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authorMarek Vasut <marek.vasut@gmail.com>2009-08-20 22:05:53 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2009-08-21 00:53:12 -0700
commit1700f5fde88f9a251037bc86bde538ee32c59905 (patch)
treeaceddbec1e1c3916fe4a5fd20ab3f2a2de3e362a /drivers/input/touchscreen/ucb1400_ts.c
parent3b7307c2d66dd575ef24b88898b4bc4bddb254f4 (diff)
Input: ucb1400_ts - enable ADC Filter
This patch enables ADC filtering on UCB1400 codec by default. The benefit from this change is mostly on some Colibri boards where the ADCSYNC pin of the UCB1400 codec isn't connected causing the touchscreen to jitter very badly. This change has no visible effect on boards where the ADCSYNC pin is connected. Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Tested-by: Palo Revak <palo@bielyvlk.sk> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/touchscreen/ucb1400_ts.c')
-rw-r--r--drivers/input/touchscreen/ucb1400_ts.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ucb1400_ts.c b/drivers/input/touchscreen/ucb1400_ts.c
index 6954f550010..3b345f9cf0c 100644
--- a/drivers/input/touchscreen/ucb1400_ts.c
+++ b/drivers/input/touchscreen/ucb1400_ts.c
@@ -345,6 +345,7 @@ static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb)
static int ucb1400_ts_probe(struct platform_device *dev)
{
int error, x_res, y_res;
+ u16 fcsr;
struct ucb1400_ts *ucb = dev->dev.platform_data;
ucb->ts_idev = input_allocate_device();
@@ -382,6 +383,14 @@ static int ucb1400_ts_probe(struct platform_device *dev)
ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+ /*
+ * Enable ADC filter to prevent horrible jitter on Colibri.
+ * This also further reduces jitter on boards where ADCSYNC
+ * pin is connected.
+ */
+ fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
+ ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
+
ucb1400_adc_enable(ucb->ac97);
x_res = ucb1400_ts_read_xres(ucb);
y_res = ucb1400_ts_read_yres(ucb);