[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 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");