// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Allegro A8293 SEC driver
*
* Copyright (C) 2011 Antti Palosaari <[email protected]>
*/
#include "a8293.h"
#define A8293_FLAG_ODT 0x10
struct a8293_dev {
struct i2c_client *client;
u8 reg[2];
int volt_slew_nanos_per_mv;
};
/*
* When increasing voltage, do so in minimal steps over time, minimizing
* risk of vIN undervoltage.
*/
static int a8293_set_voltage_slew(struct a8293_dev *dev,
struct i2c_client *client,
enum fe_sec_voltage fe_sec_voltage,
int min_nanos_per_mv)
{
int ret;
u8 reg0, reg1;
int new_volt_idx;
const int idx_to_mv[] = {
0, 12709, 13042, 13375, 14042, 15042, 18042, 18709, 19042
};
const u8 idx_to_reg[] = {
0x00, 0x20, 0x21, 0x22, 0x24, 0x27, 0x28, 0x2A, 0x2B
};
int this_volt_idx;
u8 status;
int prev_volt_idx;
dev_dbg(&client->dev, "set_voltage_slew fe_sec_voltage=%d\n",
fe_sec_voltage);
/* Read status register to clear any stale faults. */
ret = i2c_master_recv(client, &status, 1);
if (ret < 0)
goto err;
/* Determine previous voltage */
switch (dev->reg[0] & 0x2F) {
case 0x00:
prev_volt_idx = 0;
break;
case 0x20:
prev_volt_idx = 1;
break;
case 0x21:
prev_volt_idx = 2;
break;
case 0x22:
prev_volt_idx = 3;
break;
case 0x24:
prev_volt_idx = 4;
break;
case 0x27:
prev_volt_idx = 5;
break;
case 0x28:
prev_volt_idx = 6;
break;
case 0x2A:
prev_volt_idx = 7;
break;
case 0x2B:
prev_volt_idx = 8;
break;
default:
prev_volt_idx = 0;
}
/* Determine new voltage */
switch (fe_sec_voltage) {
case SEC_VOLTAGE_OFF:
new_volt_idx = 0;
break;
case SEC_VOLTAGE_13:
new_volt_idx = 2;
break;
case SEC_VOLTAGE_18:
new_volt_idx = 6;
break;
default:
ret = -EINVAL;
goto err;
}
/* Slew to new voltage if new voltage is greater than current voltage */
this_volt_idx = prev_volt_idx;
if (this_volt_idx < new_volt_idx) {
while (this_volt_idx < new_volt_idx) {
int delta_mv = idx_to_mv[this_volt_idx+1] - idx_to_mv[this_volt_idx];
int min_wait_time = delta_mv * min_nanos_per_mv;
reg0 = idx_to_reg[this_volt_idx+1];
reg0 |= A8293_FLAG_ODT;
ret = i2c_master_send(client, ®0, 1);
if (ret < 0)
goto err;
dev->reg[0] = reg0;
this_volt_idx++;
usleep_range(min_wait_time, min_wait_time * 2);
}
} else { /* Else just set the voltage */
reg0 = idx_to_reg[new_volt_idx];
reg0 |= A8293_FLAG_ODT;
ret = i2c_master_send(client, ®0, 1);
if (ret < 0)
goto err;
dev->reg[0] = reg0;
}
/* TMODE=0, TGATE=1 */
reg1 = 0x82;
if (reg1 != dev->reg[1]) {
ret = i2c_master_send(client, ®1, 1);
if (ret < 0)
goto err;
dev->reg[1] = reg1;
}
usleep_range(1500, 5000);
return 0;
err:
dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
static int a8293_set_voltage_noslew(struct dvb_frontend *fe,
enum fe_sec_voltage fe_sec_voltage)
{
struct a8293_dev *dev = fe->sec_priv;
struct i2c_client *client = dev->client;
int ret;
u8 reg0, reg1;
dev_dbg(&client->dev, "set_voltage_noslew fe_sec_voltage=%d\n",
fe_sec_voltage);
switch (fe_sec_voltage) {
case SEC_VOLTAGE_OFF:
/* ENB=0 */
reg0 = 0x10;
break;
case SEC_VOLTAGE_13:
/* VSEL0=1, VSEL1=0, VSEL2=0, VSEL3=0, ENB=1*/
reg0 = 0x31;
break;
case SEC_VOLTAGE_18:
/* VSEL0=0, VSEL1=0, VSEL2=0, VSEL3=1, ENB=1*/
reg0 = 0x38;
break;
default:
ret = -EINVAL;
goto err;
}
if (reg0 != dev->reg[0]) {
ret = i2c_master_send(client, ®0, 1);
if (ret < 0)
goto err;
dev->reg[0] = reg0;
}
/* TMODE=0, TGATE=1 */
reg1 = 0x82;
if (reg1 != dev->reg[1]) {
ret = i2c_master_send(client, ®1, 1);
if (ret < 0)
goto err;
dev->reg[1] = reg1;
}
usleep_range(1500, 50000);
return 0;
err:
dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
static int a8293_set_voltage(struct dvb_frontend *fe,
enum fe_sec_voltage fe_sec_voltage)
{
struct a8293_dev *dev = fe->sec_priv;
struct i2c_client *client = dev->client;
int volt_slew_nanos_per_mv = dev->volt_slew_nanos_per_mv;
dev_dbg(&client->dev, "set_voltage volt_slew_nanos_per_mv=%d\n",
volt_slew_nanos_per_mv);
/* Use slew version if slew rate is set to a sane value */
if (volt_slew_nanos_per_mv > 0 && volt_slew_nanos_per_mv < 1600)
a8293_set_voltage_slew(dev, client, fe_sec_voltage,
volt_slew_nanos_per_mv);
else
a8293_set_voltage_noslew(fe, fe_sec_voltage);
return 0;
}
static int a8293_probe(struct i2c_client *client)
{
struct a8293_dev *dev;
struct a8293_platform_data *pdata = client->dev.platform_data;
struct dvb_frontend *fe = pdata->dvb_frontend;
int ret;
u8 buf[2];
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
ret = -ENOMEM;
goto err;
}
dev->client = client;
dev->volt_slew_nanos_per_mv = pdata->volt_slew_nanos_per_mv;
/* check if the SEC is there */
ret = i2c_master_recv(client, buf, 2);
if (ret < 0)
goto err_kfree;
/* override frontend ops */
fe->ops.set_voltage = a8293_set_voltage;
fe->sec_priv = dev;
i2c_set_clientdata(client, dev);
dev_info(&client->dev, "Allegro A8293 SEC successfully attached\n");
return 0;
err_kfree:
kfree(dev);
err:
dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}
static void a8293_remove(struct i2c_client *client)
{
struct a8293_dev *dev = i2c_get_clientdata(client);
dev_dbg(&client->dev, "\n");
kfree(dev);
}
static const struct i2c_device_id a8293_id_table[] = {
{ "a8293" },
{}
};
MODULE_DEVICE_TABLE(i2c, a8293_id_table);
static struct i2c_driver a8293_driver = {
.driver = {
.name = "a8293",
.suppress_bind_attrs = true,
},
.probe = a8293_probe,
.remove = a8293_remove,
.id_table = a8293_id_table,
};
module_i2c_driver(a8293_driver);
MODULE_AUTHOR("Antti Palosaari <[email protected]>");
MODULE_DESCRIPTION("Allegro A8293 SEC driver");
MODULE_LICENSE("GPL");
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