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Subject[PATCH v4 1/1] pinctrl: baytrail: Warn if direct IRQ GPIO set to output
Date
From: Eric Ernst <eric.ernst@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.ernst@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/pinctrl/pinctrl-baytrail.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c
index 975572e2f260..c34add934216 100644
--- a/drivers/pinctrl/pinctrl-baytrail.c
+++ b/drivers/pinctrl/pinctrl-baytrail.c
@@ -303,12 +303,22 @@ 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


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