aboutsummaryrefslogtreecommitdiff
path: root/drivers/w1/slaves/w1_ds2760.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/w1/slaves/w1_ds2760.c')
-rw-r--r--drivers/w1/slaves/w1_ds2760.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2760.c b/drivers/w1/slaves/w1_ds2760.c
new file mode 100644
index 00000000000..88a37fbccc3
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2760.c
@@ -0,0 +1,213 @@
+/*
+ * 1-Wire implementation for the ds2760 chip
+ *
+ * Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
+ *
+ * Use consistent with the GNU GPL is permitted,
+ * provided that this copyright notice is
+ * preserved in its entirety in all copies and derived works.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+
+#include "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+#include "w1_ds2760.h"
+
+static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
+ int io)
+{
+ struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+ if (!dev)
+ return 0;
+
+ mutex_lock(&sl->master->mutex);
+
+ if (addr > DS2760_DATA_SIZE || addr < 0) {
+ count = 0;
+ goto out;
+ }
+ if (addr + count > DS2760_DATA_SIZE)
+ count = DS2760_DATA_SIZE - addr;
+
+ if (!w1_reset_select_slave(sl)) {
+ if (!io) {
+ w1_write_8(sl->master, W1_DS2760_READ_DATA);
+ w1_write_8(sl->master, addr);
+ count = w1_read_block(sl->master, buf, count);
+ } else {
+ w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
+ w1_write_8(sl->master, addr);
+ w1_write_block(sl->master, buf, count);
+ /* XXX w1_write_block returns void, not n_written */
+ }
+ }
+
+out:
+ mutex_unlock(&sl->master->mutex);
+
+ return count;
+}
+
+int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
+{
+ return w1_ds2760_io(dev, buf, addr, count, 0);
+}
+
+int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
+{
+ return w1_ds2760_io(dev, buf, addr, count, 1);
+}
+
+static ssize_t w1_ds2760_read_bin(struct kobject *kobj, char *buf, loff_t off,
+ size_t count)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ return w1_ds2760_read(dev, buf, off, count);
+}
+
+static struct bin_attribute w1_ds2760_bin_attr = {
+ .attr = {
+ .name = "w1_slave",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE,
+ },
+ .size = DS2760_DATA_SIZE,
+ .read = w1_ds2760_read_bin,
+};
+
+static DEFINE_IDR(bat_idr);
+static DEFINE_MUTEX(bat_idr_lock);
+
+static int new_bat_id(void)
+{
+ int ret;
+
+ while (1) {
+ int id;
+
+ ret = idr_pre_get(&bat_idr, GFP_KERNEL);
+ if (ret == 0)
+ return -ENOMEM;
+
+ mutex_lock(&bat_idr_lock);
+ ret = idr_get_new(&bat_idr, NULL, &id);
+ mutex_unlock(&bat_idr_lock);
+
+ if (ret == 0) {
+ ret = id & MAX_ID_MASK;
+ break;
+ } else if (ret == -EAGAIN) {
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static void release_bat_id(int id)
+{
+ mutex_lock(&bat_idr_lock);
+ idr_remove(&bat_idr, id);
+ mutex_unlock(&bat_idr_lock);
+
+ return;
+}
+
+static int w1_ds2760_add_slave(struct w1_slave *sl)
+{
+ int ret;
+ int id;
+ struct platform_device *pdev;
+
+ id = new_bat_id();
+ if (id < 0) {
+ ret = id;
+ goto noid;
+ }
+
+ pdev = platform_device_alloc("ds2760-battery", id);
+ if (!pdev) {
+ ret = -ENOMEM;
+ goto pdev_alloc_failed;
+ }
+ pdev->dev.parent = &sl->dev;
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ goto pdev_add_failed;
+
+ ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
+ if (ret)
+ goto bin_attr_failed;
+
+ dev_set_drvdata(&sl->dev, pdev);
+
+ goto success;
+
+bin_attr_failed:
+pdev_add_failed:
+ platform_device_unregister(pdev);
+pdev_alloc_failed:
+ release_bat_id(id);
+noid:
+success:
+ return ret;
+}
+
+static void w1_ds2760_remove_slave(struct w1_slave *sl)
+{
+ struct platform_device *pdev = dev_get_drvdata(&sl->dev);
+ int id = pdev->id;
+
+ platform_device_unregister(pdev);
+ release_bat_id(id);
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
+
+ return;
+}
+
+static struct w1_family_ops w1_ds2760_fops = {
+ .add_slave = w1_ds2760_add_slave,
+ .remove_slave = w1_ds2760_remove_slave,
+};
+
+static struct w1_family w1_ds2760_family = {
+ .fid = W1_FAMILY_DS2760,
+ .fops = &w1_ds2760_fops,
+};
+
+static int __init w1_ds2760_init(void)
+{
+ printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
+ " chip - (c) 2004-2005, Szabolcs Gyurko\n");
+ idr_init(&bat_idr);
+ return w1_register_family(&w1_ds2760_family);
+}
+
+static void __exit w1_ds2760_exit(void)
+{
+ w1_unregister_family(&w1_ds2760_family);
+ idr_destroy(&bat_idr);
+}
+
+EXPORT_SYMBOL(w1_ds2760_read);
+EXPORT_SYMBOL(w1_ds2760_write);
+
+module_init(w1_ds2760_init);
+module_exit(w1_ds2760_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
+MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");