drivers:staging: ti-st: add the v7 btwilink driver

/*

 *  Texas Instrument's Bluetooth Driver For Shared Transport.

 *

 *  Bluetooth Driver acts as interface between HCI core and

 *  TI Shared Transport Layer.

 *

 *  Copyright (C) 2009-2010 Texas Instruments

 *  Author: Raja Mani <raja_mani@ti.com>

 *	Pavan Savoy <pavan_savoy@ti.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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#include <linux/platform_device.h>

#include <net/bluetooth/bluetooth.h>

#include <net/bluetooth/hci_core.h>

#include <linux/ti_wilink_st.h>

/* Bluetooth Driver Version */

#define VERSION               "1.0"

/* Number of seconds to wait for registration completion

 * when ST returns PENDING status.

 */

#define BT_REGISTER_TIMEOUT   6000	/* 6 sec */

/**

 * struct ti_st - driver operation structure

 * @hdev: hci device pointer which binds to bt driver

 * @reg_status: ST registration callback status

 * @st_write: write function provided by the ST driver

 *	to be used by the driver during send_frame.

 * @wait_reg_completion - completion sync between ti_st_open

 *	and ti_st_registration_completion_cb.

 */

struct ti_st {

	struct hci_dev *hdev;

	char reg_status;

	long (*st_write) (struct sk_buff *);

	struct completion wait_reg_completion;

};

/* Increments HCI counters based on pocket ID (cmd,acl,sco) */

static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)

{

	struct hci_dev *hdev = hst->hdev;

	/* Update HCI stat counters */

	switch (pkt_type) {

	case HCI_COMMAND_PKT:

		hdev->stat.cmd_tx++;

		break;

	case HCI_ACLDATA_PKT:

		hdev->stat.acl_tx++;

		break;

	case HCI_SCODATA_PKT:

		hdev->stat.sco_tx++;

		break;

	}

}

/* ------- Interfaces to Shared Transport ------ */

/* Called by ST layer to indicate protocol registration completion

 * status.ti_st_open() function will wait for signal from this

 * API when st_register() function returns ST_PENDING.

 */

static void st_registration_completion_cb(void *priv_data, char data)

{

	struct ti_st *lhst = priv_data;

	/* Save registration status for use in ti_st_open() */

	lhst->reg_status = data;

	/* complete the wait in ti_st_open() */

	complete(&lhst->wait_reg_completion);

}

/* Called by Shared Transport layer when receive data is

 * available */

static long st_receive(void *priv_data, struct sk_buff *skb)

{

	struct ti_st *lhst = priv_data;

	int err;

	if (!skb)

		return -EFAULT;

	if (!lhst) {

		kfree_skb(skb);

		return -EFAULT;

	}

	skb->dev = (void *) lhst->hdev;

	/* Forward skb to HCI core layer */

	err = hci_recv_frame(skb);

	if (err < 0) {

		BT_ERR("Unable to push skb to HCI core(%d)", err);

		return err;

	}

	lhst->hdev->stat.byte_rx += skb->len;

	return 0;

}

/* ------- Interfaces to HCI layer ------ */

/* protocol structure registered with shared transport */

static struct st_proto_s ti_st_proto = {

	.type = ST_BT,

	.recv = st_receive,

	.reg_complete_cb = st_registration_completion_cb,

};

/* Called from HCI core to initialize the device */

static int ti_st_open(struct hci_dev *hdev)

{

	unsigned long timeleft;

	struct ti_st *hst;

	int err;

	BT_DBG("%s %p", hdev->name, hdev);

	if (test_and_set_bit(HCI_RUNNING, &hdev->flags)) {

		BT_ERR("btwilink already opened");

		return -EBUSY;

	}

	/* provide contexts for callbacks from ST */

	hst = hdev->driver_data;

	ti_st_proto.priv_data = hst;

	err = st_register(&ti_st_proto);

	if (err == -EINPROGRESS) {

		/* ST is busy with either protocol registration or firmware

		 * download.

		 */

		/* Prepare wait-for-completion handler data structures.

		 */

		init_completion(&hst->wait_reg_completion);

		/* Reset ST registration callback status flag , this value

		 * will be updated in ti_st_registration_completion_cb()

		 * function whenever it called from ST driver.

		 */

		hst->reg_status = -EINPROGRESS;

		BT_DBG("waiting for registration completion signal from ST");

		timeleft = wait_for_completion_timeout

			(&hst->wait_reg_completion,

			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));

		if (!timeleft) {

			clear_bit(HCI_RUNNING, &hdev->flags);

			BT_ERR("Timeout(%d sec),didn't get reg "

					"completion signal from ST",

					BT_REGISTER_TIMEOUT / 1000);

			return -ETIMEDOUT;

		}

		/* Is ST registration callback called with ERROR status? */

		if (hst->reg_status != 0) {

			clear_bit(HCI_RUNNING, &hdev->flags);

			BT_ERR("ST registration completed with invalid "

					"status %d", hst->reg_status);

			return -EAGAIN;

		}

		err = 0;

	} else if (err != 0) {

		clear_bit(HCI_RUNNING, &hdev->flags);

		BT_ERR("st_register failed %d", err);

		return err;

	}

	/* ti_st_proto.write is filled up by the underlying shared

	 * transport driver upon registration

	 */

	hst->st_write = ti_st_proto.write;

	if (!hst->st_write) {

		BT_ERR("undefined ST write function");

		clear_bit(HCI_RUNNING, &hdev->flags);

		/* Undo registration with ST */

		err = st_unregister(ST_BT);

		if (err)

			BT_ERR("st_unregister() failed with error %d", err);

		hst->st_write = NULL;

		return err;

	}

	return err;

}

/* Close device */

static int ti_st_close(struct hci_dev *hdev)

{

	int err;

	struct ti_st *hst = hdev->driver_data;

	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))

		return 0;

	/* continue to unregister from transport */

	err = st_unregister(ST_BT);

	if (err)

		BT_ERR("st_unregister() failed with error %d", err);

	hst->st_write = NULL;

	return err;

}

static int ti_st_send_frame(struct sk_buff *skb)

{

	struct hci_dev *hdev;

	struct ti_st *hst;

	long len;

	hdev = (struct hci_dev *)skb->dev;

	if (!test_bit(HCI_RUNNING, &hdev->flags))

		return -EBUSY;

	hst = hdev->driver_data;

	/* Prepend skb with frame type */

	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);

	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,

			skb->len);

	/* Insert skb to shared transport layer's transmit queue.

	 * Freeing skb memory is taken care in shared transport layer,

	 * so don't free skb memory here.

	 */

	len = hst->st_write(skb);

	if (len < 0) {

		kfree_skb(skb);

		BT_ERR("ST write failed (%ld)", len);

		/* Try Again, would only fail if UART has gone bad */

		return -EAGAIN;

	}

	/* ST accepted our skb. So, Go ahead and do rest */

	hdev->stat.byte_tx += len;

	ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);

	return 0;

}

static void ti_st_destruct(struct hci_dev *hdev)

{

	BT_DBG("%s", hdev->name);

	kfree(hdev->driver_data);

}

static int bt_ti_probe(struct platform_device *pdev)

{

	static struct ti_st *hst;

	struct hci_dev *hdev;

	int err;

	hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL);

	if (!hst)

		return -ENOMEM;

	/* Expose "hciX" device to user space */

	hdev = hci_alloc_dev();

	if (!hdev) {

		kfree(hst);

		return -ENOMEM;

	}

	BT_DBG("hdev %p", hdev);

	hst->hdev = hdev;

	hdev->bus = HCI_UART;

	hdev->driver_data = hst;

	hdev->open = ti_st_open;

	hdev->close = ti_st_close;

	hdev->flush = NULL;

	hdev->send = ti_st_send_frame;

	hdev->destruct = ti_st_destruct;

	hdev->owner = THIS_MODULE;

	err = hci_register_dev(hdev);

	if (err < 0) {

		BT_ERR("Can't register HCI device error %d", err);

		kfree(hst);

		hci_free_dev(hdev);

		return err;

	}

	BT_DBG("HCI device registered (hdev %p)", hdev);

	dev_set_drvdata(&pdev->dev, hst);

	return err;

}

static int bt_ti_remove(struct platform_device *pdev)

{

	struct hci_dev *hdev;

	struct ti_st *hst = dev_get_drvdata(&pdev->dev);

	if (!hst)

		return -EFAULT;

	hdev = hst->hdev;

	ti_st_close(hdev);

	hci_unregister_dev(hdev);

	hci_free_dev(hdev);

	kfree(hst);

	dev_set_drvdata(&pdev->dev, NULL);

	return 0;

}

static struct platform_driver btwilink_driver = {

	.probe = bt_ti_probe,

	.remove = bt_ti_remove,

	.driver = {

		.name = "btwilink",

		.owner = THIS_MODULE,

	},

};

/* ------- Module Init/Exit interfaces ------ */

static int __init btwilink_init(void)

{

	BT_INFO("Bluetooth Driver for TI WiLink - Version %s", VERSION);

	return platform_driver_register(&btwilink_driver);

}

static void __exit btwilink_exit(void)

{

	platform_driver_unregister(&btwilink_driver);

}

module_init(btwilink_init);

module_exit(btwilink_exit);

/* ------ Module Info ------ */

MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");

MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);

MODULE_VERSION(VERSION);

MODULE_LICENSE("GPL");