korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-13 22:56:27 +08:00
Code Issues Packages Projects Releases Wiki Activity

mfd: Use bulk read to fill WM8350 register cache

Browse Source 
Some I2C controllers have high overheads for setting up I2C operations
which makes the register cache setup on startup excessively slow since
it does a lot of small transactions. Reduce this overhead by doing a
bulk read of the entire register bank and filtering out what we don't
need later.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
This commit is contained in:
Mark Brown 2009-02-04 22:43:55 +01:00 committed by Samuel Ortiz
parent 22e2df7d5f
commit 9dfd338198
1 changed files with 12 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/mfd/wm8350-core.c
View File

@ -1238,7 +1238,7 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int type, int mode)
}
wm8350->reg_cache =
kzalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);
kmalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);
if (wm8350->reg_cache == NULL)
return -ENOMEM;
@ -1246,17 +1246,20 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int type, int mode)
* a PMIC so the device many not be in a virgin state and we
* can't rely on the silicon values.
*/
ret = wm8350->read_dev(wm8350, 0,
sizeof(u16) * (WM8350_MAX_REGISTER + 1),
wm8350->reg_cache);
if (ret < 0) {
dev_err(wm8350->dev,
"failed to read initial cache values\n");
goto out;
}
/* Mask out uncacheable/unreadable bits and the audio. */
for (i = 0; i < WM8350_MAX_REGISTER; i++) {
/* audio register range */
if (wm8350_reg_io_map[i].readable &&
(i < WM8350_CLOCK_CONTROL_1 || i > WM8350_AIF_TEST)) {
ret = wm8350->read_dev(wm8350, i, 2, (char *)&value);
if (ret < 0) {
dev_err(wm8350->dev,
"failed to read initial cache value\n");
goto out;
}
value = be16_to_cpu(value);
value = be16_to_cpu(wm8350->reg_cache[i]);
value &= wm8350_reg_io_map[i].readable;
value &= ~wm8350_reg_io_map[i].vol;
wm8350->reg_cache[i] = value;