powerpc/powernv: Basic support for OPAL

[pandora-kernel.git] / arch / powerpc / platforms / powernv / opal.c

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
new file mode 100644 (file)
index 0000000..8d55107
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -0,0 +1,154 @@
+/*
+ * PowerNV OPAL high level interfaces
+ *
+ * Copyright 2011 IBM Corp.
+ *
+ * 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.
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+#include "powernv.h"
+
+struct opal {
+       u64 base;
+       u64 entry;
+} opal;
+
+static struct device_node *opal_node;
+static DEFINE_SPINLOCK(opal_write_lock);
+
+int __init early_init_dt_scan_opal(unsigned long node,
+                                  const char *uname, int depth, void *data)
+{
+       const void *basep, *entryp;
+       unsigned long basesz, entrysz;
+
+       if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
+               return 0;
+
+       basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
+       entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
+
+       if (!basep || !entryp)
+               return 1;
+
+       opal.base = of_read_number(basep, basesz/4);
+       opal.entry = of_read_number(entryp, entrysz/4);
+
+       pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%ld)\n",
+                opal.base, basep, basesz);
+       pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%ld)\n",
+                opal.entry, entryp, entrysz);
+
+       powerpc_firmware_features |= FW_FEATURE_OPAL;
+       if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
+               powerpc_firmware_features |= FW_FEATURE_OPALv2;
+               printk("OPAL V2 detected !\n");
+       } else {
+               printk("OPAL V1 detected !\n");
+       }
+
+       return 1;
+}
+
+int opal_get_chars(uint32_t vtermno, char *buf, int count)
+{
+       s64 len, rc;
+       u64 evt;
+
+       if (!opal.entry)
+               return 0;
+       opal_poll_events(&evt);
+       if ((evt & OPAL_EVENT_CONSOLE_INPUT) == 0)
+               return 0;
+       len = count;
+       rc = opal_console_read(vtermno, &len, buf);
+       if (rc == OPAL_SUCCESS)
+               return len;
+       return 0;
+}
+
+int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
+{
+       int written = 0;
+       s64 len, rc = OPAL_BUSY;
+       unsigned long flags;
+       u64 evt;
+
+       if (!opal.entry)
+               return 0;
+
+       /* We want put_chars to be atomic to avoid mangling of hvsi
+        * packets. To do that, we first test for room and return
+        * -EAGAIN if there isn't enough
+        */
+       spin_lock_irqsave(&opal_write_lock, flags);
+       rc = opal_console_write_buffer_space(vtermno, &len);
+       if (rc || len < total_len) {
+               spin_unlock_irqrestore(&opal_write_lock, flags);
+               /* Closed -> drop characters */
+               if (rc)
+                       return total_len;
+               opal_poll_events(&evt);
+               return -EAGAIN;
+       }
+
+       /* We still try to handle partial completions, though they
+        * should no longer happen.
+        */
+       while(total_len > 0 && (rc == OPAL_BUSY ||
+                               rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
+               len = total_len;
+               rc = opal_console_write(vtermno, &len, data);
+               if (rc == OPAL_SUCCESS) {
+                       total_len -= len;
+                       data += len;
+                       written += len;
+               }
+               /* This is a bit nasty but we need that for the console to
+                * flush when there aren't any interrupts. We will clean
+                * things a bit later to limit that to synchronous path
+                * such as the kernel console and xmon/udbg
+                */
+               do
+                       opal_poll_events(&evt);
+               while(rc == OPAL_SUCCESS && (evt & OPAL_EVENT_CONSOLE_OUTPUT));
+       }
+       spin_unlock_irqrestore(&opal_write_lock, flags);
+       return written;
+}
+
+static int __init opal_init(void)
+{
+       struct device_node *np, *consoles;
+
+       opal_node = of_find_node_by_path("/ibm,opal");
+       if (!opal_node) {
+               pr_warn("opal: Node not found\n");
+               return -ENODEV;
+       }
+       if (firmware_has_feature(FW_FEATURE_OPALv2))
+               consoles = of_find_node_by_path("/ibm,opal/consoles");
+       else
+               consoles = of_node_get(opal_node);
+
+       /* Register serial ports */
+       for_each_child_of_node(consoles, np) {
+               if (strcmp(np->name, "serial"))
+                       continue;
+               of_platform_device_create(np, NULL, NULL);
+       }
+       of_node_put(consoles);
+       return 0;
+}
+subsys_initcall(opal_init);