Re: [PATCH] iio: adf4350: Convert to use GPIO descriptor

["Ardelean, Alexandru" <alexandru.Ardelean@analog.com>]

On Mon, 2019-12-02 at 09:38 +0100, Linus Walleij wrote:
> The lock detect GPIO line is better to grab using
> a GPIO descriptor. We drop the pdata for this: clients using board
> files can use machine descriptor tables to pass this GPIO from
> static data.

Hey,

Thanks for the patch.
A question inline. Maybe to Jonathan as well.
Other than that this looks good.

> 
> Cc: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/iio/frequency/adf4350.c       | 30 +++++++--------------------
>  include/linux/iio/frequency/adf4350.h |  4 ----
>  2 files changed, 8 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/iio/frequency/adf4350.c
> b/drivers/iio/frequency/adf4350.c
> index ae0ca09ae062..1c2dc9b00f31 100644
> --- a/drivers/iio/frequency/adf4350.c
> +++ b/drivers/iio/frequency/adf4350.c
> @@ -14,11 +14,10 @@
>  #include <linux/err.h>
>  #include <linux/module.h>
>  #include <linux/gcd.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <asm/div64.h>
>  #include <linux/clk.h>
>  #include <linux/of.h>
> -#include <linux/of_gpio.h>
>  
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> @@ -34,6 +33,7 @@ enum {
>  struct adf4350_state {
>  	struct spi_device		*spi;
>  	struct regulator		*reg;
> +	struct gpio_desc		*lock_detect_gpiod;
>  	struct adf4350_platform_data	*pdata;
>  	struct clk			*clk;
>  	unsigned long			clkin;
> @@ -61,7 +61,6 @@ static struct adf4350_platform_data default_pdata = {
>  	.r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
>  	.r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
>  			    ADF4350_REG4_MUTE_TILL_LOCK_EN,
> -	.gpio_lock_detect = -1,
>  };
>  
>  static int adf4350_sync_config(struct adf4350_state *st)
> @@ -317,8 +316,8 @@ static ssize_t adf4350_read(struct iio_dev
> *indio_dev,
>  			(u64)st->fpfd;
>  		do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
>  		/* PLL unlocked? return error */
> -		if (gpio_is_valid(st->pdata->gpio_lock_detect))
> -			if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
> +		if (st->lock_detect_gpiod)
> +			if (!gpiod_get_value(st->lock_detect_gpiod)) {
>  				dev_dbg(&st->spi->dev, "PLL un-locked\n");
>  				ret = -EBUSY;
>  			}
> @@ -381,7 +380,6 @@ static struct adf4350_platform_data
> *adf4350_parse_dt(struct device *dev)
>  	struct device_node *np = dev->of_node;
>  	struct adf4350_platform_data *pdata;
>  	unsigned int tmp;
> -	int ret;
>  
>  	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>  	if (!pdata)
> @@ -401,12 +399,6 @@ static struct adf4350_platform_data
> *adf4350_parse_dt(struct device *dev)
>  	of_property_read_u32(np, "adi,reference-div-factor", &tmp);
>  	pdata->ref_div_factor = tmp;
>  
> -	ret = of_get_gpio(np, 0);
> -	if (ret < 0)
> -		pdata->gpio_lock_detect = -1;
> -	else
> -		pdata->gpio_lock_detect = ret;
> -
>  	pdata->ref_doubler_en = of_property_read_bool(np,
>  			"adi,reference-doubler-enable");
>  	pdata->ref_div2_en = of_property_read_bool(np,
> @@ -561,16 +553,10 @@ static int adf4350_probe(struct spi_device *spi)
>  
>  	memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
>  
> -	if (gpio_is_valid(pdata->gpio_lock_detect)) {
> -		ret = devm_gpio_request(&spi->dev, pdata->gpio_lock_detect,
> -					indio_dev->name);
> -		if (ret) {
> -			dev_err(&spi->dev, "fail to request lock detect
> GPIO-%d",
> -				pdata->gpio_lock_detect);
> -			goto error_disable_reg;
> -		}
> -		gpio_direction_input(pdata->gpio_lock_detect);
> -	}
> +	st->lock_detect_gpiod = devm_gpiod_get_optional(&spi->dev, NULL,

Would it make sense to name the GPIO here?
Maybe name it "lock-detect"?

I do realize that this goes into the realm of changing some default
behavior.
And I am not sure how acceptable this is [generally].

Thanks
Alex

> +							GPIOD_IN);
> +	if (IS_ERR(st->lock_detect_gpiod))
> +		return PTR_ERR(st->lock_detect_gpiod);
>  
>  	if (pdata->power_up_frequency) {
>  		ret = adf4350_set_freq(st, pdata->power_up_frequency);
> diff --git a/include/linux/iio/frequency/adf4350.h
> b/include/linux/iio/frequency/adf4350.h
> index ce9490bfeb89..de45cf2ee1e4 100644
> --- a/include/linux/iio/frequency/adf4350.h
> +++ b/include/linux/iio/frequency/adf4350.h
> @@ -103,9 +103,6 @@
>   * @r2_user_settings:	User defined settings for ADF4350/1
> REGISTER_2.
>   * @r3_user_settings:	User defined settings for ADF4350/1
> REGISTER_3.
>   * @r4_user_settings:	User defined settings for ADF4350/1
> REGISTER_4.
> - * @gpio_lock_detect:	Optional, if set with a valid GPIO number,
> - *			pll lock state is tested upon read.
> - *			If not used - set to -1.
>   */
>  
>  struct adf4350_platform_data {
> @@ -121,7 +118,6 @@ struct adf4350_platform_data {
>  	unsigned		r2_user_settings;
>  	unsigned		r3_user_settings;
>  	unsigned		r4_user_settings;
> -	int			gpio_lock_detect;
>  };
>  
>  #endif /* IIO_PLL_ADF4350_H_ */