[PATCH V4 0/2] irqchip: qcom: Add IRQ combiner driver

[PATCH V4 0/2] irqchip: qcom: Add IRQ combiner driver

[Agustin Vega-Frias]

Add support for IRQ combiners in the Top-level Control and Status
Registers (TCSR) hardware block in Qualcomm Technologies chips.

The first patch adds support for ResourceSource/IRQ domain mapping
when using Extended IRQ Resources with a specific ResourceSource.
The core ACPI resource management code has been changed to lookup
the IRQ domain when an IRQ resource indicates a ResourceSource,
and register the IRQ on that domain, instead of a GSI.

The second patch takes advantage of the new capabilities to implement
the driver for the IRQ combiners.

Changes V1 -> V2:
* Remove use of GPIO library for the combiner
* Refactor to use fwnode/ResourceSource to IRQ domain mapping
  introduced in ACPI core

Changes V2 -> V3:
* Removed parsing of _PRS to find IRQs
* Removed acpi_irq_domain_create and acpi_irq_domain_remove

Changes V3 -> V3:
* Add a DSDT device probe table that is used to probe DSDT IRQ chips
  as necessary when converting HW IRQs to Linux IRQs
* Describe IRQ combiner registers as ACPI Register resources

Agustin Vega-Frias (2):
  ACPI: Add support for ResourceSource/IRQ domain mapping
  irqchip: qcom: Add IRQ combiner driver

 drivers/acpi/Makefile               |   1 +
 drivers/acpi/irqdomain.c            | 135 +++++++++++++++
 drivers/acpi/resource.c             |  21 ++-
 drivers/irqchip/Kconfig             |   8 +
 drivers/irqchip/Makefile            |   1 +
 drivers/irqchip/qcom-irq-combiner.c | 332 ++++++++++++++++++++++++++++++++++++
 include/asm-generic/vmlinux.lds.h   |   1 +
 include/linux/acpi.h                |  50 ++++++
 include/linux/irqchip.h             |  17 +-
 9 files changed, 554 insertions(+), 12 deletions(-)
 create mode 100644 drivers/acpi/irqdomain.c
 create mode 100644 drivers/irqchip/qcom-irq-combiner.c

-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 0/2] irqchip: qcom: Add IRQ combiner driver

[Agustin Vega-Frias]

Add support for IRQ combiners in the Top-level Control and Status
Registers (TCSR) hardware block in Qualcomm Technologies chips.

The first patch adds support for ResourceSource/IRQ domain mapping
when using Extended IRQ Resources with a specific ResourceSource.
The core ACPI resource management code has been changed to lookup
the IRQ domain when an IRQ resource indicates a ResourceSource,
and register the IRQ on that domain, instead of a GSI.

The second patch takes advantage of the new capabilities to implement
the driver for the IRQ combiners.

Changes V1 -> V2:
* Remove use of GPIO library for the combiner
* Refactor to use fwnode/ResourceSource to IRQ domain mapping
  introduced in ACPI core

Changes V2 -> V3:
* Removed parsing of _PRS to find IRQs
* Removed acpi_irq_domain_create and acpi_irq_domain_remove

Changes V3 -> V3:
* Add a DSDT device probe table that is used to probe DSDT IRQ chips
  as necessary when converting HW IRQs to Linux IRQs
* Describe IRQ combiner registers as ACPI Register resources

Agustin Vega-Frias (2):
  ACPI: Add support for ResourceSource/IRQ domain mapping
  irqchip: qcom: Add IRQ combiner driver

 drivers/acpi/Makefile               |   1 +
 drivers/acpi/irqdomain.c            | 135 +++++++++++++++
 drivers/acpi/resource.c             |  21 ++-
 drivers/irqchip/Kconfig             |   8 +
 drivers/irqchip/Makefile            |   1 +
 drivers/irqchip/qcom-irq-combiner.c | 332 ++++++++++++++++++++++++++++++++++++
 include/asm-generic/vmlinux.lds.h   |   1 +
 include/linux/acpi.h                |  50 ++++++
 include/linux/irqchip.h             |  17 +-
 9 files changed, 554 insertions(+), 12 deletions(-)
 create mode 100644 drivers/acpi/irqdomain.c
 create mode 100644 drivers/irqchip/qcom-irq-combiner.c

-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 1/2] ACPI: Add support for ResourceSource/IRQ domain mapping

[Agustin Vega-Frias]

This allows irqchip drivers to associate an ACPI DSDT device to
an IRQ domain and provides support for using the ResourceSource
in Extended IRQ Resources to find the domain and map the IRQs
specified on that domain.

Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
---
 drivers/acpi/Makefile             |   1 +
 drivers/acpi/irqdomain.c          | 135 ++++++++++++++++++++++++++++++++++++++
 drivers/acpi/resource.c           |  21 +++---
 include/asm-generic/vmlinux.lds.h |   1 +
 include/linux/acpi.h              |  50 ++++++++++++++
 include/linux/irqchip.h           |  17 ++++-
 6 files changed, 213 insertions(+), 12 deletions(-)
 create mode 100644 drivers/acpi/irqdomain.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 9ed0878..81bdc95 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -57,6 +57,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
 acpi-y				+= acpi_lpat.o
 acpi-$(CONFIG_ACPI_GENERIC_GSI) += gsi.o
 acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
+acpi-y				+= irqdomain.o
 
 # These are (potentially) separate modules
 
diff --git a/drivers/acpi/irqdomain.c b/drivers/acpi/irqdomain.c
new file mode 100644
index 0000000..0429607
--- /dev/null
+++ b/drivers/acpi/irqdomain.c
@@ -0,0 +1,135 @@
+/*
+ * ACPI ResourceSource/IRQ domain mapping support
+ *
+ * Copyright (c) 2016, 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.
+ */
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+/**
+ * acpi_irq_domain_ensure_probed() - Check if the device has registered
+ *                                   an IRQ domain and probe as necessary
+ *
+ * @device: Device to check and probe
+ *
+ * Returns: 0 on success, -ENODEV otherwise
+ */
+static int acpi_irq_domain_ensure_probed(struct acpi_device *device)
+{
+	struct acpi_dsdt_probe_entry *entry;
+
+	if (irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY) != 0)
+		return 0;
+
+	for (entry = &__dsdt_acpi_probe_table;
+	     entry < &__dsdt_acpi_probe_table_end; e++)
+		if (strcmp(e->_hid, acpi_device_hid(device)) == 0)
+			return e->probe(device);
+
+	return -ENODEV;
+}
+
+/**
+ * acpi_irq_domain_register_irq() - Register the mapping for an IRQ produced
+ *                                  by the given acpi_resource_source to a
+ *                                  Linux IRQ number
+ * @source: IRQ source
+ * @hwirq: Hardware IRQ number
+ * @trigger: trigger type of the IRQ number to be mapped
+ * @polarity: polarity of the IRQ to be mapped
+ *
+ * Returns: a valid linux IRQ number on success
+ *          -ENODEV if the given acpi_resource_source cannot be found
+ *          -EPROBE_DEFER if the IRQ domain has not been registered
+ *          -EINVAL for all other errors
+ */
+int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
+				 int trigger, int polarity)
+{
+	struct irq_fwspec fwspec;
+	struct acpi_device *device;
+	acpi_handle handle;
+	acpi_status status;
+	int ret;
+
+	if (source->string_length == 0)
+		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
+
+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	device = acpi_bus_get_acpi_device(handle);
+	if (!device)
+		return -ENODEV;
+
+	if (acpi_irq_domain_ensure_probed(device))
+		return -ENODEV;
+
+	fwspec.fwnode = &device->fwnode;
+	fwspec.param[0] = hwirq;
+	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
+	fwspec.param_count = 2;
+
+	ret = irq_create_fwspec_mapping(&fwspec);
+	acpi_bus_put_acpi_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_irq_domain_register_irq);
+
+/**
+ * acpi_irq_domain_unregister_irq() - Delete the mapping for an IRQ produced
+ *                                    by the given acpi_resource_source to a
+ *                                    Linux IRQ number
+ * @source: IRQ source
+ * @hwirq: Hardware IRQ number
+ *
+ * Returns: 0 on success
+ *          -ENODEV if the given acpi_resource_source cannot be found
+ *          -EINVAL for all other errors
+ */
+int acpi_irq_domain_unregister_irq(struct acpi_resource_source *source,
+				   u32 hwirq)
+{
+	struct irq_domain *domain;
+	struct acpi_device *device;
+	acpi_handle handle;
+	acpi_status status;
+	int ret = 0;
+
+	if (source->string_length == 0) {
+		acpi_unregister_gsi(hwirq);
+		return 0;
+	}
+
+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	device = acpi_bus_get_acpi_device(handle);
+	if (!device)
+		return -ENODEV;
+
+	domain = irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY);
+	if (!domain) {
+		ret = -EINVAL;
+		goto out_put_device;
+	}
+
+	irq_dispose_mapping(irq_find_mapping(domain, hwirq));
+
+out_put_device:
+	acpi_bus_put_acpi_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_irq_domain_unregister_irq);
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 56241eb..8e69a7a 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -381,14 +381,15 @@ static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
 	res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET;
 }
 
-static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
+static void acpi_dev_get_irqresource(struct resource *res, u32 hwirq,
+				     struct acpi_resource_source *source,
 				     u8 triggering, u8 polarity, u8 shareable,
 				     bool legacy)
 {
 	int irq, p, t;
 
-	if (!valid_IRQ(gsi)) {
-		acpi_dev_irqresource_disabled(res, gsi);
+	if ((source->string_length == 0) && !valid_IRQ(hwirq)) {
+		acpi_dev_irqresource_disabled(res, hwirq);
 		return;
 	}
 
@@ -402,25 +403,25 @@ static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
 	 * using extended IRQ descriptors we take the IRQ configuration
 	 * from _CRS directly.
 	 */
-	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
+	if (legacy && !acpi_get_override_irq(hwirq, &t, &p)) {
 		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
 
 		if (triggering != trig || polarity != pol) {
-			pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
-				   t ? "level" : "edge", p ? "low" : "high");
+			pr_warn("ACPI: IRQ %d override to %s, %s\n", hwirq,
+				t ? "level" : "edge", p ? "low" : "high");
 			triggering = trig;
 			polarity = pol;
 		}
 	}
 
 	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
-	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
+	irq = acpi_irq_domain_register_irq(source, hwirq, triggering, polarity);
 	if (irq >= 0) {
 		res->start = irq;
 		res->end = irq;
 	} else {
-		acpi_dev_irqresource_disabled(res, gsi);
+		acpi_dev_irqresource_disabled(res, hwirq);
 	}
 }
 
@@ -448,6 +449,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 {
 	struct acpi_resource_irq *irq;
 	struct acpi_resource_extended_irq *ext_irq;
+	struct acpi_resource_source dummy = { 0, 0, NULL };
 
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_IRQ:
@@ -460,7 +462,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 			acpi_dev_irqresource_disabled(res, 0);
 			return false;
 		}
-		acpi_dev_get_irqresource(res, irq->interrupts[index],
+		acpi_dev_get_irqresource(res, irq->interrupts[index], &dummy,
 					 irq->triggering, irq->polarity,
 					 irq->sharable, true);
 		break;
@@ -471,6 +473,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 			return false;
 		}
 		acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
+					 &ext_irq->resource_source,
 					 ext_irq->triggering, ext_irq->polarity,
 					 ext_irq->sharable, false);
 		break;
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3074796..f808afdc 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -563,6 +563,7 @@
 	IRQCHIP_OF_MATCH_TABLE()					\
 	ACPI_PROBE_TABLE(irqchip)					\
 	ACPI_PROBE_TABLE(clksrc)					\
+	ACPI_PROBE_TABLE(dsdt)						\
 	EARLYCON_TABLE()
 
 #define INIT_TEXT							\
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ddbeda6..619cd4f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -26,6 +26,7 @@
 #include <linux/resource_ext.h>
 #include <linux/device.h>
 #include <linux/property.h>
+#include <linux/irqdomain.h>
 
 #ifndef _LINUX
 #define _LINUX
@@ -309,6 +310,11 @@ static inline bool acpi_sci_irq_valid(void)
 void acpi_set_irq_model(enum acpi_irq_model_id model,
 			struct fwnode_handle *fwnode);
 
+int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
+				 int trigger, int polarity);
+int acpi_irq_domain_unregister_irq(struct acpi_resource_source *source,
+				   u32 hwirq);
+
 #ifdef CONFIG_X86_IO_APIC
 extern int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity);
 #else
@@ -1024,6 +1030,43 @@ struct acpi_probe_entry {
 					  (&ACPI_PROBE_TABLE_END(t) -	\
 					   &ACPI_PROBE_TABLE(t)));	\
 	})
+
+#define ACPI_HID_LEN 9
+
+typedef int (*acpi_dsdt_handler)(struct acpi_device *);
+
+/**
+ * struct acpi_probe_dsdt_entry - boot-time probing entry for DSDT devices
+ * @hid:		_HID of the device
+ * @fn:		Callback to the driver being probed
+ * @driver_data:	Sideband data provided back to the driver
+ */
+struct acpi_dsdt_probe_entry {
+	__u8 _hid[ACPI_HID_LEN];
+	acpi_dsdt_handler probe;
+};
+
+#define ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)			\
+	static const struct acpi_dsdt_probe_entry __acpi_probe_##name	\
+		__used __section(__dsdt_acpi_probe_table) =		\
+		{							\
+			._hid = hid,					\
+			.probe = fn,					\
+		}
+
+extern struct acpi_dsdt_probe_entry __dsdt_acpi_probe_table;
+extern struct acpi_dsdt_probe_entry __dsdt_acpi_probe_table_end;
+
+#define MADT_IRQCHIP_ACPI_DECLARE(name, subtable, validate, data, fn)	\
+	ACPI_DECLARE_PROBE_ENTRY(irqchip, name, ACPI_SIG_MADT,		\
+				 subtable, validate, data, fn)
+
+#define DSDT_IRQCHIP_ACPI_DECLARE(name, hid, fn)	\
+	ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)
+
+#define __IRQCHIP_ACPI_DECLARE(_a1, _a2, _a3, _a4, _a5, type, ...)	\
+	type##_IRQCHIP_ACPI_DECLARE
+
 #else
 static inline int acpi_dev_get_property(struct acpi_device *adev,
 					const char *name, acpi_object_type type,
@@ -1101,6 +1144,13 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 		     (void *) data }
 
 #define acpi_probe_device_table(t)	({ int __r = 0; __r;})
+
+#define ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)			\
+	static const void *__acpi_probe_##name[]			\
+		__attribute__((unused))				\
+		 = { (void *) hid,					\
+		     (void *) fn }
+
 #endif
 
 #ifdef CONFIG_ACPI_TABLE_UPGRADE
diff --git a/include/linux/irqchip.h b/include/linux/irqchip.h
index 89c34b2..c2d0c12 100644
--- a/include/linux/irqchip.h
+++ b/include/linux/irqchip.h
@@ -29,6 +29,10 @@
 /*
  * This macro must be used by the different irqchip drivers to declare
  * the association between their version and their initialization function.
+ * Two syntaxes are supported depending on the table where the irqchip device
+ * is declared:
+ *
+ * - MADT irqchip syntax, which requires the following five arguments:
  *
  * @name: name that must be unique accross all IRQCHIP_ACPI_DECLARE of the
  * same file.
@@ -37,10 +41,17 @@
  *            Can be NULL.
  * @data: data to be checked by the validate function.
  * @fn: initialization function
+ *
+ * - DSDT irqchip syntax, which requires the following three arguments:
+ *
+ * @name: name that must be unique across all IRQCHIP_ACPI_DECLARE of the
+ * same file.
+ * @hid: _HID of the DSDT device
+ * @fn: initialization function
  */
-#define IRQCHIP_ACPI_DECLARE(name, subtable, validate, data, fn)	\
-	ACPI_DECLARE_PROBE_ENTRY(irqchip, name, ACPI_SIG_MADT, 		\
-				 subtable, validate, data, fn)
+
+#define IRQCHIP_ACPI_DECLARE(...)					\
+	__IRQCHIP_ACPI_DECLARE(__VA_ARGS__, MADT, _unused, DSDT)(__VA_ARGS__)
 
 #ifdef CONFIG_IRQCHIP
 void irqchip_init(void);
-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 1/2] ACPI: Add support for ResourceSource/IRQ domain mapping

[Agustin Vega-Frias]

This allows irqchip drivers to associate an ACPI DSDT device to
an IRQ domain and provides support for using the ResourceSource
in Extended IRQ Resources to find the domain and map the IRQs
specified on that domain.

Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
---
 drivers/acpi/Makefile             |   1 +
 drivers/acpi/irqdomain.c          | 135 ++++++++++++++++++++++++++++++++++++++
 drivers/acpi/resource.c           |  21 +++---
 include/asm-generic/vmlinux.lds.h |   1 +
 include/linux/acpi.h              |  50 ++++++++++++++
 include/linux/irqchip.h           |  17 ++++-
 6 files changed, 213 insertions(+), 12 deletions(-)
 create mode 100644 drivers/acpi/irqdomain.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 9ed0878..81bdc95 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -57,6 +57,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
 acpi-y				+= acpi_lpat.o
 acpi-$(CONFIG_ACPI_GENERIC_GSI) += gsi.o
 acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
+acpi-y				+= irqdomain.o
 
 # These are (potentially) separate modules
 
diff --git a/drivers/acpi/irqdomain.c b/drivers/acpi/irqdomain.c
new file mode 100644
index 0000000..0429607
--- /dev/null
+++ b/drivers/acpi/irqdomain.c
@@ -0,0 +1,135 @@
+/*
+ * ACPI ResourceSource/IRQ domain mapping support
+ *
+ * Copyright (c) 2016, 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.
+ */
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+/**
+ * acpi_irq_domain_ensure_probed() - Check if the device has registered
+ *                                   an IRQ domain and probe as necessary
+ *
+ * @device: Device to check and probe
+ *
+ * Returns: 0 on success, -ENODEV otherwise
+ */
+static int acpi_irq_domain_ensure_probed(struct acpi_device *device)
+{
+	struct acpi_dsdt_probe_entry *entry;
+
+	if (irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY) != 0)
+		return 0;
+
+	for (entry = &__dsdt_acpi_probe_table;
+	     entry < &__dsdt_acpi_probe_table_end; e++)
+		if (strcmp(e->_hid, acpi_device_hid(device)) == 0)
+			return e->probe(device);
+
+	return -ENODEV;
+}
+
+/**
+ * acpi_irq_domain_register_irq() - Register the mapping for an IRQ produced
+ *                                  by the given acpi_resource_source to a
+ *                                  Linux IRQ number
+ * @source: IRQ source
+ * @hwirq: Hardware IRQ number
+ * @trigger: trigger type of the IRQ number to be mapped
+ * @polarity: polarity of the IRQ to be mapped
+ *
+ * Returns: a valid linux IRQ number on success
+ *          -ENODEV if the given acpi_resource_source cannot be found
+ *          -EPROBE_DEFER if the IRQ domain has not been registered
+ *          -EINVAL for all other errors
+ */
+int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
+				 int trigger, int polarity)
+{
+	struct irq_fwspec fwspec;
+	struct acpi_device *device;
+	acpi_handle handle;
+	acpi_status status;
+	int ret;
+
+	if (source->string_length == 0)
+		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
+
+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	device = acpi_bus_get_acpi_device(handle);
+	if (!device)
+		return -ENODEV;
+
+	if (acpi_irq_domain_ensure_probed(device))
+		return -ENODEV;
+
+	fwspec.fwnode = &device->fwnode;
+	fwspec.param[0] = hwirq;
+	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
+	fwspec.param_count = 2;
+
+	ret = irq_create_fwspec_mapping(&fwspec);
+	acpi_bus_put_acpi_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_irq_domain_register_irq);
+
+/**
+ * acpi_irq_domain_unregister_irq() - Delete the mapping for an IRQ produced
+ *                                    by the given acpi_resource_source to a
+ *                                    Linux IRQ number
+ * @source: IRQ source
+ * @hwirq: Hardware IRQ number
+ *
+ * Returns: 0 on success
+ *          -ENODEV if the given acpi_resource_source cannot be found
+ *          -EINVAL for all other errors
+ */
+int acpi_irq_domain_unregister_irq(struct acpi_resource_source *source,
+				   u32 hwirq)
+{
+	struct irq_domain *domain;
+	struct acpi_device *device;
+	acpi_handle handle;
+	acpi_status status;
+	int ret = 0;
+
+	if (source->string_length == 0) {
+		acpi_unregister_gsi(hwirq);
+		return 0;
+	}
+
+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	device = acpi_bus_get_acpi_device(handle);
+	if (!device)
+		return -ENODEV;
+
+	domain = irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY);
+	if (!domain) {
+		ret = -EINVAL;
+		goto out_put_device;
+	}
+
+	irq_dispose_mapping(irq_find_mapping(domain, hwirq));
+
+out_put_device:
+	acpi_bus_put_acpi_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_irq_domain_unregister_irq);
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 56241eb..8e69a7a 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -381,14 +381,15 @@ static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
 	res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET;
 }
 
-static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
+static void acpi_dev_get_irqresource(struct resource *res, u32 hwirq,
+				     struct acpi_resource_source *source,
 				     u8 triggering, u8 polarity, u8 shareable,
 				     bool legacy)
 {
 	int irq, p, t;
 
-	if (!valid_IRQ(gsi)) {
-		acpi_dev_irqresource_disabled(res, gsi);
+	if ((source->string_length == 0) && !valid_IRQ(hwirq)) {
+		acpi_dev_irqresource_disabled(res, hwirq);
 		return;
 	}
 
@@ -402,25 +403,25 @@ static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
 	 * using extended IRQ descriptors we take the IRQ configuration
 	 * from _CRS directly.
 	 */
-	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
+	if (legacy && !acpi_get_override_irq(hwirq, &t, &p)) {
 		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
 
 		if (triggering != trig || polarity != pol) {
-			pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
-				   t ? "level" : "edge", p ? "low" : "high");
+			pr_warn("ACPI: IRQ %d override to %s, %s\n", hwirq,
+				t ? "level" : "edge", p ? "low" : "high");
 			triggering = trig;
 			polarity = pol;
 		}
 	}
 
 	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
-	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
+	irq = acpi_irq_domain_register_irq(source, hwirq, triggering, polarity);
 	if (irq >= 0) {
 		res->start = irq;
 		res->end = irq;
 	} else {
-		acpi_dev_irqresource_disabled(res, gsi);
+		acpi_dev_irqresource_disabled(res, hwirq);
 	}
 }
 
@@ -448,6 +449,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 {
 	struct acpi_resource_irq *irq;
 	struct acpi_resource_extended_irq *ext_irq;
+	struct acpi_resource_source dummy = { 0, 0, NULL };
 
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_IRQ:
@@ -460,7 +462,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 			acpi_dev_irqresource_disabled(res, 0);
 			return false;
 		}
-		acpi_dev_get_irqresource(res, irq->interrupts[index],
+		acpi_dev_get_irqresource(res, irq->interrupts[index], &dummy,
 					 irq->triggering, irq->polarity,
 					 irq->sharable, true);
 		break;
@@ -471,6 +473,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
 			return false;
 		}
 		acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
+					 &ext_irq->resource_source,
 					 ext_irq->triggering, ext_irq->polarity,
 					 ext_irq->sharable, false);
 		break;
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3074796..f808afdc 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -563,6 +563,7 @@
 	IRQCHIP_OF_MATCH_TABLE()					\
 	ACPI_PROBE_TABLE(irqchip)					\
 	ACPI_PROBE_TABLE(clksrc)					\
+	ACPI_PROBE_TABLE(dsdt)						\
 	EARLYCON_TABLE()
 
 #define INIT_TEXT							\
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ddbeda6..619cd4f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -26,6 +26,7 @@
 #include <linux/resource_ext.h>
 #include <linux/device.h>
 #include <linux/property.h>
+#include <linux/irqdomain.h>
 
 #ifndef _LINUX
 #define _LINUX
@@ -309,6 +310,11 @@ static inline bool acpi_sci_irq_valid(void)
 void acpi_set_irq_model(enum acpi_irq_model_id model,
 			struct fwnode_handle *fwnode);
 
+int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
+				 int trigger, int polarity);
+int acpi_irq_domain_unregister_irq(struct acpi_resource_source *source,
+				   u32 hwirq);
+
 #ifdef CONFIG_X86_IO_APIC
 extern int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity);
 #else
@@ -1024,6 +1030,43 @@ struct acpi_probe_entry {
 					  (&ACPI_PROBE_TABLE_END(t) -	\
 					   &ACPI_PROBE_TABLE(t)));	\
 	})
+
+#define ACPI_HID_LEN 9
+
+typedef int (*acpi_dsdt_handler)(struct acpi_device *);
+
+/**
+ * struct acpi_probe_dsdt_entry - boot-time probing entry for DSDT devices
+ * @hid:		_HID of the device
+ * @fn:		Callback to the driver being probed
+ * @driver_data:	Sideband data provided back to the driver
+ */
+struct acpi_dsdt_probe_entry {
+	__u8 _hid[ACPI_HID_LEN];
+	acpi_dsdt_handler probe;
+};
+
+#define ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)			\
+	static const struct acpi_dsdt_probe_entry __acpi_probe_##name	\
+		__used __section(__dsdt_acpi_probe_table) =		\
+		{							\
+			._hid = hid,					\
+			.probe = fn,					\
+		}
+
+extern struct acpi_dsdt_probe_entry __dsdt_acpi_probe_table;
+extern struct acpi_dsdt_probe_entry __dsdt_acpi_probe_table_end;
+
+#define MADT_IRQCHIP_ACPI_DECLARE(name, subtable, validate, data, fn)	\
+	ACPI_DECLARE_PROBE_ENTRY(irqchip, name, ACPI_SIG_MADT,		\
+				 subtable, validate, data, fn)
+
+#define DSDT_IRQCHIP_ACPI_DECLARE(name, hid, fn)	\
+	ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)
+
+#define __IRQCHIP_ACPI_DECLARE(_a1, _a2, _a3, _a4, _a5, type, ...)	\
+	type##_IRQCHIP_ACPI_DECLARE
+
 #else
 static inline int acpi_dev_get_property(struct acpi_device *adev,
 					const char *name, acpi_object_type type,
@@ -1101,6 +1144,13 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 		     (void *) data }
 
 #define acpi_probe_device_table(t)	({ int __r = 0; __r;})
+
+#define ACPI_DECLARE_DSDT_PROBE_ENTRY(name, hid, fn)			\
+	static const void *__acpi_probe_##name[]			\
+		__attribute__((unused))				\
+		 = { (void *) hid,					\
+		     (void *) fn }
+
 #endif
 
 #ifdef CONFIG_ACPI_TABLE_UPGRADE
diff --git a/include/linux/irqchip.h b/include/linux/irqchip.h
index 89c34b2..c2d0c12 100644
--- a/include/linux/irqchip.h
+++ b/include/linux/irqchip.h
@@ -29,6 +29,10 @@
 /*
  * This macro must be used by the different irqchip drivers to declare
  * the association between their version and their initialization function.
+ * Two syntaxes are supported depending on the table where the irqchip device
+ * is declared:
+ *
+ * - MADT irqchip syntax, which requires the following five arguments:
  *
  * @name: name that must be unique accross all IRQCHIP_ACPI_DECLARE of the
  * same file.
@@ -37,10 +41,17 @@
  *            Can be NULL.
  * @data: data to be checked by the validate function.
  * @fn: initialization function
+ *
+ * - DSDT irqchip syntax, which requires the following three arguments:
+ *
+ * @name: name that must be unique across all IRQCHIP_ACPI_DECLARE of the
+ * same file.
+ * @hid: _HID of the DSDT device
+ * @fn: initialization function
  */
-#define IRQCHIP_ACPI_DECLARE(name, subtable, validate, data, fn)	\
-	ACPI_DECLARE_PROBE_ENTRY(irqchip, name, ACPI_SIG_MADT, 		\
-				 subtable, validate, data, fn)
+
+#define IRQCHIP_ACPI_DECLARE(...)					\
+	__IRQCHIP_ACPI_DECLARE(__VA_ARGS__, MADT, _unused, DSDT)(__VA_ARGS__)
 
 #ifdef CONFIG_IRQCHIP
 void irqchip_init(void);
-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 2/2] irqchip: qcom: Add IRQ combiner driver

[Agustin Vega-Frias]

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.

Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
---
 drivers/irqchip/Kconfig             |   8 +
 drivers/irqchip/Makefile            |   1 +
 drivers/irqchip/qcom-irq-combiner.c | 332 ++++++++++++++++++++++++++++++++++++
 3 files changed, 341 insertions(+)
 create mode 100644 drivers/irqchip/qcom-irq-combiner.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 82b0b5d..05ecd91 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -279,3 +279,11 @@ config EZNPS_GIC
 config STM32_EXTI
 	bool
 	select IRQ_DOMAIN
+
+config QCOM_IRQ_COMBINER
+	bool "QCOM IRQ combiner support"
+	depends on ARCH_QCOM
+	select IRQ_DOMAIN
+	help
+	  Say yes here to add support for the IRQ combiner devices embedded
+	  in Qualcomm Technologies chips.
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e4dbfc8..1818a0b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -74,3 +74,4 @@ obj-$(CONFIG_LS_SCFG_MSI)		+= irq-ls-scfg-msi.o
 obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o
 obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o
 obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o
+obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o
diff --git a/drivers/irqchip/qcom-irq-combiner.c b/drivers/irqchip/qcom-irq-combiner.c
new file mode 100644
index 0000000..b117cd7
--- /dev/null
+++ b/drivers/irqchip/qcom-irq-combiner.c
@@ -0,0 +1,332 @@
+/* Copyright (c) 2015-2016, 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.
+ */
+
+#include <linux/acpi.h>
+#include <linux/err.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+
+#define REG_SIZE 32
+
+struct combiner_reg {
+	void __iomem *addr;
+	unsigned long mask;
+};
+
+struct combiner {
+	struct irq_chip     irq_chip;
+	struct irq_domain   *domain;
+	int                 parent_irq;
+	u32                 nirqs;
+	u32                 nregs;
+	struct combiner_reg regs[0];
+};
+
+static inline u32 irq_register(int irq)
+{
+	return irq / REG_SIZE;
+}
+
+static inline u32 irq_bit(int irq)
+{
+	return irq % REG_SIZE;
+
+}
+
+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++) {
+		int virq;
+		int hwirq;
+		u32 bit;
+		u32 status;
+
+		if (combiner->regs[reg].mask == 0)
+			continue;
+
+		status = readl_relaxed(combiner->regs[reg].addr);
+		status &= combiner->regs[reg].mask;
+
+		while (status) {
+			bit = __ffs(status);
+			status &= ~(1 << bit);
+			hwirq = irq_nr(reg, bit);
+			virq = irq_find_mapping(combiner->domain, hwirq);
+			if (virq >= 0)
+				generic_handle_irq(virq);
+
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+/*
+ * irqchip callbacks
+ */
+
+static void combiner_irq_chip_mask_irq(struct irq_data *data)
+{
+	struct combiner *combiner = irq_data_get_irq_chip_data(data);
+	struct combiner_reg *reg = combiner->regs + irq_register(data->hwirq);
+
+	clear_bit(irq_bit(data->hwirq), &reg->mask);
+}
+
+static void combiner_irq_chip_unmask_irq(struct irq_data *data)
+{
+	struct combiner *combiner = irq_data_get_irq_chip_data(data);
+	struct combiner_reg *reg = combiner->regs + irq_register(data->hwirq);
+
+	set_bit(irq_bit(data->hwirq), &reg->mask);
+}
+
+/*
+ * irq_domain_ops callbacks
+ */
+
+static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
+				   irq_hw_number_t hwirq)
+{
+	struct combiner *combiner = domain->host_data;
+
+	if (hwirq >= combiner->nirqs)
+		return -EINVAL;
+
+	irq_set_chip_and_handler(irq, &combiner->irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, combiner);
+	irq_set_parent(irq, combiner->parent_irq);
+	irq_set_noprobe(irq);
+	return 0;
+}
+
+static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+	irq_set_parent(irq, -1);
+}
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
+				  unsigned long *hwirq, unsigned int *type)
+{
+	if (is_acpi_node(fws->fwnode)) {
+		if (fws->param_count != 2)
+			return -EINVAL;
+
+		*hwirq = fws->param[0];
+		*type = fws->param[1];
+		return 0;
+	}
+
+	return -EINVAL;
+}
+#endif
+
+static const struct irq_domain_ops domain_ops = {
+	.map = combiner_irq_map,
+	.unmap = combiner_irq_unmap,
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+	.translate = combiner_irq_translate
+#endif
+};
+
+/*
+ * Device probing
+ */
+
+static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
+{
+	int *count = context;
+
+	if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		++(*count);
+	return AE_OK;
+}
+
+static int count_registers(struct acpi_device *adev)
+{
+	acpi_status status;
+	int count = 0;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     count_registers_cb, &count);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return count;
+}
+
+struct get_registers_context {
+	struct device *dev;
+	struct combiner *combiner;
+	int err;
+};
+
+static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
+{
+	struct get_registers_context *ctx = context;
+	struct acpi_resource_generic_register *reg;
+	phys_addr_t paddr;
+	void __iomem *vaddr;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		return AE_OK;
+
+	reg = &ares->data.generic_reg;
+	paddr = reg->address;
+	if ((reg->space_id != ACPI_SPACE_MEM) ||
+	    (reg->bit_offset != 0) ||
+	    (reg->bit_width > REG_SIZE)) {
+		dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
+		ctx->err = -EINVAL;
+		return AE_ERROR;
+	}
+
+	vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
+	if (IS_ERR(vaddr)) {
+		dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
+		ctx->err = PTR_ERR(vaddr);
+		return AE_ERROR;
+	}
+
+	ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
+	ctx->combiner->nirqs += reg->bit_width;
+	ctx->combiner->nregs++;
+	return AE_OK;
+}
+
+static int get_registers(struct acpi_device *adev, struct combiner *comb)
+{
+	acpi_status status;
+	struct get_registers_context ctx;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	ctx.dev = &adev->dev;
+	ctx.combiner = comb;
+	ctx.err = 0;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     get_registers_cb, &ctx);
+	if (ACPI_FAILURE(status))
+		return ctx.err;
+	return 0;
+}
+
+static acpi_status get_parent_irq_cb(struct acpi_resource *ares, void *context)
+{
+	int *irq = context;
+	struct acpi_resource_extended_irq *eirq;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
+		return AE_OK;
+
+	eirq = &ares->data.extended_irq;
+	*irq = acpi_irq_domain_register_irq(&eirq->resource_source,
+					    eirq->interrupts[0],
+					    eirq->triggering, eirq->polarity);
+	return AE_OK;
+}
+
+static int get_parent_irq(struct acpi_device *adev)
+{
+	acpi_status status;
+	int irq = -1;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     get_parent_irq_cb, &irq);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return irq;
+}
+
+static int __init combiner_probe(struct acpi_device *adev)
+{
+	struct combiner *combiner;
+	size_t alloc_sz;
+	u32 nregs;
+	int err;
+
+	nregs = count_registers(adev);
+	if (nregs <= 0) {
+		dev_err(&adev->dev, "Error reading register resources\n");
+		return -EINVAL;
+	}
+
+	alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
+	combiner = devm_kzalloc(&adev->dev, alloc_sz, GFP_KERNEL);
+	if (!combiner)
+		return -ENOMEM;
+
+	err = get_registers(adev, combiner);
+	if (err < 0)
+		return err;
+
+	combiner->parent_irq = get_parent_irq(adev);
+	if (combiner->parent_irq <= 0) {
+		dev_err(&adev->dev, "Error getting IRQ resource\n");
+		return -EINVAL;
+	}
+
+	combiner->domain = irq_domain_create_linear(
+		&adev->fwnode, combiner->nirqs, &domain_ops, combiner);
+	if (!combiner->domain)
+		/* Errors printed by irq_domain_create_linear */
+		return -ENODEV;
+
+	irq_set_chained_handler_and_data(combiner->parent_irq,
+					 combiner_handle_irq, combiner);
+	combiner->irq_chip.irq_mask = combiner_irq_chip_mask_irq;
+	combiner->irq_chip.irq_unmask = combiner_irq_chip_unmask_irq;
+	combiner->irq_chip.name = dev_name(&adev->dev);
+
+	dev_info(&adev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+		 combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
+	return 0;
+}
+
+IRQCHIP_ACPI_DECLARE(qcom_combiner, "QCOM80B1", combiner_probe);
-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 2/2] irqchip: qcom: Add IRQ combiner driver

[Agustin Vega-Frias]

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.

Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
---
 drivers/irqchip/Kconfig             |   8 +
 drivers/irqchip/Makefile            |   1 +
 drivers/irqchip/qcom-irq-combiner.c | 332 ++++++++++++++++++++++++++++++++++++
 3 files changed, 341 insertions(+)
 create mode 100644 drivers/irqchip/qcom-irq-combiner.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 82b0b5d..05ecd91 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -279,3 +279,11 @@ config EZNPS_GIC
 config STM32_EXTI
 	bool
 	select IRQ_DOMAIN
+
+config QCOM_IRQ_COMBINER
+	bool "QCOM IRQ combiner support"
+	depends on ARCH_QCOM
+	select IRQ_DOMAIN
+	help
+	  Say yes here to add support for the IRQ combiner devices embedded
+	  in Qualcomm Technologies chips.
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e4dbfc8..1818a0b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -74,3 +74,4 @@ obj-$(CONFIG_LS_SCFG_MSI)		+= irq-ls-scfg-msi.o
 obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o
 obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o
 obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o
+obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o
diff --git a/drivers/irqchip/qcom-irq-combiner.c b/drivers/irqchip/qcom-irq-combiner.c
new file mode 100644
index 0000000..b117cd7
--- /dev/null
+++ b/drivers/irqchip/qcom-irq-combiner.c
@@ -0,0 +1,332 @@
+/* Copyright (c) 2015-2016, 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.
+ */
+
+#include <linux/acpi.h>
+#include <linux/err.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+
+#define REG_SIZE 32
+
+struct combiner_reg {
+	void __iomem *addr;
+	unsigned long mask;
+};
+
+struct combiner {
+	struct irq_chip     irq_chip;
+	struct irq_domain   *domain;
+	int                 parent_irq;
+	u32                 nirqs;
+	u32                 nregs;
+	struct combiner_reg regs[0];
+};
+
+static inline u32 irq_register(int irq)
+{
+	return irq / REG_SIZE;
+}
+
+static inline u32 irq_bit(int irq)
+{
+	return irq % REG_SIZE;
+
+}
+
+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++) {
+		int virq;
+		int hwirq;
+		u32 bit;
+		u32 status;
+
+		if (combiner->regs[reg].mask == 0)
+			continue;
+
+		status = readl_relaxed(combiner->regs[reg].addr);
+		status &= combiner->regs[reg].mask;
+
+		while (status) {
+			bit = __ffs(status);
+			status &= ~(1 << bit);
+			hwirq = irq_nr(reg, bit);
+			virq = irq_find_mapping(combiner->domain, hwirq);
+			if (virq >= 0)
+				generic_handle_irq(virq);
+
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+/*
+ * irqchip callbacks
+ */
+
+static void combiner_irq_chip_mask_irq(struct irq_data *data)
+{
+	struct combiner *combiner = irq_data_get_irq_chip_data(data);
+	struct combiner_reg *reg = combiner->regs + irq_register(data->hwirq);
+
+	clear_bit(irq_bit(data->hwirq), &reg->mask);
+}
+
+static void combiner_irq_chip_unmask_irq(struct irq_data *data)
+{
+	struct combiner *combiner = irq_data_get_irq_chip_data(data);
+	struct combiner_reg *reg = combiner->regs + irq_register(data->hwirq);
+
+	set_bit(irq_bit(data->hwirq), &reg->mask);
+}
+
+/*
+ * irq_domain_ops callbacks
+ */
+
+static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
+				   irq_hw_number_t hwirq)
+{
+	struct combiner *combiner = domain->host_data;
+
+	if (hwirq >= combiner->nirqs)
+		return -EINVAL;
+
+	irq_set_chip_and_handler(irq, &combiner->irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, combiner);
+	irq_set_parent(irq, combiner->parent_irq);
+	irq_set_noprobe(irq);
+	return 0;
+}
+
+static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+	irq_set_parent(irq, -1);
+}
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
+				  unsigned long *hwirq, unsigned int *type)
+{
+	if (is_acpi_node(fws->fwnode)) {
+		if (fws->param_count != 2)
+			return -EINVAL;
+
+		*hwirq = fws->param[0];
+		*type = fws->param[1];
+		return 0;
+	}
+
+	return -EINVAL;
+}
+#endif
+
+static const struct irq_domain_ops domain_ops = {
+	.map = combiner_irq_map,
+	.unmap = combiner_irq_unmap,
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+	.translate = combiner_irq_translate
+#endif
+};
+
+/*
+ * Device probing
+ */
+
+static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
+{
+	int *count = context;
+
+	if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		++(*count);
+	return AE_OK;
+}
+
+static int count_registers(struct acpi_device *adev)
+{
+	acpi_status status;
+	int count = 0;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     count_registers_cb, &count);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return count;
+}
+
+struct get_registers_context {
+	struct device *dev;
+	struct combiner *combiner;
+	int err;
+};
+
+static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
+{
+	struct get_registers_context *ctx = context;
+	struct acpi_resource_generic_register *reg;
+	phys_addr_t paddr;
+	void __iomem *vaddr;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		return AE_OK;
+
+	reg = &ares->data.generic_reg;
+	paddr = reg->address;
+	if ((reg->space_id != ACPI_SPACE_MEM) ||
+	    (reg->bit_offset != 0) ||
+	    (reg->bit_width > REG_SIZE)) {
+		dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
+		ctx->err = -EINVAL;
+		return AE_ERROR;
+	}
+
+	vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
+	if (IS_ERR(vaddr)) {
+		dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
+		ctx->err = PTR_ERR(vaddr);
+		return AE_ERROR;
+	}
+
+	ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
+	ctx->combiner->nirqs += reg->bit_width;
+	ctx->combiner->nregs++;
+	return AE_OK;
+}
+
+static int get_registers(struct acpi_device *adev, struct combiner *comb)
+{
+	acpi_status status;
+	struct get_registers_context ctx;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	ctx.dev = &adev->dev;
+	ctx.combiner = comb;
+	ctx.err = 0;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     get_registers_cb, &ctx);
+	if (ACPI_FAILURE(status))
+		return ctx.err;
+	return 0;
+}
+
+static acpi_status get_parent_irq_cb(struct acpi_resource *ares, void *context)
+{
+	int *irq = context;
+	struct acpi_resource_extended_irq *eirq;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
+		return AE_OK;
+
+	eirq = &ares->data.extended_irq;
+	*irq = acpi_irq_domain_register_irq(&eirq->resource_source,
+					    eirq->interrupts[0],
+					    eirq->triggering, eirq->polarity);
+	return AE_OK;
+}
+
+static int get_parent_irq(struct acpi_device *adev)
+{
+	acpi_status status;
+	int irq = -1;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     get_parent_irq_cb, &irq);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return irq;
+}
+
+static int __init combiner_probe(struct acpi_device *adev)
+{
+	struct combiner *combiner;
+	size_t alloc_sz;
+	u32 nregs;
+	int err;
+
+	nregs = count_registers(adev);
+	if (nregs <= 0) {
+		dev_err(&adev->dev, "Error reading register resources\n");
+		return -EINVAL;
+	}
+
+	alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
+	combiner = devm_kzalloc(&adev->dev, alloc_sz, GFP_KERNEL);
+	if (!combiner)
+		return -ENOMEM;
+
+	err = get_registers(adev, combiner);
+	if (err < 0)
+		return err;
+
+	combiner->parent_irq = get_parent_irq(adev);
+	if (combiner->parent_irq <= 0) {
+		dev_err(&adev->dev, "Error getting IRQ resource\n");
+		return -EINVAL;
+	}
+
+	combiner->domain = irq_domain_create_linear(
+		&adev->fwnode, combiner->nirqs, &domain_ops, combiner);
+	if (!combiner->domain)
+		/* Errors printed by irq_domain_create_linear */
+		return -ENODEV;
+
+	irq_set_chained_handler_and_data(combiner->parent_irq,
+					 combiner_handle_irq, combiner);
+	combiner->irq_chip.irq_mask = combiner_irq_chip_mask_irq;
+	combiner->irq_chip.irq_unmask = combiner_irq_chip_unmask_irq;
+	combiner->irq_chip.name = dev_name(&adev->dev);
+
+	dev_info(&adev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+		 combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
+	return 0;
+}
+
+IRQCHIP_ACPI_DECLARE(qcom_combiner, "QCOM80B1", combiner_probe);
-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V4 1/2] ACPI: Add support for ResourceSource/IRQ domain mapping

[Timur Tabi]

Just a few nits:

Agustin Vega-Frias wrote:
> +int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
> +				 int trigger, int polarity)
> +{
> +	struct irq_fwspec fwspec;
> +	struct acpi_device *device;
> +	acpi_handle handle;
> +	acpi_status status;
> +	int ret;
> +
> +	if (source->string_length == 0)

Would (!source->string_length) be more meaningful?

> +		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
> +
> +	status = acpi_get_handle(NULL, source->string_ptr, &handle);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	device = acpi_bus_get_acpi_device(handle);
> +	if (!device)
> +		return -ENODEV;
> +
> +	if (acpi_irq_domain_ensure_probed(device))
> +		return -ENODEV;
> +
> +	fwspec.fwnode = &device->fwnode;
> +	fwspec.param[0] = hwirq;
> +	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
> +	fwspec.param_count = 2;
> +
> +	ret = irq_create_fwspec_mapping(&fwspec);
> +	acpi_bus_put_acpi_device(device);
> +	return ret;

Blank line before 'return'.

> -static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
> +static void acpi_dev_get_irqresource(struct resource *res, u32 hwirq,
> +				     struct acpi_resource_source *source,

This should probably be a 'const', because ...

> @@ -448,6 +449,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
>   {
>   	struct acpi_resource_irq *irq;
>   	struct acpi_resource_extended_irq *ext_irq;
> +	struct acpi_resource_source dummy = { 0, 0, NULL };

... then you can make this a static const, which will reduce code size 
and improve performance.

> @@ -1024,6 +1030,43 @@ struct acpi_probe_entry {
>   					  (&ACPI_PROBE_TABLE_END(t) -	\
>   					   &ACPI_PROBE_TABLE(t)));	\
>   	})
> +
> +#define ACPI_HID_LEN 9

Please add a comment for this.

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V4 1/2] ACPI: Add support for ResourceSource/IRQ domain mapping

[Timur Tabi]

Just a few nits:

Agustin Vega-Frias wrote:
> +int acpi_irq_domain_register_irq(struct acpi_resource_source *source, u32 hwirq,
> +				 int trigger, int polarity)
> +{
> +	struct irq_fwspec fwspec;
> +	struct acpi_device *device;
> +	acpi_handle handle;
> +	acpi_status status;
> +	int ret;
> +
> +	if (source->string_length == 0)

Would (!source->string_length) be more meaningful?

> +		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
> +
> +	status = acpi_get_handle(NULL, source->string_ptr, &handle);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	device = acpi_bus_get_acpi_device(handle);
> +	if (!device)
> +		return -ENODEV;
> +
> +	if (acpi_irq_domain_ensure_probed(device))
> +		return -ENODEV;
> +
> +	fwspec.fwnode = &device->fwnode;
> +	fwspec.param[0] = hwirq;
> +	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
> +	fwspec.param_count = 2;
> +
> +	ret = irq_create_fwspec_mapping(&fwspec);
> +	acpi_bus_put_acpi_device(device);
> +	return ret;

Blank line before 'return'.

> -static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
> +static void acpi_dev_get_irqresource(struct resource *res, u32 hwirq,
> +				     struct acpi_resource_source *source,

This should probably be a 'const', because ...

> @@ -448,6 +449,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
>   {
>   	struct acpi_resource_irq *irq;
>   	struct acpi_resource_extended_irq *ext_irq;
> +	struct acpi_resource_source dummy = { 0, 0, NULL };

... then you can make this a static const, which will reduce code size 
and improve performance.

> @@ -1024,6 +1030,43 @@ struct acpi_probe_entry {
>   					  (&ACPI_PROBE_TABLE_END(t) -	\
>   					   &ACPI_PROBE_TABLE(t)));	\
>   	})
> +
> +#define ACPI_HID_LEN 9

Please add a comment for this.

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.