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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
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>
-rw-r--r--drivers/input/touchscreen/ucb1400_ts.c9
-rw-r--r--include/linux/ucb1400.h4
2 files changed, 13 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);
diff --git a/include/linux/ucb1400.h b/include/linux/ucb1400.h
index ed889f4168f..ae779bb8cc0 100644
--- a/include/linux/ucb1400.h
+++ b/include/linux/ucb1400.h
@@ -73,6 +73,10 @@
#define UCB_ADC_DATA 0x68
#define UCB_ADC_DAT_VALID (1 << 15)
+
+#define UCB_FCSR 0x6c
+#define UCB_FCSR_AVE (1 << 12)
+
#define UCB_ADC_DAT_MASK 0x3ff
#define UCB_ID 0x7e