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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IBM OPAL I2C driver
* Copyright (C) 2014 IBM
*/
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/firmware.h>
#include <asm/opal.h>
static int i2c_opal_translate_error(int rc)
{
switch (rc) {
case OPAL_NO_MEM:
return -ENOMEM;
case OPAL_PARAMETER:
return -EINVAL;
case OPAL_I2C_ARBT_LOST:
return -EAGAIN;
case OPAL_I2C_TIMEOUT:
return -ETIMEDOUT;
case OPAL_I2C_NACK_RCVD:
return -ENXIO;
case OPAL_I2C_STOP_ERR:
return -EBUSY;
default:
return -EIO;
}
}
static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
{
struct opal_msg msg;
int token, rc;
token = opal_async_get_token_interruptible();
if (token < 0) {
if (token != -ERESTARTSYS)
pr_err("Failed to get the async token\n");
return token;
}
rc = opal_i2c_request(token, bus_id, req);
if (rc != OPAL_ASYNC_COMPLETION) {
rc = i2c_opal_translate_error(rc);
goto exit;
}
rc = opal_async_wait_response(token, &msg);
if (rc)
goto exit;
rc = opal_get_async_rc(msg);
if (rc != OPAL_SUCCESS) {
rc = i2c_opal_translate_error(rc);
goto exit;
}
exit:
opal_async_release_token(token);
return rc;
}
static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
unsigned long opal_id = (unsigned long)adap->algo_data;
struct opal_i2c_request req;
int rc, i;
/* We only support fairly simple combinations here of one
* or two messages
*/
memset(&req, 0, sizeof(req));
switch(num) {
case 1:
req.type = (msgs[0].flags & I2C_M_RD) ?
OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
req.addr = cpu_to_be16(msgs[0].addr);
req.size = cpu_to_be32(msgs[0].len);
req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
break;
case 2:
req.type = (msgs[1].flags & I2C_M_RD) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
req.addr = cpu_to_be16(msgs[0].addr);
req.subaddr_sz = msgs[0].len;
for (i = 0; i < msgs[0].len; i++)
req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
req.subaddr = cpu_to_be32(req.subaddr);
req.size = cpu_to_be32(msgs[1].len);
req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
break;
}
rc = i2c_opal_send_request(opal_id, &req);
if (rc)
return rc;
return num;
}
static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data)
{
unsigned long opal_id = (unsigned long)adap->algo_data;
struct opal_i2c_request req;
u8 local[2];
int rc;
memset(&req, 0, sizeof(req));
req.addr = cpu_to_be16(addr);
switch (size) {
case I2C_SMBUS_BYTE:
req.buffer_ra = cpu_to_be64(__pa(&data->byte));
req.size = cpu_to_be32(1);
fallthrough;
case I2C_SMBUS_QUICK:
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
break;
case I2C_SMBUS_BYTE_DATA:
req.buffer_ra = cpu_to_be64(__pa(&data->byte));
req.size = cpu_to_be32(1);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
case I2C_SMBUS_WORD_DATA:
if (!read_write) {
local[0] = data->word & 0xff;
local[1] = (data->word >> 8) & 0xff;
}
req.buffer_ra = cpu_to_be64(__pa(local));
req.size = cpu_to_be32(2);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
req.size = cpu_to_be32(data->block[0]);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
default:
return -EINVAL;
}
rc = i2c_opal_send_request(opal_id, &req);
if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
data->word = ((u16)local[1]) << 8;
data->word |= local[0];
}
return rc;
}
static u32 i2c_opal_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
}
static const struct i2c_algorithm i2c_opal_algo = {
.master_xfer = i2c_opal_master_xfer,
.smbus_xfer = i2c_opal_smbus_xfer,
.functionality = i2c_opal_func,
};
/*
* For two messages, we basically support simple smbus transactions of a
* write-then-anything.
*/
static const struct i2c_adapter_quirks i2c_opal_quirks = {
.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
.max_comb_1st_msg_len = 4,
};
static int i2c_opal_probe(struct platform_device *pdev)
{
struct i2c_adapter *adapter;
const char *pname;
u32 opal_id;
int rc;
if (!pdev->dev.of_node)
return -ENODEV;
rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
if (rc) {
dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
return -EIO;
}
adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
if (!adapter)
return -ENOMEM;
adapter->algo = &i2c_opal_algo;
adapter->algo_data = (void *)(unsigned long)opal_id;
adapter->quirks = &i2c_opal_quirks;
adapter->dev.parent = &pdev->dev;
adapter->dev.of_node = of_node_get(pdev->dev.of_node);
pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
if (pname)
strscpy(adapter->name, pname, sizeof(adapter->name));
else
strscpy(adapter->name, "opal", sizeof(adapter->name));
platform_set_drvdata(pdev, adapter);
rc = i2c_add_adapter(adapter);
if (rc)
dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
return rc;
}
static int i2c_opal_remove(struct platform_device *pdev)
{
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
i2c_del_adapter(adapter);
return 0;
}
static const struct of_device_id i2c_opal_of_match[] = {
{
.compatible = "ibm,opal-i2c",
},
{ }
};
MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
static struct platform_driver i2c_opal_driver = {
.probe = i2c_opal_probe,
.remove = i2c_opal_remove,
.driver = {
.name = "i2c-opal",
.of_match_table = i2c_opal_of_match,
},
};
static int __init i2c_opal_init(void)
{
if (!firmware_has_feature(FW_FEATURE_OPAL))
return -ENODEV;
return platform_driver_register(&i2c_opal_driver);
}
module_init(i2c_opal_init);
static void __exit i2c_opal_exit(void)
{
return platform_driver_unregister(&i2c_opal_driver);
}
module_exit(i2c_opal_exit);
MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("IBM OPAL I2C driver");
MODULE_LICENSE("GPL");
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