include/drivers/console/ipi_console.h

/* ipi_console.c - Console messages to/from another processor */

/*
 * Copyright (c) 2015 Intel Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _IPI_CONSOLE_H_
#define _IPI_CONSOLE_H_

#include <nanokernel.h>
#include <device.h>
#include <misc/ring_buffer.h>

#define IPI_CONSOLE_STDOUT	(1 << 0)
#define IPI_CONSOLE_PRINTK	(1 << 1)

/* Good way to determine these numbers other than trial-and-error?
 * using printf() in the fiber seems to require a lot more stack space */
#define IPI_CONSOLE_STACK_SIZE		512
#define IPI_CONSOLE_PRI			2

struct ipi_console_receiver_config_info {
	/** Name of the low-level IPI driver to bind to */
	char *bind_to;

	/** Stack for the receiver's fiber, which prints out messages as
	 * they come in. Should be sized IPI_CONSOLE_STACK_SIZE */
	char *fiber_stack;

	/** Ring buffer data area for stashing characters from the interrupt
	 * callback */
	uint32_t *ring_buf_data;

	/** Size of ring_buf_data in 32-bit chunks */
	unsigned int rb_size32;

	/** Line buffer for incoming messages, characters accumulate here
	 * and then are sent to printk() once full (including a trailing NULL)
	 * or a carriage return seen */
	char *line_buf;

	/** Size in bytes of the line buffer. Must be at least 2 */
	unsigned int lb_size;

	/** Destination for received console messages, one of
	 * IPI_CONSOLE_STDOUT or IPI_CONSOLE_PRINTK */
	unsigned int flags;
};

struct ipi_console_receiver_runtime_data {
	/** Buffer for received bytes from the low-level IPI device */
	struct ring_buf rb;

	/** Semaphore to wake up the fiber to print out messages */
	struct nano_sem sem;

	/** pointer to the bound low-level IPI device */
	struct device *ipi_device;
};

struct ipi_console_sender_config_info {
	/** Name of the low-level driver to bind to */
	char *bind_to;

	/** Source of messages to forward, hooks will be installed.
	 * Can be IPI_CONSOLE_STDOUT, IPI_CONSOLE_PRINTK, or both */
	int flags;
};

#if CONFIG_IPI_CONSOLE_RECEIVER
int ipi_console_receiver_init(struct device *d);
#endif

#if CONFIG_IPI_CONSOLE_SENDER
int ipi_console_sender_init(struct device *d);
#endif

#endif /* _IPI_CONSOLE_H_ */