i2400m/USB: probe/disconnect, dev init/shutdown and reset backends

Implements probe/disconnect for the USB device, as well as main
backends for the generic driver to control the USB device
(bus_dev_start(), bus_dev_stop() and bus_reset()).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/wimax/i2400m/usb.c

+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Linux driver model glue for USB device, reset & fw upload
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Yanir Lubetkin <yanirx.lubetkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * See i2400m-usb.h for a general description of this driver.
+ *
+ * This file implements driver model glue, and hook ups for the
+ * generic driver to implement the bus-specific functions (device
+ * communication setup/tear down, firmware upload and resetting).
+ *
+ * ROADMAP
+ *
+ * i2400mu_probe()
+ *   alloc_netdev()...
+ *     i2400mu_netdev_setup()
+ *       i2400mu_init()
+ *       i2400m_netdev_setup()
+ *   i2400m_setup()...
+ *
+ * i2400mu_disconnect
+ *   i2400m_release()
+ *   free_netdev()
+ *
+ * i2400mu_suspend()
+ *   i2400m_cmd_enter_powersave()
+ *   i2400mu_notification_release()
+ *
+ * i2400mu_resume()
+ *   i2400mu_notification_setup()
+ *
+ * i2400mu_bus_dev_start()        Called by i2400m_dev_start() [who is
+ *   i2400mu_tx_setup()           called by i2400m_setup()]
+ *   i2400mu_rx_setup()
+ *   i2400mu_notification_setup()
+ *
+ * i2400mu_bus_dev_stop()         Called by i2400m_dev_stop() [who is
+ *   i2400mu_notification_release()  called by i2400m_release()]
+ *   i2400mu_rx_release()
+ *   i2400mu_tx_release()
+ *
+ * i2400mu_bus_reset()            Called by i2400m->bus_reset
+ *   __i2400mu_reset()
+ *     __i2400mu_send_barker()
+ *   usb_reset_device()
+ */
+#include "i2400m-usb.h"
+#include <linux/wimax/i2400m.h>
+#include <linux/debugfs.h>
+
+
+#define D_SUBMODULE usb
+#include "usb-debug-levels.h"
+
+
+/* Our firmware file name */
+#define I2400MU_FW_FILE_NAME "i2400m-fw-usb-" I2400M_FW_VERSION ".sbcf"
+
+static
+int i2400mu_bus_dev_start(struct i2400m *i2400m)
+{
+	int result;
+	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+	struct device *dev = &i2400mu->usb_iface->dev;
+
+	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+	result = i2400mu_tx_setup(i2400mu);
+	if (result < 0)
+		goto error_usb_tx_setup;
+	result = i2400mu_rx_setup(i2400mu);
+	if (result < 0)
+		goto error_usb_rx_setup;
+	result = i2400mu_notification_setup(i2400mu);
+	if (result < 0)
+		goto error_notif_setup;
+	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+	return result;
+
+error_notif_setup:
+	i2400mu_rx_release(i2400mu);
+error_usb_rx_setup:
+	i2400mu_tx_release(i2400mu);
+error_usb_tx_setup:
+	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+	return result;
+}
+
+
+static
+void i2400mu_bus_dev_stop(struct i2400m *i2400m)
+{
+	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+	struct device *dev = &i2400mu->usb_iface->dev;
+
+	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+	i2400mu_notification_release(i2400mu);
+	i2400mu_rx_release(i2400mu);
+	i2400mu_tx_release(i2400mu);
+	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+}
+
+
+/*
+ * Sends a barker buffer to the device
+ *
+ * This helper will allocate a kmalloced buffer and use it to transmit
+ * (then free it). Reason for this is that other arches cannot use
+ * stack/vmalloc/text areas for DMA transfers.
+ *
+ * Error recovery here is simpler: anything is considered a hard error
+ * and will move the reset code to use a last-resort bus-based reset.
+ */
+static
+int __i2400mu_send_barker(struct i2400mu *i2400mu,
+			  const __le32 *barker,
+			  size_t barker_size,
+			  unsigned endpoint)
+{
+	struct usb_endpoint_descriptor *epd = NULL;
+	int pipe, actual_len, ret;
+	struct device *dev = &i2400mu->usb_iface->dev;
+	void *buffer;
+	int do_autopm = 1;
+
+	ret = usb_autopm_get_interface(i2400mu->usb_iface);
+	if (ret < 0) {
+		dev_err(dev, "RESET: can't get autopm: %d\n", ret);
+		do_autopm = 0;
+	}
+	ret = -ENOMEM;
+	buffer = kmalloc(barker_size, GFP_KERNEL);
+	if (buffer == NULL)
+		goto error_kzalloc;
+	epd = usb_get_epd(i2400mu->usb_iface, endpoint);
+	pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
+	memcpy(buffer, barker, barker_size);
+	ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
+			   &actual_len, HZ);
+	if (ret < 0) {
+		if (ret != -EINVAL)
+			dev_err(dev, "E: barker error: %d\n", ret);
+	} else if (actual_len != barker_size) {
+		dev_err(dev, "E: only %d bytes transmitted\n", actual_len);
+		ret = -EIO;
+	}
+	kfree(buffer);
+error_kzalloc:
+	if (do_autopm)
+		usb_autopm_put_interface(i2400mu->usb_iface);
+	return ret;
+}
+
+
+/*
+ * Reset a device at different levels (warm, cold or bus)
+ *
+ * @i2400m: device descriptor
+ * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
+ *
+ * Warm and cold resets get a USB reset if they fail.
+ *
+ * Warm reset:
+ *
+ * The device will be fully reset internally, but won't be
+ * disconnected from the USB bus (so no reenumeration will
+ * happen). Firmware upload will be neccessary.
+ *
+ * The device will send a reboot barker in the notification endpoint
+ * that will trigger the driver to reinitialize the state
+ * automatically from notif.c:i2400m_notification_grok() into
+ * i2400m_dev_bootstrap_delayed().
+ *
+ * Cold and bus (USB) reset:
+ *
+ * The device will be fully reset internally, disconnected from the
+ * USB bus an a reenumeration will happen. Firmware upload will be
+ * neccessary. Thus, we don't do any locking or struct
+ * reinitialization, as we are going to be fully disconnected and
+ * reenumerated.
+ *
+ * Note we need to return -ENODEV if a warm reset was requested and we
+ * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
+ * and wimax_dev->op_reset.
+ *
+ * WARNING: no driver state saved/fixed
+ */
+static
+int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
+{
+	int result;
+	struct i2400mu *i2400mu =
+		container_of(i2400m, struct i2400mu, i2400m);
+	struct device *dev = i2400m_dev(i2400m);
+	static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+	};
+	static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+	};
+
+	d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
+	if (rt == I2400M_RT_WARM)
+		result = __i2400mu_send_barker(i2400mu, i2400m_WARM_BOOT_BARKER,
+					       sizeof(i2400m_WARM_BOOT_BARKER),
+					       I2400MU_EP_BULK_OUT);
+	else if (rt == I2400M_RT_COLD)
+		result = __i2400mu_send_barker(i2400mu, i2400m_COLD_BOOT_BARKER,
+					       sizeof(i2400m_COLD_BOOT_BARKER),
+					       I2400MU_EP_RESET_COLD);
+	else if (rt == I2400M_RT_BUS) {
+do_bus_reset:
+		result = usb_reset_device(i2400mu->usb_dev);
+		switch (result) {
+		case 0:
+		case -EINVAL:	/* device is gone */
+		case -ENODEV:
+		case -ENOENT:
+		case -ESHUTDOWN:
+			result = rt == I2400M_RT_WARM ? -ENODEV : 0;
+			break;	/* We assume the device is disconnected */
+		default:
+			dev_err(dev, "USB reset failed (%d), giving up!\n",
+				result);
+		}
+	} else
+		BUG();
+	if (result < 0
+	    && result != -EINVAL	/* device is gone */
+	    && rt != I2400M_RT_BUS) {
+		dev_err(dev, "%s reset failed (%d); trying USB reset\n",
+			rt == I2400M_RT_WARM ? "warm" : "cold", result);
+		rt = I2400M_RT_BUS;
+		goto do_bus_reset;
+	}
+	d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
+	return result;
+}
+
+
+static
+void i2400mu_netdev_setup(struct net_device *net_dev)
+{
+	struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
+	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+	i2400mu_init(i2400mu);
+	i2400m_netdev_setup(net_dev);
+}
+
+
+/*
+ * Debug levels control; see debug.h
+ */
+struct d_level D_LEVEL[] = {
+	D_SUBMODULE_DEFINE(usb),
+	D_SUBMODULE_DEFINE(fw),
+	D_SUBMODULE_DEFINE(notif),
+	D_SUBMODULE_DEFINE(rx),
+	D_SUBMODULE_DEFINE(tx),
+};
+size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
+
+
+#define __debugfs_register(prefix, name, parent)			\
+do {									\
+	result = d_level_register_debugfs(prefix, name, parent);	\
+	if (result < 0)							\
+		goto error;						\
+} while (0)
+
+
+static
+int i2400mu_debugfs_add(struct i2400mu *i2400mu)
+{
+	int result;
+	struct device *dev = &i2400mu->usb_iface->dev;
+	struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
+	struct dentry *fd;
+
+	dentry = debugfs_create_dir("i2400m-usb", dentry);
+	result = PTR_ERR(dentry);
+	if (IS_ERR(dentry)) {
+		if (result == -ENODEV)
+			result = 0;	/* No debugfs support */
+		goto error;
+	}
+	i2400mu->debugfs_dentry = dentry;
+	__debugfs_register("dl_", usb, dentry);
+	__debugfs_register("dl_", fw, dentry);
+	__debugfs_register("dl_", notif, dentry);
+	__debugfs_register("dl_", rx, dentry);
+	__debugfs_register("dl_", tx, dentry);
+
+	/* Don't touch these if you don't know what you are doing */
+	fd = debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
+			       &i2400mu->rx_size_auto_shrink);
+	result = PTR_ERR(fd);
+	if (IS_ERR(fd) && result != -ENODEV) {
+		dev_err(dev, "Can't create debugfs entry "
+			"rx_size_auto_shrink: %d\n", result);
+		goto error;
+	}
+
+	fd = debugfs_create_size_t("rx_size", 0600, dentry,
+				   &i2400mu->rx_size);
+	result = PTR_ERR(fd);
+	if (IS_ERR(fd) && result != -ENODEV) {
+		dev_err(dev, "Can't create debugfs entry "
+			"rx_size: %d\n", result);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	debugfs_remove_recursive(i2400mu->debugfs_dentry);
+	return result;
+}
+
+
+/*
+ * Probe a i2400m interface and register it
+ *
+ * @iface:   USB interface to link to
+ * @id:      USB class/subclass/protocol id
+ * @returns: 0 if ok, < 0 errno code on error.
+ *
+ * Alloc a net device, initialize the bus-specific details and then
+ * calls the bus-generic initialization routine. That will register
+ * the wimax and netdev devices, upload the firmware [using
+ * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
+ * communication with the device and then will start to talk to it to
+ * finnish setting it up.
+ */
+static
+int i2400mu_probe(struct usb_interface *iface,
+		  const struct usb_device_id *id)
+{
+	int result;
+	struct net_device *net_dev;
+	struct device *dev = &iface->dev;
+	struct i2400m *i2400m;
+	struct i2400mu *i2400mu;
+	struct usb_device *usb_dev = interface_to_usbdev(iface);
+
+	if (usb_dev->speed != USB_SPEED_HIGH)
+		dev_err(dev, "device not connected as high speed\n");
+
+	/* Allocate instance [calls i2400m_netdev_setup() on it]. */
+	result = -ENOMEM;
+	net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d",
+			       i2400mu_netdev_setup);
+	if (net_dev == NULL) {
+		dev_err(dev, "no memory for network device instance\n");
+		goto error_alloc_netdev;
+	}
+	SET_NETDEV_DEV(net_dev, dev);
+	i2400m = net_dev_to_i2400m(net_dev);
+	i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+	i2400m->wimax_dev.net_dev = net_dev;
+	i2400mu->usb_dev = usb_get_dev(usb_dev);
+	i2400mu->usb_iface = iface;
+	usb_set_intfdata(iface, i2400mu);
+
+	i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
+	i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
+	i2400m->bus_dev_start = i2400mu_bus_dev_start;
+	i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
+	i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
+	i2400m->bus_reset = i2400mu_bus_reset;
+	i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
+	i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
+	i2400m->bus_fw_name = I2400MU_FW_FILE_NAME;
+	i2400m->bus_bm_mac_addr_impaired = 0;
+
+	iface->needs_remote_wakeup = 1;		/* autosuspend (15s delay) */
+	device_init_wakeup(dev, 1);
+	usb_autopm_enable(i2400mu->usb_iface);
+	usb_dev->autosuspend_delay = 15 * HZ;
+	usb_dev->autosuspend_disabled = 0;
+
+	result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
+	if (result < 0) {
+		dev_err(dev, "cannot setup device: %d\n", result);
+		goto error_setup;
+	}
+	result = i2400mu_debugfs_add(i2400mu);
+	if (result < 0) {
+		dev_err(dev, "Can't register i2400mu's debugfs: %d\n", result);
+		goto error_debugfs_add;
+	}
+	return 0;
+
+error_debugfs_add:
+	i2400m_release(i2400m);
+error_setup:
+	usb_set_intfdata(iface, NULL);
+	usb_put_dev(i2400mu->usb_dev);
+	free_netdev(net_dev);
+error_alloc_netdev:
+	return result;
+}
+
+
+/*
+ * Disconect a i2400m from the system.
+ *
+ * i2400m_stop() has been called before, so al the rx and tx contexts
+ * have been taken down already. Make sure the queue is stopped,
+ * unregister netdev and i2400m, free and kill.
+ */
+static
+void i2400mu_disconnect(struct usb_interface *iface)
+{
+	struct i2400mu *i2400mu = usb_get_intfdata(iface);
+	struct i2400m *i2400m = &i2400mu->i2400m;
+	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+	struct device *dev = &iface->dev;
+
+	d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
+
+	debugfs_remove_recursive(i2400mu->debugfs_dentry);
+	i2400m_release(i2400m);
+	usb_set_intfdata(iface, NULL);
+	usb_put_dev(i2400mu->usb_dev);
+	free_netdev(net_dev);
+	d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
+}
+
+
+/*
+ * Get the device ready for USB port or system standby and hibernation
+ *
+ * USB port and system standby are handled the same.
+ *
+ * When the system hibernates, the USB device is powered down and then
+ * up, so we don't really have to do much here, as it will be seen as
+ * a reconnect. Still for simplicity we consider this case the same as
+ * suspend, so that the device has a chance to do notify the base
+ * station (if connected).
+ *
+ * So at the end, the three cases require common handling.
+ *
+ * If at the time of this call the device's firmware is not loaded,
+ * nothing has to be done.
+ *
+ * If the firmware is loaded, we need to:
+ *
+ *  - tell the device to go into host interface power save mode, wait
+ *    for it to ack
+ *
+ *    This is quite more interesting than it is; we need to execute a
+ *    command, but this time, we don't want the code in usb-{tx,rx}.c
+ *    to call the usb_autopm_get/put_interface() barriers as it'd
+ *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
+ *    as a poor man's semaphore. Ugly, but it works.
+ *
+ *    As well, the device might refuse going to sleep for whichever
+ *    reason. In this case we just fail. For system suspend/hibernate,
+ *    we *can't* fail. We look at usb_dev->auto_pm to see if the
+ *    suspend call comes from the USB stack or from the system and act
+ *    in consequence.
+ *
+ *  - stop the notification endpoint polling
+ */
+static
+int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
+{
+	int result = 0;
+	struct device *dev = &iface->dev;
+	struct i2400mu *i2400mu = usb_get_intfdata(iface);
+	struct usb_device *usb_dev = i2400mu->usb_dev;
+	struct i2400m *i2400m = &i2400mu->i2400m;
+
+	d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
+	if (i2400m->updown == 0)
+		goto no_firmware;
+	d_printf(1, dev, "fw up, requesting standby\n");
+	atomic_dec(&i2400mu->do_autopm);
+	result = i2400m_cmd_enter_powersave(i2400m);
+	atomic_inc(&i2400mu->do_autopm);
+	if (result < 0 && usb_dev->auto_pm == 0) {
+		/* System suspend, can't fail */
+		dev_err(dev, "failed to suspend, will reset on resume\n");
+		result = 0;
+	}
+	if (result < 0)
+		goto error_enter_powersave;
+	i2400mu_notification_release(i2400mu);
+	d_printf(1, dev, "fw up, got standby\n");
+error_enter_powersave:
+no_firmware:
+	d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
+		iface, pm_msg.event, result);
+	return result;
+}
+
+
+static
+int i2400mu_resume(struct usb_interface *iface)
+{
+	int ret = 0;
+	struct device *dev = &iface->dev;
+	struct i2400mu *i2400mu = usb_get_intfdata(iface);
+	struct i2400m *i2400m = &i2400mu->i2400m;
+
+	d_fnstart(3, dev, "(iface %p)\n", iface);
+	if (i2400m->updown == 0) {
+		d_printf(1, dev, "fw was down, no resume neeed\n");
+		goto out;
+	}
+	d_printf(1, dev, "fw was up, resuming\n");
+	i2400mu_notification_setup(i2400mu);
+	/* USB has flow control, so we don't need to give it time to
+	 * come back; otherwise, we'd use something like a get-state
+	 * command... */
+out:
+	d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
+	return ret;
+}
+
+
+static
+struct usb_device_id i2400mu_id_table[] = {
+	{ USB_DEVICE(0x8086, 0x0181) },
+	{ USB_DEVICE(0x8086, 0x1403) },
+	{ USB_DEVICE(0x8086, 0x1405) },
+	{ USB_DEVICE(0x8086, 0x0180) },
+	{ USB_DEVICE(0x8086, 0x0182) },
+	{ USB_DEVICE(0x8086, 0x1406) },
+	{ USB_DEVICE(0x8086, 0x1403) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
+
+
+static
+struct usb_driver i2400mu_driver = {
+	.name = KBUILD_MODNAME,
+	.suspend = i2400mu_suspend,
+	.resume = i2400mu_resume,
+	.probe = i2400mu_probe,
+	.disconnect = i2400mu_disconnect,
+	.id_table = i2400mu_id_table,
+	.supports_autosuspend = 1,
+};
+
+static
+int __init i2400mu_driver_init(void)
+{
+	return usb_register(&i2400mu_driver);
+}
+module_init(i2400mu_driver_init);
+
+
+static
+void __exit i2400mu_driver_exit(void)
+{
+	flush_scheduled_work();	/* for the stuff we schedule from sysfs.c */
+	usb_deregister(&i2400mu_driver);
+}
+module_exit(i2400mu_driver_exit);
+
+MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
+MODULE_DESCRIPTION("Intel 2400M WiMAX networking for USB");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE(I2400MU_FW_FILE_NAME);