Messages in this thread | | | From | Mark-PK Tsai <> | Subject | Re: [PATCH v2] irqchip/irq-mst: Support polarity configuration | Date | Thu, 11 Mar 2021 11:12:42 +0800 |
| |
From: Daniel Palmer <daniel@0x0f.com>
>On Mon, 8 Mar 2021 at 23:30, Mark-PK Tsai <mark-pk.tsai@mediatek.com> wrote: >> From: Daniel Palmer <daniel@0x0f.com> >> >On Mon, 8 Mar 2021 at 15:05, Mark-PK Tsai <mark-pk.tsai@mediatek.com> wrote: >> >> +static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type) >> > > +{ >> >> + if (type != IRQ_TYPE_LEVEL_LOW && type != IRQ_TYPE_LEVEL_HIGH) >> >> + return -EINVAL; >> >> + >> > >> >Does this mean we can't do rising or falling edge interrupts? >> >> Yes, the interrupt of mst-intc is either level high or level low. >> Actually the input signal can be pulse, but it will be converted to level >> by the latch in mst-intc. > >Are the GPIO connected interrupts meant to be configured as level >interrupts then? >For the MStar MSC313(e) there are 4 (that I know of) GPIO lines that >are wired into the mst-intc that requires EOI. >Until this patch with those lines configured as a rising edge a single >interrupt came each time the GPIO was pulled up as far as I remember. > >I'm probably misunderstanding but a level interrupt doesn't seem to >make sense for a GPIO as it can't be serviced to clear the interrupt.
As I understand it, there are 2 types of mst-intc, one we need do EOI operation(fiq) and the other we don't(irq). For a fiq controller, the input edge signal will be convert to level and keep the interrupt status until we do EOI operation. That means if a rising edge input if trigger the ouput line will keep high until we clear the interrupt status.
And I think you're right, make these kind of interrupts edge may make more sense. So I will modify the patch as following:
static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type) { - if (type != IRQ_TYPE_LEVEL_LOW && type != IRQ_TYPE_LEVEL_HIGH) - return -EINVAL; - - if (type == IRQ_TYPE_LEVEL_LOW) { + if (type == IRQ_TYPE_EDGE_FALLING) { + mst_set_irq(data, INTC_REV_POLARITY); + type = IRQ_TYPE_EDGE_RISING; + } else if (type == IRQ_TYPE_LEVEL_LOW) { mst_set_irq(data, INTC_REV_POLARITY); type = IRQ_TYPE_LEVEL_HIGH; }
| |