linux-kernel - Re: [PATCH 2/3] staging: iio: ad5933: use clock framework for clock reference

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Message-ID: <20181216121448.69a11744@archlinux>
Date:   Sun, 16 Dec 2018 12:14:48 +0000
From:   Jonathan Cameron <jic23@...nel.org>
To:     Marcelo Schmitt <marcelo.schmitt1@...il.com>
Cc:     lars@...afoo.de, Michael.Hennerich@...log.com, knaack.h@....de,
        pmeerw@...erw.net, gregkh@...uxfoundation.org,
        stefan.popa@...log.com, alexandru.Ardelean@...log.com,
        linux-iio@...r.kernel.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org, kernel-usp@...glegroups.com
Subject: Re: [PATCH 2/3] staging: iio: ad5933: use clock framework for clock
 reference

On Sat, 8 Dec 2018 16:19:38 -0200
Marcelo Schmitt <marcelo.schmitt1@...il.com> wrote:

> Add the option to specify the external clock (MCLK) using the clock
> framework.
> Also remove the old platform data structure.
> 
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@...il.com>
> Signed-off-by: Gabriel Capella <gabriel@...ella.pro>
> Co-Developed-by: Gabriel Capella <gabriel@...ella.pro>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
>  .../staging/iio/impedance-analyzer/ad5933.c   | 43 ++++++++++---------
>  1 file changed, 22 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
> index 730bc397a26b..3134295f014f 100644
> --- a/drivers/staging/iio/impedance-analyzer/ad5933.c
> +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
> @@ -16,6 +16,7 @@
>  #include <linux/err.h>
>  #include <linux/delay.h>
>  #include <linux/module.h>
> +#include <linux/clk.h>
>  
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> @@ -82,20 +83,10 @@
>  #define AD5933_POLL_TIME_ms		10
>  #define AD5933_INIT_EXCITATION_TIME_ms	100
>  
> -/**
> - * struct ad5933_platform_data - platform specific data
> - * @ext_clk_hz:		the external clock frequency in Hz, if not set
> - *			the driver uses the internal clock (16.776 MHz)
> - * @vref_mv:		the external reference voltage in millivolt
> - */
> -
> -struct ad5933_platform_data {
> -	unsigned long			ext_clk_hz;
> -};
> -
>  struct ad5933_state {
>  	struct i2c_client		*client;
>  	struct regulator		*reg;
> +	struct clk			*mclk;
>  	struct delayed_work		work;
>  	struct mutex			lock; /* Protect sensor state */
>  	unsigned long			mclk_hz;
> @@ -111,9 +102,6 @@ struct ad5933_state {
>  	unsigned int			poll_time_jiffies;
>  };
>  
> -static struct ad5933_platform_data ad5933_default_pdata  = {
> -};
> -
>  #define AD5933_CHANNEL(_type, _extend_name, _info_mask_separate, _address, \
>  		_scan_index, _realbits) { \
>  	.type = (_type), \
> @@ -690,9 +678,9 @@ static int ad5933_probe(struct i2c_client *client,
>  			const struct i2c_device_id *id)
>  {
>  	int ret;
> -	struct ad5933_platform_data *pdata = dev_get_platdata(&client->dev);
>  	struct ad5933_state *st;
>  	struct iio_dev *indio_dev;
> +	unsigned long ext_clk_hz = 0;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
>  	if (!indio_dev)
> @@ -704,9 +692,6 @@ static int ad5933_probe(struct i2c_client *client,
>  
>  	mutex_init(&st->lock);
>  
> -	if (!pdata)
> -		pdata = &ad5933_default_pdata;
> -
>  	st->reg = devm_regulator_get(&client->dev, "vdd");
>  	if (IS_ERR(st->reg))
>  		return PTR_ERR(st->reg);
> @@ -723,8 +708,21 @@ static int ad5933_probe(struct i2c_client *client,
>  
>  	st->vref_mv = ret / 1000;
>  
> -	if (pdata->ext_clk_hz) {
> -		st->mclk_hz = pdata->ext_clk_hz;
> +	st->mclk = devm_clk_get(&client->dev, "mclk");
> +	if (IS_ERR(st->mclk) && PTR_ERR(st->mclk) != -ENOENT) {
> +		ret = PTR_ERR(st->mclk);
> +		goto error_disable_reg;
> +	}
> +
> +	if (!IS_ERR(st->mclk)) {
> +		ret = clk_prepare_enable(st->mclk);
> +		if (ret < 0)
> +			goto error_disable_reg;
> +		ext_clk_hz = clk_get_rate(st->mclk);
> +	}
> +
> +	if (ext_clk_hz) {
> +		st->mclk_hz = ext_clk_hz;
>  		st->ctrl_lb = AD5933_CTRL_EXT_SYSCLK;
>  	} else {
>  		st->mclk_hz = AD5933_INT_OSC_FREQ_Hz;
> @@ -744,7 +742,7 @@ static int ad5933_probe(struct i2c_client *client,
>  
>  	ret = ad5933_register_ring_funcs_and_init(indio_dev);
>  	if (ret)
> -		goto error_disable_reg;
> +		goto error_disable_mclk;
>  
>  	ret = ad5933_setup(st);
>  	if (ret)
> @@ -758,6 +756,8 @@ static int ad5933_probe(struct i2c_client *client,
>  
>  error_unreg_ring:
>  	iio_kfifo_free(indio_dev->buffer);
> +error_disable_mclk:
> +	clk_disable_unprepare(st->mclk);
>  error_disable_reg:
>  	regulator_disable(st->reg);
>  
> @@ -772,6 +772,7 @@ static int ad5933_remove(struct i2c_client *client)
>  	iio_device_unregister(indio_dev);
>  	iio_kfifo_free(indio_dev->buffer);
>  	regulator_disable(st->reg);
> +	clk_disable_unprepare(st->mclk);
>  
>  	return 0;
>  }