Adds a nolock function to the w1 interface to avoid locking the

[karo-tx-linux.git] / drivers / w1 / slaves / w1_ds2780.c

diff --git a/drivers/w1/slaves/w1_ds2780.c b/drivers/w1/slaves/w1_ds2780.c
index 274c8f38303f5748478c47309c6e255b5c69ead1..39f78c0b143cb495a15eff9d67f5e4b7eb6ce4be 100644 (file)
--- a/drivers/w1/slaves/w1_ds2780.c
+++ b/drivers/w1/slaves/w1_ds2780.c
@@ -26,20 +26,14 @@
 #include "../w1_family.h"
 #include "w1_ds2780.h"
 
-int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
-                       int io)
+static int w1_ds2780_do_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 -ENODEV;
+       if (addr > DS2780_DATA_SIZE || addr < 0)
+               return 0;
 
-       mutex_lock(&sl->master->mutex);
-
-       if (addr > DS2780_DATA_SIZE || addr < 0) {
-               count = 0;
-               goto out;
-       }
        count = min_t(int, count, DS2780_DATA_SIZE - addr);
 
        if (w1_reset_select_slave(sl) == 0) {
@@ -47,7 +41,6 @@ int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
                        w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
                        w1_write_8(sl->master, addr);
                        w1_write_block(sl->master, buf, count);
-                       /* XXX w1_write_block returns void, not n_written */
                } else {
                        w1_write_8(sl->master, W1_DS2780_READ_DATA);
                        w1_write_8(sl->master, addr);
@@ -55,13 +48,42 @@ int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
                }
        }
 
-out:
+       return count;
+}
+
+int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
+                       int io)
+{
+       struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+       int ret;
+
+       if (!dev)
+               return -ENODEV;
+
+       mutex_lock(&sl->master->mutex);
+
+       ret = w1_ds2780_do_io(dev, buf, addr, count, io);
+
        mutex_unlock(&sl->master->mutex);
 
-       return count;
+       return ret;
 }
 EXPORT_SYMBOL(w1_ds2780_io);
 
+int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
+                       int io)
+{
+       int ret;
+
+       if (!dev)
+               return -ENODEV;
+
+       ret = w1_ds2780_do_io(dev, buf, addr, count, io);
+
+       return ret;
+}
+EXPORT_SYMBOL(w1_ds2780_io_nolock);
+
 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
 {
        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
@@ -99,43 +121,7 @@ static struct bin_attribute w1_ds2780_bin_attr = {
        .read = w1_ds2780_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);
-}
+static DEFINE_IDA(bat_ida);
 
 static int w1_ds2780_add_slave(struct w1_slave *sl)
 {
@@ -143,7 +129,7 @@ static int w1_ds2780_add_slave(struct w1_slave *sl)
        int id;
        struct platform_device *pdev;
 
-       id = new_bat_id();
+       id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
        if (id < 0) {
                ret = id;
                goto noid;
@@ -172,7 +158,7 @@ bin_attr_failed:
 pdev_add_failed:
        platform_device_unregister(pdev);
 pdev_alloc_failed:
-       release_bat_id(id);
+       ida_simple_remove(&bat_ida, id);
 noid:
        return ret;
 }
@@ -183,7 +169,7 @@ static void w1_ds2780_remove_slave(struct w1_slave *sl)
        int id = pdev->id;
 
        platform_device_unregister(pdev);
-       release_bat_id(id);
+       ida_simple_remove(&bat_ida, id);
        sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
 }
 
@@ -199,14 +185,14 @@ static struct w1_family w1_ds2780_family = {
 
 static int __init w1_ds2780_init(void)
 {
-       idr_init(&bat_idr);
+       ida_init(&bat_ida);
        return w1_register_family(&w1_ds2780_family);
 }
 
 static void __exit w1_ds2780_exit(void)
 {
        w1_unregister_family(&w1_ds2780_family);
-       idr_destroy(&bat_idr);
+       ida_destroy(&bat_ida);
 }
 
 module_init(w1_ds2780_init);