ARM: sunxi: New watchdog driver for Allwinner A10/A13

This patch adds the driver for the watchdog found in the Allwinner A10 and A13 SoCs. It has DT-support and uses the new watchdog framework.

Signed-off-by Carlo Caione <[email protected]>

Acked-by Maxime Ripard <[email protected]>

---
 drivers/watchdog/Kconfig     |  10 ++
 drivers/watchdog/Makefile    |   1 +
 drivers/watchdog/sunxi_wdt.c | 241 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 252 insertions(+)
 create mode 100644 drivers/watchdog/sunxi_wdt.c

drivers/watchdog/Kconfig +10 -0

index 362085d..d1d53f3 100644
@@ -290,6 +290,16 @@ config ORION_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called orion_wdt.
 
+config SUNXI_WATCHDOG
+	tristate "Allwinner SoCs watchdog support"
+	depends on ARCH_SUNXI
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the watchdog timer
+	  in Allwinner SoCs.
+	  To compile this driver as a module, choose M here: the
+	  module will be called sunxi_wdt.
+
 config COH901327_WATCHDOG
 	bool "ST-Ericsson COH 901 327 watchdog"
 	depends on ARCH_U300

drivers/watchdog/Makefile +1 -0

index 2f26a0b..6c5bb27 100644
@@ -46,6 +46,7 @@ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
 obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
 obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
 obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
+obj-$(CONFIG_SUNXI_WATCHDOG) += sunxi_wdt.o
 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o

drivers/watchdog/sunxi_wdt.c new file +14 -0

new file mode 100644
index 0000000..11bfaf2
@@ -0,0 +1,241 @@
+/*
+ *      sunxi Watchdog Driver
+ *
+ *      Copyright (c) 2013 Carlo Caione
+ *                    2012 Henrik Nordstrom
+ *
+ *      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.
+ *
+ *      Based on xen_wdt.c
+ *      (c) Copyright 2010 Novell, Inc.
+ */

drivers/watchdog/sunxi_wdt.c new file +59 -0

+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define WDT_MAX_TIMEOUT         16
+#define WDT_MIN_TIMEOUT         1
+#define WDT_MODE_TIMEOUT(n)     ((n) << 3)
+#define WDT_TIMEOUT_MASK        WDT_MODE_TIMEOUT(0x0F)
+
+#define WDT_CTRL                0x00
+#define WDT_CTRL_RELOAD         ((1 << 0) | (0x0a57 << 1))
+
+#define WDT_MODE                0x04
+#define WDT_MODE_EN             (1 << 0)
+#define WDT_MODE_RST_EN         (1 << 1)
+
+#define DRV_NAME		"sunxi-wdt"
+#define DRV_VERSION		"1.0"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout = WDT_MAX_TIMEOUT;
+
+struct sunxi_wdt_dev {
+	struct watchdog_device wdt_dev;
+	void __iomem *wdt_base;
+};
+
+/*
+ * wdt_timeout_map maps the watchdog timer interval value in seconds to
+ * the value of the register WDT_MODE bit 3:6
+ *
+ * [timeout seconds] = register value
+ *
+ */
+
+static const int wdt_timeout_map[] = {
+	[1] = 0b0001,  /* 1s  */
+	[2] = 0b0010,  /* 2s  */
+	[3] = 0b0011,  /* 3s  */
+	[4] = 0b0100,  /* 4s  */
+	[5] = 0b0101,  /* 5s  */
+	[6] = 0b0110,  /* 6s  */
+	[8] = 0b0111,  /* 8s  */
+	[10] = 0b1000, /* 10s */
+	[12] = 0b1001, /* 12s */
+	[14] = 0b1010, /* 14s */
+	[16] = 0b1011, /* 16s */
+};
+
+static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+
+	iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
+
+	return 0;
+}
+