Re: [PATCH 5/7] drivers: pinctrl: msm: setup GPIO irqchip hierarchy

[Lina Iyer <ilina@codeaurora.org>]

On Thu, Dec 20 2018 at 13:03 -0700, Stephen Boyd wrote:
>Quoting Lina Iyer (2018-12-19 14:11:03)
>> To allow GPIOs to wakeup the system from suspend or deep idle, the
>> wakeup capable GPIOs are setup in hierarchy with interrupts from the
>> wakeup-parent irqchip.
>>
>> In older SoC's, the TLMM will handover detection to the parent irqchip
>> and in newer SoC's, the parent irqchip may also be active as well as the
>> TLMM and therefore the GPIOs need to be masked at TLMM to avoid
>> duplicate interrupts. To enable both these configurations to exist,
>> allow the parent irqchip to dictate the TLMM irqchip's behavior when
>> masking/unmasking the interrupt.
>>
>> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
>
>I don't think I gave a signed-off-by, so you need to ask to forge my
>sign off here. Please change it to be:
>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
>
>and I'm not sure how much I wrote vs. you wrote anymore so perhaps also
>add a
>
> Co-developed-by: Stephen Boyd <swboyd@chromium.org>
>
I meant to do that. I will add this tag instead. Sorry about that.

>And finally, please just email my chromium.org email for this series
>because I apparently messed up the address once and now it's all going
>to the wrong inbox. Thanks!
>
Sure.

>> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
>
>Can you Cc Linus Walleij and Bjorn Andersson on the whole patch series
>next time? Would be good to have their review on major pinctrl driver
>changes.
>
Bjorn is already included. Will make sure to include Linus in the next
spin.

>> @@ -967,11 +994,86 @@ static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl)
>>         return device_property_read_u16_array(pctrl->dev, "gpios", NULL, 0) > 0;
>>  }
>>
>> +static int msm_gpio_domain_translate(struct irq_domain *d,
>> +                                    struct irq_fwspec *fwspec,
>> +                                    unsigned long *hwirq, unsigned int *type)
>> +{
>> +       if (is_of_node(fwspec->fwnode)) {
>> +               if (fwspec->param_count < 2)
>> +                       return -EINVAL;
>> +               *hwirq = fwspec->param[0];
>> +               *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
>> +               return 0;
>> +       }
>> +
>> +       return -EINVAL;
>> +}
>
>Maybe this can be a generic function in gpiolib?
>
>> +
>> +static int msm_gpio_domain_alloc(struct irq_domain *domain, unsigned int virq,
>> +                                unsigned int nr_irqs, void *arg)
>> +{
>> +       int ret;
>> +       irq_hw_number_t hwirq;
>> +       struct gpio_chip *gc = domain->host_data;
>> +       struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
>> +       struct irq_fwspec *fwspec = arg;
>> +       struct qcom_irq_fwspec parent = { };
>> +       unsigned int type;
>> +
>> +       ret = msm_gpio_domain_translate(domain, fwspec, &hwirq, &type);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
>> +                                           &pctrl->irq_chip, gc);
>> +       if (ret < 0)
>> +               return ret;
>> +
>> +       if (!domain->parent)
>> +               return 0;
>> +
>> +       parent.fwspec.fwnode      = domain->parent->fwnode;
>> +       parent.fwspec.param_count = 2;
>> +       parent.fwspec.param[0]    = hwirq;
>> +       parent.fwspec.param[1]    = type;
>> +
>> +       ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &parent);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (parent.mask)
>> +               set_bit(hwirq, pctrl->wakeup_masked_irqs);
>> +
>> +       return 0;
>> +}
>> +
>> +/*
>> + * TODO: Get rid of this and push it into gpiochip_to_irq()
>
>Hmm.. yeah we need to do this still. I think we can have a generic two
>cell function similar to irq_domain_xlate_twocell() that does the fwspec
>creation and uses some of the things that we pass to
>gpiochip_irqchip_add(), like the default level type. This existing
>function is not good to have, so there's work to do to get rid of this.
>
>I was also thinking that maybe we can make the alloc function above take
>a struct gpio_irq_fwspec structure that tells the alloc function what
>gpiochip the irq is for. That would mean that we need to change the
>gpio_to_irq() function below to be generic and stuff the chip inside the
>fwspec wrapper structure:
>
>	struct gpio_irq_fwspec {
>		struct irq_fwspec fwspec;
>		struct gpio_chip *chip;
>		unsigned int offset;
>	};
>
>but I seem to recall that was not working for some reason.
>
I didn't attemp this. I am hoping we can solve this even after this
patch set separately. That said, I will try this.

>> + */
>> +static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
>> +{
>> +       struct irq_fwspec fwspec;
>> +
>> +       fwspec.fwnode = of_node_to_fwnode(chip->of_node);
>> +       fwspec.param[0] = offset;
>> +       fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
>> +       fwspec.param_count = 2;
>> +
>> +       return irq_create_fwspec_mapping(&fwspec);
>> +}
>> +
>> +static const struct irq_domain_ops msm_gpio_domain_ops = {
>> +       .translate = msm_gpio_domain_translate,
>> +       .alloc     = msm_gpio_domain_alloc,
>> +       .free      = irq_domain_free_irqs_top,
>> +};
>> +

Thanks,
Lina