rockchip: rk3328: add sdram driver in U-Boot

Add sdram driver in U-Boot for get the correct sdram size from
sys_reg, so that U-Boot can co-work with Rockchip loader or SPL
to get different dram capability and then tell the kernel.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

arch/arm/mach-rockchip/rk3328/Makefile

@@ -6,4 +6,5 @@
 
 obj-y += clk_rk3328.o
 obj-y += rk3328.o
+obj-y += sdram_rk3328.o
 obj-y += syscon_rk3328.o

arch/arm/mach-rockchip/rk3328/sdram_rk3328.c

+/*
+ * (C) Copyright 2017 Rockchip Electronics Co., Ltd.
+ *
+ * SPDX-License-Identifier:     GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <ram.h>
+#include <syscon.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/grf_rk3328.h>
+#include <asm/arch/sdram_common.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+struct dram_info {
+	struct ram_info info;
+	struct rk3328_grf_regs *grf;
+};
+
+static int rk3328_dmc_probe(struct udevice *dev)
+{
+	struct dram_info *priv = dev_get_priv(dev);
+
+	priv->grf = syscon_get_first_range(ROCKCHIP_SYSCON_GRF);
+	debug("%s: grf=%p\n", __func__, priv->grf);
+	priv->info.base = CONFIG_SYS_SDRAM_BASE;
+	priv->info.size = rockchip_sdram_size(
+				(phys_addr_t)&priv->grf->os_reg[2]);
+
+	return 0;
+}
+
+static int rk3328_dmc_get_info(struct udevice *dev, struct ram_info *info)
+{
+	struct dram_info *priv = dev_get_priv(dev);
+
+	*info = priv->info;
+
+	return 0;
+}
+
+static struct ram_ops rk3328_dmc_ops = {
+	.get_info = rk3328_dmc_get_info,
+};
+
+
+static const struct udevice_id rk3328_dmc_ids[] = {
+	{ .compatible = "rockchip,rk3328-dmc" },
+	{ }
+};
+
+U_BOOT_DRIVER(dmc_rk3328) = {
+	.name = "rockchip_rk3328_dmc",
+	.id = UCLASS_RAM,
+	.of_match = rk3328_dmc_ids,
+	.ops = &rk3328_dmc_ops,
+	.probe = rk3328_dmc_probe,
+	.priv_auto_alloc_size = sizeof(struct dram_info),
+};