[PATCH v5 3/7] iio: adc: stm32-adc: split channel init into several routines

Olivier Moysan
2021-10-14T13:16:21Z

Split stm32_adc_chan_of_init channel initialization function into
several routines to increase readability and prepare channel
generic binding handling.

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
---
drivers/iio/adc/stm32-adc.c | 131 ++++++++++++++++++++++++------------
1 file changed, 87 insertions(+), 44 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 5088de835bb1..2f137d14f141 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -194,6 +194,7 @@ struct stm32_adc_cfg {
* @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
* @cal: optional calibration data on some devices
* @chan_name: channel name array
+ * @num_diff: number of differential channels
*/
struct stm32_adc {
struct stm32_adc_common *common;
@@ -217,6 +218,7 @@ struct stm32_adc {
u32 smpr_val[2];
struct stm32_adc_calib cal;
char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
+ u32 num_diff;
};

struct stm32_adc_diff_channel {
@@ -1706,17 +1708,11 @@ static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
}
}

-static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
+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 stm32_adc *adc = iio_priv(indio_dev);
const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
- struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
- struct property *prop;
- const __be32 *cur;
- struct iio_chan_spec *channels;
- int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
- u32 val, smp = 0;
+ int num_channels = 0, ret;

ret = of_property_count_u32_elems(node, "st,adc-channels");
if (ret > adc_info->max_channels) {
@@ -1727,41 +1723,54 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
}

ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
- sizeof(*diff));
+ sizeof(struct stm32_adc_diff_channel));
if (ret > adc_info->max_channels) {
dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
return -EINVAL;
} else if (ret > 0) {
- int size = ret * sizeof(*diff) / sizeof(u32);
-
- num_diff = ret;
+ adc->num_diff = ret;
num_channels += ret;
+ }
+
+ return num_channels;
+}
+
+static int stm32_adc_legacy_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 stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
+ 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;
+
+ if (num_diff) {
ret = of_property_read_u32_array(node, "st,adc-diff-channels",
(u32 *)diff, size);
- if (ret)
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to get diff channels %d\n", ret);
return ret;
- }
+ }

- if (!num_channels) {
- dev_err(&indio_dev->dev, "No channels configured\n");
- return -ENODATA;
- }
+ for (i = 0; i < num_diff; i++) {
+ if (diff[i].vinp >= adc_info->max_channels ||
+ diff[i].vinn >= adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
+ diff[i].vinp, diff[i].vinn);
+ return -EINVAL;
+ }

- /* 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) {
- dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
- return -EINVAL;
+ stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+ diff[i].vinp, diff[i].vinn,
+ scan_index, true);
+ scan_index++;
+ }
}

- if (timestamping)
- num_channels++;
-
- channels = devm_kcalloc(&indio_dev->dev, num_channels,
- sizeof(struct iio_chan_spec), GFP_KERNEL);
- if (!channels)
- return -ENOMEM;
-
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);
@@ -1771,8 +1780,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
/* 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 miss-configured\n", val);
+ dev_err(&indio_dev->dev, "channel %d misconfigured\n", val);
return -EINVAL;
}
}
@@ -1781,19 +1789,54 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
scan_index++;
}

- for (i = 0; i < num_diff; i++) {
- if (diff[i].vinp >= adc_info->max_channels ||
- diff[i].vinn >= adc_info->max_channels) {
- dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
- diff[i].vinp, diff[i].vinn);
- return -EINVAL;
- }
- stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
- diff[i].vinp, diff[i].vinn, scan_index,
- true);
- scan_index++;
+ return scan_index;
+}
+
+static int stm32_adc_chan_of_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;
+ int scan_index = 0, num_channels = 0, ret, i;
+ u32 smp = 0;
+
+ ret = stm32_adc_get_legacy_chan_count(indio_dev, adc);
+ if (ret < 0)
+ return ret;
+ num_channels = ret;
+
+ if (!num_channels) {
+ dev_err(&indio_dev->dev, "No channels configured\n");
+ return -ENODATA;
}

+ if (num_channels > adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Channel number [%d] exceeds %d\n",
+ num_channels, adc_info->max_channels);
+ return -EINVAL;
+ }
+
+ /* 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) {
+ dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
+ return -EINVAL;
+ }
+
+ if (timestamping)
+ num_channels++;
+
+ channels = devm_kcalloc(&indio_dev->dev, num_channels,
+ sizeof(struct iio_chan_spec), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels);
+ if (ret < 0)
+ return ret;
+ scan_index = ret;
+
for (i = 0; i < scan_index; i++) {
/*
* Using of_property_read_u32_index(), smp value will only be