linux-kernel - Re: [PATCH 2/2] pinctrl: sx150x: support setting multiple pins at once

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Date:   Wed, 23 Nov 2016 10:17:28 +0100
From:   Neil Armstrong <narmstrong@...libre.com>
To:     Peter Rosin <peda@...ntia.se>, linux-kernel@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Andrey Smirnov <andrew.smirnov@...il.com>,
        linux-gpio@...r.kernel.org
Subject: Re: [PATCH 2/2] pinctrl: sx150x: support setting multiple pins at
 once

On 11/22/2016 05:06 PM, Peter Rosin wrote:
> The mask of a possible oscio pin is cached, making it easier to test
> for the exception.
> 
> Signed-off-by: Peter Rosin <peda@...ntia.se>
> ---
>  drivers/pinctrl/pinctrl-sx150x.c | 37 +++++++++++++++++++++++++++++--------
>  1 file changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-sx150x.c b/drivers/pinctrl/pinctrl-sx150x.c
> index ef4ef88e0ee9..5bcede2b2cd8 100644
> --- a/drivers/pinctrl/pinctrl-sx150x.c
> +++ b/drivers/pinctrl/pinctrl-sx150x.c
> @@ -114,6 +114,7 @@ struct sx150x_pinctrl {
>  	} irq;
>  	struct mutex lock;
>  	const struct sx150x_device_data *data;
> +	unsigned long oscio_mask;
>  };
>  
>  static const struct pinctrl_pin_desc sx150x_8_pins[] = {
> @@ -290,14 +291,7 @@ static const struct pinctrl_ops sx150x_pinctrl_ops = {
>  
>  static bool sx150x_pin_is_oscio(struct sx150x_pinctrl *pctl, unsigned int pin)
>  {
> -	if (pin >= pctl->data->npins)
> -		return false;
> -
> -	/* OSCIO pin is only present in 789 devices */
> -	if (pctl->data->model != SX150X_789)
> -		return false;
> -
> -	return !strcmp(pctl->data->pins[pin].name, "oscio");
> +	return !!(BIT(pin) & pctl->oscio_mask);
>  }
>  
>  static int sx150x_gpio_get_direction(struct gpio_chip *chip,
> @@ -395,6 +389,15 @@ static void sx150x_gpio_set(struct gpio_chip *chip, unsigned int offset,
>  
>  }
>  
> +static void sx150x_gpio_set_multiple(struct gpio_chip *chip,
> +				     unsigned long *mask,
> +				     unsigned long *bits)
> +{
> +	struct sx150x_pinctrl *pctl = gpiochip_get_data(chip);
> +
> +	regmap_write_bits(pctl->regmap, pctl->data->reg_data, *mask, *bits);
> +}
> +
>  static int sx150x_gpio_direction_input(struct gpio_chip *chip,
>  				       unsigned int offset)
>  {
> @@ -996,6 +999,20 @@ static int sx150x_regmap_reg_write(void *context, unsigned int reg,
>  	return 0;
>  }
>  
> +static void sx150x_oscio_mask_init(struct sx150x_pinctrl *pctl)
> +{
> +	int pin;
> +
> +	/* OSCIO pin is only present in 789 devices */
> +	if (pctl->data->model != SX150X_789)
> +		return;
> +
> +	for (pin = 0; pin < pctl->data->npins; ++pin) {
> +		if (!strcmp(pctl->data->pins[pin].name, "oscio"))
> +			pctl->oscio_mask |= BIT(pin);
> +	}
> +}
> +

This is quite over-engineered since we have one a maximum of a single oscio line, we could only store the pin number or -1...

>  static bool sx150x_reg_volatile(struct device *dev, unsigned int reg)
>  {
>  	struct sx150x_pinctrl *pctl = i2c_get_clientdata(to_i2c_client(dev));
> @@ -1045,6 +1062,8 @@ static int sx150x_probe(struct i2c_client *client,
>  	if (!pctl->data)
>  		return -EINVAL;
>  
> +	sx150x_oscio_mask_init(pctl);
> +
>  	pctl->regmap = devm_regmap_init(dev, NULL, pctl,
>  					&sx150x_regmap_config);
>  	if (IS_ERR(pctl->regmap)) {
> @@ -1069,6 +1088,8 @@ static int sx150x_probe(struct i2c_client *client,
>  	pctl->gpio.direction_output = sx150x_gpio_direction_output;
>  	pctl->gpio.get = sx150x_gpio_get;
>  	pctl->gpio.set = sx150x_gpio_set;
> +	if (!pctl->oscio_mask)
> +		pctl->gpio.set_multiple = sx150x_gpio_set_multiple;
>  	pctl->gpio.set_single_ended = sx150x_gpio_set_single_ended;
>  	pctl->gpio.parent = dev;
>  #ifdef CONFIG_OF_GPIO
> 

Here, a simple if (pctl->data->model != SX150X_789) would be enough, and please a comment to say why set_multiple is not acceptable for oscio.