root/drivers/soc/ti/ti_sci_inta_msi.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Texas Instruments' K3 Interrupt Aggregator MSI bus
 *
 * Copyright (C) 2018-2019 Texas Instruments Incorporated - http://www.ti.com/
 *      Lokesh Vutla <lokeshvutla@ti.com>
 */

#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/soc/ti/ti_sci_inta_msi.h>
#include <linux/soc/ti/ti_sci_protocol.h>

static void ti_sci_inta_msi_write_msg(struct irq_data *data,
                                      struct msi_msg *msg)
{
        /* Nothing to do */
}

static void ti_sci_inta_msi_compose_msi_msg(struct irq_data *data,
                                            struct msi_msg *msg)
{
        /* Nothing to do */
}

static void ti_sci_inta_msi_update_chip_ops(struct msi_domain_info *info)
{
        struct irq_chip *chip = info->chip;

        if (WARN_ON(!chip))
                return;

        chip->irq_request_resources = irq_chip_request_resources_parent;
        chip->irq_release_resources = irq_chip_release_resources_parent;
        chip->irq_compose_msi_msg = ti_sci_inta_msi_compose_msi_msg;
        chip->irq_write_msi_msg = ti_sci_inta_msi_write_msg;
        chip->irq_set_type = irq_chip_set_type_parent;
        chip->irq_unmask = irq_chip_unmask_parent;
        chip->irq_mask = irq_chip_mask_parent;
        chip->irq_ack = irq_chip_ack_parent;
}

struct irq_domain *ti_sci_inta_msi_create_irq_domain(struct fwnode_handle *fwnode,
                                                     struct msi_domain_info *info,
                                                     struct irq_domain *parent)
{
        struct irq_domain *domain;

        ti_sci_inta_msi_update_chip_ops(info);
        info->flags |= MSI_FLAG_FREE_MSI_DESCS;

        domain = msi_create_irq_domain(fwnode, info, parent);
        if (domain)
                irq_domain_update_bus_token(domain, DOMAIN_BUS_TI_SCI_INTA_MSI);

        return domain;
}
EXPORT_SYMBOL_GPL(ti_sci_inta_msi_create_irq_domain);

static int ti_sci_inta_msi_alloc_descs(struct device *dev,
                                       struct ti_sci_resource *res)
{
        struct msi_desc msi_desc;
        int set, i, count = 0;

        memset(&msi_desc, 0, sizeof(msi_desc));
        msi_desc.nvec_used = 1;

        for (set = 0; set < res->sets; set++) {
                for (i = 0; i < res->desc[set].num; i++, count++) {
                        msi_desc.msi_index = res->desc[set].start + i;
                        if (msi_insert_msi_desc(dev, &msi_desc))
                                goto fail;
                }

                for (i = 0; i < res->desc[set].num_sec; i++, count++) {
                        msi_desc.msi_index = res->desc[set].start_sec + i;
                        if (msi_insert_msi_desc(dev, &msi_desc))
                                goto fail;
                }
        }
        return count;
fail:
        msi_free_msi_descs(dev);
        return -ENOMEM;
}

int ti_sci_inta_msi_domain_alloc_irqs(struct device *dev,
                                      struct ti_sci_resource *res)
{
        struct platform_device *pdev = to_platform_device(dev);
        int ret, nvec;

        if (pdev->id < 0)
                return -ENODEV;

        ret = msi_setup_device_data(dev);
        if (ret)
                return ret;

        guard(msi_descs_lock)(dev);
        nvec = ti_sci_inta_msi_alloc_descs(dev, res);
        if (nvec <= 0)
                return nvec;

        /* Use alloc ALL as it's unclear whether there are gaps in the indices */
        ret = msi_domain_alloc_irqs_all_locked(dev, MSI_DEFAULT_DOMAIN, nvec);
        if (ret)
                dev_err(dev, "Failed to allocate IRQs %d\n", ret);
        return ret;
}
EXPORT_SYMBOL_GPL(ti_sci_inta_msi_domain_alloc_irqs);