Initial import

1 files changed, 236 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/scom.c b/arch/powerpc/sysdev/scom.c
new file mode 100644
index 000000000..6f5a8d177
--- /dev/null
+++ b/arch/powerpc/sysdev/scom.c
@@ -0,0 +1,236 @@
+/*
+ * 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/debugfs.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <asm/debug.h>
+#include <asm/prom.h>
+#include <asm/scom.h>
+#include <asm/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 0;
+
+	/*
+	 * 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 0;
+
+	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*) dn->full_name;
+	ent->path.size = strlen(dn->full_name);
+
+	dir = debugfs_create_dir(ent->name, root);
+	if (!dir) {
+		of_node_put(dn);
+		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 */