From eb54ddd4d78e62647b7096e4ada7389dbdf2cea7 Mon Sep 17 00:00:00 2001 From: Eric Millbrandt Date: Fri, 3 Sep 2010 10:31:05 -0700 Subject: Input: wm97xx-core - add retries to wm97xx_read_aux_adc Add logic to wm97xx_read_aux_adc() to retry reading the adc if the sample failed. This could occur if the previous sample was still in the return register or the sample timed-out. Also avoid a pathologic failure mode by disabling the digitizer and returning -EBUSY after 5 retries. Signed-off-by: Eric Millbrandt Acked-by: Mark Brown Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/wm97xx-core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c index 770537c14628..6b75c9f660ae 100644 --- a/drivers/input/touchscreen/wm97xx-core.c +++ b/drivers/input/touchscreen/wm97xx-core.c @@ -125,6 +125,8 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel) { int power_adc = 0, auxval; u16 power = 0; + int rc = 0; + int timeout = 0; /* get codec */ mutex_lock(&wm->codec_mutex); @@ -143,7 +145,9 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel) /* Turn polling mode on to read AUX ADC */ wm->pen_probably_down = 1; - wm->codec->poll_sample(wm, adcsel, &auxval); + + while (rc != RC_VALID && timeout++ < 5) + rc = wm->codec->poll_sample(wm, adcsel, &auxval); if (power_adc) wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000); @@ -152,8 +156,15 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel) wm->pen_probably_down = 0; + if (timeout >= 5) { + dev_err(wm->dev, + "timeout reading auxadc %d, disabling digitiser\n", + adcsel); + wm->codec->dig_enable(wm, false); + } + mutex_unlock(&wm->codec_mutex); - return auxval & 0xfff; + return (rc == RC_VALID ? auxval & 0xfff : -EBUSY); } EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc); -- cgit v1.2.2