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>
diff --git a/drivers/shared_irq/shared_irq.c b/drivers/shared_irq/shared_irq.c
new file mode 100644
index 0000000..d8ee000
--- /dev/null
+++ b/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 */
+
