/*
* Copyright (c) 2011 Jiri Michalec
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @file
*
* General functions and structures used in rtl8139 driver
*/
#include "general.h"
#include <mem.h>
#include <errno.h>
#include <stdint.h>
/** Copy block of the memory from wrapped source buffer.
*
* Start on the specific offset in the source buffer and * copy data_size bytes
* - continue from the buffer start after getting the end
*
* @param dest The destination memory
* @param src_begin The begin of the source buffer
* @param src_offset The offset in the source buffer to start copy
* @param src_size The source buffer size
* @param data_size The amount of data to copy
*
* @return NULL if the error occures, dest if succeed
*/
void *rtl8139_memcpy_wrapped(void *dest, const void *src, size_t src_offset,
size_t src_size, size_t data_size)
{
src_offset %= src_size;
if (data_size > src_size)
return NULL;
size_t to_src_end = src_size - src_offset;
if (data_size <= to_src_end) {
return memcpy(dest, src + src_offset, data_size);
}
size_t rem_size = data_size - to_src_end;
/*
* First copy the end part of the data (from the source begining),
* then copy the begining
*/
memcpy(dest + to_src_end, src, rem_size);
return memcpy(dest, src + src_offset, to_src_end);
}
/** Initialize the timer register structures
*
* The structure will be initialized to the state that the first call of
* rtl8139_timer_act_step function will be the period expiration
*
* @param ta The timer structure
* @param timer_freq The timer frequency in kHz
* @param time The requested time
*
* @return EOK if succeed, error code otherwise
*/
errno_t rtl8139_timer_act_init(rtl8139_timer_act_t *ta, uint32_t timer_freq,
const struct timespec *time)
{
if (!ta || timer_freq == 0 || !time)
return EINVAL;
memset(ta, 0, sizeof(rtl8139_timer_act_t));
uint32_t tics_per_ms = timer_freq;
uint32_t seconds_in_reg = UINT32_MAX / (tics_per_ms * 1000);
ta->full_val = seconds_in_reg * tics_per_ms * 1000;
struct timespec remains = *time;
ta->full_skips = remains.tv_sec / seconds_in_reg;
remains.tv_sec = remains.tv_sec % seconds_in_reg;
if (NSEC2USEC(remains.tv_nsec) > RTL8139_USEC_IN_SEC) {
remains.tv_sec += NSEC2USEC(remains.tv_nsec) / RTL8139_USEC_IN_SEC;
remains.tv_nsec = NSEC2USEC(remains.tv_nsec) % RTL8139_USEC_IN_SEC;
/* it can be increased above seconds_in_reg again */
ta->full_skips += remains.tv_sec / seconds_in_reg;
remains.tv_sec = remains.tv_sec % seconds_in_reg;
}
ta->last_val = SEC2MSEC(remains.tv_sec) + NSEC2MSEC(remains.tv_nsec);
ta->last_val *= tics_per_ms;
/* Force inital setting in the next step */
ta->full_skips_remains = 0;
ta->last_run = 1;
return EOK;
}
/** Make one step timer step
*
* @param ta Timer structure
* @param new_reg[out] Register value to set
*
* @return Nonzero if whole period expired, zero if part of period expired
*/
int rtl8139_timer_act_step(rtl8139_timer_act_t *ta, uint32_t *new_reg)
{
uint32_t next_val = 0;
int expired = 0;
if (ta->last_run || (ta->last_val == 0 && ta->full_skips_remains == 0)) {
ta->full_skips_remains = ta->full_skips;
ta->last_run = 0;
expired = 1;
}
if (ta->full_skips_remains > 0) {
next_val = ta->full_val;
ta->full_skips_remains--;
} else {
next_val = ta->last_val;
ta->last_run = 1;
}
if (new_reg)
*new_reg = next_val;
return expired;
}