[BATTERY] ds2760 W1 slave

This is W1 slave for ds2760 chip, found inside almost every HP iPaq and
HTC PDAs/phones.

Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

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 000000000000..88a37fbccc3f
--- /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");