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authorMark Brown <broonie@opensource.wolfsonmicro.com>2009-02-04 22:43:55 +0100
committerSamuel Ortiz <samuel@sortiz.org>2009-04-05 00:32:19 +0200
commit9dfd338198bec67ebc82ed363078f9d8aa74ec3e (patch)
tree90edfba283a4679650e5a9e0d68c6122d12b69a9 /drivers/mfd
parent22e2df7d5ff50e5a62d4945b13c83525a2617ef5 (diff)
downloadop-kernel-dev-9dfd338198bec67ebc82ed363078f9d8aa74ec3e.zip
op-kernel-dev-9dfd338198bec67ebc82ed363078f9d8aa74ec3e.tar.gz
mfd: Use bulk read to fill WM8350 register cache
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>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/wm8350-core.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index b457a05..f22b18b 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -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;
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