mirror of https://gitee.com/openkylin/linux.git
158 lines
3.7 KiB
C
158 lines
3.7 KiB
C
|
/*
|
||
|
* Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux
|
||
|
*
|
||
|
* Copyright (C) 2017 Axentia Technologies AB
|
||
|
*
|
||
|
* Author: Peter Rosin <peda@axentia.se>
|
||
|
*
|
||
|
* 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.
|
||
|
*/
|
||
|
|
||
|
#include <linux/err.h>
|
||
|
#include <linux/i2c.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/mux/driver.h>
|
||
|
#include <linux/property.h>
|
||
|
|
||
|
#define ADG792A_LDSW BIT(0)
|
||
|
#define ADG792A_RESETB BIT(1)
|
||
|
#define ADG792A_DISABLE(mux) (0x50 | (mux))
|
||
|
#define ADG792A_DISABLE_ALL (0x5f)
|
||
|
#define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state))
|
||
|
#define ADG792A_MUX_ALL(state) (0xc0 | (state))
|
||
|
|
||
|
static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset)
|
||
|
{
|
||
|
u8 data = ADG792A_RESETB | ADG792A_LDSW;
|
||
|
|
||
|
/* ADG792A_RESETB is active low, the chip resets when it is zero. */
|
||
|
if (reset)
|
||
|
data &= ~ADG792A_RESETB;
|
||
|
|
||
|
return i2c_smbus_write_byte_data(i2c, cmd, data);
|
||
|
}
|
||
|
|
||
|
static int adg792a_set(struct mux_control *mux, int state)
|
||
|
{
|
||
|
struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent);
|
||
|
u8 cmd;
|
||
|
|
||
|
if (mux->chip->controllers == 1) {
|
||
|
/* parallel mux controller operation */
|
||
|
if (state == MUX_IDLE_DISCONNECT)
|
||
|
cmd = ADG792A_DISABLE_ALL;
|
||
|
else
|
||
|
cmd = ADG792A_MUX_ALL(state);
|
||
|
} else {
|
||
|
unsigned int controller = mux_control_get_index(mux);
|
||
|
|
||
|
if (state == MUX_IDLE_DISCONNECT)
|
||
|
cmd = ADG792A_DISABLE(controller);
|
||
|
else
|
||
|
cmd = ADG792A_MUX(controller, state);
|
||
|
}
|
||
|
|
||
|
return adg792a_write_cmd(i2c, cmd, 0);
|
||
|
}
|
||
|
|
||
|
static const struct mux_control_ops adg792a_ops = {
|
||
|
.set = adg792a_set,
|
||
|
};
|
||
|
|
||
|
static int adg792a_probe(struct i2c_client *i2c,
|
||
|
const struct i2c_device_id *id)
|
||
|
{
|
||
|
struct device *dev = &i2c->dev;
|
||
|
struct mux_chip *mux_chip;
|
||
|
s32 idle_state[3];
|
||
|
u32 cells;
|
||
|
int ret;
|
||
|
int i;
|
||
|
|
||
|
if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
|
||
|
return -ENODEV;
|
||
|
|
||
|
ret = device_property_read_u32(dev, "#mux-control-cells", &cells);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
if (cells >= 2)
|
||
|
return -EINVAL;
|
||
|
|
||
|
mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0);
|
||
|
if (IS_ERR(mux_chip))
|
||
|
return PTR_ERR(mux_chip);
|
||
|
|
||
|
mux_chip->ops = &adg792a_ops;
|
||
|
|
||
|
ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
|
||
|
ret = device_property_read_u32_array(dev, "idle-state",
|
||
|
(u32 *)idle_state,
|
||
|
mux_chip->controllers);
|
||
|
if (ret < 0) {
|
||
|
idle_state[0] = MUX_IDLE_AS_IS;
|
||
|
idle_state[1] = MUX_IDLE_AS_IS;
|
||
|
idle_state[2] = MUX_IDLE_AS_IS;
|
||
|
}
|
||
|
|
||
|
for (i = 0; i < mux_chip->controllers; ++i) {
|
||
|
struct mux_control *mux = &mux_chip->mux[i];
|
||
|
|
||
|
mux->states = 4;
|
||
|
|
||
|
switch (idle_state[i]) {
|
||
|
case MUX_IDLE_DISCONNECT:
|
||
|
case MUX_IDLE_AS_IS:
|
||
|
case 0 ... 4:
|
||
|
mux->idle_state = idle_state[i];
|
||
|
break;
|
||
|
default:
|
||
|
dev_err(dev, "invalid idle-state %d\n", idle_state[i]);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
ret = devm_mux_chip_register(dev, mux_chip);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
|
||
|
if (cells)
|
||
|
dev_info(dev, "3x single pole quadruple throw muxes registered\n");
|
||
|
else
|
||
|
dev_info(dev, "triple pole quadruple throw mux registered\n");
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static const struct i2c_device_id adg792a_id[] = {
|
||
|
{ .name = "adg792a", },
|
||
|
{ .name = "adg792g", },
|
||
|
{ }
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(i2c, adg792a_id);
|
||
|
|
||
|
static const struct of_device_id adg792a_of_match[] = {
|
||
|
{ .compatible = "adi,adg792a", },
|
||
|
{ .compatible = "adi,adg792g", },
|
||
|
{ }
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(of, adg792a_of_match);
|
||
|
|
||
|
static struct i2c_driver adg792a_driver = {
|
||
|
.driver = {
|
||
|
.name = "adg792a",
|
||
|
.of_match_table = of_match_ptr(adg792a_of_match),
|
||
|
},
|
||
|
.probe = adg792a_probe,
|
||
|
.id_table = adg792a_id,
|
||
|
};
|
||
|
module_i2c_driver(adg792a_driver);
|
||
|
|
||
|
MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver");
|
||
|
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
|
||
|
MODULE_LICENSE("GPL v2");
|