diff options
Diffstat (limited to 'drivers/pinctrl/intel/pinctrl-baytrail.c')
| -rw-r--r-- | drivers/pinctrl/intel/pinctrl-baytrail.c | 55 |
1 files changed, 53 insertions, 2 deletions
diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c index 1cc660e6458e..f89c9fcd4e1b 100644 --- a/drivers/pinctrl/intel/pinctrl-baytrail.c +++ b/drivers/pinctrl/intel/pinctrl-baytrail.c @@ -32,6 +32,7 @@ #define BYT_VAL_REG 0x008 #define BYT_DFT_REG 0x00c #define BYT_INT_STAT_REG 0x800 +#define BYT_DIRECT_IRQ_REG 0x980 #define BYT_DEBOUNCE_REG 0x9d0 /* BYT_CONF0_REG register bits */ @@ -1475,6 +1476,51 @@ static void byt_gpio_irq_handler(struct irq_desc *desc) chip->irq_eoi(data); } +static bool byt_direct_irq_sanity_check(struct intel_pinctrl *vg, int pin, u32 conf0) +{ + int direct_irq, ioapic_direct_irq_base; + u8 *match, direct_irq_mux[16]; + u32 trig; + + memcpy_fromio(direct_irq_mux, vg->communities->pad_regs + BYT_DIRECT_IRQ_REG, + sizeof(direct_irq_mux)); + match = memchr(direct_irq_mux, pin, sizeof(direct_irq_mux)); + if (!match) { + dev_warn(vg->dev, FW_BUG "pin %i: direct_irq_en set but no IRQ assigned, clearing\n", pin); + return false; + } + + direct_irq = match - direct_irq_mux; + /* Base IO-APIC pin numbers come from atom-e3800-family-datasheet.pdf */ + ioapic_direct_irq_base = (vg->communities->npins == BYT_NGPIO_SCORE) ? 51 : 67; + dev_dbg(vg->dev, "Pin %i: uses direct IRQ %d (IO-APIC %d)\n", pin, + direct_irq, direct_irq + ioapic_direct_irq_base); + + /* + * Testing has shown that the way direct IRQs work is that the combination of the + * direct-irq-en flag and the direct IRQ mux connect the output of the GPIO's IRQ + * trigger block, which normally sets the status flag in the IRQ status reg at + * 0x800, to one of the IO-APIC pins according to the mux registers. + * + * This means that: + * 1. The TRIG_MASK bits must be set to configure the GPIO's IRQ trigger block + * 2. The TRIG_LVL bit *must* be set, so that the GPIO's input value is directly + * passed (1:1 or inverted) to the IO-APIC pin, if TRIG_LVL is not set, + * selecting edge mode operation then on the first edge the IO-APIC pin goes + * high, but since no write-to-clear write will be done to the IRQ status reg + * at 0x800, the detected edge condition will never get cleared. + */ + trig = conf0 & BYT_TRIG_MASK; + if (trig != (BYT_TRIG_POS | BYT_TRIG_LVL) && + trig != (BYT_TRIG_NEG | BYT_TRIG_LVL)) { + dev_warn(vg->dev, FW_BUG "pin %i: direct_irq_en set without trigger (conf0: %xh), clearing\n", + pin, conf0); + return false; + } + + return true; +} + static void byt_init_irq_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask, unsigned int ngpios) @@ -1502,8 +1548,13 @@ static void byt_init_irq_valid_mask(struct gpio_chip *chip, value = readl(reg); if (value & BYT_DIRECT_IRQ_EN) { - clear_bit(i, valid_mask); - dev_dbg(vg->dev, "excluding GPIO %d from IRQ domain\n", i); + if (byt_direct_irq_sanity_check(vg, i, value)) { + clear_bit(i, valid_mask); + } else { + value &= ~(BYT_DIRECT_IRQ_EN | BYT_TRIG_POS | + BYT_TRIG_NEG | BYT_TRIG_LVL); + writel(value, reg); + } } else if ((value & BYT_PIN_MUX) == byt_get_gpio_mux(vg, i)) { byt_gpio_clear_triggering(vg, i); dev_dbg(vg->dev, "disabling GPIO %d\n", i); |