1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/comedi/drivers/addi_watchdog.c b/drivers/comedi/drivers/addi_watchdog.c
new file mode 100644
index 000000000000..69b323fb869f
--- /dev/null
+++ b/drivers/comedi/drivers/addi_watchdog.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * COMEDI driver for the watchdog subdevice found on some addi-data boards
+ * Copyright (c) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * Based on implementations in various addi-data COMEDI drivers.
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
+ */
+
+#include <linux/module.h>
+#include "../comedidev.h"
+#include "addi_tcw.h"
+#include "addi_watchdog.h"
+
+struct addi_watchdog_private {
+	unsigned long iobase;
+	unsigned int wdog_ctrl;
+};
+
+/*
+ * The watchdog subdevice is configured with two INSN_CONFIG instructions:
+ *
+ * Enable the watchdog and set the reload timeout:
+ *	data[0] = INSN_CONFIG_ARM
+ *	data[1] = timeout reload value
+ *
+ * Disable the watchdog:
+ *	data[0] = INSN_CONFIG_DISARM
+ */
+static int addi_watchdog_insn_config(struct comedi_device *dev,
+				     struct comedi_subdevice *s,
+				     struct comedi_insn *insn,
+				     unsigned int *data)
+{
+	struct addi_watchdog_private *spriv = s->private;
+	unsigned int reload;
+
+	switch (data[0]) {
+	case INSN_CONFIG_ARM:
+		spriv->wdog_ctrl = ADDI_TCW_CTRL_ENA;
+		reload = data[1] & s->maxdata;
+		outl(reload, spriv->iobase + ADDI_TCW_RELOAD_REG);
+
+		/* Time base is 20ms, let the user know the timeout */
+		dev_info(dev->class_dev, "watchdog enabled, timeout:%dms\n",
+			 20 * reload + 20);
+		break;
+	case INSN_CONFIG_DISARM:
+		spriv->wdog_ctrl = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	outl(spriv->wdog_ctrl, spriv->iobase + ADDI_TCW_CTRL_REG);
+
+	return insn->n;
+}
+
+static int addi_watchdog_insn_read(struct comedi_device *dev,
+				   struct comedi_subdevice *s,
+				   struct comedi_insn *insn,
+				   unsigned int *data)
+{
+	struct addi_watchdog_private *spriv = s->private;
+	int i;
+
+	for (i = 0; i < insn->n; i++)
+		data[i] = inl(spriv->iobase + ADDI_TCW_STATUS_REG);
+
+	return insn->n;
+}
+
+static int addi_watchdog_insn_write(struct comedi_device *dev,
+				    struct comedi_subdevice *s,
+				    struct comedi_insn *insn,
+				    unsigned int *data)
+{
+	struct addi_watchdog_private *spriv = s->private;
+	int i;
+
+	if (spriv->wdog_ctrl == 0) {
+		dev_warn(dev->class_dev, "watchdog is disabled\n");
+		return -EINVAL;
+	}
+
+	/* "ping" the watchdog */
+	for (i = 0; i < insn->n; i++) {
+		outl(spriv->wdog_ctrl | ADDI_TCW_CTRL_TRIG,
+		     spriv->iobase + ADDI_TCW_CTRL_REG);
+	}
+
+	return insn->n;
+}
+
+void addi_watchdog_reset(unsigned long iobase)
+{
+	outl(0x0, iobase + ADDI_TCW_CTRL_REG);
+	outl(0x0, iobase + ADDI_TCW_RELOAD_REG);
+}
+EXPORT_SYMBOL_GPL(addi_watchdog_reset);
+
+int addi_watchdog_init(struct comedi_subdevice *s, unsigned long iobase)
+{
+	struct addi_watchdog_private *spriv;
+
+	spriv = comedi_alloc_spriv(s, sizeof(*spriv));
+	if (!spriv)
+		return -ENOMEM;
+
+	spriv->iobase = iobase;
+
+	s->type		= COMEDI_SUBD_TIMER;
+	s->subdev_flags	= SDF_WRITABLE;
+	s->n_chan	= 1;
+	s->maxdata	= 0xff;
+	s->insn_config	= addi_watchdog_insn_config;
+	s->insn_read	= addi_watchdog_insn_read;
+	s->insn_write	= addi_watchdog_insn_write;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(addi_watchdog_init);
+
+static int __init addi_watchdog_module_init(void)
+{
+	return 0;
+}
+module_init(addi_watchdog_module_init);
+
+static void __exit addi_watchdog_module_exit(void)
+{
+}
+module_exit(addi_watchdog_module_exit);
+
+MODULE_DESCRIPTION("ADDI-DATA Watchdog subdevice");
+MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
+MODULE_LICENSE("GPL");