277 lines
6.5 KiB
C
277 lines
6.5 KiB
C
// 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 void i2c_opal_remove(struct platform_device *pdev)
|
|
{
|
|
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
|
|
|
|
i2c_del_adapter(adapter);
|
|
}
|
|
|
|
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_new = 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");
|