Add Nokia CBUS support

[linux-2.6-omap-h63xx.git] / drivers / cbus / retu-wdt.c

diff --git a/drivers/cbus/retu-wdt.c b/drivers/cbus/retu-wdt.c
new file mode 100644 (file)
index 0000000..b7b20b7
--- /dev/null
+++ b/drivers/cbus/retu-wdt.c
@@ -0,0 +1,202 @@
+/**
+ * drivers/cbus/retu-wdt.c
+ *
+ * Driver for Retu watchdog
+ *
+ * Copyright (C) 2004, 2005 Nokia Corporation
+ *
+ * Written by Amit Kucheria <amit.kucheria@nokia.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/init.h>
+
+#include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+
+#include "cbus.h"
+#include "retu.h"
+
+/* Watchdog timeout in seconds */
+#define RETU_WDT_MIN_TIMER 0
+#define RETU_WDT_DEFAULT_TIMER 32
+#define RETU_WDT_MAX_TIMER 63
+
+static struct completion retu_wdt_completion;
+static DEFINE_MUTEX(retu_wdt_mutex);
+
+/* Current period of watchdog */
+static unsigned int period_val = RETU_WDT_DEFAULT_TIMER;
+static int counter_param = RETU_WDT_MAX_TIMER;
+
+static int retu_modify_counter(unsigned int new)
+{
+       int ret = 0;
+
+       if (new < RETU_WDT_MIN_TIMER || new > RETU_WDT_MAX_TIMER)
+               return -EINVAL;
+
+       mutex_lock(&retu_wdt_mutex);
+
+       period_val = new;
+       retu_write_reg(RETU_REG_WATCHDOG, (u16)period_val);
+
+       mutex_unlock(&retu_wdt_mutex);
+       return ret;
+}
+
+static ssize_t retu_wdt_period_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       /* Show current max counter */
+       return sprintf(buf, "%u\n", (u16)period_val);
+}
+
+static ssize_t retu_wdt_period_store(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       unsigned int new_period;
+       int ret;
+
+       if (sscanf(buf, "%u", &new_period) != 1) {
+               printk(KERN_ALERT "retu_wdt_period_store: Invalid input\n");
+               return -EINVAL;
+       }
+
+       ret = retu_modify_counter(new_period);
+       if (ret < 0)
+               return ret;
+
+       return strnlen(buf, count);
+}
+
+static ssize_t retu_wdt_counter_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       u16 counter;
+
+       /* Show current value in watchdog counter */
+       counter = retu_read_reg(RETU_REG_WATCHDOG);
+
+       /* Only the 5 LSB are important */
+       return snprintf(buf, PAGE_SIZE, "%u\n", (counter & 0x3F));
+}
+
+static DEVICE_ATTR(period, S_IRUGO | S_IWUSR, retu_wdt_period_show, \
+                       retu_wdt_period_store);
+static DEVICE_ATTR(counter, S_IRUGO, retu_wdt_counter_show, NULL);
+
+static int __devinit retu_wdt_probe(struct device *dev)
+{
+       int ret;
+
+       ret = device_create_file(dev, &dev_attr_period);
+       if (ret) {
+               printk(KERN_ERR "retu_wdt_probe: Error creating "
+                                       "sys device file: period\n");
+               return ret;
+       }
+
+       ret = device_create_file(dev, &dev_attr_counter);
+       if (ret) {
+               device_remove_file(dev, &dev_attr_period);
+               printk(KERN_ERR "retu_wdt_probe: Error creating "
+                                       "sys device file: counter\n");
+       }
+
+       return ret;
+}
+
+static int __devexit retu_wdt_remove(struct device *dev)
+{
+       device_remove_file(dev, &dev_attr_period);
+       device_remove_file(dev, &dev_attr_counter);
+       return 0;
+}
+
+static void retu_wdt_device_release(struct device *dev)
+{
+       complete(&retu_wdt_completion);
+}
+
+static struct platform_device retu_wdt_device = {
+       .name = "retu-watchdog",
+       .id = -1,
+       .dev = {
+               .release = retu_wdt_device_release,
+       },
+};
+
+static struct device_driver retu_wdt_driver = {
+       .name = "retu-watchdog",
+       .bus = &platform_bus_type,
+       .probe = retu_wdt_probe,
+       .remove = __devexit_p(retu_wdt_remove),
+};
+
+static int __init retu_wdt_init(void)
+{
+       int ret;
+
+       init_completion(&retu_wdt_completion);
+
+       ret = driver_register(&retu_wdt_driver);
+       if (ret)
+               return ret;
+
+       ret = platform_device_register(&retu_wdt_device);
+       if (ret)
+               goto exit1;
+
+       /* passed as module parameter? */
+       ret = retu_modify_counter(counter_param);
+       if (ret == -EINVAL) {
+               ret = retu_modify_counter(RETU_WDT_DEFAULT_TIMER);
+               printk(KERN_INFO
+                      "retu_wdt_init: Intializing to default value\n");
+       }
+
+       printk(KERN_INFO "Retu watchdog driver initialized\n");
+       return ret;
+
+exit1:
+       driver_unregister(&retu_wdt_driver);
+       wait_for_completion(&retu_wdt_completion);
+
+       return ret;
+}
+
+static void __exit retu_wdt_exit(void)
+{
+       platform_device_unregister(&retu_wdt_device);
+       driver_unregister(&retu_wdt_driver);
+
+       wait_for_completion(&retu_wdt_completion);
+}
+
+module_init(retu_wdt_init);
+module_exit(retu_wdt_exit);
+module_param(counter_param, int, 0);
+
+MODULE_DESCRIPTION("Retu WatchDog");
+MODULE_AUTHOR("Amit Kucheria");
+MODULE_LICENSE("GPL");
+