[linux-2.6-block.git] / arch / powerpc / sysdev / scom.c

/*
 * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
 *                <benh@kernel.crashing.org>
 *     and        David Gibson, IBM Corporation.
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/debugfs.h>
#include <asm/prom.h>
#include <asm/scom.h>
#include <linux/uaccess.h>

const struct scom_controller *scom_controller;
EXPORT_SYMBOL_GPL(scom_controller);

struct device_node *scom_find_parent(struct device_node *node)
{
	struct device_node *par, *tmp;
	const u32 *p;

	for (par = of_node_get(node); par;) {
		if (of_get_property(par, "scom-controller", NULL))
			break;
		p = of_get_property(par, "scom-parent", NULL);
		tmp = par;
		if (p == NULL)
			par = of_get_parent(par);
		else
			par = of_find_node_by_phandle(*p);
		of_node_put(tmp);
	}
	return par;
}
EXPORT_SYMBOL_GPL(scom_find_parent);

scom_map_t scom_map_device(struct device_node *dev, int index)
{
	struct device_node *parent;
	unsigned int cells, size;
	const __be32 *prop, *sprop;
	u64 reg, cnt;
	scom_map_t ret;

	parent = scom_find_parent(dev);

	if (parent == NULL)
		return NULL;

	/*
	 * We support "scom-reg" properties for adding scom registers
	 * to a random device-tree node with an explicit scom-parent
	 *
	 * We also support the simple "reg" property if the device is
	 * a direct child of a scom controller.
	 *
	 * In case both exist, "scom-reg" takes precedence.
	 */
	prop = of_get_property(dev, "scom-reg", &size);
	sprop = of_get_property(parent, "#scom-cells", NULL);
	if (!prop && parent == dev->parent) {
		prop = of_get_property(dev, "reg", &size);
		sprop = of_get_property(parent, "#address-cells", NULL);
	}
	if (!prop)
		return NULL;
	cells = sprop ? be32_to_cpup(sprop) : 1;
	size >>= 2;

	if (index >= (size / (2*cells)))
		return NULL;

	reg = of_read_number(&prop[index * cells * 2], cells);
	cnt = of_read_number(&prop[index * cells * 2 + cells], cells);

	ret = scom_map(parent, reg, cnt);
	of_node_put(parent);

	return ret;
}
EXPORT_SYMBOL_GPL(scom_map_device);

#ifdef CONFIG_SCOM_DEBUGFS
struct scom_debug_entry {
	struct device_node *dn;
	struct debugfs_blob_wrapper path;
	char name[16];
};

static ssize_t scom_debug_read(struct file *filp, char __user *ubuf,
			       size_t count, loff_t *ppos)
{
	struct scom_debug_entry *ent = filp->private_data;
	u64 __user *ubuf64 = (u64 __user *)ubuf;
	loff_t off = *ppos;
	ssize_t done = 0; 
	u64 reg, reg_cnt, val;
	scom_map_t map;
	int rc;

	if (off < 0 || (off & 7) || (count & 7))
		return -EINVAL;
	reg = off >> 3;
	reg_cnt = count >> 3;

	map = scom_map(ent->dn, reg, reg_cnt);
	if (!scom_map_ok(map))
		return -ENXIO;

	for (reg = 0; reg < reg_cnt; reg++) {
		rc = scom_read(map, reg, &val);
		if (!rc)
			rc = put_user(val, ubuf64);
		if (rc) {
			if (!done)
				done = rc;
			break;
		}
		ubuf64++;
		*ppos += 8;
		done += 8;
	}
	scom_unmap(map);
	return done;
}

static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,
				size_t count, loff_t *ppos)
{
	struct scom_debug_entry *ent = filp->private_data;
	u64 __user *ubuf64 = (u64 __user *)ubuf;
	loff_t off = *ppos;
	ssize_t done = 0; 
	u64 reg, reg_cnt, val;
	scom_map_t map;
	int rc;

	if (off < 0 || (off & 7) || (count & 7))
		return -EINVAL;
	reg = off >> 3;
	reg_cnt = count >> 3;

	map = scom_map(ent->dn, reg, reg_cnt);
	if (!scom_map_ok(map))
		return -ENXIO;

	for (reg = 0; reg < reg_cnt; reg++) {
		rc = get_user(val, ubuf64);
		if (!rc)
			rc = scom_write(map, reg,  val);
		if (rc) {
			if (!done)
				done = rc;
			break;
		}
		ubuf64++;
		done += 8;
	}
	scom_unmap(map);
	return done;
}

static const struct file_operations scom_debug_fops = {
	.read =		scom_debug_read,
	.write =	scom_debug_write,
	.open =		simple_open,
	.llseek =	default_llseek,
};

static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
			       int i)
{
	struct scom_debug_entry *ent;
	struct dentry *dir;

	ent = kzalloc(sizeof(*ent), GFP_KERNEL);
	if (!ent)
		return -ENOMEM;

	ent->dn = of_node_get(dn);
	snprintf(ent->name, 16, "%08x", i);
	ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);
	ent->path.size = strlen((char *)ent->path.data);

	dir = debugfs_create_dir(ent->name, root);
	if (!dir) {
		of_node_put(dn);
		kfree(ent->path.data);
		kfree(ent);
		return -1;
	}

	debugfs_create_blob("devspec", 0400, dir, &ent->path);
	debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);

	return 0;
}

static int scom_debug_init(void)
{
	struct device_node *dn;
	struct dentry *root;
	int i, rc;

	root = debugfs_create_dir("scom", powerpc_debugfs_root);
	if (!root)
		return -1;

	i = rc = 0;
	for_each_node_with_property(dn, "scom-controller") {
		int id = of_get_ibm_chip_id(dn);
		if (id == -1)
			id = i;
		rc |= scom_debug_init_one(root, dn, id);
		i++;
	}

	return rc;
}
device_initcall(scom_debug_init);
#endif /* CONFIG_SCOM_DEBUGFS */
Commit	Line	Data
ab814b93 BH	1	/*
	2	* Copyright 2010 Benjamin Herrenschmidt, IBM Corp
	3	* <benh@kernel.crashing.org>
	4	* and David Gibson, IBM Corporation.
	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 as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	14	* the GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	#include <linux/kernel.h>
ab814b93	22	#include <linux/slab.h>
66b15db6	23	#include <linux/export.h>
7644d581	24	#include <asm/debugfs.h>
ab814b93 BH	25	#include <asm/prom.h>
ab814b93 BH	26	#include <asm/scom.h>
7c0f6ba6	27	#include <linux/uaccess.h>
ab814b93 BH	28
	29	const struct scom_controller *scom_controller;
	30	EXPORT_SYMBOL_GPL(scom_controller);
	31
	32	struct device_node scom_find_parent(struct device_node node)
	33	{
	34	struct device_node par, tmp;
	35	const u32 *p;
	36
	37	for (par = of_node_get(node); par;) {
	38	if (of_get_property(par, "scom-controller", NULL))
	39	break;
	40	p = of_get_property(par, "scom-parent", NULL);
	41	tmp = par;
	42	if (p == NULL)
	43	par = of_get_parent(par);
	44	else
	45	par = of_find_node_by_phandle(*p);
	46	of_node_put(tmp);
	47	}
	48	return par;
	49	}
	50	EXPORT_SYMBOL_GPL(scom_find_parent);
	51
	52	scom_map_t scom_map_device(struct device_node *dev, int index)
	53	{
	54	struct device_node *parent;
	55	unsigned int cells, size;
5f33af4c	56	const __be32 prop, sprop;
ab814b93 BH	57	u64 reg, cnt;
	58	scom_map_t ret;
	59
	60	parent = scom_find_parent(dev);
	61
	62	if (parent == NULL)
3347c9f6	63	return NULL;
ab814b93	64
5f33af4c BH	65	/*
	66	* We support "scom-reg" properties for adding scom registers
	67	* to a random device-tree node with an explicit scom-parent
	68	*
	69	* We also support the simple "reg" property if the device is
	70	* a direct child of a scom controller.
	71	*
	72	* In case both exist, "scom-reg" takes precedence.
	73	*/
ab814b93	74	prop = of_get_property(dev, "scom-reg", &size);
5f33af4c BH	75	sprop = of_get_property(parent, "#scom-cells", NULL);
	76	if (!prop && parent == dev->parent) {
	77	prop = of_get_property(dev, "reg", &size);
	78	sprop = of_get_property(parent, "#address-cells", NULL);
	79	}
ab814b93	80	if (!prop)
5f33af4c BH	81	return NULL;
5f33af4c BH	82	cells = sprop ? be32_to_cpup(sprop) : 1;
ab814b93 BH	83	size >>= 2;
	84
	85	if (index >= (size / (2*cells)))
3347c9f6	86	return NULL;
ab814b93 BH	87
	88	reg = of_read_number(&prop[index * cells * 2], cells);
	89	cnt = of_read_number(&prop[index * cells * 2 + cells], cells);
	90
	91	ret = scom_map(parent, reg, cnt);
	92	of_node_put(parent);
	93
	94	return ret;
	95	}
	96	EXPORT_SYMBOL_GPL(scom_map_device);
	97
	98	#ifdef CONFIG_SCOM_DEBUGFS
	99	struct scom_debug_entry {
	100	struct device_node *dn;
cda13552 BH	101	struct debugfs_blob_wrapper path;
cda13552 BH	102	char name[16];
ab814b93 BH	103	};
ab814b93 BH	104
cda13552 BH	105	static ssize_t scom_debug_read(struct file filp, char __user ubuf,
cda13552 BH	106	size_t count, loff_t *ppos)
ab814b93	107	{
cda13552 BH	108	struct scom_debug_entry *ent = filp->private_data;
	109	u64 __user ubuf64 = (u64 __user )ubuf;
	110	loff_t off = *ppos;
	111	ssize_t done = 0;
	112	u64 reg, reg_cnt, val;
	113	scom_map_t map;
	114	int rc;
	115
	116	if (off < 0 \|\| (off & 7) \|\| (count & 7))
	117	return -EINVAL;
	118	reg = off >> 3;
	119	reg_cnt = count >> 3;
	120
	121	map = scom_map(ent->dn, reg, reg_cnt);
	122	if (!scom_map_ok(map))
	123	return -ENXIO;
	124
	125	for (reg = 0; reg < reg_cnt; reg++) {
	126	rc = scom_read(map, reg, &val);
	127	if (!rc)
	128	rc = put_user(val, ubuf64);
	129	if (rc) {
	130	if (!done)
	131	done = rc;
	132	break;
	133	}
	134	ubuf64++;
	135	*ppos += 8;
	136	done += 8;
	137	}
	138	scom_unmap(map);
	139	return done;
ab814b93	140	}
ab814b93	141
cda13552 BH	142	static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,
cda13552 BH	143	size_t count, loff_t *ppos)
ab814b93	144	{
cda13552 BH	145	struct scom_debug_entry *ent = filp->private_data;
	146	u64 __user ubuf64 = (u64 __user )ubuf;
	147	loff_t off = *ppos;
	148	ssize_t done = 0;
	149	u64 reg, reg_cnt, val;
	150	scom_map_t map;
	151	int rc;
	152
	153	if (off < 0 \|\| (off & 7) \|\| (count & 7))
	154	return -EINVAL;
	155	reg = off >> 3;
	156	reg_cnt = count >> 3;
	157
	158	map = scom_map(ent->dn, reg, reg_cnt);
	159	if (!scom_map_ok(map))
	160	return -ENXIO;
	161
	162	for (reg = 0; reg < reg_cnt; reg++) {
	163	rc = get_user(val, ubuf64);
	164	if (!rc)
	165	rc = scom_write(map, reg, val);
	166	if (rc) {
	167	if (!done)
	168	done = rc;
	169	break;
	170	}
	171	ubuf64++;
	172	done += 8;
	173	}
	174	scom_unmap(map);
	175	return done;
ab814b93 BH	176	}
ab814b93 BH	177
cda13552 BH	178	static const struct file_operations scom_debug_fops = {
	179	.read = scom_debug_read,
	180	.write = scom_debug_write,
	181	.open = simple_open,
	182	.llseek = default_llseek,
	183	};
ab814b93 BH	184
	185	static int scom_debug_init_one(struct dentry root, struct device_node dn,
	186	int i)
	187	{
	188	struct scom_debug_entry *ent;
	189	struct dentry *dir;
	190
	191	ent = kzalloc(sizeof(*ent), GFP_KERNEL);
	192	if (!ent)
	193	return -ENOMEM;
	194
	195	ent->dn = of_node_get(dn);
cda13552	196	snprintf(ent->name, 16, "%08x", i);
b7c670d6 RH	197	ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);
b7c670d6 RH	198	ent->path.size = strlen((char *)ent->path.data);
ab814b93 BH	199
	200	dir = debugfs_create_dir(ent->name, root);
	201	if (!dir) {
	202	of_node_put(dn);
b7c670d6	203	kfree(ent->path.data);
ab814b93 BH	204	kfree(ent);
	205	return -1;
	206	}
	207
cda13552 BH	208	debugfs_create_blob("devspec", 0400, dir, &ent->path);
cda13552 BH	209	debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);
ab814b93 BH	210
	211	return 0;
	212	}
	213
	214	static int scom_debug_init(void)
	215	{
	216	struct device_node *dn;
	217	struct dentry *root;
	218	int i, rc;
	219
	220	root = debugfs_create_dir("scom", powerpc_debugfs_root);
	221	if (!root)
	222	return -1;
	223
	224	i = rc = 0;
762fd3ab BH	225	for_each_node_with_property(dn, "scom-controller") {
	226	int id = of_get_ibm_chip_id(dn);
	227	if (id == -1)
	228	id = i;
	229	rc \|= scom_debug_init_one(root, dn, id);
	230	i++;
	231	}
ab814b93 BH	232
	233	return rc;
	234	}
	235	device_initcall(scom_debug_init);
	236	#endif /* CONFIG_SCOM_DEBUGFS */