From: Eric Ernst <eric.er...@linux.intel.com> For Baytrail, you should never set a GPIO set to direct_irq to output mode. When direct_irq_en is set for a GPIO, it is tied directly to an APIC internally, and making the pad output does not make any sense. Assert a WARN() in the event this happens.
Signed-off-by: Eric Ernst <eric.er...@linux.intel.com> --- drivers/pinctrl/pinctrl-baytrail.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c index e59983423991..7f0a2bac7c82 100644 --- a/drivers/pinctrl/pinctrl-baytrail.c +++ b/drivers/pinctrl/pinctrl-baytrail.c @@ -43,6 +43,7 @@ #define BYT_INT_STAT_REG 0x800 /* BYT_CONF0_REG register bits */ +#define BYT_DIRECT_IRQ_EN BIT(27) #define BYT_TRIG_NEG BIT(26) #define BYT_TRIG_POS BIT(25) #define BYT_TRIG_LVL BIT(24) @@ -256,12 +257,22 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int value) { struct byt_gpio *vg = to_byt_gpio(chip); + void __iomem *conf_reg = byt_gpio_reg(chip, gpio, BYT_CONF0_REG); void __iomem *reg = byt_gpio_reg(chip, gpio, BYT_VAL_REG); unsigned long flags; u32 reg_val; spin_lock_irqsave(&vg->lock, flags); + /* + * Before making any direction modifications, do a check if gpio + * is set for direct IRQ. On baytrail, setting GPIO to output does + * not make sense, so let's at least warn the caller before they shoot + * themselves in the foot. + */ + WARN(readl(conf_reg) & BYT_DIRECT_IRQ_EN, + "Potential Error: Setting GPIO with direct_irq_en to output"); + reg_val = readl(reg) | BYT_DIR_MASK; reg_val &= ~BYT_OUTPUT_EN; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/