1 files changed, 150 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-lpc.c b/arch/powerpc/platforms/powernv/opal-lpc.c
index 79d83cad3d67..70eff22aef73 100644
--- a/arch/powerpc/platforms/powernv/opal-lpc.c
+++ b/arch/powerpc/platforms/powernv/opal-lpc.c
@@ -12,12 +12,16 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/bug.h>
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/slab.h>
 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
 #include <asm/xics.h>
 #include <asm/opal.h>
 #include <asm/prom.h>
+#include <asm/uaccess.h>
 
 static int opal_lpc_chip_id = -1;
 
@@ -176,6 +180,152 @@ static const struct ppc_pci_io opal_lpc_io = {
         .outsl  = opal_lpc_outsl,
 };
 
+#ifdef CONFIG_DEBUG_FS
+struct lpc_debugfs_entry {
+        enum OpalLPCAddressType lpc_type;
+};
+
+static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
+                              size_t count, loff_t *ppos)
+{
+        struct lpc_debugfs_entry *lpc = filp->private_data;
+        u32 data, pos, len, todo;
+        int rc;
+
+        if (!access_ok(VERIFY_WRITE, ubuf, count))
+                return -EFAULT;
+
+        todo = count;
+        while (todo) {
+                pos = *ppos;
+
+                /*
+                 * Select access size based on count and alignment and
+                 * access type. IO and MEM only support byte acceses,
+                 * FW supports all 3.
+                 */
+                len = 1;
+                if (lpc->lpc_type == OPAL_LPC_FW) {
+                        if (todo > 3 && (pos & 3) == 0)
+                                len = 4;
+                        else if (todo > 1 && (pos & 1) == 0)
+                                len = 2;
+                }
+                rc = opal_lpc_read(opal_lpc_chip_id, lpc->lpc_type, pos,
+                                   &data, len);
+                if (rc)
+                        return -ENXIO;
+                switch(len) {
+                case 4:
+                        rc = __put_user((u32)data, (u32 __user *)ubuf);
+                        break;
+                case 2:
+                        rc = __put_user((u16)data, (u16 __user *)ubuf);
+                        break;
+                default:
+                        rc = __put_user((u8)data, (u8 __user *)ubuf);
+                        break;
+                }
+                if (rc)
+                        return -EFAULT;
+                *ppos += len;
+                ubuf += len;
+                todo -= len;
+        }
+
+        return count;
+}
+
+static ssize_t lpc_debug_write(struct file *filp, const char __user *ubuf,
+                               size_t count, loff_t *ppos)
+{
+        struct lpc_debugfs_entry *lpc = filp->private_data;
+        u32 data, pos, len, todo;
+        int rc;
+
+        if (!access_ok(VERIFY_READ, ubuf, count))
+                return -EFAULT;
+
+        todo = count;
+        while (todo) {
+                pos = *ppos;
+
+                /*
+                 * Select access size based on count and alignment and
+                 * access type. IO and MEM only support byte acceses,
+                 * FW supports all 3.
+                 */
+                len = 1;
+                if (lpc->lpc_type == OPAL_LPC_FW) {
+                        if (todo > 3 && (pos & 3) == 0)
+                                len = 4;
+                        else if (todo > 1 && (pos & 1) == 0)
+                                len = 2;
+                }
+                switch(len) {
+                case 4:
+                        rc = __get_user(data, (u32 __user *)ubuf);
+                        break;
+                case 2:
+                        rc = __get_user(data, (u16 __user *)ubuf);
+                        break;
+                default:
+                        rc = __get_user(data, (u8 __user *)ubuf);
+                        break;
+                }
+                if (rc)
+                        return -EFAULT;
+
+                rc = opal_lpc_write(opal_lpc_chip_id, lpc->lpc_type, pos,
+                                    data, len);
+                if (rc)
+                        return -ENXIO;
+                *ppos += len;
+                ubuf += len;
+                todo -= len;
+        }
+
+        return count;
+}
+
+static const struct file_operations lpc_fops = {
+        .read =         lpc_debug_read,
+        .write =        lpc_debug_write,
+        .open =         simple_open,
+        .llseek =       default_llseek,
+};
+
+static int opal_lpc_debugfs_create_type(struct dentry *folder,
+                                        const char *fname,
+                                        enum OpalLPCAddressType type)
+{
+        struct lpc_debugfs_entry *entry;
+        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+        if (!entry)
+                return -ENOMEM;
+        entry->lpc_type = type;
+        debugfs_create_file(fname, 0600, folder, entry, &lpc_fops);
+        return 0;
+}
+
+static int opal_lpc_init_debugfs(void)
+{
+        struct dentry *root;
+        int rc = 0;
+
+        if (opal_lpc_chip_id < 0)
+                return -ENODEV;
+
+        root = debugfs_create_dir("lpc", powerpc_debugfs_root);
+
+        rc |= opal_lpc_debugfs_create_type(root, "io", OPAL_LPC_IO);
+        rc |= opal_lpc_debugfs_create_type(root, "mem", OPAL_LPC_MEM);
+        rc |= opal_lpc_debugfs_create_type(root, "fw", OPAL_LPC_FW);
+        return rc;
+}
+device_initcall(opal_lpc_init_debugfs);
+#endif  /* CONFIG_DEBUG_FS */
+
 void opal_lpc_init(void)
 {
         struct device_node *np;