mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
92 lines
1.8 KiB
C
92 lines
1.8 KiB
C
|
/*
|
||
|
|
* L3 code
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008, Christian Pellegrin <chripell@evolware.org>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License version 2 as
|
||
|
|
* published by the Free Software Foundation.
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* based on:
|
||
|
|
*
|
||
|
|
* L3 bus algorithm module.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2001 Russell King, All Rights Reserved.
|
||
|
|
*
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/delay.h>
|
||
|
|
|
||
|
|
#include <sound/l3.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Send one byte of data to the chip. Data is latched into the chip on
|
||
|
|
* the rising edge of the clock.
|
||
|
|
*/
|
||
|
|
static void sendbyte(struct l3_pins *adap, unsigned int byte)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = 0; i < 8; i++) {
|
||
|
|
adap->setclk(0);
|
||
|
|
udelay(adap->data_hold);
|
||
|
|
adap->setdat(byte & 1);
|
||
|
|
udelay(adap->data_setup);
|
||
|
|
adap->setclk(1);
|
||
|
|
udelay(adap->clock_high);
|
||
|
|
byte >>= 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Send a set of bytes to the chip. We need to pulse the MODE line
|
||
|
|
* between each byte, but never at the start nor at the end of the
|
||
|
|
* transfer.
|
||
|
|
*/
|
||
|
|
static void sendbytes(struct l3_pins *adap, const u8 *buf,
|
||
|
|
int len)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = 0; i < len; i++) {
|
||
|
|
if (i) {
|
||
|
|
udelay(adap->mode_hold);
|
||
|
|
adap->setmode(0);
|
||
|
|
udelay(adap->mode);
|
||
|
|
}
|
||
|
|
adap->setmode(1);
|
||
|
|
udelay(adap->mode_setup);
|
||
|
|
sendbyte(adap, buf[i]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int l3_write(struct l3_pins *adap, u8 addr, u8 *data, int len)
|
||
|
|
{
|
||
|
|
adap->setclk(1);
|
||
|
|
adap->setdat(1);
|
||
|
|
adap->setmode(1);
|
||
|
|
udelay(adap->mode);
|
||
|
|
|
||
|
|
adap->setmode(0);
|
||
|
|
udelay(adap->mode_setup);
|
||
|
|
sendbyte(adap, addr);
|
||
|
|
udelay(adap->mode_hold);
|
||
|
|
|
||
|
|
sendbytes(adap, data, len);
|
||
|
|
|
||
|
|
adap->setclk(1);
|
||
|
|
adap->setdat(1);
|
||
|
|
adap->setmode(0);
|
||
|
|
|
||
|
|
return len;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(l3_write);
|
||
|
|
|
||
|
|
MODULE_DESCRIPTION("L3 bit-banging driver");
|
||
|
|
MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
|
||
|
|
MODULE_LICENSE("GPL");
|