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From: <Claudiu.Beznea@microchip.com>
To: <uwe@kleine-koenig.org>, <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org, alexandre.belloni@bootlin.com,
	Ludovic.Desroches@microchip.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/3] pwm: atmel: use a constant for maximum prescale value
Date: Mon, 19 Aug 2019 09:27:23 +0000
Message-ID: <65d0bea5-b1f2-d0d3-509f-944551cb9ec2@microchip.com> (raw)
In-Reply-To: <20190815214133.11134-2-uwe@kleine-koenig.org>



On 16.08.2019 00:41, Uwe Kleine-König wrote:
> External E-Mail
> 
> 
> The maximal prescale value is 10 for all supported variants. So drop the
> member in the variant description and introduce a global constant instead.
> 
> This reduces the size of the variant descriptions and the .apply() callback
> can be compiled a bit more effectively.
> 
> Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>

Tested on SAMA5D2_Xplained.

> ---
>  drivers/pwm/pwm-atmel.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
> index ac3d7a200b9e..d7a6d32b5774 100644
> --- a/drivers/pwm/pwm-atmel.c
> +++ b/drivers/pwm/pwm-atmel.c
> @@ -50,6 +50,8 @@
>  #define PWMV2_CPRD		0x0C
>  #define PWMV2_CPRDUPD		0x10
>  
> +#define PWM_MAX_PRES		10
> +
>  struct atmel_pwm_registers {
>  	u8 period;
>  	u8 period_upd;
> @@ -59,7 +61,6 @@ struct atmel_pwm_registers {
>  
>  struct atmel_pwm_config {
>  	u32 max_period;
> -	u32 max_pres;
>  };
>  
>  struct atmel_pwm_data {
> @@ -126,7 +127,7 @@ static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
>  	for (*pres = 0; cycles > atmel_pwm->data->cfg.max_period; cycles >>= 1)
>  		(*pres)++;
>  
> -	if (*pres > atmel_pwm->data->cfg.max_pres) {
> +	if (*pres > PWM_MAX_PRES) {
>  		dev_err(chip->dev, "pres exceeds the maximum value\n");
>  		return -EINVAL;
>  	}
> @@ -289,7 +290,6 @@ static const struct atmel_pwm_data atmel_sam9rl_pwm_data = {
>  	.cfg = {
>  		/* 16 bits to keep period and duty. */
>  		.max_period	= 0xffff,
> -		.max_pres	= 10,
>  	},
>  };
>  
> @@ -303,7 +303,6 @@ static const struct atmel_pwm_data atmel_sama5_pwm_data = {
>  	.cfg = {
>  		/* 16 bits to keep period and duty. */
>  		.max_period	= 0xffff,
> -		.max_pres	= 10,
>  	},
>  };
>  
> @@ -317,7 +316,6 @@ static const struct atmel_pwm_data mchp_sam9x60_pwm_data = {
>  	.cfg = {
>  		/* 32 bits to keep period and duty. */
>  		.max_period	= 0xffffffff,
> -		.max_pres	= 10,
>  	},
>  };
>  
> 
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Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-15 21:41 [PATCH 1/3] pwm: atmel: Add link to reference manual Uwe Kleine-König
2019-08-15 21:41 ` [PATCH 2/3] pwm: atmel: use a constant for maximum prescale value Uwe Kleine-König
2019-08-19  9:27   ` Claudiu.Beznea [this message]
2019-08-15 21:41 ` [PATCH 3/3] pwm: atmel: replace loop in prescale calculation by ad-hoc calculation Uwe Kleine-König
2019-08-19  9:27   ` Claudiu.Beznea
2019-08-16  9:37 ` [PATCH 4/3] pwm: atmel: document known weaknesses of both hardware and software Uwe Kleine-König
2019-08-16 20:43   ` Alexandre Belloni
2019-08-19  8:10     ` Uwe Kleine-König
2019-08-19  9:26   ` Claudiu.Beznea
2019-08-19 10:46     ` Uwe Kleine-König
2019-08-19 12:28       ` Claudiu.Beznea
2019-08-19 15:20         ` Uwe Kleine-König
2019-08-19  9:26 ` [PATCH 1/3] pwm: atmel: Add link to reference manual Claudiu.Beznea
2019-08-19  9:46   ` Nicolas.Ferre

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