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

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 Merrifield pin control hardware the 20 kOhm sounds plausible
because it gives a good trade off between weakness and minimization of leakage
current (will be only 50 uA with the above choice).

Fixes: 4e80c8f50574 ("pinctrl: intel: Add Intel Merrifield pin controller support")
Depends-on: 2956b5d94a76 ("pinctrl / gpio: Introduce .set_config() callback for GPIO chips")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/pinctrl/intel/pinctrl-merrifield.c b/drivers/pinctrl/intel/pinctrl-merrifield.c
index e4ff8da..3ae141e 100644 (file)
--- a/drivers/pinctrl/intel/pinctrl-merrifield.c
+++ b/drivers/pinctrl/intel/pinctrl-merrifield.c
@@ -745,6 +745,10 @@ static int mrfld_config_set_pin(struct mrfld_pinctrl *mp, unsigned int pin,
                mask |= BUFCFG_Px_EN_MASK | BUFCFG_PUPD_VAL_MASK;
                bits |= BUFCFG_PU_EN;
 
+               /* Set default strength value in case none is given */
+               if (arg == 1)
+                       arg = 20000;
+
                switch (arg) {
                case 50000:
                        bits |= BUFCFG_PUPD_VAL_50K << BUFCFG_PUPD_VAL_SHIFT;
@@ -765,6 +769,10 @@ static int mrfld_config_set_pin(struct mrfld_pinctrl *mp, unsigned int pin,
                mask |= BUFCFG_Px_EN_MASK | BUFCFG_PUPD_VAL_MASK;
                bits |= BUFCFG_PD_EN;
 
+               /* Set default strength value in case none is given */
+               if (arg == 1)
+                       arg = 20000;
+
                switch (arg) {
                case 50000:
                        bits |= BUFCFG_PUPD_VAL_50K << BUFCFG_PUPD_VAL_SHIFT;