Re: [PATCH v2 11/15] pwm: crc: Implement get_state() method

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 6/11/20 11:37 PM, Uwe Kleine-König wrote:
> Hello,
> 
> On Sun, Jun 07, 2020 at 08:18:36PM +0200, Hans de Goede wrote:
>> Implement the pwm_ops.get_state() method to complete the support for the
>> new atomic PWM API.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>   drivers/pwm/pwm-crc.c | 29 +++++++++++++++++++++++++++++
>>   1 file changed, 29 insertions(+)
>>
>> diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
>> index 58c7e9ef7278..6c75a3470bc8 100644
>> --- a/drivers/pwm/pwm-crc.c
>> +++ b/drivers/pwm/pwm-crc.c
>> @@ -114,8 +114,37 @@ static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>>   	return 0;
>>   }
>>   
>> +static void crc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
>> +			       struct pwm_state *state)
>> +{
>> +	struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip);
>> +	struct device *dev = crc_pwm->chip.dev;
>> +	unsigned int clk_div, clk_div_reg, duty_cycle_reg;
>> +	int error;
>> +
>> +	error = regmap_read(crc_pwm->regmap, PWM0_CLK_DIV, &clk_div_reg);
>> +	if (error) {
>> +		dev_err(dev, "Error reading PWM0_CLK_DIV %d\n", error);
>> +		return;
>> +	}
>> +
>> +	error = regmap_read(crc_pwm->regmap, PWM0_DUTY_CYCLE, &duty_cycle_reg);
>> +	if (error) {
>> +		dev_err(dev, "Error reading PWM0_DUTY_CYCLE %d\n", error);
>> +		return;
>> +	}
> 
> I assume that duty_cycle_reg cannot be bigger than 0xff? Would it make
> sense to mask the value accordingly to get more robust code?
> 
>> +	clk_div = (clk_div_reg & ~PWM_OUTPUT_ENABLE) + 1;
>> +
>> +	state->period     = clk_div * NSEC_PER_MHZ * 256 / PWM_BASE_CLK_MHZ;
>> +	state->duty_cycle = duty_cycle_reg * state->period / PWM_MAX_LEVEL;
>> +	state->polarity   = PWM_POLARITY_NORMAL;
>> +	state->enabled    = !!(clk_div_reg & PWM_OUTPUT_ENABLE);
> 
> These aligned = look strange (IMHO). If you don't feel strong here I'd
> like to see a single space before a =.

Ok, will change for the next version.

Regards,

Hans