[PATCH v2] stagging:iio:ad9834: add devicetree property support

[Gwenhael Goavec-Merou]

ad9834 driver needs some default properties. Currently these parameters are
provided through platform_data.
This patch adds a function to create this pdata based on device-tree node.

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-me...@trabucayre.com>
---
Changes v1 -> v2:
        - use clock bindings for input clock (Lars-Peter Clausen)
        - provides a default value for freq0/1 and phase0/1 (Lars-Peter Clausen)
---
 drivers/staging/iio/frequency/ad9834.c | 71 +++++++++++++++++++++++++++++++++-
 drivers/staging/iio/frequency/ad9834.h |  1 +
 2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9834.c 
b/drivers/staging/iio/frequency/ad9834.c
index 6366216..24a3e84 100644
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -18,6 +18,7 @@
 #include <linux/err.h>
 #include <linux/module.h>
 #include <asm/div64.h>
+#include <linux/clk.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -316,24 +317,76 @@ static const struct iio_info ad9833_info = {
        .driver_module = THIS_MODULE,
 };
 
+#if defined(CONFIG_OF)
+static struct ad9834_platform_data *ad9834_parse_dt(struct spi_device *spi)
+{
+       struct ad9834_platform_data *pdata;
+       struct device_node *np = spi->dev.of_node;
+
+       pdata = devm_kzalloc(&spi->dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return ERR_PTR(-ENOMEM);
+
+       pdata->freq0 = 134000;
+       of_property_read_u32(np, "freq0", &pdata->freq0);
+
+       pdata->freq1 = 134000;
+       of_property_read_u32(np, "freq1", &pdata->freq1);
+
+       pdata->phase0 = 0;
+       of_property_read_u16(np, "phase0", &pdata->phase0);
+
+       pdata->phase1 = 0;
+       of_property_read_u16(np, "phase1", &pdata->phase1);
+
+       pdata->en_div2 = of_property_read_bool(np, "en_div2");
+       pdata->en_signbit_msb_out = of_property_read_bool(np,
+                                       "en_signbit_msb_out");
+
+       return pdata;
+}
+#else
+static struct ad9834_platform_data *ad9834_parse_dt(struct spi_device *spi)
+{
+       return NULL;
+}
+#endif
+
 static int ad9834_probe(struct spi_device *spi)
 {
        struct ad9834_platform_data *pdata = dev_get_platdata(&spi->dev);
        struct ad9834_state *st;
        struct iio_dev *indio_dev;
        struct regulator *reg;
+       struct clk *clk = NULL;
        int ret;
 
+       if (!pdata && spi->dev.of_node) {
+               pdata = ad9834_parse_dt(spi);
+               if (IS_ERR(pdata))
+                       return PTR_ERR(pdata);
+       }
+
        if (!pdata) {
                dev_dbg(&spi->dev, "no platform data?\n");
                return -ENODEV;
        }
 
+       if (!pdata->mclk) {
+               clk = devm_clk_get(&spi->dev, NULL);
+               if (IS_ERR(clk))
+                       return -EPROBE_DEFER;
+
+               ret = clk_prepare_enable(clk);
+               if (ret < 0)
+                       return ret;
+       }
+
        reg = devm_regulator_get(&spi->dev, "vcc");
        if (!IS_ERR(reg)) {
                ret = regulator_enable(reg);
                if (ret)
-                       return ret;
+                       goto error_disable_clk;
        }
 
        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
@@ -343,7 +396,14 @@ static int ad9834_probe(struct spi_device *spi)
        }
        spi_set_drvdata(spi, indio_dev);
        st = iio_priv(indio_dev);
-       st->mclk = pdata->mclk;
+
+       if (clk) {
+               st->clk = clk;
+               st->mclk = clk_get_rate(clk);
+       } else {
+               st->mclk = pdata->mclk;
+       }
+
        st->spi = spi;
        st->devid = spi_get_device_id(spi)->driver_data;
        st->reg = reg;
@@ -418,6 +478,9 @@ static int ad9834_probe(struct spi_device *spi)
 error_disable_reg:
        if (!IS_ERR(reg))
                regulator_disable(reg);
+error_disable_clk:
+       if (clk)
+               clk_disable_unprepare(clk);
 
        return ret;
 }
@@ -428,6 +491,10 @@ static int ad9834_remove(struct spi_device *spi)
        struct ad9834_state *st = iio_priv(indio_dev);
 
        iio_device_unregister(indio_dev);
+
+       if (st->clk)
+               clk_disable_unprepare(st->clk);
+
        if (!IS_ERR(st->reg))
                regulator_disable(st->reg);
 
diff --git a/drivers/staging/iio/frequency/ad9834.h 
b/drivers/staging/iio/frequency/ad9834.h
index 40fdd5d..fd9cccf 100644
--- a/drivers/staging/iio/frequency/ad9834.h
+++ b/drivers/staging/iio/frequency/ad9834.h
@@ -53,6 +53,7 @@
 struct ad9834_state {
        struct spi_device               *spi;
        struct regulator                *reg;
+       struct clk                              *clk;
        unsigned int                    mclk;
        unsigned short                  control;
        unsigned short                  devid;
-- 
2.9.3

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