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

/*

 * 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);