Re: [PATCH] ASoC: qcom: soundwire: Enable soundwire bus clock for version 1.6

From: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: agross@kernel.org, lgirdwood@gmail.com, broonie@kernel.org,
	robh+dt@kernel.org, plai@codeaurora.org, bgoswami@codeaurora.org,
	perex@perex.cz, tiwai@suse.com, srinivas.kandagatla@linaro.org,
	rohitkr@codeaurora.org, linux-arm-msm@vger.kernel.org,
	alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, swboyd@chromium.org,
	judyhsiao@chromium.org,
	Venkata Prasad Potturu <potturu@codeaurora.org>
Subject: Re: [PATCH] ASoC: qcom: soundwire: Enable soundwire bus clock for version 1.6
Date: Fri, 8 Oct 2021 11:00:59 +0530	[thread overview]
Message-ID: <7969646f-6dfb-b03f-886c-38987fe01395@codeaurora.org> (raw)
In-Reply-To: <YVyE+ytKVmOh85c3@ripper>

Thanks for Your time Bjorn!!!

On 10/5/2021 10:31 PM, Bjorn Andersson wrote:
> On Fri 01 Oct 09:24 PDT 2021, Srinivasa Rao Mandadapu wrote:
>
>> Add support for soundwire 1.6 version to gate RX/TX bus clock.
>>
>> Signed-off-by: Venkata Prasad Potturu <potturu@codeaurora.org>
>> Signed-off-by: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>
>> ---
>>   drivers/soundwire/qcom.c | 12 +++++++++++-
>>   1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
>> index 0ef79d6..599b3ed 100644
>> --- a/drivers/soundwire/qcom.c
>> +++ b/drivers/soundwire/qcom.c
>> @@ -127,6 +127,7 @@ struct qcom_swrm_ctrl {
>>   	struct device *dev;
>>   	struct regmap *regmap;
>>   	void __iomem *mmio;
>> +	char __iomem *swrm_hctl_reg;
>>   	struct completion broadcast;
>>   	struct completion enumeration;
>>   	struct work_struct slave_work;
>> @@ -610,6 +611,12 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
>>   	val = FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK, ctrl->rows_index);
>>   	val |= FIELD_PREP(SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK, ctrl->cols_index);
>>   
>> +	if (ctrl->swrm_hctl_reg) {
>> +		val = ioread32(ctrl->swrm_hctl_reg);
>> +		val &= 0xFFFFFFFD;
> That's a tricky way of saying:
>
> 	val &= ~BIT(1);
>
> That said, naming bit 1 is still a very good thing.
Okay. will change accordingly.
>
>> +		iowrite32(val, ctrl->swrm_hctl_reg);
>> +	}
>> +
>>   	ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
>>   
>>   	/* Enable Auto enumeration */
>> @@ -1200,7 +1207,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>>   	struct qcom_swrm_ctrl *ctrl;
>>   	const struct qcom_swrm_data *data;
>>   	int ret;
>> -	u32 val;
>> +	int val, swrm_hctl_reg = 0;
>>   
>>   	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
>>   	if (!ctrl)
>> @@ -1251,6 +1258,9 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>>   	ctrl->bus.port_ops = &qcom_swrm_port_ops;
>>   	ctrl->bus.compute_params = &qcom_swrm_compute_params;
>>   
>> +	if (!of_property_read_u32(dev->of_node, "qcom,swrm-hctl-reg", &swrm_hctl_reg))
>> +		ctrl->swrm_hctl_reg = devm_ioremap(&pdev->dev, swrm_hctl_reg, 0x4);
> Nack.
>
> You may not pull an address to a single register out of an undocumented
> DT property and blindly ioremap that.
>
> And you surely should check for errors here, to avoid magical errors
> caused by this ioremap failing and your bit not being cleared.
>
> Thanks,
> Bjorn
Okay. will add error check, as Bossart Suggested.
>
>> +
>>   	ret = qcom_swrm_get_port_config(ctrl);
>>   	if (ret)
>>   		goto err_clk;
>> -- 
>> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.,
>> is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
>>
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.,
is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.