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![Edward A. James](/assets/img/avatar_default.png)
Reset causes problems for operations requiring multiple scoms (e.g. i2c over scom). Instead, reset scom engine during probe. Signed-off-by: Edward A. James <eajames@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
261 lines
5.6 KiB
C
261 lines
5.6 KiB
C
/*
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* SCOM FSI Client device driver
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*
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* Copyright (C) IBM Corporation 2016
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/fsi.h>
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#include <linux/module.h>
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#include <linux/cdev.h>
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#include <linux/delay.h>
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#include <linux/fs.h>
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#include <linux/uaccess.h>
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#include <linux/slab.h>
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#include <linux/miscdevice.h>
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#include <linux/list.h>
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#include <linux/idr.h>
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#define FSI_ENGID_SCOM 0x5
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#define SCOM_FSI2PIB_DELAY 50
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/* SCOM engine register set */
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#define SCOM_DATA0_REG 0x00
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#define SCOM_DATA1_REG 0x04
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#define SCOM_CMD_REG 0x08
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#define SCOM_RESET_REG 0x1C
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#define SCOM_RESET_CMD 0x80000000
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#define SCOM_WRITE_CMD 0x80000000
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struct scom_device {
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struct list_head link;
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struct fsi_device *fsi_dev;
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struct miscdevice mdev;
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char name[32];
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int idx;
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};
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#define to_scom_dev(x) container_of((x), struct scom_device, mdev)
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static struct list_head scom_devices;
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static DEFINE_IDA(scom_ida);
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static int put_scom(struct scom_device *scom_dev, uint64_t value,
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uint32_t addr)
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{
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int rc;
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uint32_t data;
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data = cpu_to_be32((value >> 32) & 0xffffffff);
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rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
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sizeof(uint32_t));
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if (rc)
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return rc;
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data = cpu_to_be32(value & 0xffffffff);
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rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
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sizeof(uint32_t));
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if (rc)
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return rc;
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data = cpu_to_be32(SCOM_WRITE_CMD | addr);
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return fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
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sizeof(uint32_t));
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}
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static int get_scom(struct scom_device *scom_dev, uint64_t *value,
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uint32_t addr)
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{
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uint32_t result, data;
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int rc;
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*value = 0ULL;
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data = cpu_to_be32(addr);
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rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
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sizeof(uint32_t));
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if (rc)
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return rc;
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rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &result,
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sizeof(uint32_t));
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if (rc)
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return rc;
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*value |= (uint64_t)cpu_to_be32(result) << 32;
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rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &result,
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sizeof(uint32_t));
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if (rc)
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return rc;
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*value |= cpu_to_be32(result);
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return 0;
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}
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static ssize_t scom_read(struct file *filep, char __user *buf, size_t len,
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loff_t *offset)
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{
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int rc;
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struct miscdevice *mdev =
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(struct miscdevice *)filep->private_data;
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struct scom_device *scom = to_scom_dev(mdev);
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struct device *dev = &scom->fsi_dev->dev;
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uint64_t val;
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if (len != sizeof(uint64_t))
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return -EINVAL;
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rc = get_scom(scom, &val, *offset);
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if (rc) {
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dev_dbg(dev, "get_scom fail:%d\n", rc);
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return rc;
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}
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rc = copy_to_user(buf, &val, len);
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if (rc)
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dev_dbg(dev, "copy to user failed:%d\n", rc);
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return rc ? rc : len;
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}
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static ssize_t scom_write(struct file *filep, const char __user *buf,
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size_t len, loff_t *offset)
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{
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int rc;
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struct miscdevice *mdev = filep->private_data;
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struct scom_device *scom = to_scom_dev(mdev);
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struct device *dev = &scom->fsi_dev->dev;
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uint64_t val;
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if (len != sizeof(uint64_t))
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return -EINVAL;
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rc = copy_from_user(&val, buf, len);
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if (rc) {
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dev_dbg(dev, "copy from user failed:%d\n", rc);
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return -EINVAL;
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}
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rc = put_scom(scom, val, *offset);
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if (rc) {
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dev_dbg(dev, "put_scom failed with:%d\n", rc);
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return rc;
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}
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return len;
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}
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static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
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{
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switch (whence) {
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case SEEK_CUR:
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break;
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case SEEK_SET:
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file->f_pos = offset;
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break;
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default:
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return -EINVAL;
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}
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return offset;
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}
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static const struct file_operations scom_fops = {
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.owner = THIS_MODULE,
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.llseek = scom_llseek,
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.read = scom_read,
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.write = scom_write,
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};
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static int scom_probe(struct device *dev)
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{
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uint32_t data;
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struct fsi_device *fsi_dev = to_fsi_dev(dev);
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struct scom_device *scom;
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scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL);
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if (!scom)
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return -ENOMEM;
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scom->idx = ida_simple_get(&scom_ida, 1, INT_MAX, GFP_KERNEL);
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snprintf(scom->name, sizeof(scom->name), "scom%d", scom->idx);
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scom->fsi_dev = fsi_dev;
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scom->mdev.minor = MISC_DYNAMIC_MINOR;
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scom->mdev.fops = &scom_fops;
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scom->mdev.name = scom->name;
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scom->mdev.parent = dev;
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list_add(&scom->link, &scom_devices);
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data = cpu_to_be32(SCOM_RESET_CMD);
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fsi_device_write(fsi_dev, SCOM_RESET_REG, &data, sizeof(uint32_t));
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return misc_register(&scom->mdev);
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}
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static int scom_remove(struct device *dev)
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{
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struct scom_device *scom, *scom_tmp;
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struct fsi_device *fsi_dev = to_fsi_dev(dev);
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list_for_each_entry_safe(scom, scom_tmp, &scom_devices, link) {
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if (scom->fsi_dev == fsi_dev) {
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list_del(&scom->link);
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ida_simple_remove(&scom_ida, scom->idx);
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misc_deregister(&scom->mdev);
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}
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}
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return 0;
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}
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static struct fsi_device_id scom_ids[] = {
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{
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.engine_type = FSI_ENGID_SCOM,
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.version = FSI_VERSION_ANY,
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},
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{ 0 }
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};
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static struct fsi_driver scom_drv = {
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.id_table = scom_ids,
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.drv = {
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.name = "scom",
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.bus = &fsi_bus_type,
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.probe = scom_probe,
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.remove = scom_remove,
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}
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};
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static int scom_init(void)
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{
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INIT_LIST_HEAD(&scom_devices);
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return fsi_driver_register(&scom_drv);
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}
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static void scom_exit(void)
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{
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struct list_head *pos;
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struct scom_device *scom;
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list_for_each(pos, &scom_devices) {
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scom = list_entry(pos, struct scom_device, link);
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misc_deregister(&scom->mdev);
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devm_kfree(&scom->fsi_dev->dev, scom);
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}
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fsi_driver_unregister(&scom_drv);
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}
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module_init(scom_init);
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module_exit(scom_exit);
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MODULE_LICENSE("GPL");
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