Re: [PATCH 2/4] clk: qcom: lpassaudiocc-sc7280: Add support for LPASS resets for QCM6490

[Taniya Das <quic_tdas@quicinc.com>]

On 5/31/2024 9:56 PM, Krzysztof Kozlowski wrote:
> On 31/05/2024 12:22, Taniya Das wrote:
>> On the QCM6490 boards the LPASS firmware controls the complete clock
>> controller functionalities. But the LPASS resets are required to be
>> controlled from the high level OS. The Audio SW driver should be able to
>> assert/deassert the audio resets as required. Thus in clock driver add
>> support for the same.
>>
>> Signed-off-by: Taniya Das <quic_tdas@quicinc.com>
>> ---
>>   drivers/clk/qcom/lpassaudiocc-sc7280.c | 28 ++++++++++++++++++++++++++
>>   1 file changed, 28 insertions(+)
>>
>> diff --git a/drivers/clk/qcom/lpassaudiocc-sc7280.c b/drivers/clk/qcom/lpassaudiocc-sc7280.c
>> index c43d0b1af7f7..7fdfd07c111c 100644
>> --- a/drivers/clk/qcom/lpassaudiocc-sc7280.c
>> +++ b/drivers/clk/qcom/lpassaudiocc-sc7280.c
>> @@ -1,6 +1,7 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>>   /*
>>    * Copyright (c) 2021, The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
>>    */
>>   
>>   #include <linux/clk-provider.h>
>> @@ -869,10 +870,36 @@ static struct platform_driver lpass_aon_cc_sc7280_driver = {
>>   	},
>>   };
>>   
>> +static const struct of_device_id lpass_audio_cc_qcm6490_match_table[] = {
>> +	{ .compatible = "qcom,qcm6490-lpassaudiocc" },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, lpass_audio_cc_qcm6490_match_table);
>> +
>> +static int lpass_audio_cc_qcm6490_probe(struct platform_device *pdev)
>> +{
>> +	lpass_audio_cc_sc7280_regmap_config.name = "lpassaudio_cc_reset";
>> +	lpass_audio_cc_sc7280_regmap_config.max_register = 0xc8;
>> +
>> +	return qcom_cc_probe_by_index(pdev, 1, &lpass_audio_cc_reset_sc7280_desc);
>> +}
>> +
>> +static struct platform_driver lpass_audio_cc_qcm6490_driver = {
>> +	.probe = lpass_audio_cc_qcm6490_probe,
>> +	.driver = {
>> +		.name = "lpass_audio_cc-qcm6490",
>> +		.of_match_table = lpass_audio_cc_qcm6490_match_table,
>> +	},
>> +};
>> +
>>   static int __init lpass_audio_cc_sc7280_init(void)
>>   {
>>   	int ret;
>>   
>> +	ret = platform_driver_register(&lpass_audio_cc_qcm6490_driver);
>> +	if (ret)
>> +		return ret;
>> +
>>   	ret = platform_driver_register(&lpass_aon_cc_sc7280_driver);
> Why this is a new platform driver?  There should be just one driver with
> different match data.
> 

The main problem for me is that the current board(QCM6490) needs to be 
only support a subset of the entire(only resets) functionality the 
SC7280. If I redesign the probe function to pick the match data then I 
might accidentally break the existing functionalities on SC7280 boards.

Hence I thought to have a separate driver registration which looked a 
cleaner approach to go away from the "of_device_is_compatible".

> Best regards,
> Krzysztof
> 

-- 
Thanks & Regards,
Taniya Das.