Messages in this thread Patch in this message | | | From | eric.ernst@linux ... | Subject | [PATCH v2 1/1] PINCTRL: Warn if direct IRQ GPIO set to output | Date | Mon, 2 Jun 2014 14:12:07 -0700 |
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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> --- drivers/pinctrl/pinctrl-baytrail.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c index e59983423991..fde3767df254 100644 --- a/drivers/pinctrl/pinctrl-baytrail.c +++ b/drivers/pinctrl/pinctrl-baytrail.c @@ -47,6 +47,7 @@ #define BYT_TRIG_POS BIT(25) #define BYT_TRIG_LVL BIT(24) #define BYT_PIN_MUX 0x07 +#define BYT_DIRECTIRQ BIT(27) /* BYT_VAL_REG register bits */ #define BYT_INPUT_EN BIT(2) /* 0: input enabled (active low)*/ @@ -256,19 +257,29 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int value) { struct byt_gpio *vg = to_byt_gpio(chip); - void __iomem *reg = byt_gpio_reg(chip, gpio, BYT_VAL_REG); + void __iomem *conf_reg = byt_gpio_reg(chip, gpio, BYT_CONF0_REG); + void __iomem *value_reg = byt_gpio_reg(chip, gpio, BYT_VAL_REG); unsigned long flags; u32 reg_val; spin_lock_irqsave(&vg->lock, flags); - reg_val = readl(reg) | BYT_DIR_MASK; + /* + * 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_DIRECTIRQ), + "Potential Error: Setting GPIO with direct_irq_en to output"); + + reg_val = readl(value_reg) | BYT_DIR_MASK; reg_val &= ~BYT_OUTPUT_EN; if (value) - writel(reg_val | BYT_LEVEL, reg); + writel(reg_val | BYT_LEVEL, value_reg); else - writel(reg_val & ~BYT_LEVEL, reg); + writel(reg_val & ~BYT_LEVEL, value_reg); spin_unlock_irqrestore(&vg->lock, flags); -- 1.7.9.5
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