Re: [PATCH v5 2/2] pwm: Add clock based PWM output driver

From: Nikita Travkin
Date: Sat Feb 19 2022 - 01:48:58 EST


Hi,

Krzysztof Kozlowski писал(а) 14.02.2022 16:19:
> On 12/02/2022 17:23, Nikita Travkin wrote:
>> Some systems have clocks exposed to external devices. If the clock
>> controller supports duty-cycle configuration, such clocks can be used as
>> pwm outputs. In fact PWM and CLK subsystems are interfaced with in a
>> similar way and an "opposite" driver already exists (clk-pwm). Add a
>> driver that would enable pwm devices to be used via clk subsystem.
>>
>> Signed-off-by: Nikita Travkin <nikita@xxxxxxx>
>> --
>>
>
> (...)
>
>> +
>> +static int pwm_clk_probe(struct platform_device *pdev)
>> +{
>> + struct pwm_clk_chip *chip;
>> + int ret;
>> +
>> + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
>> + if (!chip)
>> + return -ENOMEM;
>> +
>> + chip->clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(chip->clk))
>> + return dev_err_probe(&pdev->dev, PTR_ERR(chip->clk),
>> + "Failed to get clock\n");
>> +
>> + chip->chip.dev = &pdev->dev;
>> + chip->chip.ops = &pwm_clk_ops;
>> + chip->chip.npwm = 1;
>> +
>> + ret = clk_prepare(chip->clk);
>> + if (ret < 0)
>> + return dev_err_probe(&pdev->dev, ret, "Failed to prepare clock\n");
>> +
>> + ret = pwmchip_add(&chip->chip);
>> + if (ret < 0)
>> + return dev_err_probe(&pdev->dev, ret, "Failed to add pwm chip\n");
>
> You need to cleanup - unprepare the clock.
>

Oops, I will add unprepare in v6, Thanks!

Nikita

>> +
>> + platform_set_drvdata(pdev, chip);
>> + return 0;
>> +}
>> +
>
>
> Best regards,
> Krzysztof