Re: [PATCH V10 3/4] iio: adc: Add support for QCOM PMIC5 Gen3 ADC

Jonathan Cameron
2026-01-31T17:39:56Z

On Fri, 30 Jan 2026 17:24:20 +0530
Jishnu Prakash <jishnu.prakash@oss.qualcomm.com> wrote:

> The ADC architecture on PMIC5 Gen3 is similar to that on PMIC5 Gen2,
> with all SW communication to ADC going through PMK8550 which
> communicates with other PMICs through PBS.
>
> One major difference is that the register interface used here is that
> of an SDAM (Shared Direct Access Memory) peripheral present on PMK8550.
> There may be more than one SDAM used for ADC5 Gen3 and each has eight
> channels, which may be used for either immediate reads (same functionality
> as previous PMIC5 and PMIC5 Gen2 ADC peripherals) or recurring measurements
> (same as ADC_TM functionality).
>
> By convention, we reserve the first channel of the first SDAM for all
> immediate reads and use the remaining channels across all SDAMs for
> ADC_TM monitoring functionality.
>
> Add support for PMIC5 Gen3 ADC driver for immediate read functionality.
> ADC_TM is implemented as an auxiliary thermal driver under this ADC
> driver.
>
> Signed-off-by: Jishnu Prakash <jishnu.prakash@oss.qualcomm.com>
Hi Jishnu

Whilst there are a couple of comments below, I think this is ready to go.
Unfortunately this is just a few days too late to merge for this coming
cycle as I need to send the IIO pull request today or tomorrow (due to going
through char-misc) so this would get no soak time in next.

Also, I'm not sure how we actually want to merge this given close coupling with
the thermal driver. Perhaps best bet is I do an immutable branch of next rc1
once available that we pull into both trees. That would have the first 3 patches
on it.

Jonathan

> diff --git a/drivers/iio/adc/qcom-spmi-adc5-gen3.c b/drivers/iio/adc/qcom-spmi-adc5-gen3.c
> new file mode 100644
> index 000000000000..f8168a14b907
> --- /dev/null
> +++ b/drivers/iio/adc/qcom-spmi-adc5-gen3.c
> @@ -0,0 +1,860 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/cleanup.h>
> +#include <linux/completion.h>
> +#include <linux/container_of.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
If you happen to be spinning again for some reason, I think you might be able to replace
this device.h include with a forwards declaration of struct device;

If you can that would be good as we are trying to reduce includes of these
mega headers.

> +#include <linux/device/devres.h>
> +#include <linux/dev_printk.h>
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/iio/adc/qcom-adc5-gen3-common.h>
> +#include <linux/iio/iio.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
> +#include <linux/unaligned.h>

> +static int adc5_gen3_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct iio_dev *indio_dev;
> + struct adc5_chip *adc;
> + struct regmap *regmap;
> + int ret, i;
> + u32 *reg;
> +
> + regmap = dev_get_regmap(dev->parent, NULL);
> + if (!regmap)
> + return -ENODEV;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + adc->dev_data.regmap = regmap;
> + adc->dev = dev;
> +
> + ret = device_property_count_u32(dev, "reg");
> + if (ret < 0)
> + return ret;
> +
> + adc->dev_data.num_sdams = ret;
> +
> + reg = devm_kcalloc(dev, adc->dev_data.num_sdams, sizeof(u32),
> + GFP_KERNEL);
> + if (!reg)
> + return -ENOMEM;
> +
> + ret = device_property_read_u32_array(dev, "reg", reg,
> + adc->dev_data.num_sdams);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "Failed to read reg property\n");
> +
> + adc->dev_data.base = devm_kcalloc(dev, adc->dev_data.num_sdams,
> + sizeof(*adc->dev_data.base),
> + GFP_KERNEL);
> + if (!adc->dev_data.base)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, indio_dev);
> + init_completion(&adc->complete);
> + ret = devm_mutex_init(dev, &adc->lock);

I'd move this stuff up to before you get reg so you can keep all the stuff
related to num_sdams together.

> + if (ret)
> + return ret;
> +
> + for (i = 0; i < adc->dev_data.num_sdams; i++) {
> + adc->dev_data.base[i].base_addr = reg[i];
>