[mirror_ubuntu-bionic-kernel.git] / drivers / fsi / fsi-scom.c

/*
 * 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 <linux/fsi.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/list.h>
#include <linux/idr.h>

#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((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)
{
	uint32_t data;
	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);

	data = cpu_to_be32(SCOM_RESET_CMD);
	fsi_device_write(fsi_dev, SCOM_RESET_REG, &data, sizeof(uint32_t));

	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");
Commit	Line	Data
680ca6dc CB	1	/*
	2	* SCOM FSI Client device driver
	3	*
	4	* Copyright (C) IBM Corporation 2016
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*/
	15
	16	#include <linux/fsi.h>
	17	#include <linux/module.h>
	18	#include <linux/cdev.h>
	19	#include <linux/delay.h>
	20	#include <linux/fs.h>
	21	#include <linux/uaccess.h>
	22	#include <linux/slab.h>
	23	#include <linux/miscdevice.h>
	24	#include <linux/list.h>
	25	#include <linux/idr.h>
	26
	27	#define FSI_ENGID_SCOM 0x5
	28
	29	#define SCOM_FSI2PIB_DELAY 50
	30
	31	/* SCOM engine register set */
	32	#define SCOM_DATA0_REG 0x00
	33	#define SCOM_DATA1_REG 0x04
	34	#define SCOM_CMD_REG 0x08
	35	#define SCOM_RESET_REG 0x1C
	36
	37	#define SCOM_RESET_CMD 0x80000000
	38	#define SCOM_WRITE_CMD 0x80000000
	39
	40	struct scom_device {
	41	struct list_head link;
	42	struct fsi_device *fsi_dev;
	43	struct miscdevice mdev;
	44	char name[32];
	45	int idx;
	46	};
	47
	48	#define to_scom_dev(x) container_of((x), struct scom_device, mdev)
	49
	50	static struct list_head scom_devices;
	51
	52	static DEFINE_IDA(scom_ida);
	53
	54	static int put_scom(struct scom_device *scom_dev, uint64_t value,
	55	uint32_t addr)
	56	{
	57	int rc;
	58	uint32_t data;
	59
680ca6dc CB	60	data = cpu_to_be32((value >> 32) & 0xffffffff);
	61	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
	62	sizeof(uint32_t));
	63	if (rc)
	64	return rc;
	65
	66	data = cpu_to_be32(value & 0xffffffff);
	67	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
	68	sizeof(uint32_t));
	69	if (rc)
	70	return rc;
	71
	72	data = cpu_to_be32(SCOM_WRITE_CMD \| addr);
	73	return fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
	74	sizeof(uint32_t));
	75	}
	76
	77	static int get_scom(struct scom_device scom_dev, uint64_t value,
	78	uint32_t addr)
	79	{
	80	uint32_t result, data;
	81	int rc;
	82
	83	*value = 0ULL;
	84	data = cpu_to_be32(addr);
	85	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
	86	sizeof(uint32_t));
	87	if (rc)
	88	return rc;
	89
	90	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &result,
	91	sizeof(uint32_t));
	92	if (rc)
	93	return rc;
	94
	95	*value \|= (uint64_t)cpu_to_be32(result) << 32;
	96	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &result,
	97	sizeof(uint32_t));
	98	if (rc)
	99	return rc;
	100
	101	*value \|= cpu_to_be32(result);
	102
	103	return 0;
	104	}
	105
	106	static ssize_t scom_read(struct file filep, char __user buf, size_t len,
	107	loff_t *offset)
	108	{
	109	int rc;
	110	struct miscdevice *mdev =
	111	(struct miscdevice *)filep->private_data;
	112	struct scom_device *scom = to_scom_dev(mdev);
	113	struct device *dev = &scom->fsi_dev->dev;
	114	uint64_t val;
	115
	116	if (len != sizeof(uint64_t))
	117	return -EINVAL;
	118
	119	rc = get_scom(scom, &val, *offset);
	120	if (rc) {
	121	dev_dbg(dev, "get_scom fail:%d\n", rc);
	122	return rc;
	123	}
124
125	rc = copy_to_user(buf, &val, len);
126	if (rc)
127	dev_dbg(dev, "copy to user failed:%d\n", rc);
128
129	return rc ? rc : len;
130	}
131
132	static ssize_t scom_write(struct file filep, const char __user buf,
133	size_t len, loff_t *offset)
134	{
135	int rc;
136	struct miscdevice *mdev = filep->private_data;
137	struct scom_device *scom = to_scom_dev(mdev);
138	struct device *dev = &scom->fsi_dev->dev;
139	uint64_t val;
140
141	if (len != sizeof(uint64_t))
142	return -EINVAL;
143
144	rc = copy_from_user(&val, buf, len);
145	if (rc) {
146	dev_dbg(dev, "copy from user failed:%d\n", rc);
147	return -EINVAL;
148	}
149
150	rc = put_scom(scom, val, *offset);
151	if (rc) {
152	dev_dbg(dev, "put_scom failed with:%d\n", rc);
153	return rc;
154	}
155
156	return len;
157	}
158
159	static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
160	{
161	switch (whence) {
162	case SEEK_CUR:
163	break;
164	case SEEK_SET:
165	file->f_pos = offset;
166	break;
167	default:
168	return -EINVAL;
169	}
170
171	return offset;
172	}
173
174	static const struct file_operations scom_fops = {
175	.owner = THIS_MODULE,
176	.llseek = scom_llseek,
177	.read = scom_read,
178	.write = scom_write,
179	};
180
181	static int scom_probe(struct device *dev)
182	{
47a6623b	183	uint32_t data;
680ca6dc CB	184	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	185	struct scom_device *scom;
	186
	187	scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL);
	188	if (!scom)
	189	return -ENOMEM;
	190
	191	scom->idx = ida_simple_get(&scom_ida, 1, INT_MAX, GFP_KERNEL);
	192	snprintf(scom->name, sizeof(scom->name), "scom%d", scom->idx);
	193	scom->fsi_dev = fsi_dev;
	194	scom->mdev.minor = MISC_DYNAMIC_MINOR;
	195	scom->mdev.fops = &scom_fops;
	196	scom->mdev.name = scom->name;
	197	scom->mdev.parent = dev;
	198	list_add(&scom->link, &scom_devices);
	199
47a6623b EJ	200	data = cpu_to_be32(SCOM_RESET_CMD);
	201	fsi_device_write(fsi_dev, SCOM_RESET_REG, &data, sizeof(uint32_t));
	202
680ca6dc CB	203	return misc_register(&scom->mdev);
	204	}
	205
	206	static int scom_remove(struct device *dev)
	207	{
	208	struct scom_device scom, scom_tmp;
	209	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	210
	211	list_for_each_entry_safe(scom, scom_tmp, &scom_devices, link) {
	212	if (scom->fsi_dev == fsi_dev) {
	213	list_del(&scom->link);
	214	ida_simple_remove(&scom_ida, scom->idx);
	215	misc_deregister(&scom->mdev);
	216	}
	217	}
	218
	219	return 0;
	220	}
	221
	222	static struct fsi_device_id scom_ids[] = {
	223	{
	224	.engine_type = FSI_ENGID_SCOM,
	225	.version = FSI_VERSION_ANY,
	226	},
	227	{ 0 }
	228	};
	229
	230	static struct fsi_driver scom_drv = {
	231	.id_table = scom_ids,
	232	.drv = {
	233	.name = "scom",
	234	.bus = &fsi_bus_type,
	235	.probe = scom_probe,
	236	.remove = scom_remove,
	237	}
	238	};
	239
	240	static int scom_init(void)
	241	{
	242	INIT_LIST_HEAD(&scom_devices);
	243	return fsi_driver_register(&scom_drv);
	244	}
	245
	246	static void scom_exit(void)
	247	{
	248	struct list_head *pos;
	249	struct scom_device *scom;
	250
	251	list_for_each(pos, &scom_devices) {
	252	scom = list_entry(pos, struct scom_device, link);
	253	misc_deregister(&scom->mdev);
	254	devm_kfree(&scom->fsi_dev->dev, scom);
	255	}
	256	fsi_driver_unregister(&scom_drv);
	257	}
	258
	259	module_init(scom_init);
	260	module_exit(scom_exit);
	261	MODULE_LICENSE("GPL");