Re: [PATCH v8 7/7] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990

[Balakrishna Godavarthi]

Hi Matthias,

On 2018-06-26 06:35, Matthias Kaehlcke wrote:
> On Mon, Jun 25, 2018 at 07:10:13PM +0530, Balakrishna Godavarthi wrote:
> > Add support to set voltage/current of various regulators
> > to power up/down Bluetooth chip wcn3990.
> >
> > Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
> > ---
> > changes in v8:
> >     * closing qca buffer, if qca_power_setup fails
> >     * chnaged ibs start timer function call location.
> >     * updated review comments.
> >
> > changes in v7:
> >     * addressed review comments.
> >
> > changes in v6:
> >     * Hooked up qca_power to qca_serdev.
> >     * renamed all the naming inconsistency functions with qca_*
> >     * leveraged common code of ROME for wcn3990.
> >     * created wrapper functions for re-usable blocks.
> >     * updated function of _*regulator_enable and _*regualtor_disable.
> >     * removed redundant comments and functions.
> >     * addressed review comments.
> >
> > Changes in v5:
> >     * updated regulator vddpa min_uV to 1304000.
> >       * addressed review comments.
> >
> > Changes in v4:
> >     * Segregated the changes of btqca from hci_qca
> >     * rebased all changes on top of bluetooth-next.
> >     * addressed review comments.
> >
> > ---
> > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> > index 28187a89b850..bd4c9a78716f 100644
> > --- a/drivers/bluetooth/hci_qca.c
> > +++ b/drivers/bluetooth/hci_qca.c
> > ...
> > +static int qca_send_vendor_cmd(struct hci_dev *hdev, u8 cmd)
> > +{
> > +	struct hci_uart *hu = hci_get_drvdata(hdev);
> > +	struct qca_data *qca = hu->priv;
> > +	struct sk_buff *skb;
> > +
> > +	bt_dev_dbg(hdev, "sending command %02x to SoC", cmd);
> > +
> > +	skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
> > +	if (!skb) {
> > +		bt_dev_err(hdev, "Failed to allocate memory for vendor packet");
>
> As mentioned on v7, custom OOM messages should be avoided.

[Bala]: sry i might have missed it, will update.

> >  static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type 
> > speed_type)
> >  {
> > +	struct qca_serdev *qcadev;
> >  	unsigned int speed, qca_baudrate;
> >  	int ret;
> >
> > @@ -971,6 +1054,13 @@ static int qca_set_speed(struct hci_uart *hu, 
> > enum qca_speed_type speed_type)
> >  		return 0;
> >  	}
> >
> > +	qcadev = serdev_device_get_drvdata(hu->serdev);
> > +	/* Disabling hardware flow control is preferred while
> > +	 * sending change baud rate command to SoC.
> > +	 */
>
> Is it only preferred or must be?

[Bala]: must be. will update.

> > +	if (qcadev->btsoc_type == QCA_WCN3990)
> > +		hci_uart_set_flow_control(hu, true);
> > +
>
> nit: consider doing this just before qca_set_baudrate(). It doesn't
> make a difference but leaves it clearer what exactly needs to be
> 'protected' (analogy to locking).

[Bala] : will do it.

> >  	qca_baudrate = qca_get_baudrate_value(speed);
> >  	bt_dev_info(hu->hdev, "Set UART speed to %d", speed);
> >  	ret = qca_set_baudrate(hu->hdev, qca_baudrate);
> > @@ -980,8 +1070,10 @@ static int qca_set_speed(struct hci_uart *hu, 
> > enum qca_speed_type speed_type)
> >  	}
> >
> >  	host_set_baudrate(hu, speed);
> > +	if (qcadev->btsoc_type == QCA_WCN3990)
> > +		hci_uart_set_flow_control(hu, false);
>
> >  static int qca_setup(struct hci_uart *hu)
> > @@ -989,10 +1081,11 @@ static int qca_setup(struct hci_uart *hu)
> >  	struct hci_dev *hdev = hu->hdev;
> >  	struct qca_data *qca = hu->priv;
> >  	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
> > +	struct qca_serdev *qcadev;
> >  	int ret;
> >  	int soc_ver = 0;
> >
> > -	bt_dev_info(hdev, "ROME setup");
> > +	qcadev = serdev_device_get_drvdata(hu->serdev);
> >
> >  	/* Patch downloading has to be done without IBS mode */
> >  	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
> > @@ -1000,6 +1093,35 @@ static int qca_setup(struct hci_uart *hu)
> >  	/* Setup initial baudrate */
> >  	qca_set_speed(hu, QCA_INIT_SPEED);
> >
> > +	if (qcadev->btsoc_type == QCA_WCN3990) {
> > +		bt_dev_dbg(hdev, "setting up wcn3990");
> > +		hci_uart_set_flow_control(hu, true);
> > +		ret = qca_send_vendor_cmd(hdev, QCA_WCN3990_POWERON_PULSE);
> > +		if (ret)
> > +			return ret;
> > +
> > +		hci_uart_set_flow_control(hu, false);
> > +		serdev_device_close(hu->serdev);
> > +		ret = serdev_device_open(hu->serdev);
> > +		if (ret) {
> > +			bt_dev_err(hdev, "failed to open port");
> > +			return ret;
> > +		}
> > +
> > +		msleep(100);
>
> Is the sleep really related with _open() or is it rather that the
> device needs to settle after the power on pulse? In the latter case
> I'd suggest to do the sleep before _open(), if it doesn't make a
> functional difference (makes the code a bit more self documenting).
>
> > +		/* Setup initial baudrate */
> > +		qca_set_speed(hu, QCA_INIT_SPEED);
> > +		hci_uart_set_flow_control(hu, false);
>
> This is still a bit noisy with all the open/close and flow control
> stuff. If I understand correctly this essentially switches the
> controller on (or resets it?) and brings it (and the driver) into a
> sane state. Would it make sense to move the above block into a
> wcn3990_init/reset() or so?

[Bala]: It is very good idea, may be future chips also will flow same 
functions with some initial setup changes.
        will group these functions into a common functions.


--
Regards
Balakrishna.