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| author | Eric Millbrandt <emillbrandt@dekaresearch.com> | 2010-09-03 21:31:05 +0400 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-09-05 23:14:36 +0400 |
| commit | eb54ddd4d78e62647b7096e4ada7389dbdf2cea7 (patch) | |
| tree | cef6a031b465523fac6e0f5c1b1466e1aa986b02 /drivers/input/touchscreen/wm97xx-core.c | |
| parent | d3622e6f05b2134deb5ba8ca2f6bcce5391e7e6d (diff) | |
| download | linux-eb54ddd4d78e62647b7096e4ada7389dbdf2cea7.tar.xz | |
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 <emillbrandt@dekaresearch.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/touchscreen/wm97xx-core.c')
| -rw-r--r-- | drivers/input/touchscreen/wm97xx-core.c | 15 |
1 files 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); |