Staging: bluetooth: BT driver using ST for TI combo devices

This is BlueZ driver making use of Shared Transport line
discipline to communicate with the chip.
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ti-st/bt_drv.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 Texas Instruments
+ *
+ *  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 <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "st.h"
+#include "bt_drv.h"
+
+/* Define this macro to get debug msg */
+#undef DEBUG
+
+#ifdef DEBUG
+#define BT_DRV_DBG(fmt, arg...)  printk(KERN_INFO "(btdrv):"fmt"\n" , ## arg)
+#define BTDRV_API_START()        printk(KERN_INFO "(btdrv): %s Start\n", \
+	__func__)
+#define BTDRV_API_EXIT(errno)    printk(KERN_INFO "(btdrv): %s Exit(%d)\n", \
+	__func__, errno)
+#else
+#define BT_DRV_DBG(fmt, arg...)
+#define BTDRV_API_START()
+#define BTDRV_API_EXIT(errno)
+#endif
+
+#define BT_DRV_ERR(fmt, arg...)  printk(KERN_ERR "(btdrv):"fmt"\n" , ## arg)
+
+static int reset;
+static struct hci_st *hst;
+
+/* Increments HCI counters based on pocket ID (cmd,acl,sco) */
+static inline void hci_st_tx_complete(struct hci_st *hst, int pkt_type)
+{
+	struct hci_dev *hdev;
+
+	BTDRV_API_START();
+
+	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.cmd_tx++;
+		break;
+	}
+
+	BTDRV_API_EXIT(0);
+}
+
+/* ------- Interfaces to Shared Transport ------ */
+
+/* Called by ST layer to indicate protocol registration completion
+ * status.hci_st_open() function will wait for signal from this
+ * API when st_register() function returns ST_PENDING.
+ */
+static void hci_st_registration_completion_cb(char data)
+{
+	BTDRV_API_START();
+
+	/* hci_st_open() function needs value of 'data' to know
+	 * the registration status(success/fail),So have a back
+	 * up of it.
+	 */
+	hst->streg_cbdata = data;
+
+	/* Got a feedback from ST for BT driver registration
+	 * request.Wackup hci_st_open() function to continue
+	 * it's open operation.
+	 */
+	complete(&hst->wait_for_btdrv_reg_completion);
+
+	BTDRV_API_EXIT(0);
+}
+
+/* Called by Shared Transport layer when receive data is
+ * available */
+static long hci_st_receive(struct sk_buff *skb)
+{
+	int err;
+	int len;
+
+	BTDRV_API_START();
+
+	err = 0;
+	len = 0;
+
+	if (skb == NULL) {
+		BT_DRV_ERR("Invalid SKB received from ST");
+		BTDRV_API_EXIT(-EFAULT);
+		return -EFAULT;
+	}
+	if (!hst) {
+		kfree_skb(skb);
+		BT_DRV_ERR("Invalid hci_st memory,freeing SKB");
+		BTDRV_API_EXIT(-EFAULT);
+		return -EFAULT;
+	}
+	if (!test_bit(BT_DRV_RUNNING, &hst->flags)) {
+		kfree_skb(skb);
+		BT_DRV_ERR("Device is not running,freeing SKB");
+		BTDRV_API_EXIT(-EINVAL);
+		return -EINVAL;
+	}
+
+	len = skb->len;
+	skb->dev = (struct net_device *)hst->hdev;
+
+	/* Forward skb to HCI CORE layer */
+	err = hci_recv_frame(skb);
+	if (err) {
+		kfree_skb(skb);
+		BT_DRV_ERR("Unable to push skb to HCI CORE(%d),freeing SKB",
+			   err);
+		BTDRV_API_EXIT(err);
+		return err;
+	}
+	hst->hdev->stat.byte_rx += len;
+
+	BTDRV_API_EXIT(0);
+	return 0;
+}
+
+/* ------- Interfaces to HCI layer ------ */
+
+/* Called from HCI core to initialize the device */
+static int hci_st_open(struct hci_dev *hdev)
+{
+	static struct st_proto_s hci_st_proto;
+	unsigned long timeleft;
+	int err;
+
+	BTDRV_API_START();
+
+	err = 0;
+
+	BT_DRV_DBG("%s %p", hdev->name, hdev);
+
+	/* Already registered with ST ? */
+	if (test_bit(BT_ST_REGISTERED, &hst->flags)) {
+		BT_DRV_ERR("Registered with ST already,open called again?");
+		BTDRV_API_EXIT(0);
+		return 0;
+	}
+
+	/* Populate BT driver info required by ST */
+	memset(&hci_st_proto, 0, sizeof(hci_st_proto));
+
+	/* BT driver ID */
+	hci_st_proto.type = ST_BT;
+
+	/* Receive function which called from ST */
+	hci_st_proto.recv = hci_st_receive;
+
+	/* Packet match function may used in future */
+	hci_st_proto.match_packet = NULL;
+
+	/* Callback to be called when registration is pending */
+	hci_st_proto.reg_complete_cb = hci_st_registration_completion_cb;
+
+	/* This is write function pointer of ST. BT driver will make use of this
+	 * for sending any packets to chip. ST will assign and give to us, so
+	 * make it as NULL */
+	hci_st_proto.write = NULL;
+
+	/* Register with ST layer */
+	err = st_register(&hci_st_proto);
+	if (err == ST_ERR_PENDING) {
+		/* Prepare wait-for-completion handler data structures.
+		 * Needed to syncronize this and st_registration_completion_cb()
+		 * functions.
+		 */
+		init_completion(&hst->wait_for_btdrv_reg_completion);
+
+		/* Reset ST registration callback status flag , this value
+		 * will be updated in hci_st_registration_completion_cb()
+		 * function whenever it called from ST driver.
+		 */
+		hst->streg_cbdata = -EINPROGRESS;
+
+		/* ST is busy with other protocol registration(may be busy with
+		 * firmware download).So,Wait till the registration callback
+		 * (passed as a argument to st_register() function) getting
+		 * called from ST.
+		 */
+		BT_DRV_DBG(" %s waiting for reg completion signal from ST",
+			   __func__);
+
+		timeleft =
+		    wait_for_completion_timeout
+		    (&hst->wait_for_btdrv_reg_completion,
+		     msecs_to_jiffies(BT_REGISTER_TIMEOUT));
+		if (!timeleft) {
+			BT_DRV_ERR("Timeout(%ld sec),didn't get reg"
+				   "completion signal from ST",
+				   BT_REGISTER_TIMEOUT / 1000);
+			BTDRV_API_EXIT(-ETIMEDOUT);
+			return -ETIMEDOUT;
+		}
+
+		/* Is ST registration callback called with ERROR value? */
+		if (hst->streg_cbdata != 0) {
+			BT_DRV_ERR("ST reg completion CB called with invalid"
+				   "status %d", hst->streg_cbdata);
+			BTDRV_API_EXIT(-EAGAIN);
+			return -EAGAIN;
+		}
+		err = 0;
+	} else if (err == ST_ERR_FAILURE) {
+		BT_DRV_ERR("st_register failed %d", err);
+		BTDRV_API_EXIT(-EAGAIN);
+		return -EAGAIN;
+	}
+
+	/* Do we have proper ST write function? */
+	if (hci_st_proto.write != NULL) {
+		/* We need this pointer for sending any Bluetooth pkts */
+		hst->st_write = hci_st_proto.write;
+	} else {
+		BT_DRV_ERR("failed to get ST write func pointer");
+
+		/* Undo registration with ST */
+		err = st_unregister(ST_BT);
+		if (err < 0)
+			BT_DRV_ERR("st_unregister failed %d", err);
+
+		hst->st_write = NULL;
+		BTDRV_API_EXIT(-EAGAIN);
+		return -EAGAIN;
+	}
+
+	/* Registration with ST layer is completed successfully,
+	 * now chip is ready to accept commands from HCI CORE.
+	 * Mark HCI Device flag as RUNNING
+	 */
+	set_bit(HCI_RUNNING, &hdev->flags);
+
+	/* Registration with ST successful */
+	set_bit(BT_ST_REGISTERED, &hst->flags);
+
+	BTDRV_API_EXIT(err);
+	return err;
+}
+
+/* Close device */
+static int hci_st_close(struct hci_dev *hdev)
+{
+	int err;
+
+	BTDRV_API_START();
+
+	err = 0;
+
+	/* Unregister from ST layer */
+	if (test_and_clear_bit(BT_ST_REGISTERED, &hst->flags)) {
+		err = st_unregister(ST_BT);
+		if (err != ST_SUCCESS) {
+			BT_DRV_ERR("st_unregister failed %d", err);
+			BTDRV_API_EXIT(-EBUSY);
+			return -EBUSY;
+		}
+	}
+
+	hst->st_write = NULL;
+
+	/* ST layer would have moved chip to inactive state.
+	 * So,clear HCI device RUNNING flag.
+	 */
+	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) {
+		BTDRV_API_EXIT(0);
+		return 0;
+	}
+
+	BTDRV_API_EXIT(err);
+	return err;
+}
+
+/* Called from HCI CORE , Sends frames to Shared Transport */
+static int hci_st_send_frame(struct sk_buff *skb)
+{
+	struct hci_dev *hdev;
+	struct hci_st *hst;
+	long len;
+
+	BTDRV_API_START();
+
+	if (skb == NULL) {
+		BT_DRV_ERR("Invalid skb received from HCI CORE");
+		BTDRV_API_EXIT(-ENOMEM);
+		return -ENOMEM;
+	}
+	hdev = (struct hci_dev *)skb->dev;
+	if (!hdev) {
+		BT_DRV_ERR("SKB received for invalid HCI Device (hdev=NULL)");
+		BTDRV_API_EXIT(-ENODEV);
+		return -ENODEV;
+	}
+	if (!test_bit(HCI_RUNNING, &hdev->flags)) {
+		BT_DRV_ERR("Device is not running");
+		BTDRV_API_EXIT(-EBUSY);
+		return -EBUSY;
+	}
+
+	hst = (struct hci_st *)hdev->driver_data;
+
+	/* Prepend skb with frame type */
+	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
+
+	BT_DRV_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.
+	 */
+	if (!hst->st_write) {
+		kfree_skb(skb);
+		BT_DRV_ERR(" Can't write to ST, st_write null?");
+		BTDRV_API_EXIT(-EAGAIN);
+		return -EAGAIN;
+	}
+	len = hst->st_write(skb);
+	if (len < 0) {
+		/* Something went wrong in st write , free skb memory */
+		kfree_skb(skb);
+		BT_DRV_ERR(" ST write failed (%ld)", len);
+		BTDRV_API_EXIT(-EAGAIN);
+		return -EAGAIN;
+	}
+
+	/* ST accepted our skb. So, Go ahead and do rest */
+	hdev->stat.byte_tx += len;
+	hci_st_tx_complete(hst, bt_cb(skb)->pkt_type);
+
+	BTDRV_API_EXIT(0);
+	return 0;
+}
+
+static void hci_st_destruct(struct hci_dev *hdev)
+{
+	BTDRV_API_START();
+
+	if (!hdev) {
+		BT_DRV_ERR("Destruct called with invalid HCI Device"
+			   "(hdev=NULL)");
+		BTDRV_API_EXIT(0);
+		return;
+	}
+
+	BT_DRV_DBG("%s", hdev->name);
+
+	/* free hci_st memory */
+	if (hdev->driver_data != NULL)
+		kfree(hdev->driver_data);
+
+	BTDRV_API_EXIT(0);
+	return;
+}
+
+/* Creates new HCI device */
+static int hci_st_register_dev(struct hci_st *hst)
+{
+	struct hci_dev *hdev;
+
+	BTDRV_API_START();
+
+	/* Initialize and register HCI device */
+	hdev = hci_alloc_dev();
+	if (!hdev) {
+		BT_DRV_ERR("Can't allocate HCI device");
+		BTDRV_API_EXIT(-ENOMEM);
+		return -ENOMEM;
+	}
+	BT_DRV_DBG(" HCI device allocated. hdev= %p", hdev);
+
+	hst->hdev = hdev;
+	hdev->bus = HCI_UART;
+	hdev->driver_data = hst;
+	hdev->open = hci_st_open;
+	hdev->close = hci_st_close;
+	hdev->flush = NULL;
+	hdev->send = hci_st_send_frame;
+	hdev->destruct = hci_st_destruct;
+	hdev->owner = THIS_MODULE;
+
+	if (reset)
+		set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
+
+	if (hci_register_dev(hdev) < 0) {
+		BT_DRV_ERR("Can't register HCI device");
+		hci_free_dev(hdev);
+		BTDRV_API_EXIT(-ENODEV);
+		return -ENODEV;
+	}
+
+	BT_DRV_DBG(" HCI device registered. hdev= %p", hdev);
+	BTDRV_API_EXIT(0);
+	return 0;
+}
+
+/* ------- Module Init interface ------ */
+
+static int __init bt_drv_init(void)
+{
+	int err;
+
+	BTDRV_API_START();
+
+	err = 0;
+
+	BT_DRV_DBG(" Bluetooth Driver Version %s", VERSION);
+
+	/* Allocate local resource memory */
+	hst = kzalloc(sizeof(struct hci_st), GFP_KERNEL);
+	if (!hst) {
+		BT_DRV_ERR("Can't allocate control structure");
+		BTDRV_API_EXIT(-ENFILE);
+		return -ENFILE;
+	}
+
+	/* Expose "hciX" device to user space */
+	err = hci_st_register_dev(hst);
+	if (err) {
+		/* Release local resource memory */
+		kfree(hst);
+
+		BT_DRV_ERR("Unable to expose hci0 device(%d)", err);
+		BTDRV_API_EXIT(err);
+		return err;
+	}
+	set_bit(BT_DRV_RUNNING, &hst->flags);
+
+	BTDRV_API_EXIT(err);
+	return err;
+}
+
+/* ------- Module Exit interface ------ */
+
+static void __exit bt_drv_exit(void)
+{
+	BTDRV_API_START();
+
+	/* Deallocate local resource's memory  */
+	if (hst) {
+		struct hci_dev *hdev = hst->hdev;
+
+		if (hdev == NULL) {
+			BT_DRV_ERR("Invalid hdev memory");
+			kfree(hst);
+		} else {
+			hci_st_close(hdev);
+			if (test_and_clear_bit(BT_DRV_RUNNING, &hst->flags)) {
+				/* Remove HCI device (hciX) created
+				 * in module init.
+				 */
+				hci_unregister_dev(hdev);
+
+				/* Free HCI device memory */
+				hci_free_dev(hdev);
+			}
+		}
+	}
+	BTDRV_API_EXIT(0);
+}
+
+module_init(bt_drv_init);
+module_exit(bt_drv_exit);
+
+/* ------ Module Info ------ */
+
+module_param(reset, bool, 0644);
+MODULE_PARM_DESC(reset, "Send HCI reset command on initialization");
+MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
+MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");

drivers/staging/ti-st/bt_drv.h

+/*
+ *  Texas Instrument's Bluetooth Driver For Shared Transport.
+ *
+ *  Bluetooth Driver acts as interface between HCI CORE and
+ *  TI Shared Transport Layer.
+ *
+ *  Copyright (C) 2009 Texas Instruments
+ *
+ *  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
+ *
+ */
+
+#ifndef _BT_DRV_H
+#define _BT_DRV_H
+
+/* Bluetooth Driver Version */
+#define VERSION               "1.0"
+
+/* Defines number of seconds to wait for reg completion
+ * callback getting called from ST (in case,registration
+ * with ST returns PENDING status)
+ */
+#define BT_REGISTER_TIMEOUT   msecs_to_jiffies(6000)	/* 6 sec */
+
+/* BT driver's local status */
+#define BT_DRV_RUNNING        0
+#define BT_ST_REGISTERED      1
+
+/* BT driver operation structure */
+struct hci_st {
+
+	/* hci device pointer which binds to bt driver */
+	struct hci_dev *hdev;
+
+	/* used locally,to maintain various BT driver status */
+	unsigned long flags;
+
+	/* to hold ST registration callback  status */
+	char streg_cbdata;
+
+	/* write function pointer of ST driver */
+	long (*st_write) (struct sk_buff *);
+
+	/* Wait on comepletion handler needed to synchronize
+	 * hci_st_open() and hci_st_registration_completion_cb()
+	 * functions.*/
+	struct completion wait_for_btdrv_reg_completion;
+};
+
+#endif