iio: adc: stm32-adc: convert to device properties
authorNuno Sá <nuno.sa@analog.com>
Fri, 15 Jul 2022 12:29:01 +0000 (14:29 +0200)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Mon, 15 Aug 2022 21:30:00 +0000 (22:30 +0100)
Make the conversion to firmware agnostic device properties. As part of
the conversion the IIO inkern interface 'of_xlate()' is also converted to
'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
dependencies from IIO.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Tested-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220715122903.332535-14-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/iio/adc/stm32-adc.c

index 130e8dd..6256977 100644 (file)
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
+#include <linux/mod_devicetable.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
+#include <linux/property.h>
 
 #include "stm32-adc-core.h"
 
@@ -241,6 +241,7 @@ struct stm32_adc_cfg {
  * @chan_name:         channel name array
  * @num_diff:          number of differential channels
  * @int_ch:            internal channel indexes array
+ * @nsmps:             number of channels with optional sample time
  */
 struct stm32_adc {
        struct stm32_adc_common *common;
@@ -267,6 +268,7 @@ struct stm32_adc {
        char                    chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
        u32                     num_diff;
        int                     int_ch[STM32_ADC_INT_CH_NB];
+       int                     nsmps;
 };
 
 struct stm32_adc_diff_channel {
@@ -1520,8 +1522,8 @@ static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
        return ret;
 }
 
-static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
-                             const struct of_phandle_args *iiospec)
+static int stm32_adc_fwnode_xlate(struct iio_dev *indio_dev,
+                                 const struct fwnode_reference_args *iiospec)
 {
        int i;
 
@@ -1575,7 +1577,7 @@ static const struct iio_info stm32_adc_iio_info = {
        .hwfifo_set_watermark = stm32_adc_set_watermark,
        .update_scan_mode = stm32_adc_update_scan_mode,
        .debugfs_reg_access = stm32_adc_debugfs_reg_access,
-       .of_xlate = stm32_adc_of_xlate,
+       .fwnode_xlate = stm32_adc_fwnode_xlate,
 };
 
 static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
@@ -1772,14 +1774,14 @@ static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
        {},
 };
 
-static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
+static int stm32_adc_fw_get_resolution(struct iio_dev *indio_dev)
 {
-       struct device_node *node = indio_dev->dev.of_node;
+       struct device *dev = &indio_dev->dev;
        struct stm32_adc *adc = iio_priv(indio_dev);
        unsigned int i;
        u32 res;
 
-       if (of_property_read_u32(node, "assigned-resolution-bits", &res))
+       if (device_property_read_u32(dev, "assigned-resolution-bits", &res))
                res = adc->cfg->adc_info->resolutions[0];
 
        for (i = 0; i < adc->cfg->adc_info->num_res; i++)
@@ -1863,11 +1865,11 @@ static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
 
 static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm32_adc *adc)
 {
-       struct device_node *node = indio_dev->dev.of_node;
+       struct device *dev = &indio_dev->dev;
        const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
        int num_channels = 0, ret;
 
-       ret = of_property_count_u32_elems(node, "st,adc-channels");
+       ret = device_property_count_u32(dev, "st,adc-channels");
        if (ret > adc_info->max_channels) {
                dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
                return -EINVAL;
@@ -1875,8 +1877,15 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
                num_channels += ret;
        }
 
-       ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
-                                             sizeof(struct stm32_adc_diff_channel));
+       /*
+        * each st,adc-diff-channels is a group of 2 u32 so we divide @ret
+        * to get the *real* number of channels.
+        */
+       ret = device_property_count_u32(dev, "st,adc-diff-channels");
+       if (ret < 0)
+               return ret;
+
+       ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32));
        if (ret > adc_info->max_channels) {
                dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
                return -EINVAL;
@@ -1886,8 +1895,8 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
        }
 
        /* Optional sample time is provided either for each, or all channels */
-       ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
-       if (ret > 1 && ret != num_channels) {
+       adc->nsmps = device_property_count_u32(dev, "st,min-sample-time-nsecs");
+       if (adc->nsmps > 1 && adc->nsmps != num_channels) {
                dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
                return -EINVAL;
        }
@@ -1897,21 +1906,20 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm
 
 static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
                                      struct stm32_adc *adc,
-                                     struct iio_chan_spec *channels)
+                                     struct iio_chan_spec *channels,
+                                     int nchans)
 {
-       struct device_node *node = indio_dev->dev.of_node;
        const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
        struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
+       struct device *dev = &indio_dev->dev;
        u32 num_diff = adc->num_diff;
        int size = num_diff * sizeof(*diff) / sizeof(u32);
-       int scan_index = 0, val, ret, i;
-       struct property *prop;
-       const __be32 *cur;
-       u32 smp = 0;
+       int scan_index = 0, ret, i, c;
+       u32 smp = 0, smps[STM32_ADC_CH_MAX], chans[STM32_ADC_CH_MAX];
 
        if (num_diff) {
-               ret = of_property_read_u32_array(node, "st,adc-diff-channels",
-                                                (u32 *)diff, size);
+               ret = device_property_read_u32_array(dev, "st,adc-diff-channels",
+                                                    (u32 *)diff, size);
                if (ret) {
                        dev_err(&indio_dev->dev, "Failed to get diff channels %d\n", ret);
                        return ret;
@@ -1932,32 +1940,47 @@ static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
                }
        }
 
-       of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
-               if (val >= adc_info->max_channels) {
-                       dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
+       ret = device_property_read_u32_array(dev, "st,adc-channels", chans,
+                                            nchans);
+       if (ret)
+               return ret;
+
+       for (c = 0; c < nchans; c++) {
+               if (chans[c] >= adc_info->max_channels) {
+                       dev_err(&indio_dev->dev, "Invalid channel %d\n",
+                               chans[c]);
                        return -EINVAL;
                }
 
                /* Channel can't be configured both as single-ended & diff */
                for (i = 0; i < num_diff; i++) {
-                       if (val == diff[i].vinp) {
-                               dev_err(&indio_dev->dev, "channel %d misconfigured\n",  val);
+                       if (chans[c] == diff[i].vinp) {
+                               dev_err(&indio_dev->dev, "channel %d misconfigured\n",  chans[c]);
                                return -EINVAL;
                        }
                }
-               stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
-                                       0, scan_index, false);
+               stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+                                       chans[c], 0, scan_index, false);
                scan_index++;
        }
 
+       if (adc->nsmps > 0) {
+               ret = device_property_read_u32_array(dev, "st,min-sample-time-nsecs",
+                                                    smps, adc->nsmps);
+               if (ret)
+                       return ret;
+       }
+
        for (i = 0; i < scan_index; i++) {
                /*
-                * Using of_property_read_u32_index(), smp value will only be
-                * modified if valid u32 value can be decoded. This allows to
-                * get either no value, 1 shared value for all indexes, or one
-                * value per channel.
+                * This check is used with the above logic so that smp value
+                * will only be modified if valid u32 value can be decoded. This
+                * allows to get either no value, 1 shared value for all indexes,
+                * or one value per channel. The point is to have the same
+                * behavior as 'of_property_read_u32_index()'.
                 */
-               of_property_read_u32_index(node, "st,min-sample-time-nsecs", i, &smp);
+               if (i < adc->nsmps)
+                       smp = smps[i];
 
                /* Prepare sampling time settings */
                stm32_adc_smpr_init(adc, channels[i].channel, smp);
@@ -2005,22 +2028,21 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
                                       struct stm32_adc *adc,
                                       struct iio_chan_spec *channels)
 {
-       struct device_node *node = indio_dev->dev.of_node;
        const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
-       struct device_node *child;
+       struct fwnode_handle *child;
        const char *name;
        int val, scan_index = 0, ret;
        bool differential;
        u32 vin[2];
 
-       for_each_available_child_of_node(node, child) {
-               ret = of_property_read_u32(child, "reg", &val);
+       device_for_each_child_node(&indio_dev->dev, child) {
+               ret = fwnode_property_read_u32(child, "reg", &val);
                if (ret) {
                        dev_err(&indio_dev->dev, "Missing channel index %d\n", ret);
                        goto err;
                }
 
-               ret = of_property_read_string(child, "label", &name);
+               ret = fwnode_property_read_string(child, "label", &name);
                /* label is optional */
                if (!ret) {
                        if (strlen(name) >= STM32_ADC_CH_SZ) {
@@ -2047,7 +2069,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
                }
 
                differential = false;
-               ret = of_property_read_u32_array(child, "diff-channels", vin, 2);
+               ret = fwnode_property_read_u32_array(child, "diff-channels", vin, 2);
                /* diff-channels is optional */
                if (!ret) {
                        differential = true;
@@ -2064,7 +2086,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
                stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
                                        vin[1], scan_index, differential);
 
-               ret = of_property_read_u32(child, "st,min-sample-time-ns", &val);
+               ret = fwnode_property_read_u32(child, "st,min-sample-time-ns", &val);
                /* st,min-sample-time-ns is optional */
                if (!ret) {
                        stm32_adc_smpr_init(adc, channels[scan_index].channel, val);
@@ -2082,14 +2104,13 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
        return scan_index;
 
 err:
-       of_node_put(child);
+       fwnode_handle_put(child);
 
        return ret;
 }
 
-static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
+static int stm32_adc_chan_fw_init(struct iio_dev *indio_dev, bool timestamping)
 {
-       struct device_node *node = indio_dev->dev.of_node;
        struct stm32_adc *adc = iio_priv(indio_dev);
        const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
        struct iio_chan_spec *channels;
@@ -2099,7 +2120,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
        for (i = 0; i < STM32_ADC_INT_CH_NB; i++)
                adc->int_ch[i] = STM32_ADC_INT_CH_NONE;
 
-       num_channels = of_get_available_child_count(node);
+       num_channels = device_get_child_node_count(&indio_dev->dev);
        /* If no channels have been found, fallback to channels legacy properties. */
        if (!num_channels) {
                legacy = true;
@@ -2130,7 +2151,8 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
                return -ENOMEM;
 
        if (legacy)
-               ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels);
+               ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels,
+                                                num_channels);
        else
                ret = stm32_adc_generic_chan_init(indio_dev, adc, channels);
        if (ret < 0)
@@ -2212,9 +2234,6 @@ static int stm32_adc_probe(struct platform_device *pdev)
        bool timestamping = false;
        int ret;
 
-       if (!pdev->dev.of_node)
-               return -ENODEV;
-
        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
        if (!indio_dev)
                return -ENOMEM;
@@ -2223,17 +2242,16 @@ static int stm32_adc_probe(struct platform_device *pdev)
        adc->common = dev_get_drvdata(pdev->dev.parent);
        spin_lock_init(&adc->lock);
        init_completion(&adc->completion);
-       adc->cfg = (const struct stm32_adc_cfg *)
-               of_match_device(dev->driver->of_match_table, dev)->data;
+       adc->cfg = device_get_match_data(dev);
 
        indio_dev->name = dev_name(&pdev->dev);
-       indio_dev->dev.of_node = pdev->dev.of_node;
+       device_set_node(&indio_dev->dev, dev_fwnode(&pdev->dev));
        indio_dev->info = &stm32_adc_iio_info;
        indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
 
        platform_set_drvdata(pdev, indio_dev);
 
-       ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
+       ret = device_property_read_u32(dev, "reg", &adc->offset);
        if (ret != 0) {
                dev_err(&pdev->dev, "missing reg property\n");
                return -EINVAL;
@@ -2262,7 +2280,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
                }
        }
 
-       ret = stm32_adc_of_get_resolution(indio_dev);
+       ret = stm32_adc_fw_get_resolution(indio_dev);
        if (ret < 0)
                return ret;
 
@@ -2279,7 +2297,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
                timestamping = true;
        }
 
-       ret = stm32_adc_chan_of_init(indio_dev, timestamping);
+       ret = stm32_adc_chan_fw_init(indio_dev, timestamping);
        if (ret < 0)
                goto err_dma_disable;