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

From: Jonathan Cameron
Date: Sun Dec 16 2018 - 07:15:00 EST


On Sat, 8 Dec 2018 16:19:38 -0200
Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx> 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@xxxxxxxxx>
> Signed-off-by: Gabriel Capella <gabriel@xxxxxxxxxxx>
> Co-Developed-by: Gabriel Capella <gabriel@xxxxxxxxxxx>
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;
> }