![Cristian Sicilia](/assets/img/avatar_default.png)
Some parameters are aligned with parentheses. Some parentheses was opened at end of line. Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
344 lines
8.1 KiB
C
344 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* I2C bridge driver for the Greybus "generic" I2C module.
|
|
*
|
|
* Copyright 2014 Google Inc.
|
|
* Copyright 2014 Linaro Ltd.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/i2c.h>
|
|
|
|
#include "greybus.h"
|
|
#include "gbphy.h"
|
|
|
|
struct gb_i2c_device {
|
|
struct gb_connection *connection;
|
|
struct gbphy_device *gbphy_dev;
|
|
|
|
u32 functionality;
|
|
|
|
struct i2c_adapter adapter;
|
|
};
|
|
|
|
/*
|
|
* Map Greybus i2c functionality bits into Linux ones
|
|
*/
|
|
static u32 gb_i2c_functionality_map(u32 gb_i2c_functionality)
|
|
{
|
|
return gb_i2c_functionality; /* All bits the same for now */
|
|
}
|
|
|
|
static int gb_i2c_functionality_operation(struct gb_i2c_device *gb_i2c_dev)
|
|
{
|
|
struct gb_i2c_functionality_response response;
|
|
u32 functionality;
|
|
int ret;
|
|
|
|
ret = gb_operation_sync(gb_i2c_dev->connection,
|
|
GB_I2C_TYPE_FUNCTIONALITY,
|
|
NULL, 0, &response, sizeof(response));
|
|
if (ret)
|
|
return ret;
|
|
|
|
functionality = le32_to_cpu(response.functionality);
|
|
gb_i2c_dev->functionality = gb_i2c_functionality_map(functionality);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Map Linux i2c_msg flags into Greybus i2c transfer op flags.
|
|
*/
|
|
static u16 gb_i2c_transfer_op_flags_map(u16 flags)
|
|
{
|
|
return flags; /* All flags the same for now */
|
|
}
|
|
|
|
static void
|
|
gb_i2c_fill_transfer_op(struct gb_i2c_transfer_op *op, struct i2c_msg *msg)
|
|
{
|
|
u16 flags = gb_i2c_transfer_op_flags_map(msg->flags);
|
|
|
|
op->addr = cpu_to_le16(msg->addr);
|
|
op->flags = cpu_to_le16(flags);
|
|
op->size = cpu_to_le16(msg->len);
|
|
}
|
|
|
|
static struct gb_operation *
|
|
gb_i2c_operation_create(struct gb_connection *connection,
|
|
struct i2c_msg *msgs, u32 msg_count)
|
|
{
|
|
struct gb_i2c_device *gb_i2c_dev = gb_connection_get_data(connection);
|
|
struct gb_i2c_transfer_request *request;
|
|
struct gb_operation *operation;
|
|
struct gb_i2c_transfer_op *op;
|
|
struct i2c_msg *msg;
|
|
u32 data_out_size = 0;
|
|
u32 data_in_size = 0;
|
|
size_t request_size;
|
|
void *data;
|
|
u16 op_count;
|
|
u32 i;
|
|
|
|
if (msg_count > (u32)U16_MAX) {
|
|
dev_err(&gb_i2c_dev->gbphy_dev->dev, "msg_count (%u) too big\n",
|
|
msg_count);
|
|
return NULL;
|
|
}
|
|
op_count = (u16)msg_count;
|
|
|
|
/*
|
|
* In addition to space for all message descriptors we need
|
|
* to have enough to hold all outbound message data.
|
|
*/
|
|
msg = msgs;
|
|
for (i = 0; i < msg_count; i++, msg++)
|
|
if (msg->flags & I2C_M_RD)
|
|
data_in_size += (u32)msg->len;
|
|
else
|
|
data_out_size += (u32)msg->len;
|
|
|
|
request_size = sizeof(*request);
|
|
request_size += msg_count * sizeof(*op);
|
|
request_size += data_out_size;
|
|
|
|
/* Response consists only of incoming data */
|
|
operation = gb_operation_create(connection, GB_I2C_TYPE_TRANSFER,
|
|
request_size, data_in_size, GFP_KERNEL);
|
|
if (!operation)
|
|
return NULL;
|
|
|
|
request = operation->request->payload;
|
|
request->op_count = cpu_to_le16(op_count);
|
|
/* Fill in the ops array */
|
|
op = &request->ops[0];
|
|
msg = msgs;
|
|
for (i = 0; i < msg_count; i++)
|
|
gb_i2c_fill_transfer_op(op++, msg++);
|
|
|
|
if (!data_out_size)
|
|
return operation;
|
|
|
|
/* Copy over the outgoing data; it starts after the last op */
|
|
data = op;
|
|
msg = msgs;
|
|
for (i = 0; i < msg_count; i++) {
|
|
if (!(msg->flags & I2C_M_RD)) {
|
|
memcpy(data, msg->buf, msg->len);
|
|
data += msg->len;
|
|
}
|
|
msg++;
|
|
}
|
|
|
|
return operation;
|
|
}
|
|
|
|
static void gb_i2c_decode_response(struct i2c_msg *msgs, u32 msg_count,
|
|
struct gb_i2c_transfer_response *response)
|
|
{
|
|
struct i2c_msg *msg = msgs;
|
|
u8 *data;
|
|
u32 i;
|
|
|
|
if (!response)
|
|
return;
|
|
data = response->data;
|
|
for (i = 0; i < msg_count; i++) {
|
|
if (msg->flags & I2C_M_RD) {
|
|
memcpy(msg->buf, data, msg->len);
|
|
data += msg->len;
|
|
}
|
|
msg++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Some i2c transfer operations return results that are expected.
|
|
*/
|
|
static bool gb_i2c_expected_transfer_error(int errno)
|
|
{
|
|
return errno == -EAGAIN || errno == -ENODEV;
|
|
}
|
|
|
|
static int gb_i2c_transfer_operation(struct gb_i2c_device *gb_i2c_dev,
|
|
struct i2c_msg *msgs, u32 msg_count)
|
|
{
|
|
struct gb_connection *connection = gb_i2c_dev->connection;
|
|
struct device *dev = &gb_i2c_dev->gbphy_dev->dev;
|
|
struct gb_operation *operation;
|
|
int ret;
|
|
|
|
operation = gb_i2c_operation_create(connection, msgs, msg_count);
|
|
if (!operation)
|
|
return -ENOMEM;
|
|
|
|
ret = gbphy_runtime_get_sync(gb_i2c_dev->gbphy_dev);
|
|
if (ret)
|
|
goto exit_operation_put;
|
|
|
|
ret = gb_operation_request_send_sync(operation);
|
|
if (!ret) {
|
|
struct gb_i2c_transfer_response *response;
|
|
|
|
response = operation->response->payload;
|
|
gb_i2c_decode_response(msgs, msg_count, response);
|
|
ret = msg_count;
|
|
} else if (!gb_i2c_expected_transfer_error(ret)) {
|
|
dev_err(dev, "transfer operation failed (%d)\n", ret);
|
|
}
|
|
|
|
gbphy_runtime_put_autosuspend(gb_i2c_dev->gbphy_dev);
|
|
|
|
exit_operation_put:
|
|
gb_operation_put(operation);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int gb_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
|
|
int msg_count)
|
|
{
|
|
struct gb_i2c_device *gb_i2c_dev;
|
|
|
|
gb_i2c_dev = i2c_get_adapdata(adap);
|
|
|
|
return gb_i2c_transfer_operation(gb_i2c_dev, msgs, msg_count);
|
|
}
|
|
|
|
#if 0
|
|
/* Later */
|
|
static int gb_i2c_smbus_xfer(struct i2c_adapter *adap,
|
|
u16 addr, unsigned short flags, char read_write,
|
|
u8 command, int size, union i2c_smbus_data *data)
|
|
{
|
|
struct gb_i2c_device *gb_i2c_dev;
|
|
|
|
gb_i2c_dev = i2c_get_adapdata(adap);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static u32 gb_i2c_functionality(struct i2c_adapter *adap)
|
|
{
|
|
struct gb_i2c_device *gb_i2c_dev = i2c_get_adapdata(adap);
|
|
|
|
return gb_i2c_dev->functionality;
|
|
}
|
|
|
|
static const struct i2c_algorithm gb_i2c_algorithm = {
|
|
.master_xfer = gb_i2c_master_xfer,
|
|
/* .smbus_xfer = gb_i2c_smbus_xfer, */
|
|
.functionality = gb_i2c_functionality,
|
|
};
|
|
|
|
/*
|
|
* Do initial setup of the i2c device. This includes verifying we
|
|
* can support it (based on the protocol version it advertises).
|
|
* If that's OK, we get and cached its functionality bits.
|
|
*
|
|
* Note: gb_i2c_dev->connection is assumed to have been valid.
|
|
*/
|
|
static int gb_i2c_device_setup(struct gb_i2c_device *gb_i2c_dev)
|
|
{
|
|
/* Assume the functionality never changes, just get it once */
|
|
return gb_i2c_functionality_operation(gb_i2c_dev);
|
|
}
|
|
|
|
static int gb_i2c_probe(struct gbphy_device *gbphy_dev,
|
|
const struct gbphy_device_id *id)
|
|
{
|
|
struct gb_connection *connection;
|
|
struct gb_i2c_device *gb_i2c_dev;
|
|
struct i2c_adapter *adapter;
|
|
int ret;
|
|
|
|
gb_i2c_dev = kzalloc(sizeof(*gb_i2c_dev), GFP_KERNEL);
|
|
if (!gb_i2c_dev)
|
|
return -ENOMEM;
|
|
|
|
connection =
|
|
gb_connection_create(gbphy_dev->bundle,
|
|
le16_to_cpu(gbphy_dev->cport_desc->id),
|
|
NULL);
|
|
if (IS_ERR(connection)) {
|
|
ret = PTR_ERR(connection);
|
|
goto exit_i2cdev_free;
|
|
}
|
|
|
|
gb_i2c_dev->connection = connection;
|
|
gb_connection_set_data(connection, gb_i2c_dev);
|
|
gb_i2c_dev->gbphy_dev = gbphy_dev;
|
|
gb_gbphy_set_data(gbphy_dev, gb_i2c_dev);
|
|
|
|
ret = gb_connection_enable(connection);
|
|
if (ret)
|
|
goto exit_connection_destroy;
|
|
|
|
ret = gb_i2c_device_setup(gb_i2c_dev);
|
|
if (ret)
|
|
goto exit_connection_disable;
|
|
|
|
/* Looks good; up our i2c adapter */
|
|
adapter = &gb_i2c_dev->adapter;
|
|
adapter->owner = THIS_MODULE;
|
|
adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
|
|
adapter->algo = &gb_i2c_algorithm;
|
|
/* adapter->algo_data = what? */
|
|
|
|
adapter->dev.parent = &gbphy_dev->dev;
|
|
snprintf(adapter->name, sizeof(adapter->name), "Greybus i2c adapter");
|
|
i2c_set_adapdata(adapter, gb_i2c_dev);
|
|
|
|
ret = i2c_add_adapter(adapter);
|
|
if (ret)
|
|
goto exit_connection_disable;
|
|
|
|
gbphy_runtime_put_autosuspend(gbphy_dev);
|
|
return 0;
|
|
|
|
exit_connection_disable:
|
|
gb_connection_disable(connection);
|
|
exit_connection_destroy:
|
|
gb_connection_destroy(connection);
|
|
exit_i2cdev_free:
|
|
kfree(gb_i2c_dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void gb_i2c_remove(struct gbphy_device *gbphy_dev)
|
|
{
|
|
struct gb_i2c_device *gb_i2c_dev = gb_gbphy_get_data(gbphy_dev);
|
|
struct gb_connection *connection = gb_i2c_dev->connection;
|
|
int ret;
|
|
|
|
ret = gbphy_runtime_get_sync(gbphy_dev);
|
|
if (ret)
|
|
gbphy_runtime_get_noresume(gbphy_dev);
|
|
|
|
i2c_del_adapter(&gb_i2c_dev->adapter);
|
|
gb_connection_disable(connection);
|
|
gb_connection_destroy(connection);
|
|
kfree(gb_i2c_dev);
|
|
}
|
|
|
|
static const struct gbphy_device_id gb_i2c_id_table[] = {
|
|
{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_I2C) },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(gbphy, gb_i2c_id_table);
|
|
|
|
static struct gbphy_driver i2c_driver = {
|
|
.name = "i2c",
|
|
.probe = gb_i2c_probe,
|
|
.remove = gb_i2c_remove,
|
|
.id_table = gb_i2c_id_table,
|
|
};
|
|
|
|
module_gbphy_driver(i2c_driver);
|
|
MODULE_LICENSE("GPL v2");
|