dm: memory: Introduce new uclass

Introduce UCLASS_MEMORY for future Memory Controller
device drivers.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sandbox/dts/test.dts

@@ -932,6 +932,10 @@
 		};
 	};
 
+	memory-controller {
+		compatible = "sandbox,memory";
+	};
+
 	misc-test {
 		#address-cells = <1>;
 		#size-cells = <1>;

drivers/memory/Kconfig

@@ -4,6 +4,23 @@
 
 menu "Memory Controller drivers"
 
+config MEMORY
+	bool "Enable Driver Model for Memory Controller drivers"
+	depends on DM
+	help
+	  Enable driver model for Memory Controller devices.
+	  These devices provide Memory bus interface to various devices like
+	  SRAM, Ethernet adapters, FPGAs, etc.
+	  For now this uclass has no methods yet.
+
+config SANDBOX_MEMORY
+	bool "Enable Sandbox Memory Controller driver"
+	depends on SANDBOX && MEMORY
+	help
+	  This is a driver model based Memory Controller driver for sandbox.
+	  Currently it is a stub only, as there are no usable uclass methods
+	  yet.
+
 config STM32_FMC2_EBI
 	bool "Support for FMC2 External Bus Interface on STM32MP SoCs"
 	depends on ARCH_STM32MP

drivers/memory/Makefile

@@ -1,3 +1,5 @@
 
+obj-$(CONFIG_MEMORY) += memory-uclass.o
+obj-$(CONFIG_SANDBOX_MEMORY) += memory-sandbox.o
 obj-$(CONFIG_STM32_FMC2_EBI) += stm32-fmc2-ebi.o
 obj-$(CONFIG_TI_AEMIF) += ti-aemif.o

drivers/memory/memory-sandbox.c

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022
+ *     Texas Instruments Incorporated, <www.ti.com>
+ */
+
+#include <dm.h>
+
+static const struct udevice_id sandbox_memory_match[] = {
+	{ .compatible = "sandbox,memory" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(sandbox_memory) = {
+	.name	= "sandbox_memory",
+	.id	= UCLASS_MEMORY,
+	.of_match = sandbox_memory_match,
+};

drivers/memory/memory-uclass.c

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022
+ *     Texas Instruments Incorporated, <www.ti.com>
+ */
+
+#include <dm.h>
+
+UCLASS_DRIVER(memory) = {
+	.name = "memory",
+	.id = UCLASS_MEMORY,
+	.post_bind = dm_scan_fdt_dev,
+};

include/dm/uclass-id.h

@@ -77,6 +77,7 @@ enum uclass_id {
 	UCLASS_MASS_STORAGE,	/* Mass storage device */
 	UCLASS_MDIO,		/* MDIO bus */
 	UCLASS_MDIO_MUX,	/* MDIO MUX/switch */
+	UCLASS_MEMORY,		/* Memory Controller device */
 	UCLASS_MISC,		/* Miscellaneous device */
 	UCLASS_MMC,		/* SD / MMC card or chip */
 	UCLASS_MOD_EXP,		/* RSA Mod Exp device */

test/dm/Makefile

@@ -57,6 +57,7 @@ obj-$(CONFIG_LED) += led.o
 obj-$(CONFIG_DM_MAILBOX) += mailbox.o
 obj-$(CONFIG_DM_MDIO) += mdio.o
 obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o
+obj-$(CONFIG_MEMORY) += memory.o
 obj-$(CONFIG_MISC) += misc.o
 obj-$(CONFIG_DM_MMC) += mmc.o
 obj-$(CONFIG_CMD_MUX) += mux-cmd.o

test/dm/memory.c

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022
+ *     Texas Instruments Incorporated, <www.ti.com>
+ */
+
+#include <dm.h>
+#include <dm/test.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+static int dm_test_memory(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_first_device_err(UCLASS_MEMORY, &dev));
+
+	return 0;
+}
+
+DM_TEST(dm_test_memory, UT_TESTF_SCAN_FDT);