static void hci_uart_write_work(struct work_struct *work)
{
struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
struct serdev_device *serdev = hu->serdev;
struct hci_dev *hdev = hu->hdev;
struct sk_buff *skb;
/* REVISIT:
* should we cope with bad skbs or ->write() returning an error value?
*/
do {
clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
while ((skb = hci_uart_dequeue(hu))) {
int len;
len = serdev_device_write_buf(serdev,
skb->data, skb->len);
hdev->stat.byte_tx += len;
skb_pull(skb, len);
if (skb->len) {
hu->tx_skb = skb;
break;
}
hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
kfree_skb(skb);
}
} while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
clear_bit(HCI_UART_SENDING, &hu->tx_state);
}
static int qca_send_power_pulse(struct hci_uart *hu, bool on)
{
int ret;
int timeout = msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS);
u8 cmd = on ? QCA_WCN3990_POWERON_PULSE : QCA_WCN3990_POWEROFF_PULSE;
/* These power pulses are single byte command which are sent
* at required baudrate to wcn3990. On wcn3990, we have an external
* circuit at Tx pin which decodes the pulse sent at specific baudrate.
* For example, wcn3990 supports RF COEX antenna for both Wi-Fi/BT
* and also we use the same power inputs to turn on and off for
* Wi-Fi/BT. Powering up the power sources will not enable BT, until
* we send a power on pulse at 115200 bps. This algorithm will help to
* save power. Disabling hardware flow control is mandatory while
* sending power pulses to SoC.
*/
bt_dev_dbg(hu->hdev, "sending power pulse %02x to controller", cmd);
serdev_device_write_flush(hu->serdev);
hci_uart_set_flow_control(hu, true);
ret = serdev_device_write_buf(hu->serdev, &cmd, sizeof(cmd));
if (ret < 0) {
bt_dev_err(hu->hdev, "failed to send power pulse %02x", cmd);
return ret;
}
serdev_device_wait_until_sent(hu->serdev, timeout);
hci_uart_set_flow_control(hu, false);
/* Give to controller time to boot/shutdown */
if (on)
msleep(100);
else
msleep(10);
return 0;
}
