[PATCH 06/10] ram: Add driver for K210 SRAM

[Sean Anderson]

This adds a driver to handle enabling the clock for the AI SRAM. This was
previously done in board_init, but it needs to happen before relocation
now. An alternative would be to move this to board_init_early_f, but by
doing it this way we can use clk_bulk.

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
---

 MAINTAINERS            |  1 +
 drivers/ram/Kconfig    |  7 ++++++
 drivers/ram/Makefile   |  1 +
 drivers/ram/kendryte.c | 56 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 65 insertions(+)
 create mode 100644 drivers/ram/kendryte.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7e46470c70..70e01e5e7a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -928,6 +928,7 @@ M:	Sean Anderson <seanga2 at gmail.com>
 S:	Maintained
 F:	doc/device-tree-bindings/mfd/kendryte,k210-sysctl.txt
 F:	drivers/clk/kendryte/
+F:	drivers/ram/kendryte.c
 F:	include/kendryte/
 
 RNG
diff --git a/drivers/ram/Kconfig b/drivers/ram/Kconfig
index 7e6e981897..faeacdf014 100644
--- a/drivers/ram/Kconfig
+++ b/drivers/ram/Kconfig
@@ -73,6 +73,13 @@ config IMXRT_SDRAM
 	  to support external memories like sdram, psram & nand.
 	  This driver is for the sdram memory interface with the SEMC.
 
+config K210_SRAM
+	bool "Enable Kendryte K210 SRAM support"
+	depends on RAM
+	help
+	  The Kendryte K210 has three banks of SRAM. This driver does the
+	  necessary initialization.
+
 source "drivers/ram/rockchip/Kconfig"
 source "drivers/ram/sifive/Kconfig"
 source "drivers/ram/stm32mp1/Kconfig"
diff --git a/drivers/ram/Makefile b/drivers/ram/Makefile
index 769c9d6218..d36b955e00 100644
--- a/drivers/ram/Makefile
+++ b/drivers/ram/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_K3_J721E_DDRSS) += k3-j721e/
 obj-$(CONFIG_IMXRT_SDRAM) += imxrt_sdram.o
 
 obj-$(CONFIG_RAM_SIFIVE) += sifive/
+obj-$(CONFIG_K210_SRAM) += kendryte.o
diff --git a/drivers/ram/kendryte.c b/drivers/ram/kendryte.c
new file mode 100644
index 0000000000..50818bf005
--- /dev/null
+++ b/drivers/ram/kendryte.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2 at gmail.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <ram.h>
+
+static int k210_sram_probe(struct udevice *dev)
+{
+	int ret;
+	struct clk_bulk clocks;
+
+	/* Relocate as high as possible to leave more space to load payloads */
+	ret = fdtdec_setup_mem_size_base_highest();
+	if (ret)
+		return ret;
+
+	/* Enable ram bank clocks */
+	ret = clk_get_bulk(dev, &clocks);
+	if (ret)
+		return ret;
+
+	ret = clk_enable_bulk(&clocks);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int k210_sram_get_info(struct udevice *dev, struct ram_info *info)
+{
+	info->base = gd->ram_base;
+	info->size = gd->ram_size;
+
+	return 0;
+}
+
+static struct ram_ops k210_sram_ops = {
+	.get_info = k210_sram_get_info,
+};
+
+static const struct udevice_id k210_sram_ids[] = {
+	{ .compatible = "kendryte,k210-sram" },
+	{ }
+};
+
+U_BOOT_DRIVER(fu540_ddr) = {
+	.name = "k210_sram",
+	.id = UCLASS_RAM,
+	.of_match = k210_sram_ids,
+	.ops = &k210_sram_ops,
+	.probe = k210_sram_probe,
+};
-- 
2.28.0