/*
* Copyright 2013 Tilera Corporation. 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
* as published by the Free Software Foundation, version 2.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/

#ifndef _GXIO_UART_H_
#define _GXIO_UART_H_

#include "common.h"

#include <hv/drv_uart_intf.h>
#include <hv/iorpc.h>

/*
*
* An API for manipulating UART interface.
*/

/*
*
* The Rshim allows access to the processor's UART interface.
*/

/* A context object used to manage UART resources. */
typedef struct {

/* File descriptor for calling up to the hypervisor. */
int fd;

/* The VA at which our MMIO registers are mapped. */
char *mmio_base;

} gxio_uart_context_t;

/* Request UART interrupts.
*
* Request that interrupts be delivered to a tile when the UART's
* Receive FIFO is written, or the Write FIFO is read.
*
* @param context Pointer to a properly initialized gxio_uart_context_t.
* @param bind_cpu_x X coordinate of CPU to which interrupt will be delivered.
* @param bind_cpu_y Y coordinate of CPU to which interrupt will be delivered.
* @param bind_interrupt IPI interrupt number.
* @param bind_event Sub-interrupt event bit number; a negative value can
* disable the interrupt.
* @return Zero if all of the requested UART events were successfully
* configured to interrupt.
*/
extern int gxio_uart_cfg_interrupt(gxio_uart_context_t *context,
int bind_cpu_x,
int bind_cpu_y,
int bind_interrupt, int bind_event);

/* Initialize a UART context.
*
* A properly initialized context must be obtained before any of the other
* gxio_uart routines may be used.
*
* @param context Pointer to a gxio_uart_context_t, which will be initialized
* by this routine, if it succeeds.
* @param uart_index Index of the UART to use.
* @return Zero if the context was successfully initialized, else a
* GXIO_ERR_xxx error code.
*/
extern int gxio_uart_init(gxio_uart_context_t *context, int uart_index);

/* Destroy a UART context.
*
* Once destroyed, a context may not be used with any gxio_uart routines
* other than gxio_uart_init(). After this routine returns, no further
* interrupts requested on this context will be delivered. The state and
* configuration of the pins which had been attached to this context are
* unchanged by this operation.
*
* @param context Pointer to a gxio_uart_context_t.
* @return Zero if the context was successfully destroyed, else a
* GXIO_ERR_xxx error code.
*/
extern int gxio_uart_destroy(gxio_uart_context_t *context);

/* Write UART register.
* @param context Pointer to a gxio_uart_context_t.
* @param offset UART register offset.
* @param word Data will be wrote to UART reigister.
*/
extern void gxio_uart_write(gxio_uart_context_t *context, uint64_t offset,
uint64_t word);

/* Read UART register.
* @param context Pointer to a gxio_uart_context_t.
* @param offset UART register offset.
* @return Data read from UART register.
*/
extern uint64_t gxio_uart_read(gxio_uart_context_t *context, uint64_t offset);

#endif /* _GXIO_UART_H_ */