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

From: gubbaven@codeaurora.org
To: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
	Matthias Kaehlcke <mka@chromium.org>,
	linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
	robh@kernel.org, hemantg@codeaurora.org,
	linux-arm-msm@vger.kernel.org, bgodavar@codeaurora.org,
	tientzu@chromium.org, seanpaul@chromium.org,
	rjliao@codeaurora.org, yshavit@google.com
Subject: Re: [PATCH v2 1/2] Bluetooth: hci_qca: Enable clocks required for BT SOC
Date: Mon, 03 Feb 2020 12:57:42 +0530	[thread overview]
Message-ID: <b38d85546b89df7351abb9a7e25d7475@codeaurora.org> (raw)
In-Reply-To: <543135AD-707A-4945-A67D-8912D1C35EED@holtmann.org>

Hi Marcel,

On 2020-02-01 01:21, Marcel Holtmann wrote:
> Hi Venkata,
> 
>> 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@codeaurora.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;
>> +}
>> +
> 
> this function is pointless and it just complicated the code.

[Venkata] : Sure we will remove the function and will update in next 
patch set.
> 
>> 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);
> 
> 	ret = clk_prepare_enable(qcadev->susclk);

[Venkata] : Sure.We will update in next patch set.

> 
>> +	if (ret) {
>> +		/* Turn off regulators to overcome power leakage */
>> +		qca_regulator_disable(qcadev);
>> +		return ret;
>> +	}
>> +
>> 	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)
>> +		qca_setup_clock(qcadev->susclk, false);
> 
> 		clk_disable_unprepare(qcadev->susclk);

[Venkata] : Sure.We will update in next patch set.
> 
>> }
>> 
>> static int qca_init_regulators(struct qca_power *qca,
>> @@ -1839,6 +1858,12 @@ static int qca_serdev_probe(struct 
>> serdev_device *serdev)
>> 
>> 		qcadev->bt_power->vregs_on = false;
>> 
>> +		qcadev->susclk = devm_clk_get_optional(&serdev->dev, NULL);
>> +		if (IS_ERR(qcadev->susclk)) {
>> +			dev_err(&serdev->dev, "failed to acquire clk\n");
>> +			return PTR_ERR(qcadev->susclk);
>> +		}
>> +
>> 		device_property_read_u32(&serdev->dev, "max-speed",
>> 					 &qcadev->oper_speed);
>> 		if (!qcadev->oper_speed)
> 
> Regards
> 
> Marcel

Regards,
Venkata.