On Thu, 21 Sep 2023 09:43:49 -0500
David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> This removes the fclkin sysfs attribute and replaces it with getting
> the fclkin clock rate using the clk subsystem (i.e. from the
> devicetree).
>
> The fclkin clock comes from an external oscillator that is connected
> directly to the AD2S1210 chip, so users of the sysfs attributes should
> not need to be concerned with this.
>
> Also sort includes while we are touching this.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
> ---
> drivers/staging/iio/resolver/Kconfig | 1 +
> drivers/staging/iio/resolver/ad2s1210.c | 76 +++++++++----------------
> 2 files changed, 28 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/staging/iio/resolver/Kconfig b/drivers/staging/iio/resolver/Kconfig
> index 6d1e2622e0b0..bebb35822c9e 100644
> --- a/drivers/staging/iio/resolver/Kconfig
> +++ b/drivers/staging/iio/resolver/Kconfig
> @@ -7,6 +7,7 @@ menu "Resolver to digital converters"
> config AD2S1210
> tristate "Analog Devices ad2s1210 driver"
> depends on SPI
> + depends on COMMON_CLK
> depends on GPIOLIB || COMPILE_TEST
> help
> Say yes here to build support for Analog Devices spi resolver
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index 95d43b241a75..153ac7704ad7 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -5,16 +5,17 @@
> * Copyright (c) 2010-2010 Analog Devices Inc.
> * Copyright (C) 2023 BayLibre, SAS
> */
> -#include <linux/types.h>
> -#include <linux/mutex.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> #include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> #include <linux/of.h>
> -#include <linux/spi/spi.h>
> #include <linux/slab.h>
> +#include <linux/spi/spi.h>
> #include <linux/sysfs.h>
> -#include <linux/delay.h>
> -#include <linux/gpio/consumer.h>
> -#include <linux/module.h>
> +#include <linux/types.h>
No objection to cleaning up the includes, but not in same patch that does
anything more significant.
>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> @@ -91,7 +92,8 @@ struct ad2s1210_state {
> struct mutex lock;
> struct spi_device *sdev;
> struct gpio_desc *gpios[5];
> - unsigned int fclkin;
> + /** The external oscillator frequency in Hz. */
> + unsigned long fclkin;
rename it so we know the units. fclkin_hz
However, I'd stash the clk instead and then get the frequency where it's needed.
Also avoids need for a wrapper function as can just call
devm_get_clk_enabled() in probe()
Obviously give that clk a meaningful name though.
> unsigned int fexcit;
> bool hysteresis;
> u8 resolution;
> @@ -198,45 +200,6 @@ static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
> return ad2s1210_config_write(st, 0x0);
> }
>
> -static ssize_t ad2s1210_show_fclkin(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> -{
> - struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
> -
> - return sprintf(buf, "%u\n", st->fclkin);
> -}
> -
> -static ssize_t ad2s1210_store_fclkin(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf,
> - size_t len)
> -{
> - struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
> - unsigned int fclkin;
> - int ret;
> -
> - ret = kstrtouint(buf, 10, &fclkin);
> - if (ret)
> - return ret;
> - if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
> - dev_err(dev, "ad2s1210: fclkin out of range\n");
> - return -EINVAL;
> - }
> -
> - mutex_lock(&st->lock);
> - st->fclkin = fclkin;
> -
> - ret = ad2s1210_update_frequency_control_word(st);
> - if (ret < 0)
> - goto error_ret;
> - ret = ad2s1210_soft_reset(st);
> -error_ret:
> - mutex_unlock(&st->lock);
> -
> - return ret < 0 ? ret : len;
> -}
> -
> static ssize_t ad2s1210_show_fexcit(struct device *dev,
> struct device_attribute *attr,
> char *buf)
> @@ -546,8 +509,6 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> return ret;
> }
>
> -static IIO_DEVICE_ATTR(fclkin, 0644,
> - ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
> static IIO_DEVICE_ATTR(fexcit, 0644,
> ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0);
> static IIO_DEVICE_ATTR(control, 0644,
> @@ -596,7 +557,6 @@ static const struct iio_chan_spec ad2s1210_channels[] = {
> };
>
> static struct attribute *ad2s1210_attributes[] = {
> - &iio_dev_attr_fclkin.dev_attr.attr,
> &iio_dev_attr_fexcit.dev_attr.attr,
> &iio_dev_attr_control.dev_attr.attr,
> &iio_dev_attr_bits.dev_attr.attr,
> @@ -654,6 +614,24 @@ static const struct iio_info ad2s1210_info = {
> .attrs = &ad2s1210_attribute_group,
> };
>
> +static int ad2s1210_setup_clocks(struct ad2s1210_state *st)
> +{
> + struct device *dev = &st->sdev->dev;
> + struct clk *clk;
> +
> + clk = devm_clk_get_enabled(dev, NULL);
> + if (IS_ERR(clk))
> + return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n");
> +
> + st->fclkin = clk_get_rate(clk);
> + if (st->fclkin < AD2S1210_MIN_CLKIN || st->fclkin > AD2S1210_MAX_CLKIN)
> + return dev_err_probe(dev, -EINVAL,
> + "clock frequency out of range: %lu\n",
> + st->fclkin);
> +
> + return 0;
> +}
> +
> static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
> {
> struct spi_device *spi = st->sdev;
