Re: [PATCH v9 3/3] iio: addac: add AD74413R driver

Cosmin Tanislav <demonsingur@xxxxxxxxx> · Sat, 4 Dec 2021 21:51:13 +0200

On 12/4/21 19:41, Jonathan Cameron wrote:
On Fri,  3 Dec 2021 01:25:07 +0200
Cosmin Tanislav <demonsingur@xxxxxxxxx> wrote:

The AD74412R and AD74413R are quad-channel, software configurable,
input/output solutions for building and process control applications.

They contain functionality for analog output, analog input, digital input,
resistance temperature detector, and thermocouple measurements integrated
into a single chip solution with an SPI interface.

The devices feature a 16-bit ADC and four configurable 13-bit DACs to
provide four configurable input/output channels and a suite of diagnostic
functions.

The AD74413R differentiates itself from the AD74412R by being
HART-compatible.

When configured with channel 0 as voltage output, channel 1 as current
output, channel 2 as voltage input and channel 3 as current input, the
following structure is created under the corresponding IIO device.

.
├── in_current0_offset
├── in_current0_raw
├── in_current0_sampling_frequency
├── in_current0_sampling_frequency_available
├── in_current0_scale
├── in_voltage1_offset
├── in_voltage1_raw
├── in_voltage1_sampling_frequency
├── in_voltage1_sampling_frequency_available
├── in_voltage1_scale
├── in_voltage2_offset
├── in_voltage2_raw
├── in_voltage2_sampling_frequency
├── in_voltage2_sampling_frequency_available
├── in_voltage2_scale
├── in_current3_offset
├── in_current3_raw
├── in_current3_sampling_frequency
├── in_current3_sampling_frequency_available
├── in_current3_scale
├── out_voltage0_raw
├── out_voltage0_scale
├── out_current1_raw
├── out_current1_scale
├── name
├── buffer
│   ├── data_available
│   ├── enable
│   ├── length
│   └── watermark
└── scan_elements
     ├── in_current0_en
     ├── in_current0_index
     ├── in_current0_type
     ├── in_voltage1_en
     ├── in_voltage1_index
     ├── in_voltage1_type
     ├── in_voltage2_en
     ├── in_voltage2_index
     ├── in_voltage2_type
     ├── in_current3_en
     ├── in_current3_index
     └── in_current3_type

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
You haven't picked up Linus' tag from v7.  I'm assuming that wasn't deliberate
so please add it for v10. I think there is just enough stuff in here that it makes
more sense for you to spin a new version than for me to fix it whilst applying...

Yes, it wasn't deliberate.


All minor stuff so shouldn't take long hopefully + we still need a dt review
which might take a while depending on how busy Rob is.

thanks,

Jonathan

---

--- /dev/null
+++ b/drivers/iio/addac/ad74413r.c
@@ -0,0 +1,1476 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Analog Devices, Inc.
+ * Author: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
+ */
+

...

+struct ad74413r_state {
+	struct ad74413r_channel_config	channel_configs[AD74413R_CHANNEL_MAX];
+	unsigned int			gpo_gpio_offsets[AD74413R_CHANNEL_MAX];
+	unsigned int			comp_gpio_offsets[AD74413R_CHANNEL_MAX];
+	struct gpio_chip		gpo_gpiochip;
+	struct gpio_chip		comp_gpiochip;
+	struct completion		adc_data_completion;
+	unsigned int			num_gpo_gpios;
+	unsigned int			num_comparator_gpios;
+	u32				sense_resistor_ohms;
+
+	/*
+	 * Synchronize consecutive operations when doing a one-shot
+	 * conversion and when updating the ADC samples SPI message.
+	 */
+	struct mutex			lock;
+
+	const struct ad74413r_chip_info	*chip_info;
+	struct spi_device		*spi;
+	struct regulator		*refin_reg;
+	struct regmap			*regmap;
+	struct device			*dev;
+	struct iio_trigger		*trig;
+
+	size_t			adc_active_channels;
+	struct spi_message	adc_samples_msg;
+	struct spi_transfer	adc_samples_xfer[AD74413R_CHANNEL_MAX + 1];
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	struct {
+		u8 rx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX];
+		s64 timestamp;
+	} adc_samples_buf ____cacheline_aligned;
+
+	u8	adc_samples_tx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX]
+			____cacheline_aligned;
What was your thinking for needing to have both adc_samples_buf and adc_samples_tx_buf
at force alignment?  I would have expected only adc_samples_buf would be necessary,
unless there are paths in which you are writing into one whilst DMA is going on into
the other..  If there is a reason add a comment.

Sorry, this is just something I missed when removing the other extra 
____cacheline_aligned.


+	u8	reg_tx_buf[AD74413R_FRAME_SIZE];
+	u8	reg_rx_buf[AD74413R_FRAME_SIZE];
+};
+
+
+static int ad74413r_probe(struct spi_device *spi)
+{
+	struct ad74413r_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->spi = spi;
+	st->dev = &spi->dev;
+	st->chip_info = device_get_match_data(&spi->dev);
+	mutex_init(&st->lock);
+	init_completion(&st->adc_data_completion);
+
+	st->regmap = devm_regmap_init(st->dev, NULL, st,
+				      &ad74413r_regmap_config);
+	if (IS_ERR(st->regmap))
+		return PTR_ERR(st->regmap);
+
+	st->refin_reg = devm_regulator_get(st->dev, "refin");
+	if (IS_ERR(st->refin_reg))
+		return dev_err_probe(st->dev, PTR_ERR(st->refin_reg),
+				     "Failed to get refin regulator\n");
+
+	ret = regulator_enable(st->refin_reg);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(st->dev, ad74413r_regulator_disable,
+				       st->refin_reg);
+	if (ret)
+		return ret;
+
+	st->sense_resistor_ohms = 100000000;
+	device_property_read_u32(st->dev, "shunt-resistor-micro-ohms",
+				 &st->sense_resistor_ohms);
+	st->sense_resistor_ohms /= 1000000;
+
+	st->trig = devm_iio_trigger_alloc(st->dev, "%s-dev%d",
+					  st->chip_info->name, iio_device_id(indio_dev));
+	if (!st->trig)
+		return -ENOMEM;
+
+	st->trig->ops = &ad74413r_trigger_ops;
+	iio_trigger_set_drvdata(st->trig, st);
+
+	ret = devm_iio_trigger_register(st->dev, st->trig);
+	if (ret)
+		return ret;
+
+	indio_dev->name = st->chip_info->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &ad74413r_info;
+	indio_dev->trig = iio_trigger_get(st->trig);
+
+	ret = ad74413r_reset(st);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_parse_channel_configs(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_setup_channels(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_setup_gpios(st);
+	if (ret)
+		return ret;
+
+	if (st->num_gpo_gpios) {
+		st->gpo_gpiochip.owner = THIS_MODULE;
+		st->gpo_gpiochip.label = st->chip_info->name;
+		st->gpo_gpiochip.base = -1;
+		st->gpo_gpiochip.ngpio = st->num_gpo_gpios;
+		st->gpo_gpiochip.parent = st->dev;
+		st->gpo_gpiochip.can_sleep = true;
+		st->gpo_gpiochip.set = ad74413r_gpio_set;
+		st->gpo_gpiochip.set_multiple = ad74413r_gpio_set_multiple;
+		st->gpo_gpiochip.set_config = ad74413r_gpio_set_gpo_config;
+		st->gpo_gpiochip.get_direction =
+			ad74413r_gpio_get_gpo_direction;
+
+		ret = devm_gpiochip_add_data(st->dev, &st->gpo_gpiochip, st);
+		if (ret)
+			return ret;
+	}
+
+	if (st->num_comparator_gpios) {
+		st->comp_gpiochip.owner = THIS_MODULE;
+		st->comp_gpiochip.label = st->chip_info->name;
+		st->comp_gpiochip.base = -1;
+		st->comp_gpiochip.ngpio = st->num_comparator_gpios;
+		st->comp_gpiochip.parent = st->dev;
+		st->comp_gpiochip.can_sleep = true;
+		st->comp_gpiochip.get = ad74413r_gpio_get;
+		st->comp_gpiochip.get_multiple = ad74413r_gpio_get_multiple;
+		st->comp_gpiochip.set_config = ad74413r_gpio_set_comp_config;
+		st->comp_gpiochip.get_direction =
+			ad74413r_gpio_get_comp_direction;
+
+		ret = devm_gpiochip_add_data(st->dev, &st->comp_gpiochip, st);
+		if (ret)
+			return ret;
+	}
+
+	ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(st->dev, spi->irq, ad74413r_adc_data_interrupt,
+			       0, st->chip_info->name, indio_dev);
+	if (ret)
Minor, but would be good to have a dev_err_probe() here as
this is something that can result in a deferred response and it would
be good to log the debugging info.

Sure thing, will change it for the next revision.


+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(st->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad74413r_trigger_handler,
+					      &ad74413r_buffer_ops);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(st->dev, indio_dev);
+}


(sorry for sending the mail again, I was using Gmail before but now I 
tried using Thunderbird so I can disable HTML formatting.








