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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-09-19 17:45:01 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-09-20 16:09:57 +1000
commit628daa8d5abfd904a7329a660c5c374212230123 (patch)
tree83981d6c9566dd6bb16c45ea43938df8ed5d350f /arch/powerpc/platforms/powernv/opal-nvram.c
parentec27329ffb3b4f619be9f0065c473fcb36ea52ce (diff)
downloadvexpress-lsk-628daa8d5abfd904a7329a660c5c374212230123.tar.gz
powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks
Implements OPAL RTC and NVRAM support and wire all that up to the powernv platform. We use RTAS for RTC as a fallback if available. Using RTAS for nvram is not supported yet, pending some rework/cleanup and generalization of the pSeries & CHRP code. We also use RTAS fallbacks for power off and reboot Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-nvram.c')
-rw-r--r--arch/powerpc/platforms/powernv/opal-nvram.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c
new file mode 100644
index 00000000000..3f83e1ae26a
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -0,0 +1,88 @@
+/*
+ * PowerNV nvram code.
+ *
+ * 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.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/opal.h>
+#include <asm/machdep.h>
+
+static unsigned int nvram_size;
+
+static ssize_t opal_nvram_size(void)
+{
+ return nvram_size;
+}
+
+static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index)
+{
+ s64 rc;
+ int off;
+
+ if (*index >= nvram_size)
+ return 0;
+ off = *index;
+ if ((off + count) > nvram_size)
+ count = nvram_size - off;
+ rc = opal_read_nvram(__pa(buf), count, off);
+ if (rc != OPAL_SUCCESS)
+ return -EIO;
+ *index += count;
+ return count;
+}
+
+static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index)
+{
+ s64 rc = OPAL_BUSY;
+ int off;
+
+ if (*index >= nvram_size)
+ return 0;
+ off = *index;
+ if ((off + count) > nvram_size)
+ count = nvram_size - off;
+
+ while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+ rc = opal_write_nvram(__pa(buf), count, off);
+ if (rc == OPAL_BUSY_EVENT)
+ opal_poll_events(NULL);
+ }
+ *index += count;
+ return count;
+}
+
+void __init opal_nvram_init(void)
+{
+ struct device_node *np;
+ const u32 *nbytes_p;
+
+ np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram");
+ if (np == NULL)
+ return;
+
+ nbytes_p = of_get_property(np, "#bytes", NULL);
+ if (!nbytes_p) {
+ of_node_put(np);
+ return;
+ }
+ nvram_size = *nbytes_p;
+
+ printk(KERN_INFO "OPAL nvram setup, %u bytes\n", nvram_size);
+ of_node_put(np);
+
+ ppc_md.nvram_read = opal_nvram_read;
+ ppc_md.nvram_write = opal_nvram_write;
+ ppc_md.nvram_size = opal_nvram_size;
+}
+