cpu/allwinner/a10: Add minimal ramstage driver

Change-Id: I857755976b17b0e492c086162f395a77933eeed8
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4698
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/allwinner/a10/Makefile.inc

@@ -8,6 +8,7 @@ bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += uart.c
 bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += uart_console.c
 
 romstage-y	+= bootblock_media.c
+romstage-y	+= cbmem.c
 romstage-y	+= clock.c
 romstage-y	+= pinmux.c
 romstage-y	+= timer.c
@@ -16,7 +17,9 @@ romstage-y	+= uart.c
 romstage-y	+= uart_console.c
 
 ramstage-y	+= bootblock_media.c
+ramstage-y	+= cbmem.c
 ramstage-y	+= clock.c
+ramstage-y	+= cpu.c
 ramstage-y	+= monotonic_timer.c
 ramstage-y	+= timer.c
 ramstage-y	+= twi.c

src/cpu/allwinner/a10/cbmem.c

@@ -0,0 +1,18 @@
+/*
+ * Provides cbmem utilities for romstage and ramstage
+ *
+ * Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include "ram_segs.h"
+#include <cbmem.h>
+
+#if IS_ENABLED(CONFIG_DYNAMIC_CBMEM)
+
+void *cbmem_top(void)
+{
+	return a1x_get_cbmem_top();
+}
+
+#endif

src/cpu/allwinner/a10/chip.h

@@ -0,0 +1,11 @@
+/*
+ * Allwinnwer A10 devicetree config struct
+ *
+ * Copyright (C) 2013  Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include <types.h>
+
+struct cpu_allwinner_a10_config {
+};

src/cpu/allwinner/a10/cpu.c

@@ -0,0 +1,48 @@
+/*
+ * Ramstage initialization for Allwinner CPUs
+ *
+ * Copyright (C) 2014 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include <console/console.h>
+#include <device/device.h>
+#include <cpu/cpu.h>
+#include <cbmem.h>
+
+
+static void cpu_enable_resources(device_t dev)
+{
+	ram_resource(dev, 0, CONFIG_SYS_SDRAM_BASE >> 10,
+		     CONFIG_DRAM_SIZE_MB << 10);
+	/* TODO: Declare CBFS cache as reserved? There's no guarantee we won't
+	 * overwrite it. It seems to stay intact, being so high in RAM
+	 */
+}
+
+static void cpu_init(device_t dev)
+{
+	/* TODO: Check if anything else needs to be explicitly initialized */
+}
+
+static void cpu_noop(device_t dev)
+{
+}
+
+static struct device_operations cpu_ops = {
+	.read_resources   = cpu_noop,
+	.set_resources    = cpu_noop,
+	.enable_resources = cpu_enable_resources,
+	.init             = cpu_init,
+	.scan_bus         = NULL,
+};
+
+static void a1x_cpu_enable_dev(device_t dev)
+{
+	dev->ops = &cpu_ops;
+}
+
+struct chip_operations cpu_allwinner_a10_ops = {
+	CHIP_NAME("CPU Allwinner A10")
+	.enable_dev = a1x_cpu_enable_dev,
+};

src/cpu/allwinner/a10/ram_segs.h

@@ -0,0 +1,30 @@
+/*
+ * How we use DRAM on Allwinner CPUs
+ *
+ * Copyright (C) 2014  Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include <config.h>
+
+/*
+ * Put CBMEM at top of RAM
+ */
+static inline void *a1x_get_cbmem_top(void)
+{
+	return (void *)CONFIG_SYS_SDRAM_BASE + (CONFIG_DRAM_SIZE_MB << 20);
+}
+
+/*
+ * By CBFS cache, we mean a cached copy, in RAM, of the entire CBFS region.
+ */
+static inline void *a1x_get_cbfs_cache_top(void)
+{
+	/* Arbitrary 16 MiB gap for cbmem tables and bouncebuffer */
+	return a1x_get_cbmem_top() - (16 << 20);
+}
+
+static inline void *a1x_get_cbfs_cache_base(void)
+{
+	return a1x_get_cbfs_cache_top() - CONFIG_ROM_SIZE;
+}