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

Add the btwilink driver which has undergone 7 revisions
of review. Based on bluetooth maintainer comments, since
there might be some re-work needed on underlying ST driver,
park the driver here.
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ti-st/btwilink.c

+/*
+ *  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");