The new devm_iio_adc_device_alloc_chaninfo() -helper is intended to help
drivers avoid open-coding the for_each_node -loop for getting the
channel IDs. The helper provides standard way to detect the ADC channel
nodes (by the node name), and a standard way to convert the "reg",
"diff-channels", "single-channel" and the "common-mode-channel" to
channel identification numbers used in the struct iio_chan_spec.
Furthermore, the helper checks the ID is in range of 0 ... num-channels.
The original driver treated all found child nodes as channel nodes. The
new helper requires channel nodes to be named channel[@N]. This should
help avoid problems with devices which may contain also other but ADC
child nodes. Quick grep from arch/* with the rzg2l_adc's compatible
string didn't reveal any in-tree .dts with channel nodes named
othervice. Also, same grep shows all the .dts seem to have channel IDs
between 0..num of channels.
Use the new helper.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
Revision history:
v3 => v4:
- Adapt to 'drop diff-channel support' changes to ADC-helpers
- select ADC helpers in the Kconfig
- Rebased to 6.14-rc3 => channel type can no longer come from the
template.
v2 => v3:
- New patch
I picked the rzg2l_adc in this series because it has a straightforward
approach for populating the struct iio_chan_spec. Only other member
in the stuct besides the .channel, which can't use a 'template' -data,
is the .datasheet_name. This makes the rzg2l_adc well suited for example
user of this new helper. I hope this patch helps to evaluate whether these
helpers are worth the hassle.
The change is compile tested only!! Testing before applying is highly
appreciated (as always!).
---
drivers/iio/adc/Kconfig | 1 +
drivers/iio/adc/rzg2l_adc.c | 38 +++++++++++++++++--------------------
2 files changed, 18 insertions(+), 21 deletions(-)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 37b70a65da6f..e4933de0c366 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1222,6 +1222,7 @@ config RICHTEK_RTQ6056
config RZG2L_ADC
tristate "Renesas RZ/G2L ADC driver"
depends on ARCH_RZG2L || COMPILE_TEST
+ select IIO_ADC_HELPER
help
Say yes here to build support for the ADC found in Renesas
RZ/G2L family.
diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
index 883c167c0670..51c87b1bdc98 100644
--- a/drivers/iio/adc/rzg2l_adc.c
+++ b/drivers/iio/adc/rzg2l_adc.c
@@ -11,6 +11,7 @@
#include <linux/cleanup.h>
#include <linux/completion.h>
#include <linux/delay.h>
+#include <linux/iio/adc-helpers.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@@ -324,21 +325,30 @@ static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static const struct iio_chan_spec rzg2l_adc_chan_template = {
+ .indexed = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+};
+
static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l_adc *adc)
{
const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
struct iio_chan_spec *chan_array;
struct rzg2l_adc_data *data;
- unsigned int channel;
int num_channels;
- int ret;
u8 i;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
- num_channels = device_get_child_node_count(&pdev->dev);
+ num_channels = devm_iio_adc_device_alloc_chaninfo_se(&pdev->dev,
+ &rzg2l_adc_chan_template,
+ hw_params->num_channels - 1,
+ &chan_array);
+ if (num_channels < 0)
+ return num_channels;
+
if (!num_channels)
return dev_err_probe(&pdev->dev, -ENODEV, "no channel children\n");
@@ -346,26 +356,11 @@ static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l
return dev_err_probe(&pdev->dev, -EINVAL,
"num of channel children out of range\n");
- chan_array = devm_kcalloc(&pdev->dev, num_channels, sizeof(*chan_array),
- GFP_KERNEL);
- if (!chan_array)
- return -ENOMEM;
-
- i = 0;
- device_for_each_child_node_scoped(&pdev->dev, fwnode) {
- ret = fwnode_property_read_u32(fwnode, "reg", &channel);
- if (ret)
- return ret;
-
- if (channel >= hw_params->num_channels)
- return -EINVAL;
+ for (i = 0; i < num_channels; i++) {
+ int channel = chan_array[i].channel;
- chan_array[i].type = rzg2l_adc_channels[channel].type;
- chan_array[i].indexed = 1;
- chan_array[i].channel = channel;
- chan_array[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
chan_array[i].datasheet_name = rzg2l_adc_channels[channel].name;
- i++;
+ chan_array[i].type = rzg2l_adc_channels[channel].type;
}
data->num_channels = num_channels;
@@ -626,3 +621,4 @@ module_platform_driver(rzg2l_adc_driver);
MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
MODULE_DESCRIPTION("Renesas RZ/G2L ADC driver");
MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_DRIVER");
--
2.48.1
On Mon, 24 Feb 2025 20:33:29 +0200
Matti Vaittinen <mazziesaccount@gmail.com> wrote:
> The new devm_iio_adc_device_alloc_chaninfo() -helper is intended to help
> drivers avoid open-coding the for_each_node -loop for getting the
> channel IDs. The helper provides standard way to detect the ADC channel
> nodes (by the node name), and a standard way to convert the "reg",
> "diff-channels", "single-channel" and the "common-mode-channel" to
> channel identification numbers used in the struct iio_chan_spec.
Needs an update to reflecting naming and functionality simplifications.
> Furthermore, the helper checks the ID is in range of 0 ... num-channels.
>
> The original driver treated all found child nodes as channel nodes. The
> new helper requires channel nodes to be named channel[@N]. This should
> help avoid problems with devices which may contain also other but ADC
> child nodes. Quick grep from arch/* with the rzg2l_adc's compatible
> string didn't reveal any in-tree .dts with channel nodes named
> othervice. Also, same grep shows all the .dts seem to have channel IDs
otherwise
(othervice does sound cool though ;)
> between 0..num of channels.
>
> Use the new helper.
>
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>
> ---
> Revision history:
> v3 => v4:
> - Adapt to 'drop diff-channel support' changes to ADC-helpers
> - select ADC helpers in the Kconfig
> - Rebased to 6.14-rc3 => channel type can no longer come from the
> template.
>
> v2 => v3:
> - New patch
>
> I picked the rzg2l_adc in this series because it has a straightforward
> approach for populating the struct iio_chan_spec. Only other member
> in the stuct besides the .channel, which can't use a 'template' -data,
> is the .datasheet_name. This makes the rzg2l_adc well suited for example
> user of this new helper. I hope this patch helps to evaluate whether these
> helpers are worth the hassle.
This doesn't seem to match driver. It is messing with channel type.
>
> The change is compile tested only!! Testing before applying is highly
> appreciated (as always!).
> ---
> drivers/iio/adc/Kconfig | 1 +
> drivers/iio/adc/rzg2l_adc.c | 38 +++++++++++++++++--------------------
> 2 files changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 37b70a65da6f..e4933de0c366 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -1222,6 +1222,7 @@ config RICHTEK_RTQ6056
> config RZG2L_ADC
> tristate "Renesas RZ/G2L ADC driver"
> depends on ARCH_RZG2L || COMPILE_TEST
> + select IIO_ADC_HELPER
> help
> Say yes here to build support for the ADC found in Renesas
> RZ/G2L family.
> diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
> index 883c167c0670..51c87b1bdc98 100644
> --- a/drivers/iio/adc/rzg2l_adc.c
> +++ b/drivers/iio/adc/rzg2l_adc.c
> @@ -11,6 +11,7 @@
> #include <linux/cleanup.h>
> #include <linux/completion.h>
> #include <linux/delay.h>
> +#include <linux/iio/adc-helpers.h>
> #include <linux/iio/iio.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> @@ -324,21 +325,30 @@ static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static const struct iio_chan_spec rzg2l_adc_chan_template = {
> + .indexed = 1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +};
> +
> static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l_adc *adc)
> {
> const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
> struct iio_chan_spec *chan_array;
> struct rzg2l_adc_data *data;
> - unsigned int channel;
> int num_channels;
> - int ret;
> u8 i;
>
> data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> return -ENOMEM;
>
> - num_channels = device_get_child_node_count(&pdev->dev);
> + num_channels = devm_iio_adc_device_alloc_chaninfo_se(&pdev->dev,
> + &rzg2l_adc_chan_template,
> + hw_params->num_channels - 1,
> + &chan_array);
> + if (num_channels < 0)
> + return num_channels;
> +
> if (!num_channels)
> return dev_err_probe(&pdev->dev, -ENODEV, "no channel children\n");
>
> @@ -346,26 +356,11 @@ static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l
> return dev_err_probe(&pdev->dev, -EINVAL,
> "num of channel children out of range\n");
>
> - chan_array = devm_kcalloc(&pdev->dev, num_channels, sizeof(*chan_array),
> - GFP_KERNEL);
> - if (!chan_array)
> - return -ENOMEM;
> -
> - i = 0;
> - device_for_each_child_node_scoped(&pdev->dev, fwnode) {
> - ret = fwnode_property_read_u32(fwnode, "reg", &channel);
> - if (ret)
> - return ret;
> -
> - if (channel >= hw_params->num_channels)
> - return -EINVAL;
> + for (i = 0; i < num_channels; i++) {
> + int channel = chan_array[i].channel;
>
> - chan_array[i].type = rzg2l_adc_channels[channel].type;
> - chan_array[i].indexed = 1;
> - chan_array[i].channel = channel;
> - chan_array[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> chan_array[i].datasheet_name = rzg2l_adc_channels[channel].name;
> - i++;
> + chan_array[i].type = rzg2l_adc_channels[channel].type;
> }
>
> data->num_channels = num_channels;
> @@ -626,3 +621,4 @@ module_platform_driver(rzg2l_adc_driver);
> MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
> MODULE_DESCRIPTION("Renesas RZ/G2L ADC driver");
> MODULE_LICENSE("GPL v2");
> +MODULE_IMPORT_NS("IIO_DRIVER");
On 02/03/2025 05:40, Jonathan Cameron wrote: > On Mon, 24 Feb 2025 20:33:29 +0200 > Matti Vaittinen <mazziesaccount@gmail.com> wrote: > >> The new devm_iio_adc_device_alloc_chaninfo() -helper is intended to help >> drivers avoid open-coding the for_each_node -loop for getting the >> channel IDs. The helper provides standard way to detect the ADC channel >> nodes (by the node name), and a standard way to convert the "reg", >> "diff-channels", "single-channel" and the "common-mode-channel" to >> channel identification numbers used in the struct iio_chan_spec. > > Needs an update to reflecting naming and functionality simplifications. Thanks! I should've noticed this. I'll re-read and alter all the commits for the v5. > >> Furthermore, the helper checks the ID is in range of 0 ... num-channels. >> >> The original driver treated all found child nodes as channel nodes. The >> new helper requires channel nodes to be named channel[@N]. This should >> help avoid problems with devices which may contain also other but ADC >> child nodes. Quick grep from arch/* with the rzg2l_adc's compatible >> string didn't reveal any in-tree .dts with channel nodes named >> othervice. Also, same grep shows all the .dts seem to have channel IDs > otherwise > > (othervice does sound cool though ;) Thanks :D For some reason I always have difficulties spelling it! ... >> I picked the rzg2l_adc in this series because it has a straightforward >> approach for populating the struct iio_chan_spec. Only other member >> in the stuct besides the .channel, which can't use a 'template' -data, >> is the .datasheet_name. This makes the rzg2l_adc well suited for example >> user of this new helper. I hope this patch helps to evaluate whether these >> helpers are worth the hassle. > This doesn't seem to match driver. It is messing with channel type. Ah. Yes. It was simple until I rebased to never version. I'll change this. Thanks! Yours, -- Matti
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