[RFC 2/3] watchdog: add icc watchdog driver

[fixed-term.Oleksij.Rempel]

From: Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>

this driver is needed to ping over ICC bus a watchdog.

Signed-off-by: Oleksij Rempel <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>
---
 drivers/watchdog/Kconfig   |   8 ++
 drivers/watchdog/Makefile  |   1 +
 drivers/watchdog/icc_wdt.c | 185 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 194 insertions(+)
 create mode 100644 drivers/watchdog/icc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 16f2023..7e52835 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -104,6 +104,14 @@ config GPIO_WATCHDOG
 	  If you say yes here you get support for watchdog device
 	  controlled through GPIO-line.
 
+config ICC_WATCHDOG
+	tristate "ICC watchdog"
+	depends on ICC
+	select WATCHDOG_CORE
+	help
+	  If you say yes here you get support for watchdog device
+	  controlled through ICC bus.
+
 config MENF21BMC_WATCHDOG
 	tristate "MEN 14F021P00 BMC Watchdog"
 	depends on MFD_MENF21BMC
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 5c19294..40451cc 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -181,6 +181,7 @@ obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
 obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
 obj-$(CONFIG_GPIO_WATCHDOG)	+= gpio_wdt.o
+obj-$(CONFIG_ICC_WATCHDOG)	+= icc_wdt.o
 obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
diff --git a/drivers/watchdog/icc_wdt.c b/drivers/watchdog/icc_wdt.c
new file mode 100644
index 0000000..a89dc15
--- /dev/null
+++ b/drivers/watchdog/icc_wdt.c
@@ -0,0 +1,185 @@
+/*
+ * Driver for RBCM INC Gen3 Watchdog.
+ *   RBCM - Robert Bosch Car Multimedia GmbH
+ *   INC - Inter node communication.
+ *   Gen3 - Generation 3 products.
+ * Short: rig3 :)
+ *
+ * Copyright (C) Robert Bosch Car Multimedia GmbH
+ * Authors:
+ *       Oleksij Rempel
+ *              <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>
+ *              <linux@xxxxxxxxxxxxxxxx>
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset.h>
+#include <linux/watchdog.h>
+#include <linux/icc/icc.h>
+
+struct icc_wdt_priv {
+	struct device		*dev;
+	struct icc_device	*iccd;
+	struct watchdog_device	wdd;
+
+	struct icc_trf	trf;
+	bool			check_pong;
+	atomic_t		pong;
+};
+
+static int icc_wdt_feed(struct watchdog_device *wdd)
+{
+	struct icc_wdt_priv *priv = watchdog_get_drvdata(wdd);
+	struct icc_device *iccd = priv->iccd;
+
+	if (priv->check_pong && atomic_read(&priv->pong))
+		dev_warn_ratelimited(priv->dev, "making ping without getting pong\n");
+
+	atomic_set(&priv->pong, 1);
+
+	return icc_trf_xmit(iccd->iccm, &priv->trf);
+}
+
+static int icc_wdt_enable(struct watchdog_device *wdd)
+{
+	return 0;
+}
+
+static int icc_wdt_stop(struct watchdog_device *wdd)
+{
+	return 0;
+}
+
+static const struct watchdog_info icc_wdt_ident = {
+	.identity         =	"RBCM, Inc Gen3 WatchDog",
+};
+
+static struct watchdog_ops icc_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= icc_wdt_enable,
+	.stop		= icc_wdt_stop,
+	.ping		= icc_wdt_feed,
+};
+
+static int icc_wdt_rx_cb(struct icc_device *iccd, void *rx_buf, size_t size)
+{
+	struct icc_wdt_priv *priv = icc_get_drvdata(iccd);
+
+	atomic_set(&priv->pong, 0);
+
+	return 0;
+}
+
+static int icc_wdt_int_trf(struct icc_wdt_priv *priv)
+{
+	struct icc_device *iccd = priv->iccd;
+	struct icc_trf *trf = &priv->trf;
+
+	u8 *buf;
+	int ret;
+
+	ret = icc_trf_alloc(iccd->iccm, trf, 9, 1);
+	if (ret)
+		return ret;
+
+	buf = trf->data;
+	buf[0] = 0x62;
+
+	return 0;
+}
+
+static int icc_wdt_probe(struct icc_device *iccd)
+{
+	struct device *dev = &iccd->dev;
+	struct icc_wdt_priv *priv;
+	struct watchdog_device *wdd;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(struct icc_wdt_priv),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->iccd = iccd;
+
+	wdd = &priv->wdd;
+	wdd->info = &icc_wdt_ident;
+	wdd->ops = &icc_wdt_ops;
+	wdd->min_timeout = 1;
+	wdd->max_timeout = 10;
+	wdd->parent = dev;
+
+	icc_set_drvdata(iccd, priv);
+	icc_set_rxcb(iccd, icc_wdt_rx_cb);
+	watchdog_set_drvdata(wdd, priv);
+
+	/*
+	 * If 'timeout-sec' unspecified in devicetree, assume a 30 second
+	 * default, unless the max timeout is less than 30 seconds, then use
+	 * the max instead.
+	 */
+	watchdog_init_timeout(wdd, 10, dev);
+
+	ret = watchdog_register_device(wdd);
+	if (ret)
+		return ret;
+
+	ret = icc_wdt_int_trf(priv);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "Watchdog enabled\n");
+	return 0;
+}
+
+static int icc_wdt_remove(struct icc_device *iccd)
+{
+	struct icc_wdt_priv *priv = icc_get_drvdata(iccd);
+
+	watchdog_unregister_device(&priv->wdd);
+
+	return 0;
+}
+
+static const struct of_device_id icc_wdt_of_match[] = {
+	{ .compatible = "rbcm,inc-wdt-gen3" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, icc_wdt_of_match);
+
+static struct icc_driver icc_wdt_driver = {
+	.driver = {
+		.name = "inc-wdt-gen3",
+		.owner = THIS_MODULE,
+		.of_match_table	= icc_wdt_of_match,
+	},
+	.probe = icc_wdt_probe,
+	.remove = icc_wdt_remove,
+};
+
+static int __init icc_wdt_init(void)
+{
+	return icc_register_driver(&icc_wdt_driver);
+}
+module_init(icc_wdt_init);
+
+static void __exit icc_wdt_exit(void)
+{
+	icc_unregister_driver(&icc_wdt_driver);
+}
+module_exit(icc_wdt_exit);
+
+MODULE_DESCRIPTION("ICC WatchDog Driver");
+MODULE_AUTHOR("Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
-- 
1.9.1