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> --- 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"); -- 1.7.4 _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss