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authorJan Luebbe <jluebbe@debian.org>2015-07-30 17:30:26 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2015-08-03 10:37:07 +0200
commitbde98d9c2010b787a5f7173d315f221e2ad2a491 (patch)
tree39f97b1cec79931830147df3532e23d888dcd67c /drivers/watchdog
parent077f9b7ef3277ce53c195dfce555583ab050eaf1 (diff)
downloadbarebox-bde98d9c2010b787a5f7173d315f221e2ad2a491.tar.gz
watchdog: add davinci watchdog driver
This driver is based on the Linux driver (v4.0). Signed-off-by: Jan Luebbe <jluebbe@debian.org> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/Kconfig6
-rw-r--r--drivers/watchdog/Makefile1
-rw-r--r--drivers/watchdog/davinci_wdt.c172
3 files changed, 179 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 7f7b02e..582c615 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -10,6 +10,12 @@ menuconfig WATCHDOG
if WATCHDOG
+config WATCHDOG_DAVINCI
+ bool "TI Davinci"
+ depends on ARCH_DAVINCI
+ help
+ Add support for watchdog on the TI Davinci SoC.
+
config WATCHDOG_MXS28
bool "i.MX28"
depends on ARCH_IMX28
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 865fc47..1e63c49 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_WATCHDOG) += wd_core.o
+obj-$(CONFIG_WATCHDOG_DAVINCI) += davinci_wdt.o
obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
obj-$(CONFIG_WATCHDOG_JZ4740) += jz4740.o
obj-$(CONFIG_WATCHDOG_IMX_RESET_SOURCE) += imxwd.o
diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
new file mode 100644
index 0000000..ecf6e89
--- /dev/null
+++ b/drivers/watchdog/davinci_wdt.c
@@ -0,0 +1,172 @@
+/*
+ * drivers/char/watchdog/davinci_wdt.c
+ *
+ * Watchdog driver for DaVinci DM644x/DM646x processors
+ *
+ * Copyright (C) 2006-2013 Texas Instruments.
+ * Copyright (C) 2015 Jan Luebbe <jluebbe@debian.org>
+ *
+ * 2007 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <of.h>
+#include <errno.h>
+#include <malloc.h>
+#include <watchdog.h>
+
+#include <linux/clk.h>
+
+/* Timer register set definition */
+#define PID12 (0x0)
+#define EMUMGT (0x4)
+#define TIM12 (0x10)
+#define TIM34 (0x14)
+#define PRD12 (0x18)
+#define PRD34 (0x1C)
+#define TCR (0x20)
+#define TGCR (0x24)
+#define WDTCR (0x28)
+
+/* TCR bit definitions */
+#define ENAMODE12_DISABLED (0 << 6)
+#define ENAMODE12_ONESHOT (1 << 6)
+#define ENAMODE12_PERIODIC (2 << 6)
+
+/* TGCR bit definitions */
+#define TIM12RS_UNRESET (1 << 0)
+#define TIM34RS_UNRESET (1 << 1)
+#define TIMMODE_64BIT_WDOG (2 << 2)
+
+/* WDTCR bit definitions */
+#define WDEN (1 << 14)
+#define WDFLAG (1 << 15)
+#define WDKEY_SEQ0 (0xa5c6 << 16)
+#define WDKEY_SEQ1 (0xda7e << 16)
+
+/*
+ * struct to hold data for each WDT device
+ * @wd - hold watchdog device as is in WDT core
+ * @base - base io address of WD device
+ * @clk - source clock of WDT
+ * @timeout - previously configured timeout
+ */
+struct davinci_wdt {
+ struct watchdog wd;
+ void __iomem *base;
+ struct clk *clk;
+ unsigned timeout;
+};
+
+#define to_davinci_wdt(h) container_of(h, struct davinci_wdt, wd)
+
+static int davinci_wdt_start(struct watchdog *wd)
+{
+ u32 tgcr;
+ u32 timer_margin;
+ unsigned long wdt_freq;
+ struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd);
+
+ wdt_freq = clk_get_rate(davinci_wdt->clk);
+
+ /* disable, internal clock source */
+ iowrite32(0, davinci_wdt->base + TCR);
+ /* reset timer, set mode to 64-bit watchdog, and unreset */
+ iowrite32(0, davinci_wdt->base + TGCR);
+ tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
+ iowrite32(tgcr, davinci_wdt->base + TGCR);
+ /* clear counter regs */
+ iowrite32(0, davinci_wdt->base + TIM12);
+ iowrite32(0, davinci_wdt->base + TIM34);
+ /* set timeout period */
+ timer_margin = (((u64)davinci_wdt->timeout * wdt_freq) & 0xffffffff);
+ iowrite32(timer_margin, davinci_wdt->base + PRD12);
+ timer_margin = (((u64)davinci_wdt->timeout * wdt_freq) >> 32);
+ iowrite32(timer_margin, davinci_wdt->base + PRD34);
+ /* enable run continuously */
+ iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR);
+ /* Once the WDT is in pre-active state write to
+ * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are
+ * write protected (except for the WDKEY field)
+ */
+ /* put watchdog in pre-active state */
+ iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR);
+ /* put watchdog in active state */
+ iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR);
+ return 0;
+}
+
+static int davinci_wdt_ping(struct watchdog *wd)
+{
+ struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd);
+
+ /* put watchdog in service state */
+ iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR);
+ /* put watchdog in active state */
+ iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR);
+ return 0;
+}
+
+static int davinci_wdt_set_timeout(struct watchdog *wd, unsigned timeout)
+{
+ struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd);
+
+ if (!davinci_wdt->timeout) {
+ davinci_wdt->timeout = timeout;
+ davinci_wdt_start(wd);
+ } else {
+ davinci_wdt_ping(wd);
+ if (davinci_wdt->timeout != timeout)
+ pr_warn("watchdog timeout can not be changed (currently %d)\n",
+ davinci_wdt->timeout);
+ }
+
+ return 0;
+}
+
+static int davinci_wdt_probe(struct device_d *dev)
+{
+ int ret = 0;
+ struct davinci_wdt *davinci_wdt;
+
+ davinci_wdt = xzalloc(sizeof(*davinci_wdt));
+
+ davinci_wdt->base = dev_request_mem_region(dev, 0);
+ if (IS_ERR(davinci_wdt->base))
+ return PTR_ERR(davinci_wdt->base);
+
+ davinci_wdt->clk = clk_get(dev, NULL);
+ if (WARN_ON(IS_ERR(davinci_wdt->clk)))
+ return PTR_ERR(davinci_wdt->clk);
+
+ clk_enable(davinci_wdt->clk);
+
+ davinci_wdt->wd.set_timeout = davinci_wdt_set_timeout;
+
+ ret = watchdog_register(&davinci_wdt->wd);
+ if (ret < 0)
+ dev_err(dev, "cannot register watchdog device\n");
+
+ return ret;
+}
+
+static __maybe_unused struct of_device_id davinci_wdt_of_match[] = {
+ { .compatible = "ti,davinci-wdt", },
+ {},
+};
+
+static struct driver_d platform_wdt_driver = {
+ .name = "davinci-wdt",
+ .of_compatible = DRV_OF_COMPAT(davinci_wdt_of_match),
+ .probe = davinci_wdt_probe,
+};
+device_platform_driver(platform_wdt_driver);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("DaVinci Watchdog Driver");
+MODULE_LICENSE("GPL");