staging: iio: ad9834: convert to device-managed functions in probe

This change converts the driver to use device-managed functions in the
probe function. For the clock and regulator disable, some
devm_add_action_or_reset() calls are required, and then
devm_iio_device_register() function can be used register the IIO device.

The final aim here would be for IIO to export only the device-managed
functions of it's API. That's a long way to go and this a small step in
that direction.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210310095131.47476-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c
index 262c3590e64e3db820cf18046a015093696b0516..60a3ae5587b9056043ba0d865520b0a34a8949c9 100644 (file)
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -56,7 +56,6 @@
 /**
  * struct ad9834_state - driver instance specific data
  * @spi:               spi_device
- * @reg:               supply regulator
  * @mclk:              external master clock
  * @control:           cached control word
  * @xfer:              default spi transfer
@@ -70,7 +69,6 @@
 
 struct ad9834_state {
        struct spi_device               *spi;
-       struct regulator                *reg;
        struct clk                      *mclk;
        unsigned short                  control;
        unsigned short                  devid;
@@ -390,6 +388,20 @@ static const struct iio_info ad9833_info = {
        .attrs = &ad9833_attribute_group,
 };
 
+static void ad9834_disable_reg(void *data)
+{
+       struct regulator *reg = data;
+
+       regulator_disable(reg);
+}
+
+static void ad9834_disable_clk(void *data)
+{
+       struct clk *clk = data;
+
+       clk_disable_unprepare(clk);
+}
+
 static int ad9834_probe(struct spi_device *spi)
 {
        struct ad9834_state *st;
@@ -407,29 +419,35 @@ static int ad9834_probe(struct spi_device *spi)
                return ret;
        }
 
+       ret = devm_add_action_or_reset(&spi->dev, ad9834_disable_reg, reg);
+       if (ret)
+               return ret;
+
        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
        if (!indio_dev) {
                ret = -ENOMEM;
-               goto error_disable_reg;
+               return ret;
        }
-       spi_set_drvdata(spi, indio_dev);
        st = iio_priv(indio_dev);
        mutex_init(&st->lock);
        st->mclk = devm_clk_get(&spi->dev, NULL);
        if (IS_ERR(st->mclk)) {
                ret = PTR_ERR(st->mclk);
-               goto error_disable_reg;
+               return ret;
        }
 
        ret = clk_prepare_enable(st->mclk);
        if (ret) {
                dev_err(&spi->dev, "Failed to enable master clock\n");
-               goto error_disable_reg;
+               return ret;
        }
 
+       ret = devm_add_action_or_reset(&spi->dev, ad9834_disable_clk, st->mclk);
+       if (ret)
+               return ret;
+
        st->spi = spi;
        st->devid = spi_get_device_id(spi)->driver_data;
-       st->reg = reg;
        indio_dev->name = spi_get_device_id(spi)->name;
        switch (st->devid) {
        case ID_AD9833:
@@ -470,48 +488,26 @@ static int ad9834_probe(struct spi_device *spi)
        ret = spi_sync(st->spi, &st->msg);
        if (ret) {
                dev_err(&spi->dev, "device init failed\n");
-               goto error_clock_unprepare;
+               return ret;
        }
 
        ret = ad9834_write_frequency(st, AD9834_REG_FREQ0, 1000000);
        if (ret)
-               goto error_clock_unprepare;
+               return ret;
 
        ret = ad9834_write_frequency(st, AD9834_REG_FREQ1, 5000000);
        if (ret)
-               goto error_clock_unprepare;
+               return ret;
 
        ret = ad9834_write_phase(st, AD9834_REG_PHASE0, 512);
        if (ret)
-               goto error_clock_unprepare;
+               return ret;
 
        ret = ad9834_write_phase(st, AD9834_REG_PHASE1, 1024);
        if (ret)
-               goto error_clock_unprepare;
-
-       ret = iio_device_register(indio_dev);
-       if (ret)
-               goto error_clock_unprepare;
-
-       return 0;
-error_clock_unprepare:
-       clk_disable_unprepare(st->mclk);
-error_disable_reg:
-       regulator_disable(reg);
-
-       return ret;
-}
-
-static int ad9834_remove(struct spi_device *spi)
-{
-       struct iio_dev *indio_dev = spi_get_drvdata(spi);
-       struct ad9834_state *st = iio_priv(indio_dev);
-
-       iio_device_unregister(indio_dev);
-       clk_disable_unprepare(st->mclk);
-       regulator_disable(st->reg);
+               return ret;
 
-       return 0;
+       return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct spi_device_id ad9834_id[] = {
@@ -539,7 +535,6 @@ static struct spi_driver ad9834_driver = {
                .of_match_table = ad9834_of_match
        },
        .probe          = ad9834_probe,
-       .remove         = ad9834_remove,
        .id_table       = ad9834_id,
 };
 module_spi_driver(ad9834_driver);