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| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-03-17 21:40:51 +0000 |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2011-03-23 10:42:09 +0100 |
| commit | 4c4d887822070410e3be519e1a4ff933fb899ba8 (patch) | |
| tree | 0e7b58b1d53d42b745846c7456317c1e1e413da1 /drivers/mfd/wm831x-i2c.c | |
| parent | aad343107b4c153dd9f3ffc3d0f32558a25438e9 (diff) | |
| download | linux-4c4d887822070410e3be519e1a4ff933fb899ba8.tar.gz linux-4c4d887822070410e3be519e1a4ff933fb899ba8.tar.bz2 linux-4c4d887822070410e3be519e1a4ff933fb899ba8.zip | |
mfd: Remove copy from WM831x I2C write function
This saves us allocating an array on the stack, giving a meaningless
performance improvement and ensuring that if drivers ever do large writes
we'll not allocate large arrays on the stack.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/mfd/wm831x-i2c.c')
| -rw-r--r-- | drivers/mfd/wm831x-i2c.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/mfd/wm831x-i2c.c b/drivers/mfd/wm831x-i2c.c index 3853fa8e7cc2..a06cbc739716 100644 --- a/drivers/mfd/wm831x-i2c.c +++ b/drivers/mfd/wm831x-i2c.c @@ -51,17 +51,25 @@ static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg, int bytes, void *src) { struct i2c_client *i2c = wm831x->control_data; - unsigned char msg[bytes + 2]; + struct i2c_msg xfer[2]; int ret; reg = cpu_to_be16(reg); - memcpy(&msg[0], ®, 2); - memcpy(&msg[2], src, bytes); - ret = i2c_master_send(i2c, msg, bytes + 2); + xfer[0].addr = i2c->addr; + xfer[0].flags = 0; + xfer[0].len = 2; + xfer[0].buf = (char *)® + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_NOSTART; + xfer[1].len = bytes; + xfer[1].buf = (char *)src; + + ret = i2c_transfer(i2c->adapter, xfer, 2); if (ret < 0) return ret; - if (ret < bytes + 2) + if (ret != 2) return -EIO; return 0; |