dm: Add support for RAM drivers

Add support for a driver which sets up DRAM and can return information about
the amount of RAM available. This is a first step towards moving RAM init
to driver model.

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

drivers/Kconfig

@@ -34,6 +34,8 @@ source "drivers/gpio/Kconfig"
 
 source "drivers/power/Kconfig"
 
+source "drivers/ram/Kconfig"
+
 source "drivers/hwmon/Kconfig"
 
 source "drivers/watchdog/Kconfig"

drivers/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_LED) += led/
 obj-y += misc/
 obj-y += pcmcia/
 obj-y += dfu/
+obj-$(CONFIG_RAM) += ram/
 obj-y += rtc/
 obj-y += sound/
 obj-y += tpm/

drivers/ram/Kconfig

@@ -0,0 +1,18 @@
+config RAM
+	bool "Enable RAM drivers using Driver Model"
+	depends on DM
+	help
+	  This allows drivers to be provided for SDRAM and other RAM
+	  controllers and their type to be specified in the board's device
+	  tree. Generally some parameters are required to set up the RAM and
+	  the RAM size can either be statically defined or dynamically
+	  detected.
+
+config SPL_RAM_SUPPORT
+	bool "Enable RAM support in SPL"
+	depends on RAM
+	help
+	  The RAM subsystem adds a small amount of overhead to the image.
+	  If this is acceptable and you have a need to use RAM drivers in
+	  SPL, enable this option. It might provide a cleaner interface to
+	  setting up RAM (e.g. SDRAM / DDR) within SPL.

drivers/ram/Makefile

@@ -0,0 +1,7 @@
+#
+# Copyright (c) 2015 Google, Inc
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+obj-$(CONFIG_RAM) += ram-uclass.o

drivers/ram/ram-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 <ram.h>
+#include <dm.h>
+#include <errno.h>
+#include <dm/lists.h>
+#include <dm/root.h>
+
+int ram_get_info(struct udevice *dev, struct ram_info *info)
+{
+	struct ram_ops *ops = ram_get_ops(dev);
+
+	if (!ops->get_info)
+		return -ENOSYS;
+
+	return ops->get_info(dev, info);
+}
+
+UCLASS_DRIVER(ram) = {
+	.id		= UCLASS_RAM,
+	.name		= "ram",
+};

include/dm/uclass-id.h

@@ -28,6 +28,7 @@ enum uclass_id {
 	UCLASS_CPU,		/* CPU, typically part of an SoC */
 	UCLASS_CROS_EC,		/* Chrome OS EC */
 	UCLASS_DISPLAY_PORT,	/* Display port video */
+	UCLASS_RAM,		/* RAM controller */
 	UCLASS_ETH,		/* Ethernet device */
 	UCLASS_GPIO,		/* Bank of general-purpose I/O pins */
 	UCLASS_I2C,		/* I2C bus */

include/ram.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __RAM_H
+#define __RAM_H
+
+struct ram_info {
+	phys_addr_t base;
+	size_t size;
+};
+
+struct ram_ops {
+	/**
+	 * get_info() - Get basic memory info
+	 *
+	 * @dev:	Device to check (UCLASS_RAM)
+	 * @info:	Place to put info
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*get_info)(struct udevice *dev, struct ram_info *info);
+};
+
+#define ram_get_ops(dev)        ((struct ram_ops *)(dev)->driver->ops)
+
+/**
+ * ram_get_info() - Get information about a RAM device
+ *
+ * @dev:	Device to check (UCLASS_RAM)
+ * @info:	Returns RAM info
+ * @return 0 if OK, -ve on error
+ */
+int ram_get_info(struct udevice *dev, struct ram_info *info);
+
+#endif

scripts/Makefile.spl

@@ -78,6 +78,7 @@ libs-$(CONFIG_SPL_NET_SUPPORT) += net/
 libs-$(CONFIG_SPL_ETH_SUPPORT) += drivers/net/
 libs-$(CONFIG_SPL_ETH_SUPPORT) += drivers/net/phy/
 libs-$(CONFIG_SPL_USBETH_SUPPORT) += drivers/net/phy/
+libs-$(CONFIG_SPL_RAM_SUPPORT) += drivers/ram/
 libs-$(CONFIG_SPL_MUSB_NEW_SUPPORT) += drivers/usb/musb-new/
 libs-$(CONFIG_SPL_USBETH_SUPPORT) += drivers/usb/gadget/
 libs-$(CONFIG_SPL_WATCHDOG_SUPPORT) += drivers/watchdog/