irqchip: ti-sci-inta: Add support for Interrupt Aggregator driver

Texas Instruments' K3 generation SoCs has an IP Interrupt Aggregator
which is an interrupt controller that does the following:
- Converts events to interrupts that can be understood by
  an interrupt router.
- Allows for multiplexing of events to interrupts.
- Allows for grouping of multiple events to a single interrupt.

Configuration of the interrupt aggregator registers can only be done by
a system co-processor and the driver needs to send a message to this
co processor over TISCI protocol.

Add support for Interrupt Aggregator driver over TISCI protocol.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

5 files changed, 661 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 1889074c1bb7..e7932b6b414f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14436,6 +14436,7 @@ F:	drivers/reset/reset-ti-sci.c
 F:      Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
 F:      Documentation/devicetree/bindings/interrupt-controller/ti,sci-inta.txt
 F:      drivers/irqchip/irq-ti-sci-intr.c
+F:      drivers/irqchip/irq-ti-sci-inta.c
 
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:      Hans Verkuil <hverkuil@xs4all.nl>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index de102e6848a7..b8961c5ddfe0 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -382,6 +382,17 @@ config TI_SCI_INTR_IRQCHIP
           If you wish to use interrupt router irq resources managed by the
           TI System Controller, say Y here. Otherwise, say N.
 
+config TI_SCI_INTA_IRQCHIP
+        bool
+        depends on TI_SCI_PROTOCOL && ARCH_K3
+        select IRQ_DOMAIN
+        select IRQ_DOMAIN_HIERARCHY
+        help
+          This enables the irqchip driver support for K3 Interrupt aggregator
+          over TI System Control Interface available on some new TI's SoCs.
+          If you wish to use interrupt aggregator irq resources managed by the
+          TI System Controller, say Y here. Otherwise, say N.
+
 endmenu
 
 config SIFIVE_PLIC
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 1523a556bd5a..11418eb9ac11 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -89,3 +89,4 @@ obj-$(CONFIG_NDS32)			+= irq-ativic32.o
 obj-$(CONFIG_QCOM_PDC)                  += qcom-pdc.o
 obj-$(CONFIG_SIFIVE_PLIC)               += irq-sifive-plic.o
 obj-$(CONFIG_TI_SCI_INTR_IRQCHIP)       += irq-ti-sci-intr.o
+obj-$(CONFIG_TI_SCI_INTA_IRQCHIP)       += irq-ti-sci-inta.o
diff --git a/drivers/irqchip/irq-ti-sci-inta.c b/drivers/irqchip/irq-ti-sci-inta.c
new file mode 100644
index 000000000000..64c08412d6fc
--- /dev/null
+++ b/drivers/irqchip/irq-ti-sci-inta.c
@@ -0,0 +1,613 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Texas Instruments' K3 Interrupt Aggregator irqchip driver
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *      Lokesh Vutla <lokeshvutla@ti.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/irqdomain.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+#define MAX_EVENTS_PER_VINT     64
+#define TI_SCI_EVENT_IRQ        BIT(31)
+
+#define VINT_ENABLE_CLR_OFFSET  0x18
+
+/**
+ * struct ti_sci_inta_irq_domain - Structure representing a TISCI based
+ *                                 Interrupt Aggregator IRQ domain.
+ * @sci:        Pointer to TISCI handle
+ * @vint:       TISCI resource pointer representing IA inerrupts.
+ * @global_event:TISCI resource pointer representing global events.
+ * @base:       Base address of the memory mapped IO registers
+ * @ia_id:      TISCI device ID of this Interrupt Aggregator.
+ * @dst_id:     TISCI device ID of the destination irq controller.
+ */
+struct ti_sci_inta_irq_domain {
+        const struct ti_sci_handle *sci;
+        struct ti_sci_resource *vint;
+        struct ti_sci_resource *global_event;
+        void __iomem *base;
+        u16 ia_id;
+        u16 dst_id;
+};
+
+/**
+ * struct ti_sci_inta_event_desc - Description of an event coming to
+ *                                 Interrupt Aggregator.
+ * @global_event:       Global event number corresponding to this event
+ * @src_id:             TISCI device ID of the event source
+ * @src_index:          Event source index within the device.
+ */
+struct ti_sci_inta_event_desc {
+        u16 global_event;
+        u16 src_id;
+        u16 src_index;
+};
+
+/**
+ * struct ti_sci_inta_vint_desc - Description of a virtual interrupt coming out
+ *                                of Interrupt Aggregator.
+ * @lock:               lock to guard the event map
+ * @event_map:          Bitmap to manage the allocation of events to vint.
+ * @events:             Array of event descriptors assigned to this vint.
+ * @ack_needed:         Event needs to be acked via INTA. This is used when
+ *                      HW generating events cannot clear the events by itself.
+ *                      Assuming that only events from the same hw block are
+ *                      grouped. So all the events attached to vint needs
+ *                      an ack or none needs an ack.
+ */
+struct ti_sci_inta_vint_desc {
+        raw_spinlock_t lock;
+        unsigned long *event_map;
+        struct ti_sci_inta_event_desc events[MAX_EVENTS_PER_VINT];
+        bool ack_needed;
+};
+
+static void ti_sci_inta_irq_eoi(struct irq_data *data)
+{
+        struct ti_sci_inta_irq_domain *inta = data->domain->host_data;
+        struct ti_sci_inta_vint_desc *vint_desc;
+        u64 val;
+        int bit;
+
+        vint_desc = irq_data_get_irq_chip_data(data);
+        if (!vint_desc->ack_needed)
+                goto out;
+
+        for_each_set_bit(bit, vint_desc->event_map, MAX_EVENTS_PER_VINT) {
+                val = 1 << bit;
+                __raw_writeq(val, inta->base + data->hwirq * 0x1000 +
+                             VINT_ENABLE_CLR_OFFSET);
+        }
+
+out:
+        irq_chip_eoi_parent(data);
+}
+
+static struct irq_chip ti_sci_inta_irq_chip = {
+        .name                   = "INTA",
+        .irq_eoi                = ti_sci_inta_irq_eoi,
+        .irq_mask               = irq_chip_mask_parent,
+        .irq_unmask             = irq_chip_unmask_parent,
+        .irq_retrigger          = irq_chip_retrigger_hierarchy,
+        .irq_set_type           = irq_chip_set_type_parent,
+        .irq_set_affinity       = irq_chip_set_affinity_parent,
+};
+
+/**
+ * ti_sci_inta_irq_domain_translate() - Retrieve hwirq and type from
+ *                                      IRQ firmware specific handler.
+ * @domain:     Pointer to IRQ domain
+ * @fwspec:     Pointer to IRQ specific firmware structure
+ * @hwirq:      IRQ number identified by hardware
+ * @type:       IRQ type
+ *
+ * Return 0 if all went ok else appropriate error.
+ */
+static int ti_sci_inta_irq_domain_translate(struct irq_domain *domain,
+                                            struct irq_fwspec *fwspec,
+                                            unsigned long *hwirq,
+                                            unsigned int *type)
+{
+        if (is_of_node(fwspec->fwnode)) {
+                if (fwspec->param_count != 4)
+                        return -EINVAL;
+
+                *hwirq = fwspec->param[2];
+                *type = fwspec->param[3] & IRQ_TYPE_SENSE_MASK;
+
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+/**
+ * ti_sci_free_event_irq() - Free an event from vint
+ * @inta:       Pointer to Interrupt Aggregator IRQ domain
+ * @vint_desc:  Virtual interrupt descriptor containing the event.
+ * @event_index:Event Index within the vint.
+ * @dst_irq:    Destination host irq
+ * @vint:       Interrupt number within interrupt aggregator.
+ */
+static void ti_sci_free_event_irq(struct ti_sci_inta_irq_domain *inta,
+                                  struct ti_sci_inta_vint_desc *vint_desc,
+                                  u32 event_index, u16 dst_irq, u16 vint)
+{
+        struct ti_sci_inta_event_desc *event;
+        unsigned long flags;
+
+        if (event_index >= MAX_EVENTS_PER_VINT)
+                return;
+
+        event = &vint_desc->events[event_index];
+        inta->sci->ops.rm_irq_ops.free_event_irq(inta->sci,
+                                                 event->src_id,
+                                                 event->src_index,
+                                                 inta->dst_id,
+                                                 dst_irq,
+                                                 inta->ia_id, vint,
+                                                 event->global_event,
+                                                 event_index);
+
+        raw_spin_lock_irqsave(&vint_desc->lock, flags);
+        clear_bit(event_index, vint_desc->event_map);
+        raw_spin_unlock_irqrestore(&vint_desc->lock, flags);
+
+        ti_sci_release_resource(inta->global_event, event->global_event);
+}
+
+/**
+ * ti_sci_inta_irq_domain_free() - Free an IRQ from the IRQ domain
+ * @domain:     Domain to which the irqs belong
+ * @virq:       base linux virtual IRQ to be freed.
+ * @nr_irqs:    Number of continuous irqs to be freed
+ */
+static void ti_sci_inta_irq_domain_free(struct irq_domain *domain,
+                                        unsigned int virq, unsigned int nr_irqs)
+{
+        struct ti_sci_inta_irq_domain *inta = domain->host_data;
+        struct ti_sci_inta_vint_desc *vint_desc;
+        struct irq_data *data, *gic_data;
+        int event_index;
+
+        data = irq_domain_get_irq_data(domain, virq);
+        gic_data = irq_domain_get_irq_data(domain->parent->parent, virq);
+
+        vint_desc = irq_data_get_irq_chip_data(data);
+
+        /* This is the last event in the vint */
+        event_index = find_first_bit(vint_desc->event_map, MAX_EVENTS_PER_VINT);
+        ti_sci_free_event_irq(inta, vint_desc, event_index,
+                              gic_data->hwirq, data->hwirq);
+        irq_domain_free_irqs_parent(domain, virq, 1);
+        irq_domain_reset_irq_data(data);
+        ti_sci_release_resource(inta->vint, data->hwirq);
+        kfree(vint_desc->event_map);
+        kfree(vint_desc);
+}
+
+/**
+ * ti_sci_allocate_event_irq() - Allocate an event to a IA vint.
+ * @inta:       Pointer to Interrupt Aggregator IRQ domain
+ * @vint_desc:  Virtual interrupt descriptor to which the event gets attached.
+ * @src_id:     TISCI device id of the event source
+ * @src_index:  Event index with in the device.
+ * @dst_irq:    Destination host irq
+ * @vint:       Interrupt number within interrupt aggregator.
+ *
+ * Return 0 if all went ok else appropriate error value.
+ */
+static int ti_sci_allocate_event_irq(struct ti_sci_inta_irq_domain *inta,
+                                     struct ti_sci_inta_vint_desc *vint_desc,
+                                     u16 src_id, u16 src_index, u16 dst_irq,
+                                     u16 vint)
+{
+        struct ti_sci_inta_event_desc *event;
+        unsigned long flags;
+        u32 free_bit;
+        int err;
+
+        raw_spin_lock_irqsave(&vint_desc->lock, flags);
+        free_bit = find_first_zero_bit(vint_desc->event_map,
+                                       MAX_EVENTS_PER_VINT);
+        if (free_bit != MAX_EVENTS_PER_VINT)
+                set_bit(free_bit, vint_desc->event_map);
+        raw_spin_unlock_irqrestore(&vint_desc->lock, flags);
+
+        if (free_bit >= MAX_EVENTS_PER_VINT)
+                return -ENODEV;
+
+        event = &vint_desc->events[free_bit];
+
+        event->src_id = src_id;
+        event->src_index = src_index;
+        event->global_event = ti_sci_get_free_resource(inta->global_event);
+
+        err = inta->sci->ops.rm_irq_ops.set_event_irq(inta->sci,
+                                                      src_id, src_index,
+                                                      inta->dst_id,
+                                                      dst_irq,
+                                                      inta->ia_id,
+                                                      vint,
+                                                      event->global_event,
+                                                      free_bit);
+        if (err) {
+                pr_err("%s: Event allocation failed from src = %d, index = %d, to dst = %d,irq = %d,via ia_id = %d, vint = %d,global event = %d, status_bit = %d\n",
+                       __func__, src_id, src_index, inta->dst_id, dst_irq,
+                       inta->ia_id, vint, event->global_event, free_bit);
+                return err;
+        }
+
+        return 0;
+}
+
+/**
+ * alloc_parent_irq() - Allocate parent irq to Interrupt aggregator
+ * @domain:     IRQ domain corresponding to Interrupt Aggregator
+ * @virq:       Linux virtual IRQ number
+ * @src_id:     TISCI device id of the event source
+ * @src_index:  Event index with in the device.
+ * @vint:       Virtual interrupt number within IA
+ * @flags:      Corresponding IRQ flags
+ *
+ * Return pointer to vint descriptor if all went well else corresponding
+ * error pointer.
+ */
+static struct ti_sci_inta_vint_desc *alloc_parent_irq(struct irq_domain *domain,
+                                                      unsigned int virq,
+                                                      u32 src_id, u32 src_index,
+                                                      u32 vint, u32 flags)
+{
+        struct ti_sci_inta_irq_domain *inta = domain->host_data;
+        struct ti_sci_inta_vint_desc *vint_desc;
+        struct irq_data *gic_data;
+        struct irq_fwspec fwspec;
+        int err;
+
+        if (!irq_domain_get_of_node(domain->parent))
+                return ERR_PTR(-EINVAL);
+
+        vint_desc = kzalloc(sizeof(*vint_desc), GFP_KERNEL);
+        if (!vint_desc)
+                return ERR_PTR(-ENOMEM);
+
+        vint_desc->event_map = kcalloc(BITS_TO_LONGS(MAX_EVENTS_PER_VINT),
+                                       sizeof(*vint_desc->event_map),
+                                       GFP_KERNEL);
+        if (!vint_desc->event_map) {
+                kfree(vint_desc);
+                return ERR_PTR(-ENOMEM);
+        }
+
+        fwspec.fwnode = domain->parent->fwnode;
+        fwspec.param_count = 3;
+        /* Interrupt parent is Interrupt Router */
+        fwspec.param[0] = inta->ia_id;
+        fwspec.param[1] = vint;
+        fwspec.param[2] = flags | TI_SCI_EVENT_IRQ;
+
+        err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+        if (err)
+                goto err_irqs;
+
+        gic_data = irq_domain_get_irq_data(domain->parent->parent, virq);
+
+        raw_spin_lock_init(&vint_desc->lock);
+
+        err = ti_sci_allocate_event_irq(inta, vint_desc, src_id, src_index,
+                                        gic_data->hwirq, vint);
+        if (err)
+                goto err_events;
+
+        return vint_desc;
+
+err_events:
+        irq_domain_free_irqs_parent(domain, virq, 1);
+err_irqs:
+        ti_sci_release_resource(inta->vint, vint);
+        kfree(vint_desc);
+        return ERR_PTR(err);
+}
+
+/**
+ * ti_sci_inta_irq_domain_alloc() - Allocate Interrupt aggregator IRQs
+ * @domain:     Point to the interrupt aggregator IRQ domain
+ * @virq:       Corresponding Linux virtual IRQ number
+ * @nr_irqs:    Continuous irqs to be allocated
+ * @data:       Pointer to firmware specifier
+ *
+ * Return 0 if all went well else appropriate error value.
+ */
+static int ti_sci_inta_irq_domain_alloc(struct irq_domain *domain,
+                                        unsigned int virq, unsigned int nr_irqs,
+                                        void *data)
+{
+        struct ti_sci_inta_vint_desc *vint_desc;
+        struct irq_fwspec *fwspec = data;
+        int err;
+
+        vint_desc = alloc_parent_irq(domain, virq, fwspec->param[0],
+                                     fwspec->param[1], fwspec->param[2],
+                                     fwspec->param[3]);
+        if (IS_ERR(vint_desc))
+                return PTR_ERR(vint_desc);
+
+        err = irq_domain_set_hwirq_and_chip(domain, virq, fwspec->param[2],
+                                            &ti_sci_inta_irq_chip, vint_desc);
+
+        return err;
+}
+
+static const struct irq_domain_ops ti_sci_inta_irq_domain_ops = {
+        .alloc          = ti_sci_inta_irq_domain_alloc,
+        .free           = ti_sci_inta_irq_domain_free,
+        .translate      = ti_sci_inta_irq_domain_translate,
+};
+
+static int ti_sci_inta_irq_domain_probe(struct platform_device *pdev)
+{
+        struct irq_domain *parent_domain, *domain;
+        struct ti_sci_inta_irq_domain *inta;
+        struct device_node *parent_node;
+        struct device *dev = &pdev->dev;
+        struct resource *res;
+        int ret;
+
+        parent_node = of_irq_find_parent(dev_of_node(dev));
+        if (!parent_node) {
+                dev_err(dev, "Failed to get IRQ parent node\n");
+                return -ENODEV;
+        }
+
+        parent_domain = irq_find_host(parent_node);
+        if (!parent_domain)
+                return -EPROBE_DEFER;
+
+        inta = devm_kzalloc(dev, sizeof(*inta), GFP_KERNEL);
+        if (!inta)
+                return -ENOMEM;
+
+        inta->sci = devm_ti_sci_get_by_phandle(dev, "ti,sci");
+        if (IS_ERR(inta->sci)) {
+                ret = PTR_ERR(inta->sci);
+                if (ret != -EPROBE_DEFER)
+                        dev_err(dev, "ti,sci read fail %d\n", ret);
+                inta->sci = NULL;
+                return ret;
+        }
+
+        ret = of_property_read_u32(dev->of_node, "ti,sci-dev-id",
+                                   (u32 *)&inta->ia_id);
+        if (ret) {
+                dev_err(dev, "missing 'ti,sci-dev-id' property\n");
+                return -EINVAL;
+        }
+
+        inta->vint = devm_ti_sci_get_of_resource(inta->sci, dev,
+                                                 inta->ia_id,
+                                                 "ti,sci-rm-range-vint");
+        if (IS_ERR(inta->vint)) {
+                dev_err(dev, "VINT resource allocation failed\n");
+                return PTR_ERR(inta->vint);
+        }
+
+        inta->global_event =
+                devm_ti_sci_get_of_resource(inta->sci, dev,
+                                            inta->ia_id,
+                                            "ti,sci-rm-range-global-event");
+        if (IS_ERR(inta->global_event)) {
+                dev_err(dev, "Global event resource allocation failed\n");
+                return PTR_ERR(inta->global_event);
+        }
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        inta->base = devm_ioremap_resource(dev, res);
+        if (IS_ERR(inta->base))
+                return -ENODEV;
+
+        ret = of_property_read_u32(parent_node, "ti,sci-dst-id",
+                                   (u32 *)&inta->dst_id);
+
+        domain = irq_domain_add_hierarchy(parent_domain, 0, 0, dev_of_node(dev),
+                                          &ti_sci_inta_irq_domain_ops, inta);
+        if (!domain) {
+                dev_err(dev, "Failed to allocate IRQ domain\n");
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+/**
+ * ti_sci_inta_register_event() - Register a event to an interrupt aggregator
+ * @dev:        Device pointer to source generating the event
+ * @src_id:     TISCI device ID of the event source
+ * @src_index:  Event source index within the device.
+ * @virq:       Linux Virtual IRQ number
+ * @ack_needed: If explicit clearing of event is required.
+ * @flags:      Corresponding IRQ flags
+ *
+ * Creates a new irq and attaches to IA domain if virq is not specified
+ * else attaches the event to vint corresponding to virq.
+ * When using TISCI within the client drivers, source indexes are always
+ * generated dynamically and cannot be represented in DT. So client
+ * drivers should call this API instead of platform_get_irq().
+ *
+ * Return virq if all went well else appropriate error value.
+ */
+int ti_sci_inta_register_event(struct device *dev, u16 src_id, u16 src_index,
+                               unsigned int virq, bool ack_needed, u32 flags)
+{
+        struct ti_sci_inta_vint_desc *vint_desc;
+        struct ti_sci_inta_irq_domain *inta;
+        struct irq_data *data, *gic_data;
+        struct device_node *parent_node;
+        struct irq_domain *domain;
+        struct irq_fwspec fwspec;
+        int err;
+
+        parent_node = of_irq_find_parent(dev->of_node);
+        if (!parent_node)
+                return -ENODEV;
+
+        domain = irq_find_host(parent_node);
+        if (!domain)
+                return -EPROBE_DEFER;
+
+        inta = domain->host_data;
+
+        if (virq > 0) {
+                /* If Group already available */
+                data = irq_domain_get_irq_data(domain, virq);
+                gic_data = irq_domain_get_irq_data(domain->parent->parent,
+                                                   virq);
+
+                vint_desc = irq_data_get_irq_chip_data(data);
+
+                err = ti_sci_allocate_event_irq(inta, vint_desc, src_id,
+                                                src_index, gic_data->hwirq,
+                                                data->hwirq);
+                if (err)
+                        return err;
+        } else {
+                fwspec.param_count = 4;
+                fwspec.fwnode = domain->fwnode;
+                fwspec.param[0] = src_id;
+                fwspec.param[1] = src_index;
+                fwspec.param[2] = ti_sci_get_free_resource(inta->vint);
+                fwspec.param[3] = flags;
+
+                virq = irq_create_fwspec_mapping(&fwspec);
+                if (virq <= 0)
+                        ti_sci_release_resource(inta->vint, fwspec.param[2]);
+
+                data = irq_domain_get_irq_data(domain, virq);
+                vint_desc = irq_data_get_irq_chip_data(data);
+                vint_desc->ack_needed = ack_needed;
+        }
+
+        return virq;
+}
+EXPORT_SYMBOL_GPL(ti_sci_inta_register_event);
+
+/**
+ * get_event_index() - Helper api to get the event index with the vint.
+ * @vint_desc:  Pointer to the IA irq descriptor
+ * @src_id:     TISCI device ID of the event source
+ * @src_index:  Event source index within the device.
+ *
+ * Return the index if all went well else MAX_EVENTS_PER_VINT.
+ */
+static u8 get_event_index(struct ti_sci_inta_vint_desc *vint_desc, u16 src_id,
+                          u16 src_index)
+{
+        int i;
+
+        for (i = 0; i < MAX_EVENTS_PER_VINT; i++) {
+                if (vint_desc->events[i].src_id == src_id &&
+                    vint_desc->events[i].src_index == src_index)
+                        return i;
+        }
+
+        return MAX_EVENTS_PER_VINT;
+}
+
+/**
+ * is_event_last() -  Helper api to determine if the event is the last
+ *                    event within the vint
+ * @vint_desc:  Pointer to the IA irq descriptor
+ * @event_index:        Event index within the vint of IA.
+ *
+ * Return true if specified index is the last event else false.
+ */
+static bool is_event_last(struct ti_sci_inta_vint_desc *vint_desc,
+                          u8 event_index)
+{
+        unsigned long flags;
+        int next_event;
+        bool status;
+
+        raw_spin_lock_irqsave(&vint_desc->lock, flags);
+        next_event = find_next_bit(vint_desc->event_map, MAX_EVENTS_PER_VINT,
+                                   event_index + 1);
+        status = (next_event != MAX_EVENTS_PER_VINT) ? false : true;
+        if (event_index !=
+                find_first_bit(vint_desc->event_map, MAX_EVENTS_PER_VINT))
+                status = false;
+        raw_spin_unlock_irqrestore(&vint_desc->lock, flags);
+
+        return status;
+}
+
+/**
+ * ti_sci_inta_unregister_event() - Unregister a event from an IA.
+ * @dev:        Device pointer to source generating the event
+ * @src_id:     TISCI device ID of the event source
+ * @src_index:  Event source index within the device.
+ * @virq:       Linux Virtual IRQ number
+ *
+ * Deletes the event from IA interrupt descriptor. If this event is the
+ * last event then delete the vint as well.
+ */
+void ti_sci_inta_unregister_event(struct device *dev, u16 src_id,
+                                  u16 src_index, unsigned int virq)
+{
+        struct ti_sci_inta_vint_desc *vint_desc;
+        struct irq_data *data, *gic_data;
+        struct device_node *parent_node;
+        struct irq_domain *domain;
+        u8 event_index;
+
+        parent_node = of_irq_find_parent(dev->of_node);
+        if (!parent_node)
+                return;
+
+        domain = irq_find_host(parent_node);
+
+        data = irq_domain_get_irq_data(domain, virq);
+        gic_data = irq_domain_get_irq_data(domain->parent->parent, virq);
+
+        vint_desc = irq_data_get_irq_chip_data(data);
+
+        event_index = get_event_index(vint_desc, src_id, src_index);
+        if (event_index == MAX_EVENTS_PER_VINT)
+                return;
+
+        if (is_event_last(vint_desc, event_index))
+                irq_dispose_mapping(virq);
+        else
+                ti_sci_free_event_irq(domain->host_data, vint_desc,
+                                      event_index, gic_data->hwirq,
+                                      data->hwirq);
+}
+EXPORT_SYMBOL_GPL(ti_sci_inta_unregister_event);
+
+static const struct of_device_id ti_sci_inta_irq_domain_of_match[] = {
+        { .compatible = "ti,sci-inta", },
+        { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ti_sci_inta_irq_domain_of_match);
+
+static struct platform_driver ti_sci_inta_irq_domain_driver = {
+        .probe = ti_sci_inta_irq_domain_probe,
+        .driver = {
+                .name = "ti-sci-inta",
+                .of_match_table = ti_sci_inta_irq_domain_of_match,
+        },
+};
+module_platform_driver(ti_sci_inta_irq_domain_driver);
+
+MODULE_AUTHOR("Lokesh Vutla <lokeshvutla@ticom>");
+MODULE_DESCRIPTION("K3 Interrupt Aggregator driver over TI SCI protocol");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/irqchip/irq-ti-sci-inta.h b/include/linux/irqchip/irq-ti-sci-inta.h
new file mode 100644
index 000000000000..fbc3172dd776
--- /dev/null
+++ b/include/linux/irqchip/irq-ti-sci-inta.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Texas Instruments' System Control Interface (TI-SCI) irqchip
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *      Lokesh Vutla <lokeshvutla@ti.com>
+ */
+
+#ifndef __INCLUDE_LINUX_IRQCHIP_TI_SCI_INTA_H
+#define __INCLUDE_LINUX_IRQCHIP_TI_SCI_INTA_H
+
+#if IS_ENABLED(CONFIG_TI_SCI_INTA_IRQCHIP)
+int ti_sci_inta_register_event(struct device *dev, u16 src_id, u16 src_index,
+                               unsigned int virq, bool ack_needed, u32 flags);
+int ti_sci_inta_unregister_event(struct device *dev, u16 src_id, u16 src_index,
+                                 unsigned int virq);
+
+#else /* CONFIG_TI_SCI_INTA_IRQCHIP */
+
+static inline int ti_sci_inta_register_event(struct device *dev, u16 src_id,
+                                             u16 src_index, unsigned int virq,
+                                             bool ack_needed, u32 flags)
+{
+        return -EINVAL;
+}
+
+static inline int ti_sci_inta_unregister_event(struct device *dev, u16 src_id,
+                                               u16 src_index, unsigned int virq)
+{
+        return -EINVAL;
+}
+
+#endif /* CONFIG_TI_SCI_INTA_IRQCHIP */
+
+#endif /* __INCLUDE_LINUX_IRQCHIP_TI_SCI_INTA_H */