From 0b65118e6ba3024b8d9330cbca9b4c8b439d2057 Mon Sep 17 00:00:00 2001 From: David Collins Date: Sun, 24 Apr 2022 18:20:05 -0700 Subject: Input: pm8941-pwrkey - add software key press debouncing support On certain PMICs, an unexpected assertion of KPDPWR_DEB (the positive logic hardware debounced power key signal) may be seen during the falling edge of KPDPWR_N (i.e. a power key press) when it occurs close to the rising edge of SLEEP_CLK. This then triggers a spurious KPDPWR interrupt. Handle this issue by adding software debouncing support to ignore key events that occur within the hardware debounce delay after the most recent key release event. Signed-off-by: David Collins Signed-off-by: Anjelique Melendez Link: https://lore.kernel.org/r/20220422191239.6271-5-quic_amelende@quicinc.com Signed-off-by: Dmitry Torokhov --- drivers/input/misc/pm8941-pwrkey.c | 83 +++++++++++++++++++++++++++++++++++--- 1 file changed, 77 insertions(+), 6 deletions(-) (limited to 'drivers/input') diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c index 6c08ec08e8ae..4ae6d0f6afa3 100644 --- a/drivers/input/misc/pm8941-pwrkey.c +++ b/drivers/input/misc/pm8941-pwrkey.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -20,6 +21,16 @@ #define PON_REV2 0x01 +#define PON_SUBTYPE 0x05 + +#define PON_SUBTYPE_PRIMARY 0x01 +#define PON_SUBTYPE_SECONDARY 0x02 +#define PON_SUBTYPE_1REG 0x03 +#define PON_SUBTYPE_GEN2_PRIMARY 0x04 +#define PON_SUBTYPE_GEN2_SECONDARY 0x05 +#define PON_SUBTYPE_GEN3_PBS 0x08 +#define PON_SUBTYPE_GEN3_HLOS 0x09 + #define PON_RT_STS 0x10 #define PON_KPDPWR_N_SET BIT(0) #define PON_RESIN_N_SET BIT(1) @@ -60,9 +71,12 @@ struct pm8941_pwrkey { struct input_dev *input; unsigned int revision; + unsigned int subtype; struct notifier_block reboot_notifier; u32 code; + u32 sw_debounce_time_us; + ktime_t sw_debounce_end_time; const struct pm8941_data *data; }; @@ -132,20 +146,66 @@ static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data) { struct pm8941_pwrkey *pwrkey = _data; unsigned int sts; - int error; + int err; + + if (pwrkey->sw_debounce_time_us) { + if (ktime_before(ktime_get(), pwrkey->sw_debounce_end_time)) { + dev_dbg(pwrkey->dev, + "ignoring key event received before debounce end %llu us\n", + pwrkey->sw_debounce_end_time); + return IRQ_HANDLED; + } + } - error = regmap_read(pwrkey->regmap, - pwrkey->baseaddr + PON_RT_STS, &sts); - if (error) + err = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_RT_STS, &sts); + if (err) return IRQ_HANDLED; - input_report_key(pwrkey->input, pwrkey->code, - sts & pwrkey->data->status_bit); + sts &= pwrkey->data->status_bit; + + if (pwrkey->sw_debounce_time_us && !sts) + pwrkey->sw_debounce_end_time = ktime_add_us(ktime_get(), + pwrkey->sw_debounce_time_us); + + input_report_key(pwrkey->input, pwrkey->code, sts); input_sync(pwrkey->input); return IRQ_HANDLED; } +static int pm8941_pwrkey_sw_debounce_init(struct pm8941_pwrkey *pwrkey) +{ + unsigned int val, addr, mask; + int error; + + if (pwrkey->data->has_pon_pbs && !pwrkey->pon_pbs_baseaddr) { + dev_err(pwrkey->dev, + "PON_PBS address missing, can't read HW debounce time\n"); + return 0; + } + + if (pwrkey->pon_pbs_baseaddr) + addr = pwrkey->pon_pbs_baseaddr + PON_DBC_CTL; + else + addr = pwrkey->baseaddr + PON_DBC_CTL; + error = regmap_read(pwrkey->regmap, addr, &val); + if (error) + return error; + + if (pwrkey->subtype >= PON_SUBTYPE_GEN2_PRIMARY) + mask = 0xf; + else + mask = 0x7; + + pwrkey->sw_debounce_time_us = + 2 * USEC_PER_SEC / (1 << (mask - (val & mask))); + + dev_dbg(pwrkey->dev, "SW debounce time = %u us\n", + pwrkey->sw_debounce_time_us); + + return 0; +} + static int __maybe_unused pm8941_pwrkey_suspend(struct device *dev) { struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev); @@ -238,6 +298,13 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev) return error; } + error = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_SUBTYPE, + &pwrkey->subtype); + if (error) { + dev_err(&pdev->dev, "failed to read subtype: %d\n", error); + return error; + } + error = of_property_read_u32(pdev->dev.of_node, "linux,code", &pwrkey->code); if (error) { @@ -272,6 +339,10 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev) } } + error = pm8941_pwrkey_sw_debounce_init(pwrkey); + if (error) + return error; + if (pwrkey->data->pull_up_bit) { error = regmap_update_bits(pwrkey->regmap, pwrkey->baseaddr + PON_PULL_CTL, -- cgit v1.2.3-59-g8ed1b