mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 07:40:53 +07:00
0306741004
This adds aptional GPIO bit-bang based callback implementations for setting CLK, DATA and MODE L3 bus lines. It is added here to avoid possible duplicate implementations across users of the bus. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org>
139 lines
2.8 KiB
C
139 lines
2.8 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 <linux/device.h>
|
|
#include <linux/gpio.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(adap, 0);
|
|
udelay(adap->data_hold);
|
|
adap->setdat(adap, byte & 1);
|
|
udelay(adap->data_setup);
|
|
adap->setclk(adap, 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(adap, 0);
|
|
udelay(adap->mode);
|
|
}
|
|
adap->setmode(adap, 1);
|
|
udelay(adap->mode_setup);
|
|
sendbyte(adap, buf[i]);
|
|
}
|
|
}
|
|
|
|
int l3_write(struct l3_pins *adap, u8 addr, u8 *data, int len)
|
|
{
|
|
adap->setclk(adap, 1);
|
|
adap->setdat(adap, 1);
|
|
adap->setmode(adap, 1);
|
|
udelay(adap->mode);
|
|
|
|
adap->setmode(adap, 0);
|
|
udelay(adap->mode_setup);
|
|
sendbyte(adap, addr);
|
|
udelay(adap->mode_hold);
|
|
|
|
sendbytes(adap, data, len);
|
|
|
|
adap->setclk(adap, 1);
|
|
adap->setdat(adap, 1);
|
|
adap->setmode(adap, 0);
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(l3_write);
|
|
|
|
|
|
static void l3_set_clk(struct l3_pins *adap, int val)
|
|
{
|
|
gpio_set_value(adap->gpio_clk, val);
|
|
}
|
|
|
|
static void l3_set_data(struct l3_pins *adap, int val)
|
|
{
|
|
gpio_set_value(adap->gpio_data, val);
|
|
}
|
|
|
|
static void l3_set_mode(struct l3_pins *adap, int val)
|
|
{
|
|
gpio_set_value(adap->gpio_mode, val);
|
|
}
|
|
|
|
int l3_set_gpio_ops(struct device *dev, struct l3_pins *adap)
|
|
{
|
|
int ret;
|
|
|
|
if (!adap->use_gpios)
|
|
return -EINVAL;
|
|
|
|
ret = devm_gpio_request_one(dev, adap->gpio_data,
|
|
GPIOF_OUT_INIT_LOW, "l3_data");
|
|
if (ret < 0)
|
|
return ret;
|
|
adap->setdat = l3_set_data;
|
|
|
|
ret = devm_gpio_request_one(dev, adap->gpio_clk,
|
|
GPIOF_OUT_INIT_LOW, "l3_clk");
|
|
if (ret < 0)
|
|
return ret;
|
|
adap->setclk = l3_set_clk;
|
|
|
|
ret = devm_gpio_request_one(dev, adap->gpio_mode,
|
|
GPIOF_OUT_INIT_LOW, "l3_mode");
|
|
if (ret < 0)
|
|
return ret;
|
|
adap->setmode = l3_set_mode;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(l3_set_gpio_ops);
|
|
|
|
MODULE_DESCRIPTION("L3 bit-banging driver");
|
|
MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
|
|
MODULE_LICENSE("GPL");
|