Re: [PATCH] pwm: atmel-hlcdc: Convert to the atomic PWM API

[Nicolas Ferre]

Le 01/02/2017 à 15:35, Boris Brezillon a écrit :
> Implement the ->apply() hook and drop the ->enable(), ->disable,
> ->set_polarity and ->config() ones.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

Seems okay:
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>


> ---
>  drivers/pwm/pwm-atmel-hlcdc.c | 215 +++++++++++++++++-------------------------
>  1 file changed, 86 insertions(+), 129 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
> index 14fc011faa32..64f1e1662b57 100644
> --- a/drivers/pwm/pwm-atmel-hlcdc.c
> +++ b/drivers/pwm/pwm-atmel-hlcdc.c
> @@ -49,162 +49,119 @@ static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
>  	return container_of(chip, struct atmel_hlcdc_pwm, chip);
>  }
>  
> -static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
> -				  struct pwm_device *pwm,
> -				  int duty_ns, int period_ns)
> +static int atmel_hlcdc_pwm_apply(struct pwm_chip *c, struct pwm_device *pwm,
> +				 struct pwm_state *state)
>  {
>  	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
>  	struct atmel_hlcdc *hlcdc = chip->hlcdc;
> -	struct clk *new_clk = hlcdc->slow_clk;
> -	u64 pwmcval = duty_ns * 256;
> -	unsigned long clk_freq;
> -	u64 clk_period_ns;
> -	u32 pwmcfg;
> -	int pres;
> -
> -	if (!chip->errata || !chip->errata->slow_clk_erratum) {
> -		clk_freq = clk_get_rate(new_clk);
> -		if (!clk_freq)
> -			return -EINVAL;
> -
> -		clk_period_ns = (u64)NSEC_PER_SEC * 256;
> -		do_div(clk_period_ns, clk_freq);
> -	}
> -
> -	/* Errata: cannot use slow clk on some IP revisions */
> -	if ((chip->errata && chip->errata->slow_clk_erratum) ||
> -	    clk_period_ns > period_ns) {
> -		new_clk = hlcdc->sys_clk;
> -		clk_freq = clk_get_rate(new_clk);
> -		if (!clk_freq)
> -			return -EINVAL;
> -
> -		clk_period_ns = (u64)NSEC_PER_SEC * 256;
> -		do_div(clk_period_ns, clk_freq);
> -	}
> +	unsigned int status;
> +	int ret;
>  
> -	for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
> +	if (state->enabled) {
> +		struct clk *new_clk = hlcdc->slow_clk;
> +		u64 pwmcval = state->duty_cycle * 256;
> +		unsigned long clk_freq;
> +		u64 clk_period_ns;
> +		u32 pwmcfg;
> +		int pres;
> +
> +		if (!chip->errata || !chip->errata->slow_clk_erratum) {
> +			clk_freq = clk_get_rate(new_clk);
> +			if (!clk_freq)
> +				return -EINVAL;
> +
> +			clk_period_ns = (u64)NSEC_PER_SEC * 256;
> +			do_div(clk_period_ns, clk_freq);
> +		}
> +
> +		/* Errata: cannot use slow clk on some IP revisions */
> +		if ((chip->errata && chip->errata->slow_clk_erratum) ||
> +		    clk_period_ns > state->period) {
> +			new_clk = hlcdc->sys_clk;
> +			clk_freq = clk_get_rate(new_clk);
> +			if (!clk_freq)
> +				return -EINVAL;
> +
> +			clk_period_ns = (u64)NSEC_PER_SEC * 256;
> +			do_div(clk_period_ns, clk_freq);
> +		}
> +
> +		for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
>  		/* Errata: cannot divide by 1 on some IP revisions */
> -		if (!pres && chip->errata && chip->errata->div1_clk_erratum)
> -			continue;
> -
> -		if ((clk_period_ns << pres) >= period_ns)
> -			break;
> -	}
> -
> -	if (pres > ATMEL_HLCDC_PWMPS_MAX)
> -		return -EINVAL;
> -
> -	pwmcfg = ATMEL_HLCDC_PWMPS(pres);
> +			if (!pres && chip->errata &&
> +			    chip->errata->div1_clk_erratum)
> +				continue;
>  
> -	if (new_clk != chip->cur_clk) {
> -		u32 gencfg = 0;
> -		int ret;
> +			if ((clk_period_ns << pres) >= state->period)
> +				break;
> +		}
>  
> -		ret = clk_prepare_enable(new_clk);
> -		if (ret)
> -			return ret;
> +		if (pres > ATMEL_HLCDC_PWMPS_MAX)
> +			return -EINVAL;
>  
> -		clk_disable_unprepare(chip->cur_clk);
> -		chip->cur_clk = new_clk;
> +		pwmcfg = ATMEL_HLCDC_PWMPS(pres);
>  
> -		if (new_clk == hlcdc->sys_clk)
> -			gencfg = ATMEL_HLCDC_CLKPWMSEL;
> +		if (new_clk != chip->cur_clk) {
> +			u32 gencfg = 0;
> +			int ret;
>  
> -		ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
> -					 ATMEL_HLCDC_CLKPWMSEL, gencfg);
> -		if (ret)
> -			return ret;
> -	}
> +			ret = clk_prepare_enable(new_clk);
> +			if (ret)
> +				return ret;
>  
> -	do_div(pwmcval, period_ns);
> +			clk_disable_unprepare(chip->cur_clk);
> +			chip->cur_clk = new_clk;
>  
> -	/*
> -	 * The PWM duty cycle is configurable from 0/256 to 255/256 of the
> -	 * period cycle. Hence we can't set a duty cycle occupying the
> -	 * whole period cycle if we're asked to.
> -	 * Set it to 255 if pwmcval is greater than 256.
> -	 */
> -	if (pwmcval > 255)
> -		pwmcval = 255;
> +			if (new_clk == hlcdc->sys_clk)
> +				gencfg = ATMEL_HLCDC_CLKPWMSEL;
>  
> -	pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
> -
> -	return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
> -				  ATMEL_HLCDC_PWMCVAL_MASK |
> -				  ATMEL_HLCDC_PWMPS_MASK,
> -				  pwmcfg);
> -}
> -
> -static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
> -					struct pwm_device *pwm,
> -					enum pwm_polarity polarity)
> -{
> -	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> -	struct atmel_hlcdc *hlcdc = chip->hlcdc;
> -	u32 cfg = 0;
> +			ret = regmap_update_bits(hlcdc->regmap,
> +						 ATMEL_HLCDC_CFG(0),
> +						 ATMEL_HLCDC_CLKPWMSEL,
> +						 gencfg);
> +			if (ret)
> +				return ret;
> +		}
>  
> -	if (polarity == PWM_POLARITY_NORMAL)
> -		cfg = ATMEL_HLCDC_PWMPOL;
> +		do_div(pwmcval, state->period);
>  
> -	return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
> -				  ATMEL_HLCDC_PWMPOL, cfg);
> -}
> +		/*
> +		 * The PWM duty cycle is configurable from 0/256 to 255/256 of
> +		 * the period cycle. Hence we can't set a duty cycle occupying
> +		 * the whole period cycle if we're asked to.
> +		 * Set it to 255 if pwmcval is greater than 256.
> +		 */
> +		if (pwmcval > 255)
> +			pwmcval = 255;
>  
> -static int atmel_hlcdc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
> -{
> -	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> -	struct atmel_hlcdc *hlcdc = chip->hlcdc;
> -	u32 status;
> -	int ret;
> +		pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
>  
> -	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
> -	if (ret)
> -		return ret;
> +		if (state->polarity == PWM_POLARITY_NORMAL)
> +			pwmcfg |= ATMEL_HLCDC_PWMPOL;
>  
> -	while (true) {
> -		ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
> +		ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
> +					 ATMEL_HLCDC_PWMCVAL_MASK |
> +					 ATMEL_HLCDC_PWMPS_MASK |
> +					 ATMEL_HLCDC_PWMPOL,
> +					 pwmcfg);
>  		if (ret)
>  			return ret;
> -
> -		if ((status & ATMEL_HLCDC_PWM) != 0)
> -			break;
> -
> -		usleep_range(1, 10);
>  	}
>  
> -	return 0;
> -}
> -
> -static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
> -				    struct pwm_device *pwm)
> -{
> -	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> -	struct atmel_hlcdc *hlcdc = chip->hlcdc;
> -	u32 status;
> -	int ret;
> -
> -	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
> +	ret = regmap_write(hlcdc->regmap,
> +			   state->enabled ? ATMEL_HLCDC_EN : ATMEL_HLCDC_DIS,
> +			   ATMEL_HLCDC_PWM);
>  	if (ret)
> -		return;
> -
> -	while (true) {
> -		ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
> -		if (ret)
> -			return;
> -
> -		if ((status & ATMEL_HLCDC_PWM) == 0)
> -			break;
> +		return ret;
>  
> -		usleep_range(1, 10);
> -	}
> +	return regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR, status,
> +					(status & ATMEL_HLCDC_PWM) ==
> +					(state->enabled ? ATMEL_HLCDC_PWM : 0),
> +					10, 0);
>  }
>  
>  static const struct pwm_ops atmel_hlcdc_pwm_ops = {
> -	.config = atmel_hlcdc_pwm_config,
> -	.set_polarity = atmel_hlcdc_pwm_set_polarity,
> -	.enable = atmel_hlcdc_pwm_enable,
> -	.disable = atmel_hlcdc_pwm_disable,
> +	.apply = atmel_hlcdc_pwm_apply,
>  	.owner = THIS_MODULE,
>  };
>  
> 


-- 
Nicolas Ferre