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

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Date:   Tue, 4 Feb 2020 10:04:51 +0100
From:   Marcel Holtmann <marcel@...tmann.org>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     Venkata Lakshmi Narayana Gubba <gubbaven@...eaurora.org>,
        Johan Hedberg <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

Hi Bjorn,

>> 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.

I already pushed the patch, but I am happy to accept a cleanup patch.

Regards

Marcel