reset: implement a reset test

This adds a sandbox reset implementation (provider), a test client
device, instantiates them both from Sandbox's DT, and adds a DM test
that excercises everything.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/reset/Kconfig

@@ -12,4 +12,12 @@ config DM_RESET
 	  although driving such reset isgnals using GPIOs may be more
 	  appropriate in this case.
 
+config SANDBOX_RESET
+	bool "Enable the sandbox reset test driver"
+	depends on DM_MAILBOX && SANDBOX
+	help
+	  Enable support for a test reset controller implementation, which
+	  simply accepts requests to reset various HW modules without actually
+	  doing anything beyond a little error checking.
+
 endmenu

drivers/reset/Makefile

@@ -3,3 +3,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_DM_RESET) += reset-uclass.o
+obj-$(CONFIG_SANDBOX_MBOX) += sandbox-reset.o
+obj-$(CONFIG_SANDBOX_MBOX) += sandbox-reset-test.o

drivers/reset/sandbox-reset-test.c

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <reset.h>
+#include <asm/io.h>
+#include <asm/reset.h>
+
+struct sandbox_reset_test {
+	struct reset_ctl ctl;
+};
+
+int sandbox_reset_test_get(struct udevice *dev)
+{
+	struct sandbox_reset_test *sbrt = dev_get_priv(dev);
+
+	return reset_get_by_name(dev, "test", &sbrt->ctl);
+}
+
+int sandbox_reset_test_assert(struct udevice *dev)
+{
+	struct sandbox_reset_test *sbrt = dev_get_priv(dev);
+
+	return reset_assert(&sbrt->ctl);
+}
+
+int sandbox_reset_test_deassert(struct udevice *dev)
+{
+	struct sandbox_reset_test *sbrt = dev_get_priv(dev);
+
+	return reset_deassert(&sbrt->ctl);
+}
+
+int sandbox_reset_test_free(struct udevice *dev)
+{
+	struct sandbox_reset_test *sbrt = dev_get_priv(dev);
+
+	return reset_free(&sbrt->ctl);
+}
+
+static const struct udevice_id sandbox_reset_test_ids[] = {
+	{ .compatible = "sandbox,reset-ctl-test" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_reset_test) = {
+	.name = "sandbox_reset_test",
+	.id = UCLASS_MISC,
+	.of_match = sandbox_reset_test_ids,
+	.priv_auto_alloc_size = sizeof(struct sandbox_reset_test),
+};

drivers/reset/sandbox-reset.c

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <reset-uclass.h>
+#include <asm/io.h>
+#include <asm/reset.h>
+
+#define SANDBOX_RESET_SIGNALS 3
+
+struct sandbox_reset_signal {
+	bool asserted;
+};
+
+struct sandbox_reset {
+	struct sandbox_reset_signal signals[SANDBOX_RESET_SIGNALS];
+};
+
+static int sandbox_reset_request(struct reset_ctl *reset_ctl)
+{
+	debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
+
+	if (reset_ctl->id >= SANDBOX_RESET_SIGNALS)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int sandbox_reset_free(struct reset_ctl *reset_ctl)
+{
+	debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
+
+	return 0;
+}
+
+static int sandbox_reset_assert(struct reset_ctl *reset_ctl)
+{
+	struct sandbox_reset *sbr = dev_get_priv(reset_ctl->dev);
+
+	debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
+
+	sbr->signals[reset_ctl->id].asserted = true;
+
+	return 0;
+}
+
+static int sandbox_reset_deassert(struct reset_ctl *reset_ctl)
+{
+	struct sandbox_reset *sbr = dev_get_priv(reset_ctl->dev);
+
+	debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
+
+	sbr->signals[reset_ctl->id].asserted = false;
+
+	return 0;
+}
+
+static int sandbox_reset_bind(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	return 0;
+}
+
+static int sandbox_reset_probe(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	return 0;
+}
+
+static const struct udevice_id sandbox_reset_ids[] = {
+	{ .compatible = "sandbox,reset-ctl" },
+	{ }
+};
+
+struct reset_ops sandbox_reset_reset_ops = {
+	.request = sandbox_reset_request,
+	.free = sandbox_reset_free,
+	.rst_assert = sandbox_reset_assert,
+	.rst_deassert = sandbox_reset_deassert,
+};
+
+U_BOOT_DRIVER(sandbox_reset) = {
+	.name = "sandbox_reset",
+	.id = UCLASS_RESET,
+	.of_match = sandbox_reset_ids,
+	.bind = sandbox_reset_bind,
+	.probe = sandbox_reset_probe,
+	.priv_auto_alloc_size = sizeof(struct sandbox_reset),
+	.ops = &sandbox_reset_reset_ops,
+};
+
+int sandbox_reset_query(struct udevice *dev, unsigned long id)
+{
+	struct sandbox_reset *sbr = dev_get_priv(dev);
+
+	debug("%s(dev=%p, id=%ld)\n", __func__, dev, id);
+
+	if (id >= SANDBOX_RESET_SIGNALS)
+		return -EINVAL;
+
+	return sbr->signals[id].asserted;
+}