock driver.

Add sysreset driver, which uses watchdog timer to do resets and particular
watchdog device to use is hardcoded (0)
Reviewed-by: Simon Glass <sjg@chromium.org>

7 files changed, 254 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c04adfbe503..b0b6f788548 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1007,8 +1007,15 @@ config TARGET_THUNDERX_88XX
 	select OF_CONTROL
 	select SYS_CACHE_SHIFT_7
 
+config ARCH_ASPEED
+	bool "Support Aspeed SoCs"
+	select OF_CONTROL
+	select DM
+
 endchoice
 
+source "arch/arm/mach-aspeed/Kconfig"
+
 source "arch/arm/mach-at91/Kconfig"
 
 source "arch/arm/mach-bcm283x/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 4b8bf80c403..6fa950668c3 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -50,6 +50,7 @@ PLATFORM_CPPFLAGS += $(arch-y) $(tune-y)
 
 # Machine directory name.  This list is sorted alphanumerically
 # by CONFIG_* macro name.
+machine-$(CONFIG_ARCH_ASPEED)		+= aspeed
 machine-$(CONFIG_ARCH_AT91)		+= at91
 machine-$(CONFIG_ARCH_BCM283X)		+= bcm283x
 machine-$(CONFIG_ARCH_DAVINCI)		+= davinci
diff --git a/arch/arm/include/asm/arch-aspeed/timer.h b/arch/arm/include/asm/arch-aspeed/timer.h
new file mode 100644
index 00000000000..87c5b354ecf
--- /dev/null
+++ b/arch/arm/include/asm/arch-aspeed/timer.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#ifndef _ASM_ARCH_TIMER_H
+#define _ASM_ARCH_TIMER_H
+
+/* Each timer has 4 control bits in ctrl1 register.
+ * Timer1 uses bits 0:3, Timer2 uses bits 4:7 and so on,
+ * such that timer X uses bits (4 * X - 4):(4 * X - 1)
+ * If the timer does not support PWM, bit 4 is reserved.
+ */
+#define AST_TMC_EN			(1 << 0)
+#define AST_TMC_1MHZ			(1 << 1)
+#define AST_TMC_OVFINTR			(1 << 2)
+#define AST_TMC_PWM			(1 << 3)
+
+/* Timers are counted from 1 in the datasheet. */
+#define AST_TMC_CTRL1_SHIFT(n)			(4 * ((n) - 1))
+
+#define AST_TMC_RATE  (1000*1000)
+
+#ifndef __ASSEMBLY__
+
+/*
+ * All timers share control registers, which makes it harder to make them
+ * separate devices. Since only one timer is needed at the moment, making
+ * it this just one device.
+ */
+
+struct ast_timer_counter {
+	u32 status;
+	u32 reload_val;
+	u32 match1;
+	u32 match2;
+};
+
+struct ast_timer {
+	struct ast_timer_counter timers1[3];
+	u32 ctrl1;
+	u32 ctrl2;
+#ifdef CONFIG_ASPEED_AST2500
+	u32 ctrl3;
+	u32 ctrl1_clr;
+#else
+	u32 reserved[2];
+#endif
+	struct ast_timer_counter timers2[5];
+};
+
+#endif  /* __ASSEMBLY__ */
+
+#endif  /* _ASM_ARCH_TIMER_H */
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 00000000000..b292a0e67b5
--- /dev/null
+++ b/arch/arm/include/asm/arch-aspeed/wdt.h
@@ -0,0 +1,99 @@
+/*
+ * (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);
+
+/**
+ * Reset peripherals specified by mask
+ *
+ * Note, that this is only supported by ast2500 SoC
+ *
+ * @wdt: watchdog to use for this reset
+ * @mask: reset mask.
+ */
+int ast_wdt_reset_masked(struct ast_wdt *wdt, u32 mask);
+
+/**
+ * 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/Kconfig b/arch/arm/mach-aspeed/Kconfig
new file mode 100644
index 00000000000..b72ed89af74
--- /dev/null
+++ b/arch/arm/mach-aspeed/Kconfig
@@ -0,0 +1,27 @@
+if ARCH_ASPEED
+
+config SYS_ARCH
+	default "arm"
+
+config SYS_SOC
+	default "aspeed"
+
+config SYS_TEXT_BASE
+	default 0x00000000
+
+config ASPEED_AST2500
+	bool "Support Aspeed AST2500 SoC"
+	select CPU_ARM1176
+	help
+	  The Aspeed AST2500 is a ARM-based SoC with arm1176 CPU.
+	  It is used as Board Management Controller on many server boards,
+	  which is enabled by support of LPC and eSPI peripherals.
+
+config WDT_NUM
+	int "Number of Watchdog Timers"
+	default 3 if ASPEED_AST2500
+	help
+	  The number of Watchdot Timers on a SoC.
+	  AST2500 has three WDTsk earlier versions have two or fewer.
+
+endif
diff --git a/arch/arm/mach-aspeed/Makefile b/arch/arm/mach-aspeed/Makefile
new file mode 100644
index 00000000000..a14b8f751d2
--- /dev/null
+++ b/arch/arm/mach-aspeed/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (c) 2016 Google, Inc
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_ARCH_ASPEED) += ast_wdt.o
diff --git a/arch/arm/mach-aspeed/ast_wdt.c b/arch/arm/mach-aspeed/ast_wdt.c
new file mode 100644
index 00000000000..22481ab7ea1
--- /dev/null
+++ b/arch/arm/mach-aspeed/ast_wdt.c
@@ -0,0 +1,59 @@
+/*
+ * (C) Copyright 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/wdt.h>
+#include <linux/err.h>
+
+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 > CONFIG_WDT_NUM - 1)
+		return ERR_PTR(-EINVAL);
+
+	return (struct ast_wdt *)(WDT_BASE +
+				  sizeof(struct ast_wdt) * wdt_number);
+}
+
+int ast_wdt_reset_masked(struct ast_wdt *wdt, u32 mask)
+{
+#ifdef CONFIG_ASPEED_AST2500
+	if (!mask)
+		return -EINVAL;
+
+	writel(mask, &wdt->reset_mask);
+	clrbits_le32(&wdt->ctrl,
+		     WDT_CTRL_RESET_MASK << WDT_CTRL_RESET_MODE_SHIFT);
+	wdt_start(wdt, 1);
+
+	/* Wait for WDT to reset */
+	while (readl(&wdt->ctrl) & WDT_CTRL_EN)
+		;
+	wdt_stop(wdt);
+
+	return 0;
+#else
+	return -EINVAL;
+#endif
+}