Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 4.2.y-ckt 87/93] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay | Date | Tue, 26 Apr 2016 11:17:27 -0700 |
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4.2.8-ckt9 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
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: Kamal Mostafa <kamal@canonical.com> --- drivers/input/misc/pmic8xxx-pwrkey.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/input/misc/pmic8xxx-pwrkey.c b/drivers/input/misc/pmic8xxx-pwrkey.c index c4ca20e..b6d14bb 100644 --- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -92,7 +92,8 @@ static int pmic8xxx_pwrkey_probe(struct platform_device *pdev) 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; } @@ -122,8 +123,8 @@ static int pmic8xxx_pwrkey_probe(struct platform_device *pdev) 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) { -- 2.7.4
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