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pinctrl: baytrail: Warn if direct IRQ GPIO set to output

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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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Eric Ernst 2014-06-12 11:06:20 -07:00 committed by Linus Walleij
parent 1f978217a0
commit ff998356b6
1 changed files with 11 additions and 0 deletions
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11
drivers/pinctrl/pinctrl-baytrail.c
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@ -44,6 +44,7 @@
/* BYT_CONF0_REG register bits */ /* BYT_CONF0_REG register bits */
#define BYT_IODEN BIT(31) #define BYT_IODEN BIT(31)
#define BYT_DIRECT_IRQ_EN BIT(27)
#define BYT_TRIG_NEG BIT(26) #define BYT_TRIG_NEG BIT(26)
#define BYT_TRIG_POS BIT(25) #define BYT_TRIG_POS BIT(25)
#define BYT_TRIG_LVL BIT(24) #define BYT_TRIG_LVL BIT(24)
@ -303,12 +304,22 @@ static int byt_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int value) unsigned gpio, int value)
{ {
struct byt_gpio *vg = to_byt_gpio(chip); 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); void __iomem *reg = byt_gpio_reg(chip, gpio, BYT_VAL_REG);
unsigned long flags; unsigned long flags;
u32 reg_val; u32 reg_val;
spin_lock_irqsave(&vg->lock, flags); 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 = readl(reg) | BYT_DIR_MASK;
reg_val &= ~BYT_OUTPUT_EN; reg_val &= ~BYT_OUTPUT_EN;