pinctrl: cherryview: Configure HiZ pins to be input when requested as GPIOs

If the pin is in HiZ mode when it is requested as GPIO its value cannot be
read (it always returns 0). In order to cope with the Linux GPIO subsystem
where we do not have such state at all, turn the pin to be input instead.

Reported-by: Jerome Blin <jerome.blin@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c
index a2f23c357df3b0b80d0055510cad873d5504c5e9..3034fd03bced3ff7587f8bfd248c7bb212a0c16c 100644 (file)
--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -880,9 +880,22 @@ static int chv_gpio_request_enable(struct pinctrl_dev *pctldev,
                value &= ~CHV_PADCTRL1_INVRXTX_MASK;
                chv_writel(value, reg);
 
-               /* Switch to a GPIO mode */
                reg = chv_padreg(pctrl, offset, CHV_PADCTRL0);
-               value = readl(reg) | CHV_PADCTRL0_GPIOEN;
+               value = readl(reg);
+
+               /*
+                * If the pin is in HiZ mode (both TX and RX buffers are
+                * disabled) we turn it to be input now.
+                */
+               if ((value & CHV_PADCTRL0_GPIOCFG_MASK) ==
+                    (CHV_PADCTRL0_GPIOCFG_HIZ << CHV_PADCTRL0_GPIOCFG_SHIFT)) {
+                       value &= ~CHV_PADCTRL0_GPIOCFG_MASK;
+                       value |= CHV_PADCTRL0_GPIOCFG_GPI <<
+                               CHV_PADCTRL0_GPIOCFG_SHIFT;
+               }
+
+               /* Switch to a GPIO mode */
+               value |= CHV_PADCTRL0_GPIOEN;
                chv_writel(value, reg);
        }