remoteproc: Introduce a sandbox dummy driver

Introduce a dummy driver for sandbox that allows us to verify basic
functionality. This is not meant to do anything functional - but is
more or less meant as a framework plumbing debug helper.

The sandbox remoteproc driver maintains absolutey no states and is a
simple driver which just is filled with empty hooks. Idea being to give
an approximate idea to implement own remoteproc driver using this as a
template.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/remoteproc/Kconfig

@@ -12,4 +12,13 @@ config REMOTEPROC
 	bool
 	depends on DM
 
+# Please keep the configuration alphabetically sorted.
+config REMOTEPROC_SANDBOX
+	bool "Support for Test processor for Sandbox"
+	select REMOTEPROC
+	depends on DM
+	depends on SANDBOX
+	help
+	  Say 'y' here to add support for test processor which does dummy
+	  operations for sandbox platform.
 endmenu

drivers/remoteproc/Makefile

@@ -5,3 +5,6 @@
 #
 
 obj-$(CONFIG_REMOTEPROC) += rproc-uclass.o
+
+# Remote proc drivers - Please keep this list alphabetically sorted.
+obj-$(CONFIG_REMOTEPROC_SANDBOX) += sandbox_testproc.o

drivers/remoteproc/sandbox_testproc.c

@@ -0,0 +1,336 @@
+/*
+ * (C) Copyright 2015
+ * Texas Instruments Incorporated - http://www.ti.com/
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#define pr_fmt(fmt) "%s: " fmt, __func__
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <remoteproc.h>
+
+/**
+ * enum sandbox_state - different device states
+ * @sb_booted:	Entry condition, just booted
+ * @sb_init:	Initialized (basic environment is ready)
+ * @sb_reset:	Held in reset (accessible, but not running)
+ * @sb_loaded:	Loaded with image (but not running)
+ * @sb_running:	Processor is running
+ */
+enum sandbox_state {
+	sb_booted,
+	sb_init,
+	sb_reset,
+	sb_loaded,
+	sb_running
+};
+
+/**
+ * struct sandbox_test_devdata - private data per device
+ * @current_state:	device current state
+ */
+struct sandbox_test_devdata {
+	enum sandbox_state current_state;
+};
+
+/**
+ * sandbox_dev_move_to_state() - statemachine for our dummy device
+ * @dev:	device to switch state
+ * @next_state:	next proposed state
+ *
+ * This tries to follow the following statemachine:
+ *           Entry
+ *            |
+ *            v
+ *         +-------+
+ *     +---+ init  |
+ *     |   |       | <---------------------+
+ *     |   +-------+                       |
+ *     |                                   |
+ *     |                                   |
+ *     |   +--------+                      |
+ * Load|   |  reset |                      |
+ *     |   |        | <----------+         |
+ *     |   +--------+            |         |
+ *     |        |Load            |         |
+ *     |        |                |         |
+ *     |   +----v----+   reset   |         |
+ *     +-> |         |    (opt)  |         |
+ *         |  Loaded +-----------+         |
+ *         |         |                     |
+ *         +----+----+                     |
+ *              | Start                    |
+ *          +---v-----+        (opt)       |
+ *       +->| Running |        Stop        |
+ * Ping  +- |         +--------------------+
+ * (opt)    +---------+
+ *
+ * (is_running does not change state)
+ *
+ * Return: 0 when valid state transition is seen, else returns -EINVAL
+ */
+static int sandbox_dev_move_to_state(struct udevice *dev,
+				     enum sandbox_state next_state)
+{
+	struct sandbox_test_devdata *ddata = dev_get_priv(dev);
+
+	/* No state transition is OK */
+	if (ddata->current_state == next_state)
+		return 0;
+
+	debug("current_state=%d, next_state=%d\n", ddata->current_state,
+	      next_state);
+	switch (ddata->current_state) {
+	case sb_booted:
+		if (next_state == sb_init)
+			goto ok_state;
+		break;
+
+	case sb_init:
+		if (next_state == sb_reset || next_state == sb_loaded)
+			goto ok_state;
+		break;
+
+	case sb_reset:
+		if (next_state == sb_loaded || next_state == sb_init)
+			goto ok_state;
+		break;
+
+	case sb_loaded:
+		if (next_state == sb_reset || next_state == sb_init ||
+		    next_state == sb_running)
+			goto ok_state;
+		break;
+
+	case sb_running:
+		if (next_state == sb_reset || next_state == sb_init)
+			goto ok_state;
+		break;
+	};
+	return -EINVAL;
+
+ok_state:
+	ddata->current_state = next_state;
+	return 0;
+}
+
+/**
+ * sandbox_testproc_probe() - basic probe function
+ * @dev:	test proc device that is being probed.
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_probe(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	struct sandbox_test_devdata *ddata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	ddata = dev_get_priv(dev);
+	if (!ddata) {
+		debug("%s: platform private data missing\n", uc_pdata->name);
+		return -EINVAL;
+	}
+	ret = sandbox_dev_move_to_state(dev, sb_booted);
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+
+	return ret;
+}
+
+/**
+ * sandbox_testproc_init() - Simple initialization function
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_init(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	ret = sandbox_dev_move_to_state(dev, sb_init);
+
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+	if (ret)
+		debug("%s init failed\n", uc_pdata->name);
+
+	return ret;
+}
+
+/**
+ * sandbox_testproc_reset() - Reset the remote processor
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_reset(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	ret = sandbox_dev_move_to_state(dev, sb_reset);
+
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+
+	if (ret)
+		debug("%s reset failed\n", uc_pdata->name);
+	return ret;
+}
+
+/**
+ * sandbox_testproc_load() - (replace: short desc)
+ * @dev:	device to operate upon
+ * @addr:	Address of the binary image to load
+ * @size:	Size (in bytes) of the binary image to load
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_load(struct udevice *dev, ulong addr, ulong size)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	ret = sandbox_dev_move_to_state(dev, sb_loaded);
+
+	debug("%s: called(%d) Loading to %08lX %lu size\n",
+	      uc_pdata->name, ret, addr, size);
+
+	if (ret)
+		debug("%s load failed\n", uc_pdata->name);
+	return ret;
+}
+
+/**
+ * sandbox_testproc_start() - Start the remote processor
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_start(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	ret = sandbox_dev_move_to_state(dev, sb_running);
+
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+
+	if (ret)
+		debug("%s start failed\n", uc_pdata->name);
+	return ret;
+}
+
+/**
+ * sandbox_testproc_stop() - Stop the remote processor
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int sandbox_testproc_stop(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	ret = sandbox_dev_move_to_state(dev, sb_init);
+
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+
+	if (ret)
+		debug("%s stop failed\n", uc_pdata->name);
+	return ret;
+}
+
+/**
+ * sandbox_testproc_is_running() - Check if remote processor is running
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if running, 1 if not running
+ */
+static int sandbox_testproc_is_running(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	struct sandbox_test_devdata *ddata;
+	int ret = 1;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	ddata = dev_get_priv(dev);
+
+	if (ddata->current_state == sb_running)
+		ret = 0;
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+
+	return ret;
+}
+
+/**
+ * sandbox_testproc_ping() - Try pinging remote processor
+ * @dev:	device to operate upon
+ *
+ * Return: 0 if running, -EINVAL if not running
+ */
+static int sandbox_testproc_ping(struct udevice *dev)
+{
+	struct dm_rproc_uclass_pdata *uc_pdata;
+	struct sandbox_test_devdata *ddata;
+	int ret;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	ddata = dev_get_priv(dev);
+
+	if (ddata->current_state == sb_running)
+		ret = 0;
+	else
+		ret = -EINVAL;
+
+	debug("%s: called(%d)\n", uc_pdata->name, ret);
+	if (ret)
+		debug("%s: No response.(Not started?)\n", uc_pdata->name);
+
+	return ret;
+}
+
+static const struct dm_rproc_ops sandbox_testproc_ops = {
+	.init = sandbox_testproc_init,
+	.reset = sandbox_testproc_reset,
+	.load = sandbox_testproc_load,
+	.start = sandbox_testproc_start,
+	.stop = sandbox_testproc_stop,
+	.is_running = sandbox_testproc_is_running,
+	.ping = sandbox_testproc_ping,
+};
+
+static const struct udevice_id sandbox_ids[] = {
+	{.compatible = "sandbox,test-processor"},
+	{}
+};
+
+U_BOOT_DRIVER(sandbox_testproc) = {
+	.name = "sandbox_test_proc",
+	.of_match = sandbox_ids,
+	.id = UCLASS_REMOTEPROC,
+	.ops = &sandbox_testproc_ops,
+	.probe = sandbox_testproc_probe,
+	.priv_auto_alloc_size = sizeof(struct sandbox_test_devdata),
+};
+
+/* TODO(nm@ti.com): Remove this along with non-DT support */
+static struct dm_rproc_uclass_pdata proc_3_test = {
+	.name = "proc_3_legacy",
+	.mem_type = RPROC_INTERNAL_MEMORY_MAPPED,
+};
+
+U_BOOT_DEVICE(proc_3_demo) = {
+	.name = "sandbox_test_proc",
+	.platdata = &proc_3_test,
+};