forked from torvalds/linux
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
The I2CR has the capability to directly perform SCOM operations, circumventing the need to drive the FSI2PIB engine. Add a new driver to perform SCOM operations through the I2CR. Signed-off-by: Eddie James <eajames@linux.ibm.com>
- Loading branch information
1 parent
3f2296b
commit 36d0c34
Showing
3 changed files
with
163 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,154 @@ | ||
// SPDX-License-Identifier: GPL-2.0 | ||
/* Copyright (C) IBM Corporation 2023 */ | ||
|
||
#include <linux/cdev.h> | ||
#include <linux/device.h> | ||
#include <linux/fs.h> | ||
#include <linux/fsi.h> | ||
#include <linux/module.h> | ||
#include <linux/mod_devicetable.h> | ||
|
||
#include "fsi-master-i2cr.h" | ||
#include "fsi-slave.h" | ||
|
||
struct i2cr_scom { | ||
struct device dev; | ||
struct cdev cdev; | ||
struct fsi_master_i2cr *i2cr; | ||
}; | ||
|
||
static loff_t i2cr_scom_llseek(struct file *file, loff_t offset, int whence) | ||
{ | ||
switch (whence) { | ||
case SEEK_CUR: | ||
break; | ||
case SEEK_SET: | ||
file->f_pos = offset; | ||
break; | ||
default: | ||
return -EINVAL; | ||
} | ||
|
||
return offset; | ||
} | ||
|
||
static ssize_t i2cr_scom_read(struct file *filep, char __user *buf, size_t len, loff_t *offset) | ||
{ | ||
struct i2cr_scom *scom = filep->private_data; | ||
u64 data; | ||
int ret; | ||
|
||
if (len != sizeof(data)) | ||
return -EINVAL; | ||
|
||
ret = fsi_master_i2cr_read(scom->i2cr, (u32)*offset, &data); | ||
if (ret) | ||
return ret; | ||
|
||
ret = copy_to_user(buf, &data, len); | ||
if (ret) | ||
return ret; | ||
|
||
return len; | ||
} | ||
|
||
static ssize_t i2cr_scom_write(struct file *filep, const char __user *buf, size_t len, | ||
loff_t *offset) | ||
{ | ||
struct i2cr_scom *scom = filep->private_data; | ||
u64 data; | ||
int ret; | ||
|
||
if (len != sizeof(data)) | ||
return -EINVAL; | ||
|
||
ret = copy_from_user(&data, buf, len); | ||
if (ret) | ||
return ret; | ||
|
||
ret = fsi_master_i2cr_write(scom->i2cr, (u32)*offset, data); | ||
if (ret) | ||
return ret; | ||
|
||
return len; | ||
} | ||
|
||
static const struct file_operations i2cr_scom_fops = { | ||
.owner = THIS_MODULE, | ||
.open = simple_open, | ||
.llseek = i2cr_scom_llseek, | ||
.read = i2cr_scom_read, | ||
.write = i2cr_scom_write, | ||
}; | ||
|
||
static int i2cr_scom_probe(struct device *dev) | ||
{ | ||
struct fsi_device *fsi_dev = to_fsi_dev(dev); | ||
struct i2cr_scom *scom; | ||
int didx; | ||
int ret; | ||
|
||
if (!(fsi_dev->slave->master->flags & FSI_MASTER_FLAG_I2CR)) | ||
return -ENODEV; | ||
|
||
scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL); | ||
if (!scom) | ||
return -ENOMEM; | ||
|
||
scom->i2cr = to_fsi_master_i2cr(fsi_dev->slave->master); | ||
dev_set_drvdata(dev, scom); | ||
|
||
scom->dev.type = &fsi_cdev_type; | ||
scom->dev.parent = dev; | ||
device_initialize(&scom->dev); | ||
|
||
ret = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx); | ||
if (ret) | ||
return ret; | ||
|
||
dev_set_name(&scom->dev, "scom%d", didx); | ||
cdev_init(&scom->cdev, &i2cr_scom_fops); | ||
ret = cdev_device_add(&scom->cdev, &scom->dev); | ||
if (ret) | ||
fsi_free_minor(scom->dev.devt); | ||
|
||
return ret; | ||
} | ||
|
||
static int i2cr_scom_remove(struct device *dev) | ||
{ | ||
struct i2cr_scom *scom = dev_get_drvdata(dev); | ||
|
||
cdev_device_del(&scom->cdev, &scom->dev); | ||
fsi_free_minor(scom->dev.devt); | ||
|
||
return 0; | ||
} | ||
|
||
static const struct of_device_id i2cr_scom_of_ids[] = { | ||
{ .compatible = "ibm,i2cr-scom" }, | ||
{ } | ||
}; | ||
MODULE_DEVICE_TABLE(of, i2cr_scom_of_ids); | ||
|
||
static const struct fsi_device_id i2cr_scom_ids[] = { | ||
{ 0x5, FSI_VERSION_ANY }, | ||
{ } | ||
}; | ||
|
||
static struct fsi_driver i2cr_scom_driver = { | ||
.id_table = i2cr_scom_ids, | ||
.drv = { | ||
.name = "i2cr_scom", | ||
.bus = &fsi_bus_type, | ||
.of_match_table = i2cr_scom_of_ids, | ||
.probe = i2cr_scom_probe, | ||
.remove = i2cr_scom_remove, | ||
} | ||
}; | ||
|
||
module_fsi_driver(i2cr_scom_driver); | ||
|
||
MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>"); | ||
MODULE_DESCRIPTION("IBM I2C Responder SCOM driver"); | ||
MODULE_LICENSE("GPL"); |