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688d6240e0
ath_wakeup_ar3k() is never called from atomic context. It is only called by ath_hci_uart_work() that is only called in ath_open() via INIT_WORK(). All of the above functions do not enter atomic context along the way. Despite never getting called from atomic context, ath_wakeup_ar3k() calls mdelay() for busy wait. That is not necessary and can be replaced with msleep to avoid busy wait. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
280 lines
5.9 KiB
C
280 lines
5.9 KiB
C
/*
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* Atheros Communication Bluetooth HCIATH3K UART protocol
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*
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* HCIATH3K (HCI Atheros AR300x Protocol) is a Atheros Communication's
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* power management protocol extension to H4 to support AR300x Bluetooth Chip.
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*
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* Copyright (c) 2009-2010 Atheros Communications Inc.
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*
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* Acknowledgements:
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* This file is based on hci_h4.c, which was written
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* by Maxim Krasnyansky and Marcel Holtmann.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/tty.h>
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#include <linux/errno.h>
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#include <linux/ioctl.h>
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#include <linux/skbuff.h>
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#include <net/bluetooth/bluetooth.h>
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#include <net/bluetooth/hci_core.h>
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#include "hci_uart.h"
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struct ath_struct {
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struct hci_uart *hu;
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unsigned int cur_sleep;
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struct sk_buff *rx_skb;
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struct sk_buff_head txq;
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struct work_struct ctxtsw;
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};
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#define OP_WRITE_TAG 0x01
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#define INDEX_BDADDR 0x01
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struct ath_vendor_cmd {
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__u8 opcode;
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__le16 index;
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__u8 len;
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__u8 data[251];
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} __packed;
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static int ath_wakeup_ar3k(struct tty_struct *tty)
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{
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int status = tty->driver->ops->tiocmget(tty);
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if (status & TIOCM_CTS)
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return status;
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/* Clear RTS first */
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tty->driver->ops->tiocmget(tty);
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tty->driver->ops->tiocmset(tty, 0x00, TIOCM_RTS);
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msleep(20);
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/* Set RTS, wake up board */
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tty->driver->ops->tiocmget(tty);
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tty->driver->ops->tiocmset(tty, TIOCM_RTS, 0x00);
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msleep(20);
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status = tty->driver->ops->tiocmget(tty);
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return status;
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}
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static void ath_hci_uart_work(struct work_struct *work)
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{
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int status;
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struct ath_struct *ath;
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struct hci_uart *hu;
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struct tty_struct *tty;
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ath = container_of(work, struct ath_struct, ctxtsw);
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hu = ath->hu;
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tty = hu->tty;
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/* verify and wake up controller */
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if (ath->cur_sleep) {
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status = ath_wakeup_ar3k(tty);
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if (!(status & TIOCM_CTS))
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return;
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}
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/* Ready to send Data */
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clear_bit(HCI_UART_SENDING, &hu->tx_state);
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hci_uart_tx_wakeup(hu);
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}
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static int ath_open(struct hci_uart *hu)
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{
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struct ath_struct *ath;
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BT_DBG("hu %p", hu);
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ath = kzalloc(sizeof(*ath), GFP_KERNEL);
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if (!ath)
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return -ENOMEM;
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skb_queue_head_init(&ath->txq);
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hu->priv = ath;
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ath->hu = hu;
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INIT_WORK(&ath->ctxtsw, ath_hci_uart_work);
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return 0;
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}
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static int ath_close(struct hci_uart *hu)
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{
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struct ath_struct *ath = hu->priv;
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BT_DBG("hu %p", hu);
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skb_queue_purge(&ath->txq);
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kfree_skb(ath->rx_skb);
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cancel_work_sync(&ath->ctxtsw);
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hu->priv = NULL;
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kfree(ath);
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return 0;
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}
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static int ath_flush(struct hci_uart *hu)
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{
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struct ath_struct *ath = hu->priv;
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BT_DBG("hu %p", hu);
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skb_queue_purge(&ath->txq);
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return 0;
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}
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static int ath_vendor_cmd(struct hci_dev *hdev, uint8_t opcode, uint16_t index,
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const void *data, size_t dlen)
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{
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struct sk_buff *skb;
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struct ath_vendor_cmd cmd;
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if (dlen > sizeof(cmd.data))
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return -EINVAL;
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cmd.opcode = opcode;
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cmd.index = cpu_to_le16(index);
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cmd.len = dlen;
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memcpy(cmd.data, data, dlen);
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skb = __hci_cmd_sync(hdev, 0xfc0b, dlen + 4, &cmd, HCI_INIT_TIMEOUT);
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if (IS_ERR(skb))
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return PTR_ERR(skb);
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kfree_skb(skb);
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return 0;
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}
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static int ath_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
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{
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return ath_vendor_cmd(hdev, OP_WRITE_TAG, INDEX_BDADDR, bdaddr,
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sizeof(*bdaddr));
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}
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static int ath_setup(struct hci_uart *hu)
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{
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BT_DBG("hu %p", hu);
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hu->hdev->set_bdaddr = ath_set_bdaddr;
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return 0;
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}
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static const struct h4_recv_pkt ath_recv_pkts[] = {
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{ H4_RECV_ACL, .recv = hci_recv_frame },
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{ H4_RECV_SCO, .recv = hci_recv_frame },
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{ H4_RECV_EVENT, .recv = hci_recv_frame },
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};
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static int ath_recv(struct hci_uart *hu, const void *data, int count)
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{
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struct ath_struct *ath = hu->priv;
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ath->rx_skb = h4_recv_buf(hu->hdev, ath->rx_skb, data, count,
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ath_recv_pkts, ARRAY_SIZE(ath_recv_pkts));
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if (IS_ERR(ath->rx_skb)) {
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int err = PTR_ERR(ath->rx_skb);
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bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
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ath->rx_skb = NULL;
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return err;
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}
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return count;
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}
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#define HCI_OP_ATH_SLEEP 0xFC04
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static int ath_enqueue(struct hci_uart *hu, struct sk_buff *skb)
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{
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struct ath_struct *ath = hu->priv;
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if (hci_skb_pkt_type(skb) == HCI_SCODATA_PKT) {
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kfree_skb(skb);
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return 0;
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}
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/* Update power management enable flag with parameters of
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* HCI sleep enable vendor specific HCI command.
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*/
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if (hci_skb_pkt_type(skb) == HCI_COMMAND_PKT) {
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struct hci_command_hdr *hdr = (void *)skb->data;
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if (__le16_to_cpu(hdr->opcode) == HCI_OP_ATH_SLEEP)
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ath->cur_sleep = skb->data[HCI_COMMAND_HDR_SIZE];
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}
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BT_DBG("hu %p skb %p", hu, skb);
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/* Prepend skb with frame type */
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memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
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skb_queue_tail(&ath->txq, skb);
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set_bit(HCI_UART_SENDING, &hu->tx_state);
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schedule_work(&ath->ctxtsw);
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return 0;
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}
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static struct sk_buff *ath_dequeue(struct hci_uart *hu)
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{
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struct ath_struct *ath = hu->priv;
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return skb_dequeue(&ath->txq);
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}
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static const struct hci_uart_proto athp = {
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.id = HCI_UART_ATH3K,
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.name = "ATH3K",
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.manufacturer = 69,
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.open = ath_open,
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.close = ath_close,
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.flush = ath_flush,
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.setup = ath_setup,
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.recv = ath_recv,
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.enqueue = ath_enqueue,
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.dequeue = ath_dequeue,
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};
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int __init ath_init(void)
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{
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return hci_uart_register_proto(&athp);
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}
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int __exit ath_deinit(void)
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{
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return hci_uart_unregister_proto(&athp);
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}
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