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. This is the same approach taken on PPC platforms.
Signed-off-by: Daniel Drake <d...@laptop.org>
Acked-by: Grant Likely <grant.lik...@secretlab.ca>
Acked-by: Andres Salomon <dilin...@queued.net>
Cc: devicetree-discuss@lists.ozlabs.org
---
arch/x86/platform/olpc/olpc_dt.c | 103 ++++++++++++++++++++++++++++++++++++++
1 files changed, 103 insertions(+), 0 deletions(-)
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
index d39f63d..d6ee929 100644
--- a/arch/x86/platform/olpc/olpc_dt.c
+++ b/arch/x86/platform/olpc/olpc_dt.c
@@ -165,6 +165,107 @@ static struct of_pdt_ops prom_olpc_ops __initdata = {
.pkg2path = olpc_dt_pkg2path,
};
+static phandle __init olpc_dt_finddevice(const char *path)
+{
+ phandle node;
+ const void *args[] = { path };
+ void *res[] = { &node };
+
+ if (olpc_ofw("finddevice", args, res)) {
+ pr_err("olpc_dt: finddevice failed!\n");
+ return 0;
+ }
+
+ if ((s32) node == -1)
+ return 0;
+
+ return node;
+}
+
+static int __init olpc_dt_interpret(const char *words)
+{
+ int result;
+ const void *args[] = { words };
+ void *res[] = { &result };
+
+ if (olpc_ofw("interpret", args, res)) {
+ pr_err("olpc_dt: interpret failed!\n");
+ return -1;
+ }
+
+ return result;
+}
+
+/*
+ * Extract board revision directly from OFW device tree.
+ * We can't use olpc_platform_info because that hasn't been set up yet.
+ */
+static u32 __init olpc_dt_get_board_revision(void)
+{
+ phandle node;
+ __be32 rev;
+ int r;
+
+ node = olpc_dt_finddevice("/");
+ if (!node)
+ return 0;
+
+ r = olpc_dt_getproperty(node, "board-revision-int",
+ (char *) &rev, sizeof(rev));
+ if (r < 0)
+ return 0;
+
+ return be32_to_cpu(rev);
+}
+
+void __init olpc_dt_fixup(void)
+{
+ int r;
+ char buf[64];
+ phandle node;
+ u32 board_rev;
+
+ node = olpc_dt_finddevice("/battery@0");
+ if (!node)
+ return;
+
+ /*
+ * If the battery node has a compatible property, we are running a new
+ * enough firmware and don't have fixups to make.
+ */
+ r = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
+ if (r > 0)
+ return;
+
+ pr_info("PROM DT: Old firmware detected, applying fixes\n");
+
+ /* Add olpc,xo1-battery compatible marker to battery node */
+ olpc_dt_interpret("\" /battery@0\" find-device"
+ " \" olpc,xo1-battery\" +compatible"
+ " device-end");
+
+ board_rev = olpc_dt_get_board_revision();
+ if (!board_rev)
+ return;
+
+ if (board_rev >= olpc_board_pre(0xd0)) {
+ /* XO-1.5: add dcon device */
+ olpc_dt_interpret("\" /pci/display@1\" find-device"
+ " new-device"
+ " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
+ " finish-device device-end");
+ } else {
+ /* XO-1: add dcon device, mark RTC as olpc,xo1-rtc */
+ olpc_dt_interpret("\" /pci/display@1,1\" find-device"
+ " new-device"
+ " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
+ " finish-device device-end"
+ " \" /rtc\" find-device"
+ " \" olpc,xo1-rtc\" +compatible"
+ " device-end");
+ }
+}
+
void __init olpc_dt_build_devicetree(void)
{
phandle root;
@@ -172,6 +273,8 @@ void __init olpc_dt_build_devicetree(void)
if (!olpc_ofw_is_installed())
return;
+ olpc_dt_fixup();
+
root = olpc_dt_getsibling(0);
if (!root) {
pr_err("PROM: unable to get root node from OFW!\n");
--
1.7.5.2
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