On 14/02/17 02:56, Youlin Pei wrote:
> In Mediatek SOCs, the CIRQ is a low power interrupt controller
> designed to works outside MCUSYS which comprises with Cortex-Ax
> cores,CCI and GIC.
> 
> The CIRQ controller is integrated in between MCUSYS( include
> Cortex-Ax, CCI and GIC ) and interrupt sources as the second
> level interrupt controller. The external interrupts which outside
> MCUSYS will feed through CIRQ then bypass to GIC. CIRQ can monitors
> all edge trigger interupts. When an edge interrupt is triggered,
> CIRQ can record the status and generate a pulse signal to GIC when
> flush command executed.
> 
> When system enters sleep mode, MCUSYS will be turned off to improve
> power consumption, also GIC is power down. The edge trigger interrupts
> will be lost in this scenario without CIRQ.
> 
> This commit provides the CIRQ irqchip implement.
> 
> Signed-off-by: Youlin Pei <[email protected]>
> ---
>  drivers/irqchip/Makefile       |    2 +-
>  drivers/irqchip/irq-mtk-cirq.c |  288 
> ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 289 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-mtk-cirq.c
> 
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 0e55d94..db9acd1 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -61,7 +61,7 @@ obj-$(CONFIG_BCM7120_L2_IRQ)                += 
> irq-bcm7120-l2.o
>  obj-$(CONFIG_BRCMSTB_L2_IRQ)         += irq-brcmstb-l2.o
>  obj-$(CONFIG_KEYSTONE_IRQ)           += irq-keystone.o
>  obj-$(CONFIG_MIPS_GIC)                       += irq-mips-gic.o
> -obj-$(CONFIG_ARCH_MEDIATEK)          += irq-mtk-sysirq.o
> +obj-$(CONFIG_ARCH_MEDIATEK)          += irq-mtk-sysirq.o irq-mtk-cirq.o
>  obj-$(CONFIG_ARCH_DIGICOLOR)         += irq-digicolor.o
>  obj-$(CONFIG_RENESAS_H8300H_INTC)    += irq-renesas-h8300h.o
>  obj-$(CONFIG_RENESAS_H8S_INTC)               += irq-renesas-h8s.o
> diff --git a/drivers/irqchip/irq-mtk-cirq.c b/drivers/irqchip/irq-mtk-cirq.c
> new file mode 100644
> index 0000000..b5cf506
> --- /dev/null
> +++ b/drivers/irqchip/irq-mtk-cirq.c
> @@ -0,0 +1,288 @@
> +/*
> + * Copyright (c) 2016 MediaTek Inc.
> + * Author: Youlin.Pei <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/syscore_ops.h>
> +
> +#define CIRQ_ACK     0x40
> +#define CIRQ_MASK_SET        0xc0
> +#define CIRQ_MASK_CLR        0x100
> +#define CIRQ_SENS_SET        0x180
> +#define CIRQ_SENS_CLR        0x1c0
> +#define CIRQ_POL_SET 0x240
> +#define CIRQ_POL_CLR 0x280
> +#define CIRQ_CONTROL 0x300
> +
> +#define CIRQ_EN      0x1
> +#define CIRQ_EDGE    0x2
> +#define CIRQ_FLUSH   0x4
> +
> +struct mtk_cirq_chip_data {
> +     void __iomem *base;
> +     unsigned int ext_irq_start;
> +     unsigned int ext_irq_end;
> +     struct irq_domain *domain;
> +};
> +
> +static struct mtk_cirq_chip_data *cirq_data;

Question in relation to the sysirq patches that have been queued for
4.12: Are we going to see something similar with this driver, where
you're going to have to support multiple non-contiguous register sets?
I'd rather have this kind of thing from day one, instead of adding that
at a later time...

Specially given that the platform that is using this driver does also
have a sysirq controller.

> +
> +static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
> +{
> +     struct mtk_cirq_chip_data *chip_data = data->chip_data;
> +     unsigned int cirq_num = data->hwirq;
> +     u32 mask = 1 << (cirq_num % 32);
> +
> +     writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
> +}
> +
> +static void mtk_cirq_mask(struct irq_data *data)
> +{
> +     mtk_cirq_write_mask(data, CIRQ_MASK_SET);
> +     irq_chip_mask_parent(data);
> +}
> +
> +static void mtk_cirq_unmask(struct irq_data *data)
> +{
> +     mtk_cirq_write_mask(data, CIRQ_MASK_CLR);
> +     irq_chip_unmask_parent(data);
> +}
> +
> +static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)
> +{
> +     int ret;
> +
> +     switch (type & IRQ_TYPE_SENSE_MASK) {
> +     case IRQ_TYPE_EDGE_FALLING:
> +             mtk_cirq_write_mask(data, CIRQ_POL_CLR);
> +             mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
> +             break;
> +     case IRQ_TYPE_EDGE_RISING:
> +             mtk_cirq_write_mask(data, CIRQ_POL_SET);
> +             mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
> +             break;
> +     case IRQ_TYPE_LEVEL_LOW:
> +             mtk_cirq_write_mask(data, CIRQ_POL_CLR);
> +             mtk_cirq_write_mask(data, CIRQ_SENS_SET);
> +             break;
> +     case IRQ_TYPE_LEVEL_HIGH:
> +             mtk_cirq_write_mask(data, CIRQ_POL_SET);
> +             mtk_cirq_write_mask(data, CIRQ_SENS_SET);
> +             break;
> +     default:
> +             break;
> +     }
> +
> +     data = data->parent_data;
> +     ret = data->chip->irq_set_type(data, type);
> +     return ret;
> +}
> +
> +static struct irq_chip mtk_cirq_chip = {
> +     .name                   = "MT_CIRQ",
> +     .irq_mask               = mtk_cirq_mask,
> +     .irq_unmask             = mtk_cirq_unmask,
> +     .irq_eoi                = irq_chip_eoi_parent,
> +     .irq_set_type           = mtk_cirq_set_type,
> +     .irq_retrigger          = irq_chip_retrigger_hierarchy,
> +#ifdef CONFIG_SMP
> +     .irq_set_affinity       = irq_chip_set_affinity_parent,
> +#endif
> +};
> +
> +static int mtk_cirq_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 != 3)
> +                     return -EINVAL;
> +
> +             /* No PPI should point to this domain */
> +             if (fwspec->param[0] != 0)
> +                     return -EINVAL;
> +
> +             /* cirq support irq number check */
> +             if (fwspec->param[1] < cirq_data->ext_irq_start ||
> +                 fwspec->param[1] > cirq_data->ext_irq_end)
> +                     return -EINVAL;
> +
> +             *hwirq = fwspec->param[1] - cirq_data->ext_irq_start;
> +             *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
> +             return 0;
> +     }
> +
> +     return -EINVAL;
> +}
> +
> +static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int 
> virq,
> +                              unsigned int nr_irqs, void *arg)
> +{
> +     int ret;
> +     irq_hw_number_t hwirq;
> +     unsigned int type;
> +     struct irq_fwspec *fwspec = arg;
> +     struct irq_fwspec parent_fwspec = *fwspec;
> +
> +     ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);
> +     if (ret)
> +             return ret;
> +
> +     if (WARN_ON(nr_irqs != 1))
> +             return -EINVAL;
> +
> +     irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
> +                                   &mtk_cirq_chip,
> +                                   domain->host_data);
> +
> +     parent_fwspec.fwnode = domain->parent->fwnode;
> +     return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
> +                                         &parent_fwspec);
> +}
> +
> +static const struct irq_domain_ops cirq_domain_ops = {
> +     .translate      = mtk_cirq_domain_translate,
> +     .alloc          = mtk_cirq_domain_alloc,
> +     .free           = irq_domain_free_irqs_common,
> +};
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mtk_cirq_suspend(void)
> +{
> +     u32 value, mask;
> +     unsigned int irq, hwirq_num;
> +     bool pending, masked;
> +     int i, pendret, maskret;
> +
> +     hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
> +     for (i = 0; i < hwirq_num; i++) {
> +             irq = irq_find_mapping(cirq_data->domain, i);
> +             if (irq) {
> +                     pendret = irq_get_irqchip_state(irq,
> +                                                     IRQCHIP_STATE_PENDING,
> +                                                     &pending);
> +
> +                     maskret = irq_get_irqchip_state(irq,
> +                                                     IRQCHIP_STATE_MASKED,
> +                                                     &masked);
> +
> +                     if (pendret == 0 && maskret == 0 &&
> +                         (pending && !masked))
> +                             continue;
> +             }
> +
> +             mask = 1 << (i % 32);
> +             writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
> +     }

It would be worth documenting exactly what this is for. I had to go back
to our previous discussion in November to remember it.

> +
> +     /* set edge_only mode, record edge-triggerd interrupts */
> +     /* enable cirq */
> +     value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> +     value |= (CIRQ_EDGE | CIRQ_EN);
> +     writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
> +
> +     return 0;
> +}
> +
> +static void mtk_cirq_resume(void)
> +{
> +     u32 value;
> +
> +     /* flush recored interrupts, will send signals to parent controller */
> +     value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> +     writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
> +
> +     /* disable cirq */
> +     value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> +     value &= ~(CIRQ_EDGE | CIRQ_EN);
> +     writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
> +}
> +
> +static struct syscore_ops mtk_cirq_syscore_ops = {
> +     .suspend        = mtk_cirq_suspend,
> +     .resume         = mtk_cirq_resume,
> +};
> +
> +static void mtk_cirq_syscore_init(void)
> +{
> +     register_syscore_ops(&mtk_cirq_syscore_ops);
> +}
> +#else
> +static inline void mtk_cirq_syscore_init(void) {}
> +#endif
> +
> +static int __init mtk_cirq_of_init(struct device_node *node,
> +                                struct device_node *parent)
> +{
> +     struct irq_domain *domain, *domain_parent;
> +     unsigned int irq_num;
> +     int ret;
> +
> +     domain_parent = irq_find_host(parent);
> +     if (!domain_parent) {
> +             pr_err("mtk_cirq: interrupt-parent not found\n");
> +             return -EINVAL;
> +     }
> +
> +     cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
> +     if (!cirq_data)
> +             return -ENOMEM;
> +
> +     cirq_data->base = of_iomap(node, 0);
> +     if (!cirq_data->base) {
> +             pr_err("mtk_cirq: unable to map cirq register\n");
> +             ret = -ENXIO;
> +             goto out_free;
> +     }
> +
> +     ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,
> +                                      &cirq_data->ext_irq_start);
> +     if (ret)
> +             goto out_unmap;
> +
> +     ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,
> +                                      &cirq_data->ext_irq_end);
> +     if (ret)
> +             goto out_unmap;
> +
> +     irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
> +     domain = irq_domain_add_hierarchy(domain_parent, 0,
> +                                       irq_num, node,
> +                                       &cirq_domain_ops, cirq_data);
> +     if (!domain) {
> +             ret = -ENOMEM;
> +             goto out_unmap;
> +     }
> +     cirq_data->domain = domain;
> +
> +     mtk_cirq_syscore_init();
> +
> +     return 0;
> +
> +out_unmap:
> +     iounmap(cirq_data->base);
> +out_free:
> +     kfree(cirq_data);
> +     return ret;
> +}
> +
> +IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);
> 

It otherwise looks much better than the previous iteration.

Thanks,

        M.
-- 
Jazz is not dead. It just smells funny...

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