soc: ti: Add MSI domain bus support for Interrupt Aggregator

With the system coprocessor managing the range allocation of the
inputs to Interrupt Aggregator, it is difficult to represent
the device IRQs from DT.

The suggestion is to use MSI in such cases where devices wants
to allocate and group interrupts dynamically.

Create a MSI domain bus layer that allocates and frees MSIs for
a device.

APIs that are implemented:
- ti_sci_inta_msi_create_irq_domain() that creates a MSI domain
- ti_sci_inta_msi_domain_alloc_irqs() that creates MSIs for the
  specified device and resource.
- ti_sci_inta_msi_domain_free_irqs() frees the irqs attached to the device.
- ti_sci_inta_msi_get_virq() for getting the virq attached to a specific event.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

3 files changed, 34 insertions, 0 deletions

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 61706b430907..07ec8b390161 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -82,6 +82,7 @@ enum irq_domain_bus_token {
 	DOMAIN_BUS_NEXUS,
 	DOMAIN_BUS_IPI,
 	DOMAIN_BUS_FSL_MC_MSI,
+	DOMAIN_BUS_TI_SCI_INTA_MSI,
 };
 
 /**
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 7e9b81c3b50d..7c28762851a3 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -48,6 +48,14 @@ struct fsl_mc_msi_desc {
 };
 
 /**
+ * ti_sci_inta_msi_desc - TISCI based INTA specific msi descriptor data
+ * @dev_index: TISCI device index
+ */
+struct ti_sci_inta_msi_desc {
+	u16	dev_index;
+};
+
+/**
  * struct msi_desc - Descriptor structure for MSI based interrupts
  * @list:	List head for management
  * @irq:	The base interrupt number
@@ -68,6 +76,7 @@ struct fsl_mc_msi_desc {
  * @mask_base:	[PCI MSI-X] Mask register base address
  * @platform:	[platform]  Platform device specific msi descriptor data
  * @fsl_mc:	[fsl-mc]    FSL MC device specific msi descriptor data
+ * @inta:	[INTA]	    TISCI based INTA specific msi descriptor data
  */
 struct msi_desc {
 	/* Shared device/bus type independent data */
@@ -106,6 +115,7 @@ struct msi_desc {
 		 */
 		struct platform_msi_desc platform;
 		struct fsl_mc_msi_desc fsl_mc;
+		struct ti_sci_inta_msi_desc inta;
 	};
 };
 
diff --git a/include/linux/soc/ti/ti_sci_inta_msi.h b/include/linux/soc/ti/ti_sci_inta_msi.h
new file mode 100644
index 000000000000..11fb5048f5f6
--- /dev/null
+++ b/include/linux/soc/ti/ti_sci_inta_msi.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Texas Instruments' K3 TI SCI INTA MSI helper
+ *
+ * Copyright (C) 2018-2019 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla <lokeshvutla@ti.com>
+ */
+
+#ifndef __INCLUDE_LINUX_TI_SCI_INTA_MSI_H
+#define __INCLUDE_LINUX_TI_SCI_INTA_MSI_H
+
+#include <linux/msi.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+struct irq_domain
+*ti_sci_inta_msi_create_irq_domain(struct fwnode_handle *fwnode,
+				   struct msi_domain_info *info,
+				   struct irq_domain *parent);
+int ti_sci_inta_msi_domain_alloc_irqs(struct device *dev,
+				      struct ti_sci_resource *res);
+unsigned int ti_sci_inta_msi_get_virq(struct device *dev, u32 index);
+void ti_sci_inta_msi_domain_free_irqs(struct device *dev);
+#endif /* __INCLUDE_LINUX_IRQCHIP_TI_SCI_INTA_H */