On Mon, Jun 02, 2014 at 02:12:07PM -0700, eric.er...@linux.intel.com wrote:
> 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.
Subject should probably be:
pinctrl: baytrail: Warn if direct IRQ GPIO is set to output
> Signed-off-by: Eric Ernst <eric.er...@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)
Please move this definition to be first, like:
/* BYT_CONF0_REG register bits */
#define BYT_DIRECT_IRQ_EN BIT(27)
#define BYT_TRIG_NEG BIT(26)
#define BYT_TRIG_POS BIT(25)
and I would call it BYT_DIRECT_IRQ_EN since it's name in datasheet is
"direct_irq_en".
>
> /* 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);
Not sure if it is necessary to rename reg -> value_reg. It just makes
the patch bigger than it has to be since you also need to rename stuff
below.
Otherwise looks good.
> 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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