Re: [PATCH RFC 03/14] drivers: irqchip: add PDC irqdomain for wakeup capable GPIOs

[Stephen Boyd <swboyd@chromium.org>]

Quoting Lina Iyer (2019-08-29 11:11:52)
> Introduce a new domain for wakeup capable GPIOs. The domain can be
> requested using the bus token DOMAIN_BUS_WAKEUP. In the following
> patches, we will specify PDC as the wakeup-parent for the TLMM GPIO
> irqchip. Requesting a wakeup GPIO will setup the GPIO and the
> corresponding PDC interrupt as its parent.
> 
> Co-developed-by: Stephen Boyd <swboyd@chromium.org>

Per the Documentation about Co-developed-by this should have my 

Signed-off-by: Stephen Boyd <swboyd@chromium.org>

here. Please add it for the next version.

> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> ---
>  drivers/irqchip/qcom-pdc.c   | 104 ++++++++++++++++++++++++++++++++---
>  include/linux/soc/qcom/irq.h |  34 ++++++++++++
>  2 files changed, 129 insertions(+), 9 deletions(-)
>  create mode 100644 include/linux/soc/qcom/irq.h
> 
> diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
> index 338fae604af5..ad1faf634bcf 100644
> --- a/drivers/irqchip/qcom-pdc.c
> +++ b/drivers/irqchip/qcom-pdc.c
> @@ -244,6 +261,60 @@ static const struct irq_domain_ops qcom_pdc_ops = {
>         .free           = irq_domain_free_irqs_common,
>  };
>  
> +static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
> +                              unsigned int nr_irqs, void *data)
> +{
> +       struct irq_fwspec *fwspec = data;
> +       struct irq_fwspec parent_fwspec;
> +       irq_hw_number_t hwirq, parent_hwirq;
> +       unsigned int type;
> +       int ret;
> +
> +       ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
> +       if (ret)
> +               return ret;
> +
> +       ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
> +                                           &qcom_pdc_gic_chip, NULL);
> +       if (ret)
> +               return ret;
> +
> +       if (hwirq == GPIO_NO_WAKE_IRQ)
> +               return 0;
> +
> +       parent_hwirq = get_parent_hwirq(hwirq);
> +       if (parent_hwirq == PDC_NO_PARENT_IRQ)
> +               return 0;
> +
> +       if (type & IRQ_TYPE_EDGE_BOTH)
> +               type = IRQ_TYPE_EDGE_RISING;
> +
> +       if (type & IRQ_TYPE_LEVEL_MASK)
> +               type = IRQ_TYPE_LEVEL_HIGH;
> +
> +       parent_fwspec.fwnode      = domain->parent->fwnode;
> +       parent_fwspec.param_count = 3;
> +       parent_fwspec.param[0]    = 0;
> +       parent_fwspec.param[1]    = parent_hwirq;
> +       parent_fwspec.param[2]    = type;
> +
> +       return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
> +                                           &parent_fwspec);
> +}
> +
> +static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
> +                                      struct irq_fwspec *fwspec,
> +                                      enum irq_domain_bus_token bus_token)
> +{
> +       return (bus_token == DOMAIN_BUS_WAKEUP);

Drop the parenthesis please.

> +}
> +
> +static const struct irq_domain_ops qcom_pdc_gpio_ops = {
> +       .select         = qcom_pdc_gpio_domain_select,
> +       .alloc          = qcom_pdc_gpio_alloc,
> +       .free           = irq_domain_free_irqs_common,
> +};
> +
>  static int pdc_setup_pin_mapping(struct device_node *np)
>  {
>         int ret, n;
> @@ -282,7 +353,7 @@ static int pdc_setup_pin_mapping(struct device_node *np)
>  
>  static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
>  {
> -       struct irq_domain *parent_domain, *pdc_domain;
> +       struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
>         int ret;
>  
>         pdc_base = of_iomap(node, 0);
> @@ -313,8 +384,23 @@ static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
>                 goto fail;
>         }
>  
> +       pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
> +                                                     IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
> +                                                     PDC_MAX_GPIO_IRQS,
> +                                                     of_fwnode_handle(node),
> +                                                     &qcom_pdc_gpio_ops, NULL);
> +       if (!pdc_gpio_domain) {
> +               pr_err("%pOF: GIC domain add failed for GPIO domain\n", node);

s/GIC/PDC/?

> +               ret = -ENOMEM;
> +               goto remove;
> +       }
> +
> +       irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
> +
>         return 0;
>  
> +remove:
> +       irq_domain_remove(pdc_domain);
>  fail:
>         kfree(pdc_region);
>         iounmap(pdc_base);
> diff --git a/include/linux/soc/qcom/irq.h b/include/linux/soc/qcom/irq.h
> new file mode 100644
> index 000000000000..73239917dc38
> --- /dev/null
> +++ b/include/linux/soc/qcom/irq.h
> @@ -0,0 +1,34 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef __QCOM_IRQ_H
> +#define __QCOM_IRQ_H
> +
> +#include <linux/irqdomain.h>

Just forward declare struct irq_domain instead?

> +
> +#define GPIO_NO_WAKE_IRQ       ~0U
> +
> +/**
> + * QCOM specific IRQ domain flags that distinguishes the handling of wakeup
> + * capable interrupts by different interrupt controllers.
> + *
> + * IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP: Line must be masked at TLMM and the
> + *                                  interrupt configuration is done at PDC
> + * IRQ_DOMAIN_FLAG_QCOM_MPM_WAKEUP: Interrupt configuration is handled at TLMM
> + */
> +#define IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP                (1 << 17)
> +#define IRQ_DOMAIN_FLAG_QCOM_MPM_WAKEUP                (1 << 18)

Why do these numbers start at 17?

> +
> +/**
> + * irq_domain_qcom_handle_wakeup: Return if the domain handles interrupt
> + *                                configuration
> + * @parent: irq domain
> + *
> + * This QCOM specific irq domain call returns if the interrupt controller
> + * requires the interrupt be masked at the child interrupt controller.
> + */
> +static inline bool irq_domain_qcom_handle_wakeup(struct irq_domain *parent)
> +{
> +       return (parent->flags & IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP);
> +}
> +
> +#endif
> -- 
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> a Linux Foundation Collaborative Project
>