dm: x86: Add a uclass for an Low Pin Count (LPC) device

On x86 systems this device is commonly used to provide legacy port access.
It is sort-of a replacement for the old ISA bus.

Add a uclass for this, and allow it to have child devices.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index fe022f6..6c571dd 100644 (file)
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_HAVE_FSP) += cmd_hob.o
 obj-y  += gcc.o
 obj-y  += init_helpers.o
 obj-y  += interrupts.o
+obj-y  += lpc-uclass.o
 obj-y += cmd_mtrr.o
 obj-$(CONFIG_SYS_PCAT_INTERRUPTS) += pcat_interrupts.o
 obj-$(CONFIG_SYS_PCAT_TIMER) += pcat_timer.o

diff --git a/arch/x86/lib/lpc-uclass.c b/arch/x86/lib/lpc-uclass.c
new file mode 100644 (file)
index 0000000..6aeb4d4
--- /dev/null
+++ b/arch/x86/lib/lpc-uclass.c
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/root.h>
+
+static int lpc_uclass_post_bind(struct udevice *bus)
+{
+       /*
+        * Scan the device tree for devices
+        *
+        * Before relocation, only bind devices marked for pre-relocation
+        * use.
+        */
+       return dm_scan_fdt_node(bus, gd->fdt_blob, bus->of_offset,
+                               gd->flags & GD_FLG_RELOC ? false : true);
+}
+
+UCLASS_DRIVER(lpc) = {
+       .id             = UCLASS_LPC,
+       .name           = "lpc",
+       .post_bind      = lpc_uclass_post_bind,
+};

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 84a6955..79b51d3 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -39,6 +39,7 @@ enum uclass_id {
        UCLASS_PCI_GENERIC,     /* Generic PCI bus device */
        UCLASS_PCH,             /* x86 platform controller hub */
        UCLASS_ETH,             /* Ethernet device */
+       UCLASS_LPC,             /* x86 'low pin count' interface */
 
        UCLASS_COUNT,
        UCLASS_INVALID = -1,