[Intel-gfx] [PATCH v2 11/15] pwm: crc: Implement get_state() method

[Uwe Kleine-König]

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 at 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 =.

Unrelated to your series I think we should change .get_state() to return
an error indication.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |
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