In response to new device tree code in the kernel, OLPC will start
using it for probing of certain devices. However, some firmware fixes
are needed to put the devicetree into a usable state.
Retain compatibility with old firmware by fixing up the device tree
at boot-time if it does not contain the new nodes/properties that
we need for probing.
Signed-off-by: Daniel Drake <d...@laptop.org>
---
arch/x86/platform/olpc/olpc_dt.c | 87 ++++++++++++++++++++++++++++++++++++++
1 files changed, 87 insertions(+), 0 deletions(-)
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
index 09cbede..58bba78 100644
--- a/arch/x86/platform/olpc/olpc_dt.c
+++ b/arch/x86/platform/olpc/olpc_dt.c
@@ -22,6 +22,7 @@
#include <linux/of_platform.h>
#include <linux/of_pdt.h>
#include <asm/olpc_ofw.h>
+#include <asm/olpc.h>
static phandle __init olpc_dt_getsibling(phandle node)
{
@@ -164,6 +165,91 @@ static struct of_pdt_ops prom_olpc_ops __initdata = {
.pkg2path = olpc_dt_pkg2path,
};
+static char __init *prom_alloc_string(const char *str, int *len)
+{
+ int _len = strlen(str);
+ char *output = prom_early_alloc(_len + 1);
+
+ strcpy(output, str);
+ if (len)
+ *len = _len;
+ return output;
+}
+
+static void __init prom_alloc_property(struct device_node *node,
+ const char *name, const char *value)
+{
+ struct property *p = prom_early_alloc(sizeof(struct property));
+
+ p->name = prom_alloc_string(name, NULL);
+ p->value = prom_alloc_string(value, &p->length);
+ prom_add_property(node, p);
+}
+
+/* Add dcon device as child of display */
+static void __init add_dcon_node(struct device_node *display)
+{
+ struct device_node *node = prom_early_alloc(sizeof(struct device_node));
+ unsigned long flags;
+
+ kref_init(&node->kref);
+ node->name = prom_alloc_string("dcon", NULL);
+ node->full_name = (char *) node->name;
+ node->parent = display;
+
+ write_lock_irqsave(&devtree_lock, flags);
+ node->sibling = node->parent->child;
+ node->allnext = allnodes;
+ node->parent->child = node;
+ allnodes = node;
+ write_unlock_irqrestore(&devtree_lock, flags);
+
+ prom_alloc_property(node, "compatible", "olpc,xo1-dcon");
+}
+
+static void __init olpc_dt_fixup(void)
+{
+ struct device_node *node;
+
+ /*
+ * Use battery's compatible property to determine if we're running a
+ * new-enough firmware. If we have this property, no fixups are needed.
+ */
+ node = of_find_node_by_name(NULL, "battery");
+ if (node && of_get_property(node, "compatible", NULL)) {
+ of_node_put(node);
+ return;
+ }
+
+ /*
+ * Add "compatible" property to battery, it was missing from earlier
+ * firmware releases.
+ */
+ prom_alloc_property(node, "compatible", "olpc,xo1-battery");
+ of_node_put(node);
+
+ /*
+ * Mark XO-1 RTC as compatible with olpc,xo1-rtc - this was not done in
+ * earlier firmware releases.
+ */
+ node = of_find_node_by_name(NULL, "rtc");
+ if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && node) {
+ struct property *p = of_get_property(node, "compatible", NULL);
+ prom_remove_property(node, p);
+ prom_alloc_property(node, "compatible", "olpc,xo1-rtc");
+ }
+ of_node_put(node);
+
+ /*
+ * Add "dcon" device node, it was missing from earlier firmware
+ * releases.
+ */
+ node = of_find_node_by_name(NULL, "display");
+ if (node)
+ add_dcon_node(node);
+ of_node_put(node);
+}
+
void __init olpc_dt_build_devicetree(void)
{
phandle root;
@@ -177,6 +263,7 @@ void __init olpc_dt_build_devicetree(void)
return;
}
of_pdt_build_devicetree(root, &prom_olpc_ops);
+ olpc_dt_fixup();
pr_info("PROM DT: Built device tree with %u bytes of memory.\n",
prom_early_allocated);
--
1.7.4
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