releases/3.1.1/drivers-power-ds2780_battery.c-add-a-nolock-function-to-w1-interface.patch

   1 From 9fe678fa2feb4aaac0b4220de63e1b7f8ccebae6 Mon Sep 17 00:00:00 2001
   2 From: Clifton Barnes <cabarnes@indesign-llc.com>
   3 Date: Wed, 2 Nov 2011 13:39:52 -0700
   4 Subject: drivers/power/ds2780_battery.c: add a nolock function to w1 interface
   5
   6 From: Clifton Barnes <cabarnes@indesign-llc.com>
   7
   8 commit 9fe678fa2feb4aaac0b4220de63e1b7f8ccebae6 upstream.
   9
  10 Adds a nolock function to the w1 interface to avoid locking the
  11 mutex if needed.
  12
  13 Signed-off-by: Clifton Barnes <cabarnes@indesign-llc.com>
  14 Cc: Evgeniy Polyakov <zbr@ioremap.net>
  15 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  16 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  18
  19 ---
  20  drivers/w1/slaves/w1_ds2780.c |   48 ++++++++++++++++++++++++++++++------------
  21  drivers/w1/slaves/w1_ds2780.h |    2 +
  22  2 files changed, 37 insertions(+), 13 deletions(-)
  23
  24 --- a/drivers/w1/slaves/w1_ds2780.c
  25 +++ b/drivers/w1/slaves/w1_ds2780.c
  26 @@ -26,20 +26,14 @@
  27  #include "../w1_family.h"
  28  #include "w1_ds2780.h"
  29
  30 -int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  31 -                       int io)
  32 +static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
  33 +                       size_t count, int io)
  34  {
  35         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  36
  37 -       if (!dev)
  38 -               return -ENODEV;
  39 -
  40 -       mutex_lock(&sl->master->mutex);
  41 +       if (addr > DS2780_DATA_SIZE || addr < 0)
  42 +               return 0;
  43
  44 -       if (addr > DS2780_DATA_SIZE || addr < 0) {
  45 -               count = 0;
  46 -               goto out;
  47 -       }
  48         count = min_t(int, count, DS2780_DATA_SIZE - addr);
  49
  50         if (w1_reset_select_slave(sl) == 0) {
  51 @@ -47,7 +41,6 @@ int w1_ds2780_io(struct device *dev, cha
  52                         w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
  53                         w1_write_8(sl->master, addr);
  54                         w1_write_block(sl->master, buf, count);
  55 -                       /* XXX w1_write_block returns void, not n_written */
  56                 } else {
  57                         w1_write_8(sl->master, W1_DS2780_READ_DATA);
  58                         w1_write_8(sl->master, addr);
  59 @@ -55,13 +48,42 @@ int w1_ds2780_io(struct device *dev, cha
  60                 }
  61         }
  62
  63 -out:
  64 +       return count;
  65 +}
  66 +
  67 +int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  68 +                       int io)
  69 +{
  70 +       struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  71 +       int ret;
  72 +
  73 +       if (!dev)
  74 +               return -ENODEV;
  75 +
  76 +       mutex_lock(&sl->master->mutex);
  77 +
  78 +       ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  79 +
  80         mutex_unlock(&sl->master->mutex);
  81
  82 -       return count;
  83 +       return ret;
  84  }
  85  EXPORT_SYMBOL(w1_ds2780_io);
  86
  87 +int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
  88 +                       int io)
  89 +{
  90 +       int ret;
  91 +
  92 +       if (!dev)
  93 +               return -ENODEV;
  94 +
  95 +       ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  96 +
  97 +       return ret;
  98 +}
  99 +EXPORT_SYMBOL(w1_ds2780_io_nolock);
 100 +
 101  int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
 102  {
 103         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
 104 --- a/drivers/w1/slaves/w1_ds2780.h
 105 +++ b/drivers/w1/slaves/w1_ds2780.h
 106 @@ -124,6 +124,8 @@
 107
 108  extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
 109                         int io);
 110 +extern int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr,
 111 +                       size_t count, int io);
 112  extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd);
 113
 114  #endif /* !_W1_DS2780_H */