[PATCH] ppc32: nvram driver for chrp

This implements a nvram acccess method, similar to
arch/ppc64/kernel/pSeries_nvram.c tested on CHRP B50.

Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 87 insertions, 2 deletions

diff --git a/arch/ppc/platforms/Makefile b/arch/ppc/platforms/Makefile
index ff7452e5d8e5..7c5cdabf6f3c 100644
--- a/arch/ppc/platforms/Makefile
+++ b/arch/ppc/platforms/Makefile
@@ -14,6 +14,9 @@ obj-$(CONFIG_PPC_PMAC)		+= pmac_pic.o pmac_setup.o pmac_time.o \
                                         pmac_low_i2c.o pmac_cache.o
 obj-$(CONFIG_PPC_CHRP)          += chrp_setup.o chrp_time.o chrp_pci.o \
                                         chrp_pegasos_eth.o
+ifeq ($(CONFIG_PPC_CHRP),y)
+obj-$(CONFIG_NVRAM)             += chrp_nvram.o
+endif
 obj-$(CONFIG_PPC_PREP)          += prep_pci.o prep_setup.o
 ifeq ($(CONFIG_PPC_PMAC),y)
 obj-$(CONFIG_NVRAM)             += pmac_nvram.o
diff --git a/arch/ppc/platforms/chrp_nvram.c b/arch/ppc/platforms/chrp_nvram.c
new file mode 100644
index 000000000000..465ba9b090ef
--- /dev/null
+++ b/arch/ppc/platforms/chrp_nvram.c
@@ -0,0 +1,83 @@
+/*
+ *  c 2001 PPC 64 Team, 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.
+ *
+ * /dev/nvram driver for PPC
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+
+static unsigned int nvram_size;
+static unsigned char nvram_buf[4];
+static DEFINE_SPINLOCK(nvram_lock);
+
+static unsigned char chrp_nvram_read(int addr)
+{
+        unsigned long done, flags;
+        unsigned char ret;
+
+        if (addr >= nvram_size) {
+                printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n",
+                       current->comm, addr, nvram_size);
+                return 0xff;
+        }
+        spin_lock_irqsave(&nvram_lock, flags);
+        if ((call_rtas("nvram-fetch", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done)
+                ret = 0xff;
+        else
+                ret = nvram_buf[0];
+        spin_unlock_irqrestore(&nvram_lock, flags);
+
+        return ret;
+}
+
+static void chrp_nvram_write(int addr, unsigned char val)
+{
+        unsigned long done, flags;
+
+        if (addr >= nvram_size) {
+                printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n",
+                       current->comm, addr, nvram_size);
+                return;
+        }
+        spin_lock_irqsave(&nvram_lock, flags);
+        nvram_buf[0] = val;
+        if ((call_rtas("nvram-store", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done)
+                printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr);
+        spin_unlock_irqrestore(&nvram_lock, flags);
+}
+
+void __init chrp_nvram_init(void)
+{
+        struct device_node *nvram;
+        unsigned int *nbytes_p, proplen;
+
+        nvram = of_find_node_by_type(NULL, "nvram");
+        if (nvram == NULL)
+                return;
+
+        nbytes_p = (unsigned int *)get_property(nvram, "#bytes", &proplen);
+        if (nbytes_p == NULL || proplen != sizeof(unsigned int))
+                return;
+
+        nvram_size = *nbytes_p;
+
+        printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size);
+        of_node_put(nvram);
+
+        ppc_md.nvram_read_val = chrp_nvram_read;
+        ppc_md.nvram_write_val = chrp_nvram_write;
+
+        return;
+}
diff --git a/arch/ppc/platforms/chrp_setup.c b/arch/ppc/platforms/chrp_setup.c
index dad81ffd4013..f1b70ab3c6fd 100644
--- a/arch/ppc/platforms/chrp_setup.c
+++ b/arch/ppc/platforms/chrp_setup.c
@@ -454,8 +454,7 @@ void __init
 chrp_init2(void)
 {
 #ifdef CONFIG_NVRAM
-// XX replace this in a more saner way
-//      pmac_nvram_init();
+        chrp_nvram_init();
 #endif
 
         request_region(0x20,0x20,"pic1");