mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-18 18:59:44 +00:00
1a4596601f
Signed-off-by: Wolfgang Denk <wd@denx.de> [trini: Fixup common/cmd_io.c] Signed-off-by: Tom Rini <trini@ti.com>
94 lines
1.7 KiB
C
94 lines
1.7 KiB
C
/*
|
|
* (C) Copyright 2009
|
|
* Detlev Zundel, DENX Software Engineering, dzu@denx.de.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#define TWS_IMPLEMENTATION
|
|
#include <common.h>
|
|
|
|
/*=====================================================================*/
|
|
/* Public Functions */
|
|
/*=====================================================================*/
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Read bits
|
|
*/
|
|
int tws_read(uchar *buffer, int len)
|
|
{
|
|
int rem = len;
|
|
uchar accu, shift;
|
|
|
|
debug("tws_read: buffer %p len %d\n", buffer, len);
|
|
|
|
/* Configure the data pin for input */
|
|
tws_data_config_output(0);
|
|
|
|
/* Disable WR, i.e. setup a read */
|
|
tws_wr(0);
|
|
udelay(1);
|
|
|
|
/* Rise CE */
|
|
tws_ce(1);
|
|
udelay(1);
|
|
|
|
for (; rem > 0; ) {
|
|
for (shift = 0, accu = 0;
|
|
(rem > 0) && (shift < 8);
|
|
rem--, shift++) {
|
|
tws_clk(1);
|
|
udelay(10);
|
|
accu |= (tws_data_read() << shift); /* LSB first */
|
|
tws_clk(0);
|
|
udelay(10);
|
|
}
|
|
*buffer++ = accu;
|
|
}
|
|
|
|
/* Lower CE */
|
|
tws_ce(0);
|
|
|
|
return len - rem;
|
|
}
|
|
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Write bits
|
|
*/
|
|
int tws_write(uchar *buffer, int len)
|
|
{
|
|
int rem = len;
|
|
uchar accu, shift;
|
|
|
|
debug("tws_write: buffer %p len %d\n", buffer, len);
|
|
|
|
/* Configure the data pin for output */
|
|
tws_data_config_output(1);
|
|
|
|
/* Enable WR, i.e. setup a write */
|
|
tws_wr(1);
|
|
udelay(1);
|
|
|
|
/* Rise CE */
|
|
tws_ce(1);
|
|
udelay(1);
|
|
|
|
for (; rem > 0; ) {
|
|
for (shift = 0, accu = *buffer++;
|
|
(rem > 0) && (shift < 8);
|
|
rem--, shift++) {
|
|
tws_data(accu & 0x01); /* LSB first */
|
|
tws_clk(1);
|
|
udelay(10);
|
|
tws_clk(0);
|
|
udelay(10);
|
|
accu >>= 1;
|
|
}
|
|
}
|
|
|
|
/* Lower CE */
|
|
tws_ce(0);
|
|
|
|
return len - rem;
|
|
}
|