wimax: move out to staging

There are no known users of this driver as of October 2020, and it will
be removed unless someone turns out to still need it in future releases.

According to https://en.wikipedia.org/wiki/List_of_WiMAX_networks, there
have been many public wimax networks, but it appears that many of these
have migrated to LTE or discontinued their service altogether.
As most PCs and phones lack WiMAX hardware support, the remaining
networks tend to use standalone routers. These almost certainly
run Linux, but not a modern kernel or the mainline wimax driver stack.

NetworkManager appears to have dropped userspace support in 2015
https://bugzilla.gnome.org/show_bug.cgi?id=747846, the
www.linuxwimax.org
site had already shut down earlier.

WiMax is apparently still being deployed on airport campus networks
("AeroMACS"), but in a frequency band that was not supported by the old
Intel 2400m (used in Sandy Bridge laptops and earlier), which is the
only driver using the kernel's wimax stack.

Move all files into drivers/staging/wimax, including the uapi header
files and documentation, to make it easier to remove it when it gets
to that. Only minimal changes are made to the source files, in order
to make it possible to port patches across the move.

Also remove the MAINTAINERS entry that refers to a broken mailing
list and website.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-By: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Suggested-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 258 insertions, 0 deletions

diff --git a/drivers/staging/wimax/i2400m/usb-notif.c b/drivers/staging/wimax/i2400m/usb-notif.c
new file mode 100644
index 000000000000..5d429f816125
--- /dev/null
+++ b/drivers/staging/wimax/i2400m/usb-notif.c
@@ -0,0 +1,258 @@
+/*
+ * Intel Wireless WiMAX Connection 2400m over USB
+ * Notification handling
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * Intel Corporation <linux-wimax@intel.com>
+ * Yanir Lubetkin <yanirx.lubetkin@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *  - Initial implementation
+ *
+ *
+ * The notification endpoint is active when the device is not in boot
+ * mode; in here we just read and get notifications; based on those,
+ * we act to either reinitialize the device after a reboot or to
+ * submit a RX request.
+ *
+ * ROADMAP
+ *
+ * i2400mu_usb_notification_setup()
+ *
+ * i2400mu_usb_notification_release()
+ *
+ * i2400mu_usb_notification_cb()	Called when a URB is ready
+ *   i2400mu_notif_grok()
+ *     i2400m_is_boot_barker()
+ *     i2400m_dev_reset_handle()
+ *     i2400mu_rx_kick()
+ */
+#include <linux/usb.h>
+#include <linux/slab.h>
+#include "i2400m-usb.h"
+
+
+#define D_SUBMODULE notif
+#include "usb-debug-levels.h"
+
+
+static const
+__le32 i2400m_ZERO_BARKER[4] = { 0, 0, 0, 0 };
+
+
+/*
+ * Process a received notification
+ *
+ * In normal operation mode, we can only receive two types of payloads
+ * on the notification endpoint:
+ *
+ *   - a reboot barker, we do a bootstrap (the device has reseted).
+ *
+ *   - a block of zeroes: there is pending data in the IN endpoint
+ */
+static
+int i2400mu_notification_grok(struct i2400mu *i2400mu, const void *buf,
+				 size_t buf_len)
+{
+	int ret;
+	struct device *dev = &i2400mu->usb_iface->dev;
+	struct i2400m *i2400m = &i2400mu->i2400m;
+
+	d_fnstart(4, dev, "(i2400m %p buf %p buf_len %zu)\n",
+		  i2400mu, buf, buf_len);
+	ret = -EIO;
+	if (buf_len < sizeof(i2400m_ZERO_BARKER))
+		/* Not a bug, just ignore */
+		goto error_bad_size;
+	ret = 0;
+	if (!memcmp(i2400m_ZERO_BARKER, buf, sizeof(i2400m_ZERO_BARKER))) {
+		i2400mu_rx_kick(i2400mu);
+		goto out;
+	}
+	ret = i2400m_is_boot_barker(i2400m, buf, buf_len);
+	if (unlikely(ret >= 0))
+		ret = i2400m_dev_reset_handle(i2400m, "device rebooted");
+	else	/* Unknown or unexpected data in the notif message */
+		i2400m_unknown_barker(i2400m, buf, buf_len);
+error_bad_size:
+out:
+	d_fnend(4, dev, "(i2400m %p buf %p buf_len %zu) = %d\n",
+		i2400mu, buf, buf_len, ret);
+	return ret;
+}
+
+
+/*
+ * URB callback for the notification endpoint
+ *
+ * @urb: the urb received from the notification endpoint
+ *
+ * This function will just process the USB side of the transaction,
+ * checking everything is fine, pass the processing to
+ * i2400m_notification_grok() and resubmit the URB.
+ */
+static
+void i2400mu_notification_cb(struct urb *urb)
+{
+	int ret;
+	struct i2400mu *i2400mu = urb->context;
+	struct device *dev = &i2400mu->usb_iface->dev;
+
+	d_fnstart(4, dev, "(urb %p status %d actual_length %d)\n",
+		  urb, urb->status, urb->actual_length);
+	ret = urb->status;
+	switch (ret) {
+	case 0:
+		ret = i2400mu_notification_grok(i2400mu, urb->transfer_buffer,
+						urb->actual_length);
+		if (ret == -EIO && edc_inc(&i2400mu->urb_edc, EDC_MAX_ERRORS,
+					   EDC_ERROR_TIMEFRAME))
+			goto error_exceeded;
+		if (ret == -ENOMEM)	/* uff...power cycle? shutdown? */
+			goto error_exceeded;
+		break;
+	case -EINVAL:			/* while removing driver */
+	case -ENODEV:			/* dev disconnect ... */
+	case -ENOENT:			/* ditto */
+	case -ESHUTDOWN:		/* URB killed */
+	case -ECONNRESET:		/* disconnection */
+		goto out;		/* Notify around */
+	default:			/* Some error? */
+		if (edc_inc(&i2400mu->urb_edc,
+			    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
+			goto error_exceeded;
+		dev_err(dev, "notification: URB error %d, retrying\n",
+			urb->status);
+	}
+	usb_mark_last_busy(i2400mu->usb_dev);
+	ret = usb_submit_urb(i2400mu->notif_urb, GFP_ATOMIC);
+	switch (ret) {
+	case 0:
+	case -EINVAL:			/* while removing driver */
+	case -ENODEV:			/* dev disconnect ... */
+	case -ENOENT:			/* ditto */
+	case -ESHUTDOWN:		/* URB killed */
+	case -ECONNRESET:		/* disconnection */
+		break;			/* just ignore */
+	default:			/* Some error? */
+		dev_err(dev, "notification: cannot submit URB: %d\n", ret);
+		goto error_submit;
+	}
+	d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
+		urb, urb->status, urb->actual_length);
+	return;
+
+error_exceeded:
+	dev_err(dev, "maximum errors in notification URB exceeded; "
+		"resetting device\n");
+error_submit:
+	usb_queue_reset_device(i2400mu->usb_iface);
+out:
+	d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
+		urb, urb->status, urb->actual_length);
+}
+
+
+/*
+ * setup the notification endpoint
+ *
+ * @i2400m: device descriptor
+ *
+ * This procedure prepares the notification urb and handler for receiving
+ * unsolicited barkers from the device.
+ */
+int i2400mu_notification_setup(struct i2400mu *i2400mu)
+{
+	struct device *dev = &i2400mu->usb_iface->dev;
+	int usb_pipe, ret = 0;
+	struct usb_endpoint_descriptor *epd;
+	char *buf;
+
+	d_fnstart(4, dev, "(i2400m %p)\n", i2400mu);
+	buf = kmalloc(I2400MU_MAX_NOTIFICATION_LEN, GFP_KERNEL | GFP_DMA);
+	if (buf == NULL) {
+		ret = -ENOMEM;
+		goto error_buf_alloc;
+	}
+
+	i2400mu->notif_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!i2400mu->notif_urb) {
+		ret = -ENOMEM;
+		goto error_alloc_urb;
+	}
+	epd = usb_get_epd(i2400mu->usb_iface,
+			  i2400mu->endpoint_cfg.notification);
+	usb_pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
+	usb_fill_int_urb(i2400mu->notif_urb, i2400mu->usb_dev, usb_pipe,
+			 buf, I2400MU_MAX_NOTIFICATION_LEN,
+			 i2400mu_notification_cb, i2400mu, epd->bInterval);
+	ret = usb_submit_urb(i2400mu->notif_urb, GFP_KERNEL);
+	if (ret != 0) {
+		dev_err(dev, "notification: cannot submit URB: %d\n", ret);
+		goto error_submit;
+	}
+	d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
+	return ret;
+
+error_submit:
+	usb_free_urb(i2400mu->notif_urb);
+error_alloc_urb:
+	kfree(buf);
+error_buf_alloc:
+	d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
+	return ret;
+}
+
+
+/*
+ * Tear down of the notification mechanism
+ *
+ * @i2400m: device descriptor
+ *
+ * Kill the interrupt endpoint urb, free any allocated resources.
+ *
+ * We need to check if we have done it before as for example,
+ * _suspend() call this; if after a suspend() we get a _disconnect()
+ * (as the case is when hibernating), nothing bad happens.
+ */
+void i2400mu_notification_release(struct i2400mu *i2400mu)
+{
+	struct device *dev = &i2400mu->usb_iface->dev;
+
+	d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
+	if (i2400mu->notif_urb != NULL) {
+		usb_kill_urb(i2400mu->notif_urb);
+		kfree(i2400mu->notif_urb->transfer_buffer);
+		usb_free_urb(i2400mu->notif_urb);
+		i2400mu->notif_urb = NULL;
+	}
+	d_fnend(4, dev, "(i2400mu %p)\n", i2400mu);
+}