test/py: add DFU test

Add a test of DFU functionality to the Python test suite. The test
starts DFU in U-Boot, waits for USB device enumeration on the host,
executes dfu-util multiple times to test various transfer sizes, many
of which trigger USB driver edge cases, and finally aborts the DFU
command in U-Boot.

This test mirrors the functionality previously available via the shell
scripts in test/dfu, and hence those are removed too.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/test/py/tests/test_dfu.py b/test/py/tests/test_dfu.py
new file mode 100644
index 0000000..cc4b8d8
--- /dev/null
+++ b/test/py/tests/test_dfu.py
@@ -0,0 +1,262 @@
+# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0
+
+# Test U-Boot's "dfu" command. The test starts DFU in U-Boot, waits for USB
+# device enumeration on the host, executes dfu-util multiple times to test
+# various transfer sizes, many of which trigger USB driver edge cases, and
+# finally aborts the "dfu" command in U-Boot.
+
+import os
+import os.path
+import pytest
+import u_boot_utils
+
+'''
+Note: This test relies on:
+
+a) boardenv_* to contain configuration values to define which USB ports are
+available for testing. Without this, this test will be automatically skipped.
+For example:
+
+env__usb_dev_ports = (
+    {
+        "tgt_usb_ctlr": "0",
+        "host_usb_dev_node": "/dev/usbdev-p2371-2180",
+        # This parameter is optional /if/ you only have a single board
+        # attached to your host at a time.
+        "host_usb_port_path": "3-13",
+    },
+)
+
+env__dfu_configs = (
+    # eMMC, partition 1
+    {
+        "alt_info": "/dfu_test.bin ext4 0 1;/dfu_dummy.bin ext4 0 1",
+        "cmd_params": "mmc 0",
+    },
+)
+b) udev rules to set permissions on devices nodes, so that sudo is not
+required. For example:
+
+ACTION=="add", SUBSYSTEM=="block", SUBSYSTEMS=="usb", KERNELS=="3-13", MODE:="666"
+
+(You may wish to change the group ID instead of setting the permissions wide
+open. All that matters is that the user ID running the test can access the
+device.)
+'''
+
+# The set of file sizes to test. These values trigger various edge-cases such
+# as one less than, equal to, and one greater than typical USB max packet
+# sizes, and similar boundary conditions.
+test_sizes = (
+    64 - 1,
+    64,
+    64 + 1,
+    128 - 1,
+    128,
+    128 + 1,
+    960 - 1,
+    960,
+    960 + 1,
+    4096 - 1,
+    4096,
+    4096 + 1,
+    1024 * 1024 - 1,
+    1024 * 1024,
+    8 * 1024 * 1024,
+)
+
+first_usb_dev_port = None
+
+@pytest.mark.buildconfigspec('cmd_dfu')
+def test_dfu(u_boot_console, env__usb_dev_port, env__dfu_config):
+    '''Test the "dfu" command; the host system must be able to enumerate a USB
+    device when "dfu" is running, various DFU transfers are tested, and the
+    USB device must disappear when "dfu" is aborted.
+
+    Args:
+        u_boot_console: A U-Boot console connection.
+        env__usb_dev_port: The single USB device-mode port specification on
+            which to run the test. See the file-level comment above for
+            details of the format.
+        env__dfu_config: The single DFU (memory region) configuration on which
+            to run the test. See the file-level comment above for details
+            of the format.
+
+    Returns:
+        Nothing.
+    '''
+
+    def start_dfu():
+        '''Start U-Boot's dfu shell command.
+
+        This also waits for the host-side USB enumeration process to complete.
+
+        Args:
+            None.
+
+        Returns:
+            Nothing.
+        '''
+
+        u_boot_console.log.action(
+            'Starting long-running U-Boot dfu shell command')
+
+        cmd = 'setenv dfu_alt_info "%s"' % env__dfu_config['alt_info']
+        u_boot_console.run_command(cmd)
+
+        cmd = 'dfu 0 ' + env__dfu_config['cmd_params']
+        u_boot_console.run_command(cmd, wait_for_prompt=False)
+        u_boot_console.log.action('Waiting for DFU USB device to appear')
+        fh = u_boot_utils.wait_until_open_succeeds(
+            env__usb_dev_port['host_usb_dev_node'])
+        fh.close()
+
+    def stop_dfu(ignore_errors):
+        '''Stop U-Boot's dfu shell command from executing.
+
+        This also waits for the host-side USB de-enumeration process to
+        complete.
+
+        Args:
+            ignore_errors: Ignore any errors. This is useful if an error has
+                already been detected, and the code is performing best-effort
+                cleanup. In this case, we do not want to mask the original
+                error by "honoring" any new errors.
+
+        Returns:
+            Nothing.
+        '''
+
+        try:
+            u_boot_console.log.action(
+                'Stopping long-running U-Boot dfu shell command')
+            u_boot_console.ctrlc()
+            u_boot_console.log.action(
+                'Waiting for DFU USB device to disappear')
+            u_boot_utils.wait_until_file_open_fails(
+                env__usb_dev_port['host_usb_dev_node'], ignore_errors)
+        except:
+            if not ignore_errors:
+                raise
+
+    def run_dfu_util(alt_setting, fn, up_dn_load_arg):
+        '''Invoke dfu-util on the host.
+
+        Args:
+            alt_setting: The DFU "alternate setting" identifier to interact
+                with.
+            fn: The host-side file name to transfer.
+            up_dn_load_arg: '-U' or '-D' depending on whether a DFU upload or
+                download operation should be performed.
+
+        Returns:
+            Nothing.
+        '''
+
+        cmd = ['dfu-util', '-a', str(alt_setting), up_dn_load_arg, fn]
+        if 'host_usb_port_path' in env__usb_dev_port:
+            cmd += ['-p', env__usb_dev_port['host_usb_port_path']]
+        u_boot_utils.run_and_log(u_boot_console, cmd)
+        u_boot_console.wait_for('Ctrl+C to exit ...')
+
+    def dfu_write(alt_setting, fn):
+        '''Write a file to the target board using DFU.
+
+        Args:
+            alt_setting: The DFU "alternate setting" identifier to interact
+                with.
+            fn: The host-side file name to transfer.
+
+        Returns:
+            Nothing.
+        '''
+
+        run_dfu_util(alt_setting, fn, '-D')
+
+    def dfu_read(alt_setting, fn):
+        '''Read a file from the target board using DFU.
+
+        Args:
+            alt_setting: The DFU "alternate setting" identifier to interact
+                with.
+            fn: The host-side file name to transfer.
+
+        Returns:
+            Nothing.
+        '''
+
+        # dfu-util fails reads/uploads if the host file already exists
+        if os.path.exists(fn):
+            os.remove(fn)
+        run_dfu_util(alt_setting, fn, '-U')
+
+    def dfu_write_read_check(size):
+        '''Test DFU transfers of a specific size of data
+
+        This function first writes data to the board then reads it back and
+        compares the written and read back data. Measures are taken to avoid
+        certain types of false positives.
+
+        Args:
+            size: The data size to test.
+
+        Returns:
+            Nothing.
+        '''
+
+        test_f = u_boot_utils.PersistentRandomFile(u_boot_console,
+            'dfu_%d.bin' % size, size)
+        readback_fn = u_boot_console.config.result_dir + '/dfu_readback.bin'
+
+        u_boot_console.log.action('Writing test data to DFU primary ' +
+            'altsetting')
+        dfu_write(0, test_f.abs_fn)
+
+        u_boot_console.log.action('Writing dummy data to DFU secondary ' +
+            'altsetting to clear DFU buffers')
+        dfu_write(1, dummy_f.abs_fn)
+
+        u_boot_console.log.action('Reading DFU primary altsetting for ' +
+            'comparison')
+        dfu_read(0, readback_fn)
+
+        u_boot_console.log.action('Comparing written and read data')
+        written_hash = test_f.content_hash
+        read_back_hash = u_boot_utils.md5sum_file(readback_fn, size)
+        assert(written_hash == read_back_hash)
+
+    # This test may be executed against multiple USB ports. The test takes a
+    # long time, so we don't want to do the whole thing each time. Instead,
+    # execute the full test on the first USB port, and perform a very limited
+    # test on other ports. In the limited case, we solely validate that the
+    # host PC can enumerate the U-Boot USB device.
+    global first_usb_dev_port
+    if not first_usb_dev_port:
+        first_usb_dev_port = env__usb_dev_port
+    if env__usb_dev_port == first_usb_dev_port:
+        sizes = test_sizes
+    else:
+        sizes = []
+
+    dummy_f = u_boot_utils.PersistentRandomFile(u_boot_console,
+        'dfu_dummy.bin', 1024)
+
+    ignore_cleanup_errors = True
+    try:
+        start_dfu()
+
+        u_boot_console.log.action(
+            'Overwriting DFU primary altsetting with dummy data')
+        dfu_write(0, dummy_f.abs_fn)
+
+        for size in sizes:
+            with u_boot_console.log.section("Data size %d" % size):
+                dfu_write_read_check(size)
+                # Make the status of each sub-test obvious. If the test didn't
+                # pass, an exception was thrown so this code isn't executed.
+                u_boot_console.log.status_pass('OK')
+        ignore_cleanup_errors = False
+    finally:
+        stop_dfu(ignore_cleanup_errors)