drivers: add shared interrupt driver

This driver allows multiple drivers to share a common interrupt
line. This functionality is required on system that conform to the PC
interrupt structure.  In the context of Zephyr this is needed for
SOC's that have their I/O IP blocks behind a PCI interface. Due to the
limited number of interrupt lines provided by the PCI interface
multiple IP blocks may be configured to share an interrupt line.

Drivers that share interrupts  must be modified to *not* register their
own interrupt service routine as part of their configuration/initialization
but instead bind to the correct instance of this driver by name, then
register their interrupt service routine with this driver.

Change-Id: I57b517b97ebeabce484ba53c8f940da993cb391d
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>

arch/x86/core/driver_static_irq_stubs.S

@@ -79,6 +79,16 @@ by x86 platforms.
 #endif /* CONFIG_GPIO_DW_1 */
 #endif /* CONFIG_GPIO_DW */
 
+#if defined(CONFIG_SHARED_IRQ)
+#if CONFIG_SHARED_IRQ_0
+	ioapic_mkstub shared_irq_0 shared_irq_isr_0
+#endif /* CONFIG_SHIRQ_0 */
+
+#if CONFIG_SHARED_IRQ_1
+	ioapic_mkstub shared_irq_1 shared_irq_isr_1
+#endif /* CONFIG_SHARED_IRQ_1 */
+#endif /* CONFIG_SHARED_IRQ */
+
 #if defined(CONFIG_SPI_INTEL)
 #if defined(CONFIG_SPI_INTEL_PORT_0)
 	ioapic_mkstub spi_intel_irq_port_0 spi_intel_isr_0

drivers/Kconfig

@@ -51,6 +51,8 @@ source "drivers/pci/Kconfig"
 
 source "drivers/gpio/Kconfig"
 
+source "drivers/shared_irq/Kconfig"
+
 source "drivers/spi/Kconfig"
 
 source "drivers/i2c/Kconfig"

drivers/Makefile

@@ -10,6 +10,7 @@ obj-y += interrupt_controller/
 obj-$(CONFIG_PCI) += pci/
 obj-$(CONFIG_BLUETOOTH) += bluetooth/
 obj-$(CONFIG_UART_SIMPLE) += simple/
+obj-$(CONFIG_SHARED_IRQ) += shared_irq/
 obj-$(CONFIG_SPI) += spi/
 obj-$(CONFIG_GPIO) += gpio/
 obj-$(CONFIG_I2C) += i2c/

drivers/shared_irq/Kconfig

@@ -0,0 +1,67 @@
+config SHARED_IRQ
+	bool
+	prompt "Shared interrupt driver"
+	default n
+	help
+	 Include shared interrupt support in system. Shared interrupt
+	 support is NOT required in most systems. If in doubt answer no.
+
+config SHARED_IRQ_NUM_CLIENTS
+	int
+	depends on SHARED_IRQ
+	prompt "The number of clients per instance"
+	default 5
+	help
+	 Configures the maximum nuber of clients allowed per shared
+	 instance of the shared interrupt driver. To conserve RAM set
+	 this value to the lowest practical value.
+
+config SHARED_IRQ_0
+	bool "Shared interrupt instance 0"
+	depends on SHARED_IRQ
+	help
+	 Provide an instance of the shared interrupt driver when system
+	 configuration requires that multiple devices share an interrupt.
+
+config SHARED_IRQ_0_NAME
+	string "Select a name for the device"
+	depends on SHARED_IRQ_0
+	default "SHARED_IRQ0"
+
+config SHARED_IRQ_0_IRQ
+	int "instance 0 interrupt"
+	depends on SHARED_IRQ_0
+	help
+	 System interrupt number to be handled by this instance of the driver.
+
+config SHARED_IRQ_0_PRI
+	int "instance 0 interrupt priority"
+	default 0
+	depends on SHARED_IRQ_0
+	help
+	 Prioity of shared interrupt handler for the configured interrupt
+
+config SHARED_IRQ_1
+	bool "Shared interrupt instance 1"
+	select SHARED_IRQ
+	help
+	 Provide an instance of the shared interrupt driver when system
+	 configuration requires that multiple devices share an interrupt.
+
+config SHARED_IRQ_1_NAME
+	string "Select a name for the device"
+	depends on SHARED_IRQ_1
+	default "SHARED_IRQ1"
+
+config SHARED_IRQ_1_IRQ
+	int "instance 1 interrupt"
+	depends on SHARED_IRQ_1
+	help
+	 System interrupt number to be handled by this instance of the driver.
+
+config SHARED_IRQ_1_PRI
+	int "instance 1 interrupt priority"
+	default 0
+	depends on SHARED_IRQ_0
+	help
+	 Prioity of shared interrupt handler for the configured interrupt

drivers/shared_irq/Makefile

@@ -0,0 +1,3 @@
+ccflags-y +=-I$(srctree)/drivers
+
+obj-$(CONFIG_SHARED_IRQ) = shared_irq.o

drivers/shared_irq/shared_irq.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1) Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2) Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3) Neither the name of Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <nanokernel.h>
+#include <device.h>
+#include <shared_irq.h>
+#include <init.h>
+#include <board.h>
+#include <sys_io.h>
+
+/**
+ *  @brief Register a device ISR
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_func Pointer to the ISR function for the device.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static int isr_register(struct device *dev, isr_t isr_func,
+				 struct device *isr_dev)
+{
+	struct shared_irq_runtime *clients = dev->driver_data;
+	struct shared_irq_config *config = dev->config->config_info;
+	uint32_t i;
+
+	for (i = 0; i < config->client_count; i++) {
+		if (!clients->client[i].isr_dev) {
+			clients->client[i].isr_dev = isr_dev;
+			clients->client[i].isr_func = isr_func;
+			return DEV_OK;
+		}
+	}
+	return DEV_FAIL;
+}
+
+/**
+ *  @brief Enable ISR for device
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static inline int enable(struct device *dev, struct device *isr_dev)
+{
+	struct shared_irq_runtime *clients = dev->driver_data;
+	struct shared_irq_config *config = dev->config->config_info;
+	uint32_t i;
+
+	for (i = 0; i < config->client_count; i++) {
+		if (clients->client[i].isr_dev == isr_dev) {
+			clients->client[i].enabled = 1;
+			irq_enable(config->irq_num);
+			return DEV_OK;
+		}
+	}
+	return DEV_FAIL;
+}
+
+static int last_enabled_isr(struct shared_irq_runtime *clients, int count)
+{
+	uint32_t i;
+
+	for (i = 0; i < count; i++) {
+		if (clients->client[i].enabled) {
+			return 0;
+		}
+	}
+	return 1;
+}
+/**
+ *  @brief Disable ISR for device
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static inline int disable(struct device *dev, struct device *isr_dev)
+{
+	struct shared_irq_runtime *clients = dev->driver_data;
+	struct shared_irq_config *config = dev->config->config_info;
+	uint32_t i;
+
+	for (i = 0; i < config->client_count; i++) {
+		if (clients->client[i].isr_dev == isr_dev) {
+			clients->client[i].enabled = 0;
+			if (last_enabled_isr(clients, config->client_count)) {
+				irq_disable(config->irq_num);
+			}
+			return DEV_OK;
+		}
+	}
+	return DEV_FAIL;
+}
+
+void shared_irq_isr(struct device *dev)
+{
+	struct shared_irq_runtime *clients = dev->driver_data;
+	struct shared_irq_config *config = dev->config->config_info;
+	uint32_t i;
+
+	for (i = 0; i < config->client_count; i++) {
+		if (clients->client[i].isr_dev) {
+			clients->client[i].isr_func(clients->client[i].isr_dev);
+		}
+	}
+}
+
+static struct shared_irq_driver_api api_funcs = {
+	.isr_register = isr_register,
+	.enable = enable,
+	.disable = disable,
+};
+
+
+int shared_irq_initialize(struct device *dev)
+{
+	struct shared_irq_config *config = dev->config->config_info;
+
+	dev->driver_api = &api_funcs;
+	config->config(dev);
+
+	return 0;
+}
+
+#if CONFIG_SHARED_IRQ_0
+void shared_irq_config_0_irq(struct device *port);
+
+struct shared_irq_config shared_irq_config_0 = {
+	.irq_num = CONFIG_SHARED_IRQ_0_IRQ,
+	.client_count = CONFIG_SHARED_IRQ_NUM_CLIENTS,
+	.config = shared_irq_config_0_irq
+};
+
+struct shared_irq_runtime shared_irq_0_runtime;
+
+DECLARE_DEVICE_INIT_CONFIG(shared_irq_0, CONFIG_SHARED_IRQ_0_NAME,
+			   shared_irq_initialize, &shared_irq_config_0);
+pre_kernel_early_init(shared_irq_0, &shared_irq_0_runtime);
+
+IRQ_CONNECT_STATIC(shared_irq_0, CONFIG_SHARED_IRQ_0_IRQ,
+		   CONFIG_SHARED_IRQ_0_PRI, shared_irq_isr_0, 0);
+
+void shared_irq_config_0_irq(struct device *port)
+{
+	struct shared_irq_config *config = port->config->config_info;
+
+	IRQ_CONFIG(shared_irq_0, config->irq_num);
+}
+
+void shared_irq_isr_0(void *unused)
+{
+	shared_irq_isr(&__initconfig_shared_irq_01);
+}
+
+#endif /* CONFIG_SHARED_IRQ_0 */
+
+#if CONFIG_SHARED_IRQ_1
+void shared_irq_config_1_irq(struct device *port);
+
+struct shared_irq_config shared_irq_config_1 = {
+	.irq_num = CONFIG_SHARED_IRQ_1_IRQ,
+	.client_count = CONFIG_SHARED_IRQ_NUM_CLIENTS,
+	.config = shared_irq_config_1_irq
+};
+
+struct shared_irq_runtime shared_irq_1_runtime;
+
+DECLARE_DEVICE_INIT_CONFIG(shared_irq_1, CONFIG_SHARED_IRQ_1_NAME,
+			   shared_irq_initialize, &shared_irq_config_1);
+pre_kernel_early_init(shared_irq_1, &shared_irq_1_runtime);
+
+IRQ_CONNECT_STATIC(shared_irq_1, CONFIG_SHARED_IRQ_1_IRQ,
+		   CONFIG_SHARED_IRQ_1_PRI, shared_irq_isr_1, 0);
+
+void shared_irq_config_1_irq(struct device *port)
+{
+	struct shared_irq_config *config = port->config->config_info;
+
+	IRQ_CONFIG(shared_irq_1, config->irq_num);
+}
+
+void shared_irq_isr_1(void *unused)
+{
+	shared_irq_isr(&__initconfig_shared_irq_11);
+}
+
+#endif /* CONFIG_SHARED_IRQ_1 */
+

include/shared_irq.h

@@ -0,0 +1,114 @@
+/* shared_irq - Shared interrupt driver */
+
+/*
+ * Copyright (c) 2015 Intel corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1) Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2) Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3) Neither the name of Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _SHIRQ_H_
+#define _SHIRQ_H_
+
+#include <autoconf.h>
+
+typedef int (*isr_t)(struct device *dev);
+
+/* driver API definition */
+typedef int (*shared_irq_register_t)(struct device *dev,
+				isr_t isr_func,
+				struct device *isr_dev);
+typedef int (*shared_irq_enable_t)(struct device *dev, struct device *isr_dev);
+typedef int (*shared_irq_disable_t)(struct device *dev, struct device *isr_dev);
+
+struct shared_irq_driver_api {
+	shared_irq_register_t isr_register;
+	shared_irq_enable_t enable;
+	shared_irq_disable_t disable;
+};
+
+extern int shared_irq_initialize(struct device *port);
+
+typedef void (*shared_irq_config_irq_t)(struct device *port);
+
+struct shared_irq_config {
+	uint32_t irq_num;
+	shared_irq_config_irq_t config;
+	uint32_t client_count;
+};
+
+struct shared_irq_client {
+	struct device *isr_dev;
+	isr_t isr_func;
+	uint32_t enabled;
+};
+
+struct shared_irq_runtime {
+	struct shared_irq_client client[CONFIG_SHARED_IRQ_NUM_CLIENTS];
+};
+
+/**
+ *  @brief Register a device ISR
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_func Pointer to the ISR function for the device.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static inline int shared_irq_isr_register(struct device *dev, isr_t isr_func,
+				 struct device *isr_dev)
+{
+	struct shared_irq_driver_api *api;
+
+	api = (struct shared_irq_driver_api *) dev->driver_api;
+	return api->isr_register(dev, isr_func, isr_dev);
+}
+
+/**
+ *  @brief Enable ISR for device
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static inline int shared_irq_enable(struct device *dev, struct device *isr_dev)
+{
+	struct shared_irq_driver_api *api;
+
+	api = (struct shared_irq_driver_api *) dev->driver_api;
+	return api->enable(dev, isr_dev);
+}
+
+/**
+ *  @brief Disable ISR for device
+ *  @param dev Pointer to device structure for SHARED_IRQ driver instance.
+ *  @param isr_dev Pointer to the device that will service the interrupt.
+ */
+static inline int shared_irq_disable(struct device *dev, struct device *isr_dev)
+{
+	struct shared_irq_driver_api *api;
+
+	api = (struct shared_irq_driver_api *) dev->driver_api;
+	return api->disable(dev, isr_dev);
+}
+
+#endif /* _SHARED_IRQ_H_ */