Re: [PATCH v2 3/4] iio: adc: Add support for the GE HealthCare PMC ADC

From: Ian Ray
Date: Thu Oct 03 2024 - 07:57:05 EST

On Thu, Oct 03, 2024 at 01:46:40PM +0200, Herve Codina wrote:
>
> The GE HealthCare PMC Analog to Digital Converter (ADC) is a 16-Channel
> (voltage and current), 16-Bit ADC with an I2C Interface.
>
> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>

Tested-by: Ian Ray <ian.ray@xxxxxxxxxxxxxxxx>

> ---
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/gehc-pmc-adc.c | 227 +++++++++++++++++++++++++++++++++
> 3 files changed, 238 insertions(+)
> create mode 100644 drivers/iio/adc/gehc-pmc-adc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 97ece1a4b7e3..87b20f972c25 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -571,6 +571,16 @@ config FSL_MX25_ADC
> Generic Conversion Queue driver used for general purpose ADC in the
> MX25. This driver supports single measurements using the MX25 ADC.
>
> +config GEHC_PMC_ADC
> + tristate "GE HealthCare PMC ADC driver"
> + depends on I2C
> + help
> + Say yes here to build support for the GE HealthCare PMC 16-bit
> + 16-Channel ADC.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called gehc-pmc-adc.
> +
> config HI8435
> tristate "Holt Integrated Circuits HI-8435 threshold detector"
> select IIO_TRIGGERED_EVENT
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 7b91cd98c0e0..66b36dfe9a28 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -52,6 +52,7 @@ obj-$(CONFIG_ENVELOPE_DETECTOR) += envelope-detector.o
> obj-$(CONFIG_EP93XX_ADC) += ep93xx_adc.o
> obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
> obj-$(CONFIG_FSL_MX25_ADC) += fsl-imx25-gcq.o
> +obj-$(CONFIG_GEHC_PMC_ADC) += gehc-pmc-adc.o
> obj-$(CONFIG_HI8435) += hi8435.o
> obj-$(CONFIG_HX711) += hx711.o
> obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
> diff --git a/drivers/iio/adc/gehc-pmc-adc.c b/drivers/iio/adc/gehc-pmc-adc.c
> new file mode 100644
> index 000000000000..c70a93f4a61b
> --- /dev/null
> +++ b/drivers/iio/adc/gehc-pmc-adc.c
> @@ -0,0 +1,227 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * The GE HealthCare PMC ADC is a 16-Channel (Voltage and current), 16-Bit
> + * ADC with an I2C Interface.
> + *
> + * Copyright (C) 2024, GE HealthCare
> + *
> + * Authors:
> + * Herve Codina <herve.codina@xxxxxxxxxxx>
> + */
> +#include <dt-bindings/iio/adc/gehc,pmc-adc.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/i2c.h>
> +#include <linux/iio/iio.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +struct pmc_adc {
> + struct i2c_client *client;
> +};
> +
> +#define PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION 0x01
> +#define PMC_ADC_CMD_READ_VOLTAGE(_ch) (0x10 | (_ch))
> +#define PMC_ADC_CMD_READ_CURRENT(_ch) (0x20 | (_ch))
> +
> +#define PMC_ADC_VOLTAGE_CHANNEL(_ch, _ds_name) { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = (_ch), \
> + .address = PMC_ADC_CMD_READ_VOLTAGE(_ch), \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
> + .datasheet_name = (_ds_name), \
> +}
> +
> +#define PMC_ADC_CURRENT_CHANNEL(_ch, _ds_name) { \
> + .type = IIO_CURRENT, \
> + .indexed = 1, \
> + .channel = (_ch), \
> + .address = PMC_ADC_CMD_READ_CURRENT(_ch), \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
> + .datasheet_name = (_ds_name), \
> +}
> +
> +static const struct iio_chan_spec pmc_adc_channels[] = {
> + PMC_ADC_VOLTAGE_CHANNEL(0, "CH0_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(1, "CH1_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(2, "CH2_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(3, "CH3_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(4, "CH4_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(5, "CH5_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(6, "CH6_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(7, "CH7_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(8, "CH8_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(9, "CH9_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(10, "CH10_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(11, "CH11_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(12, "CH12_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(13, "CH13_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(14, "CH14_V"),
> + PMC_ADC_VOLTAGE_CHANNEL(15, "CH15_V"),
> +
> + PMC_ADC_CURRENT_CHANNEL(0, "CH0_I"),
> + PMC_ADC_CURRENT_CHANNEL(1, "CH1_I"),
> + PMC_ADC_CURRENT_CHANNEL(2, "CH2_I"),
> + PMC_ADC_CURRENT_CHANNEL(3, "CH3_I"),
> + PMC_ADC_CURRENT_CHANNEL(4, "CH4_I"),
> + PMC_ADC_CURRENT_CHANNEL(5, "CH5_I"),
> + PMC_ADC_CURRENT_CHANNEL(6, "CH6_I"),
> + PMC_ADC_CURRENT_CHANNEL(7, "CH7_I"),
> + PMC_ADC_CURRENT_CHANNEL(8, "CH8_I"),
> + PMC_ADC_CURRENT_CHANNEL(9, "CH9_I"),
> + PMC_ADC_CURRENT_CHANNEL(10, "CH10_I"),
> + PMC_ADC_CURRENT_CHANNEL(11, "CH11_I"),
> + PMC_ADC_CURRENT_CHANNEL(12, "CH12_I"),
> + PMC_ADC_CURRENT_CHANNEL(13, "CH13_I"),
> + PMC_ADC_CURRENT_CHANNEL(14, "CH14_I"),
> + PMC_ADC_CURRENT_CHANNEL(15, "CH15_I"),
> +};
> +
> +static int pmc_adc_read_raw_ch(struct pmc_adc *pmc_adc, u8 cmd, int *val)
> +{
> + s32 ret;
> +
> + ret = i2c_smbus_read_word_swapped(pmc_adc->client, cmd);
> + if (ret < 0) {
> + dev_err(&pmc_adc->client->dev, "i2c read word failed (%d)\n", ret);
> + return ret;
> + }
> +
> + *val = sign_extend32(ret, 15);
> + return 0;
> +}
> +
> +static int pmc_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct pmc_adc *pmc_adc = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_PROCESSED:
> + /* Values are directly read in mV or mA */
> + ret = pmc_adc_read_raw_ch(pmc_adc, chan->address, val);
> + if (ret)
> + return ret;
> + return IIO_VAL_INT;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int pmc_adc_fwnode_xlate(struct iio_dev *indio_dev,
> + const struct fwnode_reference_args *iiospec)
> +{
> + enum iio_chan_type expected_type;
> + unsigned int i;
> +
> + /*
> + * args[0]: Acquisition type (i.e. voltage or current)
> + * args[1]: PMC ADC channel number
> + */
> + if (iiospec->nargs != 2)
> + return -EINVAL;
> +
> + switch (iiospec->args[0]) {
> + case GEHC_PMC_ADC_VOLTAGE:
> + expected_type = IIO_VOLTAGE;
> + break;
> + case GEHC_PMC_ADC_CURRENT:
> + expected_type = IIO_CURRENT;
> + break;
> + default:
> + dev_err(&indio_dev->dev, "Invalid channel type %llu\n",
> + iiospec->args[0]);
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < indio_dev->num_channels; i++)
> + if (indio_dev->channels[i].type == expected_type &&
> + indio_dev->channels[i].channel == iiospec->args[1])
> + return i;
> +
> + dev_err(&indio_dev->dev, "Invalid channel type %llu number %llu\n",
> + iiospec->args[0], iiospec->args[1]);
> + return -EINVAL;
> +}
> +
> +static const struct iio_info pmc_adc_info = {
> + .read_raw = pmc_adc_read_raw,
> + .fwnode_xlate = pmc_adc_fwnode_xlate,
> +};
> +
> +static const char *const pmc_adc_regulator_names[] = {
> + "vdd",
> + "vdda",
> + "vddio",
> + "vref",
> +};
> +
> +static int pmc_adc_probe(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev;
> + struct pmc_adc *pmc_adc;
> + struct clk *clk;
> + s32 val;
> + int ret;
> +
> + ret = devm_regulator_bulk_get_enable(&client->dev, ARRAY_SIZE(pmc_adc_regulator_names),
> + pmc_adc_regulator_names);
> + if (ret)
> + return dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
> +
> + clk = devm_clk_get_optional_enabled(&client->dev, "osc");
> + if (IS_ERR(clk))
> + return dev_err_probe(&client->dev, PTR_ERR(clk), "Failed to get osc clock\n");
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*pmc_adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + pmc_adc = iio_priv(indio_dev);
> + pmc_adc->client = client;
> +
> + val = i2c_smbus_read_byte_data(pmc_adc->client, PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION);
> + if (val < 0)
> + return dev_err_probe(&client->dev, val, "Failed to get protocol version\n");
> +
> + if (val != 0x01)
> + return dev_err_probe(&client->dev, -EINVAL,
> + "Unsupported protocol version 0x%02x\n", val);
> +
> + indio_dev->name = "pmc_adc";
> + indio_dev->info = &pmc_adc_info;
> + indio_dev->channels = pmc_adc_channels;
> + indio_dev->num_channels = ARRAY_SIZE(pmc_adc_channels);
> +
> + return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static const struct of_device_id pmc_adc_of_match[] = {
> + { .compatible = "gehc,pmc-adc"},
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, pmc_adc_of_match);
> +
> +static const struct i2c_device_id pmc_adc_id_table[] = {
> + { "pmc-adc" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, pmc_adc_id_table);
> +
> +static struct i2c_driver pmc_adc_i2c_driver = {
> + .driver = {
> + .name = "pmc-adc",
> + .of_match_table = pmc_adc_of_match,
> + },
> + .id_table = pmc_adc_id_table,
> + .probe = pmc_adc_probe,
> +};
> +
> +module_i2c_driver(pmc_adc_i2c_driver);
> +
> +MODULE_AUTHOR("Herve Codina <herve.codina@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("GE HealthCare PMC ADC driver");
> +MODULE_LICENSE("GPL");
> --
> 2.46.1
>
>