linux-kernel - Re: [PATCH v2 1/2] Bluetooth: hci_qca: Enable clocks required for BT SOC

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Date:   Mon, 3 Feb 2020 11:56:32 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Venkata Lakshmi Narayana Gubba <gubbaven@...eaurora.org>
Cc:     marcel@...tmann.org, johan.hedberg@...il.com, mka@...omium.org,
        linux-kernel@...r.kernel.org, linux-bluetooth@...r.kernel.org,
        robh@...nel.org, hemantg@...eaurora.org,
        linux-arm-msm@...r.kernel.org, bgodavar@...eaurora.org,
        tientzu@...omium.org, seanpaul@...omium.org, rjliao@...eaurora.org,
        yshavit@...gle.com
Subject: Re: [PATCH v2 1/2] Bluetooth: hci_qca: Enable clocks required for BT
 SOC

On Thu 30 Jan 23:38 PST 2020, Venkata Lakshmi Narayana Gubba wrote:

> Instead of relying on other subsytem to turn ON clocks
> required for BT SoC to operate, voting them from the driver.
> 
> Signed-off-by: Venkata Lakshmi Narayana Gubba <gubbaven@...eaurora.org>
> ---
> v2:
>    * addressed forward declarations
>    * updated with devm_clk_get_optional()
>  
> ---
>  drivers/bluetooth/hci_qca.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index d6e0c99..73706f3 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1738,6 +1738,15 @@ static int qca_power_off(struct hci_dev *hdev)
>  	return 0;
>  }
>  
> +static int qca_setup_clock(struct clk *clk, bool enable)
> +{
> +	if (enable)
> +		return clk_prepare_enable(clk);
> +
> +	clk_disable_unprepare(clk);
> +	return 0;
> +}

As Marcel requested, inline these.

> +
>  static int qca_regulator_enable(struct qca_serdev *qcadev)
>  {
>  	struct qca_power *power = qcadev->bt_power;
> @@ -1755,6 +1764,13 @@ static int qca_regulator_enable(struct qca_serdev *qcadev)
>  
>  	power->vregs_on = true;
>  
> +	ret = qca_setup_clock(qcadev->susclk, true);
> +	if (ret) {
> +		/* Turn off regulators to overcome power leakage */

You can omit this comment as well, as the name of the function you call
is aptly named.

> +		qca_regulator_disable(qcadev);
> +		return ret;

Just return ret below instead.

> +	}
> +
>  	return 0;
>  }
>  
> @@ -1773,6 +1789,9 @@ static void qca_regulator_disable(struct qca_serdev *qcadev)
>  
>  	regulator_bulk_disable(power->num_vregs, power->vreg_bulk);
>  	power->vregs_on = false;
> +
> +	if (qcadev->susclk)

In the enable path you (correctly) rely on passing NULL to the clock
code, so do the same here.

Regards,
Bjorn