1/*
  2 * Copyright 2013 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 */
 14
 15#ifndef _GXIO_UART_H_
 16#define _GXIO_UART_H_
 17
 18#include "common.h"
 19
 20#include <hv/drv_uart_intf.h>
 21#include <hv/iorpc.h>
 22
 23/*
 24 *
 25 * An API for manipulating UART interface.
 26 */
 27
 28/*
 29 *
 30 * The Rshim allows access to the processor's UART interface.
 31 */
 32
 33/* A context object used to manage UART resources. */
 34typedef struct {
 35
 36	/* File descriptor for calling up to the hypervisor. */
 37	int fd;
 38
 39	/* The VA at which our MMIO registers are mapped. */
 40	char *mmio_base;
 41
 42} gxio_uart_context_t;
 43
 44/* Request UART interrupts.
 45 *
 46 *  Request that interrupts be delivered to a tile when the UART's
 47 *  Receive FIFO is written, or the Write FIFO is read.
 48 *
 49 * @param context Pointer to a properly initialized gxio_uart_context_t.
 50 * @param bind_cpu_x X coordinate of CPU to which interrupt will be delivered.
 51 * @param bind_cpu_y Y coordinate of CPU to which interrupt will be delivered.
 52 * @param bind_interrupt IPI interrupt number.
 53 * @param bind_event Sub-interrupt event bit number; a negative value can
 54 *  disable the interrupt.
 55 * @return Zero if all of the requested UART events were successfully
 56 *  configured to interrupt.
 57 */
 58extern int gxio_uart_cfg_interrupt(gxio_uart_context_t *context,
 59				   int bind_cpu_x,
 60				   int bind_cpu_y,
 61				   int bind_interrupt, int bind_event);
 62
 63/* Initialize a UART context.
 64 *
 65 *  A properly initialized context must be obtained before any of the other
 66 *  gxio_uart routines may be used.
 67 *
 68 * @param context Pointer to a gxio_uart_context_t, which will be initialized
 69 *  by this routine, if it succeeds.
 70 * @param uart_index Index of the UART to use.
 71 * @return Zero if the context was successfully initialized, else a
 72 *  GXIO_ERR_xxx error code.
 73 */
 74extern int gxio_uart_init(gxio_uart_context_t *context, int uart_index);
 75
 76/* Destroy a UART context.
 77 *
 78 *  Once destroyed, a context may not be used with any gxio_uart routines
 79 *  other than gxio_uart_init().  After this routine returns, no further
 80 *  interrupts requested on this context will be delivered.  The state and
 81 *  configuration of the pins which had been attached to this context are
 82 *  unchanged by this operation.
 83 *
 84 * @param context Pointer to a gxio_uart_context_t.
 85 * @return Zero if the context was successfully destroyed, else a
 86 *  GXIO_ERR_xxx error code.
 87 */
 88extern int gxio_uart_destroy(gxio_uart_context_t *context);
 89
 90/* Write UART register.
 91 * @param context Pointer to a gxio_uart_context_t.
 92 * @param offset UART register offset.
 93 * @param word Data will be wrote to UART reigister.
 94 */
 95extern void gxio_uart_write(gxio_uart_context_t *context, uint64_t offset,
 96			    uint64_t word);
 97
 98/* Read UART register.
 99 * @param context Pointer to a gxio_uart_context_t.
100 * @param offset UART register offset.
101 * @return Data read from UART register.
102 */
103extern uint64_t gxio_uart_read(gxio_uart_context_t *context, uint64_t offset);
104
105#endif /* _GXIO_UART_H_ */