linux-imx

/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only 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.

 */

​

/*

 * Driver for interrupt combiners in the Top-level Control and Status

 * Registers (TCSR) hardware block in Qualcomm Technologies chips.

 * An interrupt combiner in this block combines a set of interrupts by

 * OR'ing the individual interrupt signals into a summary interrupt

 * signal routed to a parent interrupt controller, and provides read-

 * only, 32-bit registers to query the status of individual interrupts.

 * The status bit for IRQ n is bit (n % 32) within register (n / 32)

 * of the given combiner. Thus, each combiner can be described as a set

 * of register offsets and the number of IRQs managed.

 */

​

#define pr_fmt(fmt) "QCOM80B1:" fmt

​

#include <linux/acpi.h>

#include <linux/irqchip/chained_irq.h>

#include <linux/irqdomain.h>

#include <linux/platform_device.h>

​

#define REG_SIZE 32

​

struct combiner_reg {

    void __iomem *addr;

    unsigned long enabled;

};

​

struct combiner {

    struct irq_domain   *domain;

    int                 parent_irq;

    u32                 nirqs;

    u32                 nregs;

    struct combiner_reg regs[0];

};

​

static inline int irq_nr(u32 reg, u32 bit)

{

    return reg * REG_SIZE + bit;

}

​

/*

 * Handler for the cascaded IRQ.

 */

static void combiner_handle_irq(struct irq_desc *desc)

{

    struct combiner *combiner = irq_desc_get_handler_data(desc);

    struct irq_chip *chip = irq_desc_get_chip(desc);

    u32 reg;

​

    chained_irq_enter(chip, desc);

​

    for (reg = 0; reg < combiner->nregs; reg++) {