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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>
This commit is contained in:
Mika Westerberg 2015-01-29 12:44:48 +02:00 committed by Linus Walleij
parent 34027ca2bb
commit 2479c7300e
1 changed files with 15 additions and 2 deletions
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17
drivers/pinctrl/intel/pinctrl-cherryview.c
View File

@ -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);
}