From 1700f5fde88f9a251037bc86bde538ee32c59905 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Thu, 20 Aug 2009 22:05:53 -0700 Subject: [PATCH] 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 Tested-by: Palo Revak Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/ucb1400_ts.c | 9 +++++++++ include/linux/ucb1400.h | 4 ++++ 2 files changed, 13 insertions(+) diff --git a/drivers/input/touchscreen/ucb1400_ts.c b/drivers/input/touchscreen/ucb1400_ts.c index 6954f5500108..3b345f9cf0c7 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 ed889f4168f3..ae779bb8cc0f 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 -- 2.20.1