sandbox: Add a warm and cold reset driver

Add drivers for sandbox. One can only perform a warm reset (which does
nothing). The other can perform a cold reset or a power reset (the
latter will quit U-Boot). These can be used for testing the reset uclass.

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

drivers/misc/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_MXC_OCOTP) += mxc_ocotp.o
 obj-$(CONFIG_MXS_OCOTP) += mxs_ocotp.o
 obj-$(CONFIG_NS87308) += ns87308.o
 obj-$(CONFIG_PDSP188x) += pdsp188x.o
+obj-$(CONFIG_SANDBOX) += reset_sandbox.o
 ifdef CONFIG_DM_I2C
 obj-$(CONFIG_SANDBOX) += i2c_eeprom_emul.o
 endif

drivers/misc/reset_sandbox.c

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <reset.h>
+#include <asm/state.h>
+#include <asm/test.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int sandbox_warm_reset_request(struct udevice *dev, enum reset_t type)
+{
+	struct sandbox_state *state = state_get_current();
+
+	switch (type) {
+	case RESET_WARM:
+		state->last_reset = type;
+		break;
+	default:
+		return -ENOSYS;
+	}
+	if (!state->reset_allowed[type])
+		return -EACCES;
+
+	return -EINPROGRESS;
+}
+
+static int sandbox_reset_request(struct udevice *dev, enum reset_t type)
+{
+	struct sandbox_state *state = state_get_current();
+
+	/*
+	 * If we have a device tree, the device we created from platform data
+	 * (see the U_BOOT_DEVICE() declaration below) should not do anything.
+	 * If we are that device, return an error.
+	 */
+	if (gd->fdt_blob && dev->of_offset == -1)
+		return -ENODEV;
+
+	switch (type) {
+	case RESET_COLD:
+		state->last_reset = type;
+		break;
+	case RESET_POWER:
+		state->last_reset = type;
+		if (!state->reset_allowed[type])
+			return -EACCES;
+		/* TODO: sandbox_exit(); */
+		break;
+	default:
+		return -ENOSYS;
+	}
+	if (!state->reset_allowed[type])
+		return -EACCES;
+
+	return -EINPROGRESS;
+}
+
+static struct reset_ops sandbox_reset_ops = {
+	.request	= sandbox_reset_request,
+};
+
+static const struct udevice_id sandbox_reset_ids[] = {
+	{ .compatible = "sandbox,reset" },
+	{ }
+};
+
+U_BOOT_DRIVER(reset_sandbox) = {
+	.name		= "reset_sandbox",
+	.id		= UCLASS_RESET,
+	.of_match	= sandbox_reset_ids,
+	.ops		= &sandbox_reset_ops,
+};
+
+static struct reset_ops sandbox_warm_reset_ops = {
+	.request	= sandbox_warm_reset_request,
+};
+
+static const struct udevice_id sandbox_warm_reset_ids[] = {
+	{ .compatible = "sandbox,warm-reset" },
+	{ }
+};
+
+U_BOOT_DRIVER(warm_reset_sandbox) = {
+	.name		= "warm_reset_sandbox",
+	.id		= UCLASS_RESET,
+	.of_match	= sandbox_warm_reset_ids,
+	.ops		= &sandbox_warm_reset_ops,
+};
+
+/* This is here in case we don't have a device tree */
+U_BOOT_DEVICE(reset_sandbox_non_fdt) = {
+	.name = "reset_sandbox",
+};