Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Mon, 13 Jun 2016 19:36:37 +0100 | Subject | [PATCH 3.16 031/114] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay |
| |
3.16.36-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Stephen Boyd <sboyd@codeaurora.org>
commit eda5ecc0a6b865561997e177c393f0b0136fe3b7 upstream.
The trigger delay algorithm that converts from microseconds to the register value looks incorrect. According to most of the PMIC documentation, the equation is
delay (Seconds) = (1 / 1024) * 2 ^ (x + 4)
except for one case where the documentation looks to have a formatting issue and the equation looks like
delay (Seconds) = (1 / 1024) * 2 x + 4
Most likely this driver was written with the improper documentation to begin with. According to the downstream sources the valid delays are from 2 seconds to 1/64 second, and the latter equation just doesn't make sense for that. Let's fix the algorithm and the range check to match the documentation and the downstream sources.
Reported-by: Bjorn Andersson <bjorn.andersson@linaro.org> Fixes: 92d57a73e410 ("input: Add support for Qualcomm PMIC8XXX power key") Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: John Stultz <john.stultz@linaro.org> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/input/misc/pmic8xxx-pwrkey.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -94,7 +94,8 @@ static int pmic8xxx_pwrkey_probe(struct if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay)) kpd_delay = 15625; - if (kpd_delay > 62500 || kpd_delay == 0) { + /* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */ + if (kpd_delay > USEC_PER_SEC * 2 || kpd_delay < USEC_PER_SEC / 64) { dev_err(&pdev->dev, "invalid power key trigger delay\n"); return -EINVAL; } @@ -124,8 +125,8 @@ static int pmic8xxx_pwrkey_probe(struct pwr->name = "pmic8xxx_pwrkey"; pwr->phys = "pmic8xxx_pwrkey/input0"; - delay = (kpd_delay << 10) / USEC_PER_SEC; - delay = 1 + ilog2(delay); + delay = (kpd_delay << 6) / USEC_PER_SEC; + delay = ilog2(delay); err = regmap_read(regmap, PON_CNTL_1, &pon_cntl); if (err < 0) {
| |