[PATCH v2 13/15] iio: adc: stm32-adc: convert to device properties
Fabrice Gasnier
fabrice.gasnier at foss.st.com
Mon Jul 11 07:04:44 PDT 2022
On 7/11/22 14:38, Nuno Sá wrote:
> 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 at analog.com>
> ---
> drivers/iio/adc/stm32-adc.c | 121 ++++++++++++++++++++----------------
> 1 file changed, 67 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 3985fe972892..e55859113df8 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -21,11 +21,11 @@
> #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"
>
> @@ -1530,8 +1530,8 @@ 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;
>
> @@ -1585,7 +1585,7 @@ 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)
> @@ -1782,14 +1782,14 @@ 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++)
> @@ -1873,11 +1873,11 @@ 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;
> @@ -1885,8 +1885,8 @@ 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 */
> + ret = device_property_count_u64(dev, "st,adc-diff-channels");
> if (ret > adc_info->max_channels) {
> dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
> return -EINVAL;
> @@ -1896,7 +1896,7 @@ 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");
> + ret = device_property_count_u32(dev, "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;
> @@ -1907,21 +1907,20 @@ 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;
> + u32 smp = 0, nsmps, 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;
> @@ -1942,32 +1941,51 @@ 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 (i = 0; i < nchans; i++) {
Hi Nuno,
There's an endless loop issue here due to the two for loops are using
the same index 'i'. (Please look at my earlier comments in v1)
for (i = 0; i < nchans; i++) {
...
// Here i gets cleared, num_diff may vary (example with 0 here)
for (i = 0; i < num_diff; i++) {
...
}
stm32_adc_chan_init_one(.. &channels[scan_index].. scan_index..)
scan_index++; // Still, scan index gets incremented indefinitly
}
There's an out of boudary situation with scan_index above, wich ends-up
in crashing in stm32_adc_chan_init_one().
> + if (chans[i] >= adc_info->max_channels) {
> + dev_err(&indio_dev->dev, "Invalid channel %d\n",
> + chans[i]);
> 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[i] == diff[i].vinp) {
> + dev_err(&indio_dev->dev, "channel %d misconfigured\n", chans[i]);
> 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[i], 0, scan_index, false);
> scan_index++;
> }
>
> + nsmps = device_property_count_u32(dev, "st,min-sample-time-nsecs");
> + if (nsmps) {
> + if (nsmps >= nchans)
nit: if (nsmps > nchans)
> + nsmps = nchans;
> +
There's a bit of redundancy in checking nsmps,
"st,min-sample-time-nsecs" is already sanitized in
stm32_adc_get_legacy_chan_count():
/* Optional sample time is provided either for each, or all channels */
ret = device_property_count_u32(dev, "st,min-sample-time-nsecs");
if (ret > 1 && ret != num_channels) {
dev_err(...
So just sharing my thoughts here:
- Maybe this could be dropped ?
(Thinking loudly) The earliest this gets sanitized, the less un-needed
initialisations happen before failing?
- Or the earlier check could be moved here ?
I've no strong opinion.
Best Regards,
Fabrice
> + ret = device_property_read_u32_array(dev, "st,min-sample-time-nsecs",
> + smps, 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 < nsmps)
> + smp = smps[i];
>
> /* Prepare sampling time settings */
> stm32_adc_smpr_init(adc, channels[i].channel, smp);
> @@ -2010,22 +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) {
> @@ -2050,7 +2067,7 @@ 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;
> @@ -2067,7 +2084,7 @@ 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);
> @@ -2085,14 +2102,13 @@ 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;
> @@ -2102,7 +2118,7 @@ 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;
> @@ -2133,7 +2149,8 @@ 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)
> @@ -2215,9 +2232,6 @@ 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;
> @@ -2226,17 +2240,16 @@ 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;
> @@ -2265,7 +2278,7 @@ 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;
>
> @@ -2282,7 +2295,7 @@ 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;
>
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