Commit c0be7a34 authored Oct 14, 2020 by Andy Shevchenko Committed by Greg Kroah-Hartman Nov 18, 2020

pinctrl: intel: Set default bias in case no particular value given



[ Upstream commit f3c75e7a9349d1d33eb53ddc1b31640994969f73 ]

When GPIO library asks pin control to set the bias, it doesn't pass
any value of it and argument is considered boolean (and this is true
for ACPI GpioIo() / GpioInt() resources, by the way). Thus, individual
drivers must behave well, when they got the resistance value of 1 Ohm,
i.e. transforming it to sane default.

In case of Intel pin control hardware the 5 kOhm sounds plausible
because on one hand it's a minimum of resistors present in all
hardware generations and at the same time it's high enough to minimize
leakage current (will be only 200 uA with the above choice).

Fixes: e57725ea ("pinctrl: intel: Add support for hardware debouncer")
Reported-by: Jamie McClymont <jamie@kwiius.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 88ccabbd

drivers/pinctrl/intel/pinctrl-intel.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -662,6 +662,10 @@ static int intel_config_set_pull(struct intel_pinctrl *pctrl, unsigned int pin,

		value \|= PADCFG1_TERM_UP;

		/* Set default strength value in case none is given */
		if (arg == 1)
		arg = 5000;

		switch (arg) {
		case 20000:
		value \|= PADCFG1_TERM_20K << PADCFG1_TERM_SHIFT;
		@@ -684,6 +688,10 @@ static int intel_config_set_pull(struct intel_pinctrl *pctrl, unsigned int pin,
		case PIN_CONFIG_BIAS_PULL_DOWN:
		value &= ~(PADCFG1_TERM_UP \| PADCFG1_TERM_MASK);

		/* Set default strength value in case none is given */
		if (arg == 1)
		arg = 5000;

		switch (arg) {
		case 20000:
		value \|= PADCFG1_TERM_20K << PADCFG1_TERM_SHIFT;