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// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel La Jolla Cove Adapter USB-I2C driver
*
* Copyright (c) 2023, Intel Corporation.
*/
#include <linux/acpi.h>
#include <linux/auxiliary_bus.h>
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/dev_printk.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/usb/ljca.h>
/* I2C init flags */
#define LJCA_I2C_INIT_FLAG_MODE BIT(0)
#define LJCA_I2C_INIT_FLAG_MODE_POLLING FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 0)
#define LJCA_I2C_INIT_FLAG_MODE_INTERRUPT FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 1)
#define LJCA_I2C_INIT_FLAG_ADDR_16BIT BIT(0)
#define LJCA_I2C_INIT_FLAG_FREQ GENMASK(2, 1)
#define LJCA_I2C_INIT_FLAG_FREQ_100K FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 0)
#define LJCA_I2C_INIT_FLAG_FREQ_400K FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 1)
#define LJCA_I2C_INIT_FLAG_FREQ_1M FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 2)
#define LJCA_I2C_BUF_SIZE 60u
#define LJCA_I2C_MAX_XFER_SIZE (LJCA_I2C_BUF_SIZE - sizeof(struct ljca_i2c_rw_packet))
/* I2C commands */
enum ljca_i2c_cmd {
LJCA_I2C_INIT = 1,
LJCA_I2C_XFER,
LJCA_I2C_START,
LJCA_I2C_STOP,
LJCA_I2C_READ,
LJCA_I2C_WRITE,
};
enum ljca_xfer_type {
LJCA_I2C_WRITE_XFER_TYPE,
LJCA_I2C_READ_XFER_TYPE,
};
/* I2C raw commands: Init/Start/Read/Write/Stop */
struct ljca_i2c_rw_packet {
u8 id;
__le16 len;
u8 data[] __counted_by(len);
} __packed;
struct ljca_i2c_dev {
struct ljca_client *ljca;
struct ljca_i2c_info *i2c_info;
struct i2c_adapter adap;
u8 obuf[LJCA_I2C_BUF_SIZE];
u8 ibuf[LJCA_I2C_BUF_SIZE];
};
static int ljca_i2c_init(struct ljca_i2c_dev *ljca_i2c, u8 id)
{
struct ljca_i2c_rw_packet *w_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
int ret;
w_packet->id = id;
w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
w_packet->data[0] = LJCA_I2C_INIT_FLAG_FREQ_400K;
ret = ljca_transfer(ljca_i2c->ljca, LJCA_I2C_INIT, (u8 *)w_packet,
struct_size(w_packet, data, 1), NULL, 0);
return ret < 0 ? ret : 0;
}
static int ljca_i2c_start(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr,
enum ljca_xfer_type type)
{
struct ljca_i2c_rw_packet *w_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
struct ljca_i2c_rw_packet *r_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
s16 rp_len;
int ret;
w_packet->id = ljca_i2c->i2c_info->id;
w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
w_packet->data[0] = (slave_addr << 1) | type;
ret = ljca_transfer(ljca_i2c->ljca, LJCA_I2C_START, (u8 *)w_packet,
struct_size(w_packet, data, 1), (u8 *)r_packet,
LJCA_I2C_BUF_SIZE);
if (ret < 0 || ret < sizeof(*r_packet))
return ret < 0 ? ret : -EIO;
rp_len = le16_to_cpu(r_packet->len);
if (rp_len < 0 || r_packet->id != w_packet->id) {
dev_dbg(&ljca_i2c->adap.dev,
"i2c start failed len: %d id: %d %d\n",
rp_len, r_packet->id, w_packet->id);
return -EIO;
}
return 0;
}
static void ljca_i2c_stop(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr)
{
struct ljca_i2c_rw_packet *w_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
struct ljca_i2c_rw_packet *r_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
s16 rp_len;
int ret;
w_packet->id = ljca_i2c->i2c_info->id;
w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
w_packet->data[0] = 0;
ret = ljca_transfer(ljca_i2c->ljca, LJCA_I2C_STOP, (u8 *)w_packet,
struct_size(w_packet, data, 1), (u8 *)r_packet,
LJCA_I2C_BUF_SIZE);
if (ret < 0 || ret < sizeof(*r_packet)) {
dev_dbg(&ljca_i2c->adap.dev,
"i2c stop failed ret: %d id: %d\n",
ret, w_packet->id);
return;
}
rp_len = le16_to_cpu(r_packet->len);
if (rp_len < 0 || r_packet->id != w_packet->id)
dev_dbg(&ljca_i2c->adap.dev,
"i2c stop failed len: %d id: %d %d\n",
rp_len, r_packet->id, w_packet->id);
}
static int ljca_i2c_pure_read(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
{
struct ljca_i2c_rw_packet *w_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
struct ljca_i2c_rw_packet *r_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
s16 rp_len;
int ret;
w_packet->id = ljca_i2c->i2c_info->id;
w_packet->len = cpu_to_le16(len);
w_packet->data[0] = 0;
ret = ljca_transfer(ljca_i2c->ljca, LJCA_I2C_READ, (u8 *)w_packet,
struct_size(w_packet, data, 1), (u8 *)r_packet,
LJCA_I2C_BUF_SIZE);
if (ret < 0 || ret < sizeof(*r_packet))
return ret < 0 ? ret : -EIO;
rp_len = le16_to_cpu(r_packet->len);
if (rp_len != len || r_packet->id != w_packet->id) {
dev_dbg(&ljca_i2c->adap.dev,
"i2c raw read failed len: %d id: %d %d\n",
rp_len, r_packet->id, w_packet->id);
return -EIO;
}
memcpy(data, r_packet->data, len);
return 0;
}
static int ljca_i2c_read(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr, u8 *data,
u8 len)
{
int ret;
ret = ljca_i2c_start(ljca_i2c, slave_addr, LJCA_I2C_READ_XFER_TYPE);
if (!ret)
ret = ljca_i2c_pure_read(ljca_i2c, data, len);
ljca_i2c_stop(ljca_i2c, slave_addr);
return ret;
}
static int ljca_i2c_pure_write(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
{
struct ljca_i2c_rw_packet *w_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
struct ljca_i2c_rw_packet *r_packet =
(struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
s16 rplen;
int ret;
w_packet->id = ljca_i2c->i2c_info->id;
w_packet->len = cpu_to_le16(len);
memcpy(w_packet->data, data, len);
ret = ljca_transfer(ljca_i2c->ljca, LJCA_I2C_WRITE, (u8 *)w_packet,
struct_size(w_packet, data, len), (u8 *)r_packet,
LJCA_I2C_BUF_SIZE);
if (ret < 0 || ret < sizeof(*r_packet))
return ret < 0 ? ret : -EIO;
rplen = le16_to_cpu(r_packet->len);
if (rplen != len || r_packet->id != w_packet->id) {
dev_dbg(&ljca_i2c->adap.dev,
"i2c write failed len: %d id: %d/%d\n",
rplen, r_packet->id, w_packet->id);
return -EIO;
}
return 0;
}
static int ljca_i2c_write(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr,
u8 *data, u8 len)
{
int ret;
ret = ljca_i2c_start(ljca_i2c, slave_addr, LJCA_I2C_WRITE_XFER_TYPE);
if (!ret)
ret = ljca_i2c_pure_write(ljca_i2c, data, len);
ljca_i2c_stop(ljca_i2c, slave_addr);
return ret;
}
static int ljca_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msg,
int num)
{
struct ljca_i2c_dev *ljca_i2c;
struct i2c_msg *cur_msg;
int i, ret;
ljca_i2c = i2c_get_adapdata(adapter);
if (!ljca_i2c)
return -EINVAL;
for (i = 0; i < num; i++) {
cur_msg = &msg[i];
if (cur_msg->flags & I2C_M_RD)
ret = ljca_i2c_read(ljca_i2c, cur_msg->addr,
cur_msg->buf, cur_msg->len);
else
ret = ljca_i2c_write(ljca_i2c, cur_msg->addr,
cur_msg->buf, cur_msg->len);
if (ret)
return ret;
}
return num;
}
static u32 ljca_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}
static const struct i2c_adapter_quirks ljca_i2c_quirks = {
.flags = I2C_AQ_NO_ZERO_LEN,
.max_read_len = LJCA_I2C_MAX_XFER_SIZE,
.max_write_len = LJCA_I2C_MAX_XFER_SIZE,
};
static const struct i2c_algorithm ljca_i2c_algo = {
.master_xfer = ljca_i2c_xfer,
.functionality = ljca_i2c_func,
};
static int ljca_i2c_probe(struct auxiliary_device *auxdev,
const struct auxiliary_device_id *aux_dev_id)
{
struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
struct ljca_i2c_dev *ljca_i2c;
int ret;
ljca_i2c = devm_kzalloc(&auxdev->dev, sizeof(*ljca_i2c), GFP_KERNEL);
if (!ljca_i2c)
return -ENOMEM;
ljca_i2c->ljca = ljca;
ljca_i2c->i2c_info = dev_get_platdata(&auxdev->dev);
ljca_i2c->adap.owner = THIS_MODULE;
ljca_i2c->adap.class = I2C_CLASS_HWMON;
ljca_i2c->adap.algo = &ljca_i2c_algo;
ljca_i2c->adap.quirks = &ljca_i2c_quirks;
ljca_i2c->adap.dev.parent = &auxdev->dev;
snprintf(ljca_i2c->adap.name, sizeof(ljca_i2c->adap.name), "%s-%s-%d",
dev_name(&auxdev->dev), dev_name(auxdev->dev.parent),
ljca_i2c->i2c_info->id);
device_set_node(&ljca_i2c->adap.dev, dev_fwnode(&auxdev->dev));
i2c_set_adapdata(&ljca_i2c->adap, ljca_i2c);
auxiliary_set_drvdata(auxdev, ljca_i2c);
ret = ljca_i2c_init(ljca_i2c, ljca_i2c->i2c_info->id);
if (ret)
return dev_err_probe(&auxdev->dev, -EIO,
"i2c init failed id: %d\n",
ljca_i2c->i2c_info->id);
ret = devm_i2c_add_adapter(&auxdev->dev, &ljca_i2c->adap);
if (ret)
return ret;
if (has_acpi_companion(&ljca_i2c->adap.dev))
acpi_dev_clear_dependencies(ACPI_COMPANION(&ljca_i2c->adap.dev));
return 0;
}
static void ljca_i2c_remove(struct auxiliary_device *auxdev)
{
struct ljca_i2c_dev *ljca_i2c = auxiliary_get_drvdata(auxdev);
i2c_del_adapter(&ljca_i2c->adap);
}
static const struct auxiliary_device_id ljca_i2c_id_table[] = {
{ "usb_ljca.ljca-i2c", 0 },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(auxiliary, ljca_i2c_id_table);
static struct auxiliary_driver ljca_i2c_driver = {
.probe = ljca_i2c_probe,
.remove = ljca_i2c_remove,
.id_table = ljca_i2c_id_table,
};
module_auxiliary_driver(ljca_i2c_driver);
MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-I2C driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(LJCA);
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