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Message-ID: <20181023111356.GA318@x220.localdomain>
Date: Tue, 23 Oct 2018 13:13:56 +0200
From: Slawomir Stepien <sst@...zta.fm>
To: Nishad Kamdar <nishadkamdar@...il.com>
Cc: Lars-Peter Clausen <lars@...afoo.de>,
Michael Hennerich <Michael.Hennerich@...log.com>,
Jonathan Cameron <jic23@...nel.org>,
Hartmut Knaack <knaack.h@....de>,
Peter Meerwald-Stadler <pmeerw@...erw.net>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-iio@...r.kernel.org, devel@...verdev.osuosl.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] staging: iio: ad2s1210: Switch to the gpio descriptor
interface
On paź 22, 2018 22:09, Nishad Kamdar wrote:
> Use the gpiod interface instead of the deprecated old non-descriptor
> interface.
Hi
> Signed-off-by: Nishad Kamdar <nishadkamdar@...il.com>
> ---
> Changes in v2:
> - Use the spi_device struct embedded in st instead
> of passing it as an argument to ad2s1210_setup_gpios().
> - Use an array of structs to reduce redundant code in
> in ad2s1210_setup_gpios().
> - Remove ad2s1210_free_gpios() as devm API is being used.
Some few more comments on that changes below.
> ---
> drivers/staging/iio/resolver/ad2s1210.c | 91 +++++++++++++------------
> drivers/staging/iio/resolver/ad2s1210.h | 3 -
> 2 files changed, 48 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index ac13b99bd9cb..e4c222b47574 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -15,7 +15,7 @@
> #include <linux/slab.h>
> #include <linux/sysfs.h>
> #include <linux/delay.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/module.h>
>
> #include <linux/iio/iio.h>
> @@ -69,10 +69,21 @@ enum ad2s1210_mode {
>
> static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
>
> +struct ad2s1210_gpio {
> + struct gpio_desc *ptr;
You are going to use this ptr to change a pointer it points to. So it must be a
pointer to pointer: **ptr;
> + char *name;
I guess it should be const char *.
> + unsigned long flags;
> +};
> +
> struct ad2s1210_state {
> const struct ad2s1210_platform_data *pdata;
> struct mutex lock;
> struct spi_device *sdev;
> + struct gpio_desc *sample;
> + struct gpio_desc *a0;
> + struct gpio_desc *a1;
> + struct gpio_desc *res0;
> + struct gpio_desc *res1;
> unsigned int fclkin;
> unsigned int fexcit;
> bool hysteresis;
> @@ -91,8 +102,8 @@ static const int ad2s1210_mode_vals[4][2] = {
> static inline void ad2s1210_set_mode(enum ad2s1210_mode mode,
> struct ad2s1210_state *st)
> {
> - gpio_set_value(st->pdata->a[0], ad2s1210_mode_vals[mode][0]);
> - gpio_set_value(st->pdata->a[1], ad2s1210_mode_vals[mode][1]);
> + gpiod_set_value(st->a0, ad2s1210_mode_vals[mode][0]);
> + gpiod_set_value(st->a1, ad2s1210_mode_vals[mode][1]);
> st->mode = mode;
> }
>
> @@ -152,8 +163,8 @@ int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
>
> static unsigned char ad2s1210_read_resolution_pin(struct ad2s1210_state *st)
> {
> - int resolution = (gpio_get_value(st->pdata->res[0]) << 1) |
> - gpio_get_value(st->pdata->res[1]);
> + int resolution = (gpiod_get_value(st->res0) << 1) |
> + gpiod_get_value(st->res1);
>
> return ad2s1210_resolution_value[resolution];
> }
> @@ -164,10 +175,10 @@ static const int ad2s1210_res_pins[4][2] = {
>
> static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
> {
> - gpio_set_value(st->pdata->res[0],
> - ad2s1210_res_pins[(st->resolution - 10) / 2][0]);
> - gpio_set_value(st->pdata->res[1],
> - ad2s1210_res_pins[(st->resolution - 10) / 2][1]);
> + gpiod_set_value(st->res0,
> + ad2s1210_res_pins[(st->resolution - 10) / 2][0]);
> + gpiod_set_value(st->res1,
> + ad2s1210_res_pins[(st->resolution - 10) / 2][1]);
> }
>
> static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
> @@ -401,15 +412,15 @@ static ssize_t ad2s1210_clear_fault(struct device *dev,
> int ret;
>
> mutex_lock(&st->lock);
> - gpio_set_value(st->pdata->sample, 0);
> + gpiod_set_value(st->sample, 0);
> /* delay (2 * tck + 20) nano seconds */
> udelay(1);
> - gpio_set_value(st->pdata->sample, 1);
> + gpiod_set_value(st->sample, 1);
> ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
> if (ret < 0)
> goto error_ret;
> - gpio_set_value(st->pdata->sample, 0);
> - gpio_set_value(st->pdata->sample, 1);
> + gpiod_set_value(st->sample, 0);
> + gpiod_set_value(st->sample, 1);
> error_ret:
> mutex_unlock(&st->lock);
>
> @@ -466,7 +477,7 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> s16 vel;
>
> mutex_lock(&st->lock);
> - gpio_set_value(st->pdata->sample, 0);
> + gpiod_set_value(st->sample, 0);
> /* delay (6 * tck + 20) nano seconds */
> udelay(1);
>
> @@ -512,7 +523,7 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> }
>
> error_ret:
> - gpio_set_value(st->pdata->sample, 1);
> + gpiod_set_value(st->sample, 1);
> /* delay (2 * tck + 20) nano seconds */
> udelay(1);
> mutex_unlock(&st->lock);
> @@ -630,30 +641,30 @@ static const struct iio_info ad2s1210_info = {
>
> static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
> {
> - unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
> - struct gpio ad2s1210_gpios[] = {
> - { st->pdata->sample, GPIOF_DIR_IN, "sample" },
> - { st->pdata->a[0], flags, "a0" },
> - { st->pdata->a[1], flags, "a1" },
> - { st->pdata->res[0], flags, "res0" },
> - { st->pdata->res[0], flags, "res1" },
> + int ret = 0, i = 0;
You do not need to init that i with 0.
Also the ret do not have to be 0. If you return just 0 at the on this function.
> + struct spi_device *spi = st->sdev;
> + unsigned long flags = st->pdata->gpioin ? GPIOD_IN : GPIOD_OUT_LOW;
> +
> + struct ad2s1210_gpio gpios[] = {
> + {st->sample, "sample", GPIOD_IN},
> + {st->a0, "a0", flags},
> + {st->a1, "a1", flags},
> + {st->res0, "res0", flags},
> + {st->res1, "res1", flags},
To change a pointer, you need to pass an address of that pointer.
I think you should you . notation when initializing the struct.
> };
>
> - return gpio_request_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
> -}
> -
> -static void ad2s1210_free_gpios(struct ad2s1210_state *st)
> -{
> - unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
> - struct gpio ad2s1210_gpios[] = {
> - { st->pdata->sample, GPIOF_DIR_IN, "sample" },
> - { st->pdata->a[0], flags, "a0" },
> - { st->pdata->a[1], flags, "a1" },
> - { st->pdata->res[0], flags, "res0" },
> - { st->pdata->res[0], flags, "res1" },
> - };
> + for (i = 0; i < ARRAY_SIZE(gpios); i++) {
I do not know if that is a common practise, but you can set a pointer to gpio[i]
as the first instruction in this for, so you would not have to write this whole
gpio[i]:
pin = &gpios[i]
and then: pin->ptr, etc.
> + gpios[i].ptr = devm_gpiod_get(&spi->dev, gpios[i].name,
> + gpios[i].flags);
> + if (IS_ERR(gpios[i].ptr)) {
> + ret = PTR_ERR(gpios[i].ptr);
> + dev_err(&spi->dev, "Failed to request %s GPIO: %d\n",
> + gpios[i].name, ret);
> + return ret;
> + }
> + }
>
> - gpio_free_array(ad2s1210_gpios, ARRAY_SIZE(ad2s1210_gpios));
> + return ret;
> }
>
> static int ad2s1210_probe(struct spi_device *spi)
> @@ -692,18 +703,13 @@ static int ad2s1210_probe(struct spi_device *spi)
>
> ret = iio_device_register(indio_dev);
> if (ret)
> - goto error_free_gpios;
> -
Removing a empty line here, that is here to make it more readable.
> + return ret;
> st->fclkin = spi->max_speed_hz;
> spi->mode = SPI_MODE_3;
> spi_setup(spi);
> ad2s1210_initial(st);
>
> return 0;
> -
> -error_free_gpios:
> - ad2s1210_free_gpios(st);
> - return ret;
> }
>
> static int ad2s1210_remove(struct spi_device *spi)
> @@ -711,7 +717,6 @@ static int ad2s1210_remove(struct spi_device *spi)
> struct iio_dev *indio_dev = spi_get_drvdata(spi);
>
> iio_device_unregister(indio_dev);
> - ad2s1210_free_gpios(iio_priv(indio_dev));
>
> return 0;
> }
> diff --git a/drivers/staging/iio/resolver/ad2s1210.h b/drivers/staging/iio/resolver/ad2s1210.h
> index e9b2147701fc..63d479b20a6c 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.h
> +++ b/drivers/staging/iio/resolver/ad2s1210.h
> @@ -12,9 +12,6 @@
> #define _AD2S1210_H
>
> struct ad2s1210_platform_data {
> - unsigned int sample;
> - unsigned int a[2];
> - unsigned int res[2];
> bool gpioin;
> };
> #endif /* _AD2S1210_H */
--
Slawomir Stepien
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