From eda5ecc0a6b865561997e177c393f0b0136fe3b7 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Sun, 17 Apr 2016 05:21:42 -0700 Subject: [PATCH] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay 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 Fixes: 92d57a73e410 ("input: Add support for Qualcomm PMIC8XXX power key") Signed-off-by: Stephen Boyd Tested-by: John Stultz Acked-by: Bjorn Andersson Signed-off-by: Dmitry Torokhov --- 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 3f02e0e03d12..67aab86048ad 100644 --- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -353,7 +353,8 @@ 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; } @@ -385,8 +386,8 @@ 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) {