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// SPDX-License-Identifier: GPL-2.0
/*
* ADM1266 - Cascadable Super Sequencer with Margin
* Control and Fault Recording
*
* Copyright 2020 Analog Devices Inc.
*/
#include <linux/crc8.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include "pmbus.h"
#include <linux/slab.h>
#define ADM1266_PMBUS_BLOCK_MAX 255
struct adm1266_data {
struct pmbus_driver_info info;
struct i2c_client *client;
struct mutex buf_mutex;
u8 write_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned;
u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned;
};
DECLARE_CRC8_TABLE(pmbus_crc_table);
/*
* Different from Block Read as it sends data and waits for the slave to
* return a value dependent on that data. The protocol is simply a Write Block
* followed by a Read Block without the Read-Block command field and the
* Write-Block STOP bit.
*/
static int adm1266_pmbus_block_xfer(struct adm1266_data *data, u8 cmd, u8 w_len, u8 *data_w,
u8 *data_r)
{
struct i2c_client *client = data->client;
struct i2c_msg msgs[2] = {
{
.addr = client->addr,
.flags = I2C_M_DMA_SAFE,
.buf = data->write_buf,
.len = w_len + 2,
},
{
.addr = client->addr,
.flags = I2C_M_RD | I2C_M_DMA_SAFE,
.buf = data->read_buf,
.len = ADM1266_PMBUS_BLOCK_MAX + 2,
}
};
u8 addr;
u8 crc;
int ret;
mutex_lock(&data->buf_mutex);
msgs[0].buf[0] = cmd;
msgs[0].buf[1] = w_len;
memcpy(&msgs[0].buf[2], data_w, w_len);
ret = i2c_transfer(client->adapter, msgs, 2);
if (ret != 2) {
if (ret >= 0)
ret = -EPROTO;
mutex_unlock(&data->buf_mutex);
return ret;
}
if (client->flags & I2C_CLIENT_PEC) {
addr = i2c_8bit_addr_from_msg(&msgs[0]);
crc = crc8(pmbus_crc_table, &addr, 1, 0);
crc = crc8(pmbus_crc_table, msgs[0].buf, msgs[0].len, crc);
addr = i2c_8bit_addr_from_msg(&msgs[1]);
crc = crc8(pmbus_crc_table, &addr, 1, crc);
crc = crc8(pmbus_crc_table, msgs[1].buf, msgs[1].buf[0] + 1, crc);
if (crc != msgs[1].buf[msgs[1].buf[0] + 1]) {
mutex_unlock(&data->buf_mutex);
return -EBADMSG;
}
}
memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]);
ret = msgs[1].buf[0];
mutex_unlock(&data->buf_mutex);
return ret;
}
static int adm1266_probe(struct i2c_client *client)
{
struct adm1266_data *data;
int i;
data = devm_kzalloc(&client->dev, sizeof(struct adm1266_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
data->info.pages = 17;
data->info.format[PSC_VOLTAGE_OUT] = linear;
for (i = 0; i < data->info.pages; i++)
data->info.func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT;
crc8_populate_msb(pmbus_crc_table, 0x7);
mutex_init(&data->buf_mutex);
return pmbus_do_probe(client, &data->info);
}
static const struct of_device_id adm1266_of_match[] = {
{ .compatible = "adi,adm1266" },
{ }
};
MODULE_DEVICE_TABLE(of, adm1266_of_match);
static const struct i2c_device_id adm1266_id[] = {
{ "adm1266", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, adm1266_id);
static struct i2c_driver adm1266_driver = {
.driver = {
.name = "adm1266",
.of_match_table = adm1266_of_match,
},
.probe_new = adm1266_probe,
.remove = pmbus_do_remove,
.id_table = adm1266_id,
};
module_i2c_driver(adm1266_driver);
MODULE_AUTHOR("Alexandru Tachici <alexandru.tachici@analog.com>");
MODULE_DESCRIPTION("PMBus driver for Analog Devices ADM1266");
MODULE_LICENSE("GPL v2");
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