ram: add RAM driver for Broadcom MIPS SoCs

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/ram/Makefile

@@ -7,3 +7,4 @@
 obj-$(CONFIG_RAM) += ram-uclass.o
 obj-$(CONFIG_SANDBOX) += sandbox_ram.o
 obj-$(CONFIG_STM32_SDRAM) += stm32_sdram.o
+obj-$(CONFIG_ARCH_BMIPS) += bmips_ram.o

drivers/ram/bmips_ram.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/arch/mips/bcm63xx/cpu.c:
+ *	Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ *	Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <ram.h>
+#include <asm/io.h>
+#include <dm/device.h>
+
+#define MEMC_CFG_REG		0x4
+#define MEMC_CFG_32B_SHIFT	1
+#define MEMC_CFG_32B_MASK	(1 << MEMC_CFG_32B_SHIFT)
+#define MEMC_CFG_COL_SHIFT	3
+#define MEMC_CFG_COL_MASK	(0x3 << MEMC_CFG_COL_SHIFT)
+#define MEMC_CFG_ROW_SHIFT	6
+#define MEMC_CFG_ROW_MASK	(0x3 << MEMC_CFG_ROW_SHIFT)
+
+#define DDR_CSEND_REG		0x8
+
+struct bmips_ram_priv;
+
+struct bmips_ram_hw {
+	ulong (*get_ram_size)(struct bmips_ram_priv *);
+};
+
+struct bmips_ram_priv {
+	void __iomem *regs;
+	const struct bmips_ram_hw *hw;
+};
+
+static ulong bcm6328_get_ram_size(struct bmips_ram_priv *priv)
+{
+	return readl_be(priv->regs + DDR_CSEND_REG) << 24;
+}
+
+static ulong bcm6358_get_ram_size(struct bmips_ram_priv *priv)
+{
+	unsigned int cols = 0, rows = 0, is_32bits = 0, banks = 0;
+	u32 val;
+
+	val = readl_be(priv->regs + MEMC_CFG_REG);
+	rows = (val & MEMC_CFG_ROW_MASK) >> MEMC_CFG_ROW_SHIFT;
+	cols = (val & MEMC_CFG_COL_MASK) >> MEMC_CFG_COL_SHIFT;
+	is_32bits = (val & MEMC_CFG_32B_MASK) ? 0 : 1;
+	banks = 2;
+
+	/* 0 => 11 address bits ... 2 => 13 address bits */
+	rows += 11;
+
+	/* 0 => 8 address bits ... 2 => 10 address bits */
+	cols += 8;
+
+	return 1 << (cols + rows + (is_32bits + 1) + banks);
+}
+
+static int bmips_ram_get_info(struct udevice *dev, struct ram_info *info)
+{
+	struct bmips_ram_priv *priv = dev_get_priv(dev);
+	const struct bmips_ram_hw *hw = priv->hw;
+
+	info->base = 0x80000000;
+	info->size = hw->get_ram_size(priv);
+
+	return 0;
+}
+
+static const struct ram_ops bmips_ram_ops = {
+	.get_info = bmips_ram_get_info,
+};
+
+static const struct bmips_ram_hw bmips_ram_bcm6328 = {
+	.get_ram_size = bcm6328_get_ram_size,
+};
+
+static const struct bmips_ram_hw bmips_ram_bcm6358 = {
+	.get_ram_size = bcm6358_get_ram_size,
+};
+
+static const struct udevice_id bmips_ram_ids[] = {
+	{
+		.compatible = "brcm,bcm6328-mc",
+		.data = (ulong)&bmips_ram_bcm6328,
+	}, {
+		.compatible = "brcm,bcm6358-mc",
+		.data = (ulong)&bmips_ram_bcm6358,
+	}, {
+		.compatible = "brcm,bcm63268-mc",
+		.data = (ulong)&bmips_ram_bcm6328,
+	},
+	{ /* sentinel */ }
+};
+
+static int bmips_ram_probe(struct udevice *dev)
+{
+	struct bmips_ram_priv *priv = dev_get_priv(dev);
+	const struct bmips_ram_hw *hw =
+		(const struct bmips_ram_hw *)dev_get_driver_data(dev);
+	fdt_addr_t addr;
+	fdt_size_t size;
+
+	addr = dev_get_addr_size_index(dev, 0, &size);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	priv->regs = ioremap(addr, size);
+	priv->hw = hw;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(bmips_ram) = {
+	.name = "bmips-mc",
+	.id = UCLASS_RAM,
+	.of_match = bmips_ram_ids,
+	.probe = bmips_ram_probe,
+	.priv_auto_alloc_size = sizeof(struct bmips_ram_priv),
+	.ops = &bmips_ram_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};