From 680ca6dcf5c222765cb2fb22959c5282865b6655 Mon Sep 17 00:00:00 2001 From: Christopher Bostic Date: Tue, 6 Jun 2017 16:08:56 -0500 Subject: drivers/fsi: Add SCOM FSI client device driver Create a simple SCOM engine device driver that reads and writes its control registers via an FSI bus. Includes changes from Edward A. James . Signed-off-by: Christopher Bostic Signed-off-by: Joel Stanley Signed-off-by: Edward A. James Signed-off-by: Jeremy Kerr Signed-off-by: Greg Kroah-Hartman --- drivers/fsi/fsi-scom.c | 263 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 263 insertions(+) create mode 100644 drivers/fsi/fsi-scom.c (limited to 'drivers/fsi/fsi-scom.c') diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c new file mode 100644 index 000000000000..98d062fd353e --- /dev/null +++ b/drivers/fsi/fsi-scom.c @@ -0,0 +1,263 @@ +/* + * SCOM FSI Client device driver + * + * Copyright (C) IBM Corporation 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define FSI_ENGID_SCOM 0x5 + +#define SCOM_FSI2PIB_DELAY 50 + +/* SCOM engine register set */ +#define SCOM_DATA0_REG 0x00 +#define SCOM_DATA1_REG 0x04 +#define SCOM_CMD_REG 0x08 +#define SCOM_RESET_REG 0x1C + +#define SCOM_RESET_CMD 0x80000000 +#define SCOM_WRITE_CMD 0x80000000 + +struct scom_device { + struct list_head link; + struct fsi_device *fsi_dev; + struct miscdevice mdev; + char name[32]; + int idx; +}; + +#define to_scom_dev(x) container_of((x), struct scom_device, mdev) + +static struct list_head scom_devices; + +static DEFINE_IDA(scom_ida); + +static int put_scom(struct scom_device *scom_dev, uint64_t value, + uint32_t addr) +{ + int rc; + uint32_t data; + + data = cpu_to_be32(SCOM_RESET_CMD); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_RESET_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32((value >> 32) & 0xffffffff); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32(value & 0xffffffff); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32(SCOM_WRITE_CMD | addr); + return fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, + sizeof(uint32_t)); +} + +static int get_scom(struct scom_device *scom_dev, uint64_t *value, + uint32_t addr) +{ + uint32_t result, data; + int rc; + + *value = 0ULL; + data = cpu_to_be32(addr); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &result, + sizeof(uint32_t)); + if (rc) + return rc; + + *value |= (uint64_t)cpu_to_be32(result) << 32; + rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &result, + sizeof(uint32_t)); + if (rc) + return rc; + + *value |= cpu_to_be32(result); + + return 0; +} + +static ssize_t scom_read(struct file *filep, char __user *buf, size_t len, + loff_t *offset) +{ + int rc; + struct miscdevice *mdev = + (struct miscdevice *)filep->private_data; + struct scom_device *scom = to_scom_dev(mdev); + struct device *dev = &scom->fsi_dev->dev; + uint64_t val; + + if (len != sizeof(uint64_t)) + return -EINVAL; + + rc = get_scom(scom, &val, *offset); + if (rc) { + dev_dbg(dev, "get_scom fail:%d\n", rc); + return rc; + } + + rc = copy_to_user(buf, &val, len); + if (rc) + dev_dbg(dev, "copy to user failed:%d\n", rc); + + return rc ? rc : len; +} + +static ssize_t scom_write(struct file *filep, const char __user *buf, + size_t len, loff_t *offset) +{ + int rc; + struct miscdevice *mdev = filep->private_data; + struct scom_device *scom = to_scom_dev(mdev); + struct device *dev = &scom->fsi_dev->dev; + uint64_t val; + + if (len != sizeof(uint64_t)) + return -EINVAL; + + rc = copy_from_user(&val, buf, len); + if (rc) { + dev_dbg(dev, "copy from user failed:%d\n", rc); + return -EINVAL; + } + + rc = put_scom(scom, val, *offset); + if (rc) { + dev_dbg(dev, "put_scom failed with:%d\n", rc); + return rc; + } + + return len; +} + +static loff_t 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 const struct file_operations scom_fops = { + .owner = THIS_MODULE, + .llseek = scom_llseek, + .read = scom_read, + .write = scom_write, +}; + +static int scom_probe(struct device *dev) +{ + struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct scom_device *scom; + + scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL); + if (!scom) + return -ENOMEM; + + scom->idx = ida_simple_get(&scom_ida, 1, INT_MAX, GFP_KERNEL); + snprintf(scom->name, sizeof(scom->name), "scom%d", scom->idx); + scom->fsi_dev = fsi_dev; + scom->mdev.minor = MISC_DYNAMIC_MINOR; + scom->mdev.fops = &scom_fops; + scom->mdev.name = scom->name; + scom->mdev.parent = dev; + list_add(&scom->link, &scom_devices); + + return misc_register(&scom->mdev); +} + +static int scom_remove(struct device *dev) +{ + struct scom_device *scom, *scom_tmp; + struct fsi_device *fsi_dev = to_fsi_dev(dev); + + list_for_each_entry_safe(scom, scom_tmp, &scom_devices, link) { + if (scom->fsi_dev == fsi_dev) { + list_del(&scom->link); + ida_simple_remove(&scom_ida, scom->idx); + misc_deregister(&scom->mdev); + } + } + + return 0; +} + +static struct fsi_device_id scom_ids[] = { + { + .engine_type = FSI_ENGID_SCOM, + .version = FSI_VERSION_ANY, + }, + { 0 } +}; + +static struct fsi_driver scom_drv = { + .id_table = scom_ids, + .drv = { + .name = "scom", + .bus = &fsi_bus_type, + .probe = scom_probe, + .remove = scom_remove, + } +}; + +static int scom_init(void) +{ + INIT_LIST_HEAD(&scom_devices); + return fsi_driver_register(&scom_drv); +} + +static void scom_exit(void) +{ + struct list_head *pos; + struct scom_device *scom; + + list_for_each(pos, &scom_devices) { + scom = list_entry(pos, struct scom_device, link); + misc_deregister(&scom->mdev); + devm_kfree(&scom->fsi_dev->dev, scom); + } + fsi_driver_unregister(&scom_drv); +} + +module_init(scom_init); +module_exit(scom_exit); +MODULE_LICENSE("GPL"); -- cgit v1.2.3