Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 649 insertions, 0 deletions

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
new file mode 100644
index 000000000..136fcf753
--- /dev/null
+++ b/drivers/iio/adc/max1027.c
@@ -0,0 +1,649 @@
+// SPDX-License-Identifier: GPL-2.0-only
+ /*
+  * iio/adc/max1027.c
+  * Copyright (C) 2014 Philippe Reynes
+  *
+  * based on linux/drivers/iio/ad7923.c
+  * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
+  * Copyright 2012 CS Systemes d'Information
+  *
+  * max1027.c
+  *
+  * Partial support for max1027 and similar chips.
+  */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MAX1027_CONV_REG  BIT(7)
+#define MAX1027_SETUP_REG BIT(6)
+#define MAX1027_AVG_REG   BIT(5)
+#define MAX1027_RST_REG   BIT(4)
+
+/* conversion register */
+#define MAX1027_TEMP      BIT(0)
+#define MAX1027_SCAN_0_N  (0x00 << 1)
+#define MAX1027_SCAN_N_M  (0x01 << 1)
+#define MAX1027_SCAN_N    (0x02 << 1)
+#define MAX1027_NOSCAN    (0x03 << 1)
+#define MAX1027_CHAN(n)   ((n) << 3)
+
+/* setup register */
+#define MAX1027_UNIPOLAR  0x02
+#define MAX1027_BIPOLAR   0x03
+#define MAX1027_REF_MODE0 (0x00 << 2)
+#define MAX1027_REF_MODE1 (0x01 << 2)
+#define MAX1027_REF_MODE2 (0x02 << 2)
+#define MAX1027_REF_MODE3 (0x03 << 2)
+#define MAX1027_CKS_MODE0 (0x00 << 4)
+#define MAX1027_CKS_MODE1 (0x01 << 4)
+#define MAX1027_CKS_MODE2 (0x02 << 4)
+#define MAX1027_CKS_MODE3 (0x03 << 4)
+
+/* averaging register */
+#define MAX1027_NSCAN_4   0x00
+#define MAX1027_NSCAN_8   0x01
+#define MAX1027_NSCAN_12  0x02
+#define MAX1027_NSCAN_16  0x03
+#define MAX1027_NAVG_4    (0x00 << 2)
+#define MAX1027_NAVG_8    (0x01 << 2)
+#define MAX1027_NAVG_16   (0x02 << 2)
+#define MAX1027_NAVG_32   (0x03 << 2)
+#define MAX1027_AVG_EN    BIT(4)
+
+/* Device can achieve 300ksps so we assume a 3.33us conversion delay */
+#define MAX1027_CONVERSION_UDELAY 4
+
+enum max1027_id {
+	max1027,
+	max1029,
+	max1031,
+	max1227,
+	max1229,
+	max1231,
+};
+
+static const struct spi_device_id max1027_id[] = {
+	{"max1027", max1027},
+	{"max1029", max1029},
+	{"max1031", max1031},
+	{"max1227", max1227},
+	{"max1229", max1229},
+	{"max1231", max1231},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, max1027_id);
+
+static const struct of_device_id max1027_adc_dt_ids[] = {
+	{ .compatible = "maxim,max1027" },
+	{ .compatible = "maxim,max1029" },
+	{ .compatible = "maxim,max1031" },
+	{ .compatible = "maxim,max1227" },
+	{ .compatible = "maxim,max1229" },
+	{ .compatible = "maxim,max1231" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids);
+
+#define MAX1027_V_CHAN(index, depth)					\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.channel = index,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.scan_index = index + 1,				\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = depth,				\
+			.storagebits = 16,				\
+			.shift = (depth == 10) ? 2 : 0,			\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+#define MAX1027_T_CHAN							\
+	{								\
+		.type = IIO_TEMP,					\
+		.channel = 0,						\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.scan_index = 0,					\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 12,					\
+			.storagebits = 16,				\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+#define MAX1X27_CHANNELS(depth)			\
+	MAX1027_T_CHAN,				\
+	MAX1027_V_CHAN(0, depth),		\
+	MAX1027_V_CHAN(1, depth),		\
+	MAX1027_V_CHAN(2, depth),		\
+	MAX1027_V_CHAN(3, depth),		\
+	MAX1027_V_CHAN(4, depth),		\
+	MAX1027_V_CHAN(5, depth),		\
+	MAX1027_V_CHAN(6, depth),		\
+	MAX1027_V_CHAN(7, depth)
+
+#define MAX1X29_CHANNELS(depth)			\
+	MAX1X27_CHANNELS(depth),		\
+	MAX1027_V_CHAN(8, depth),		\
+	MAX1027_V_CHAN(9, depth),		\
+	MAX1027_V_CHAN(10, depth),		\
+	MAX1027_V_CHAN(11, depth)
+
+#define MAX1X31_CHANNELS(depth)			\
+	MAX1X29_CHANNELS(depth),		\
+	MAX1027_V_CHAN(12, depth),		\
+	MAX1027_V_CHAN(13, depth),		\
+	MAX1027_V_CHAN(14, depth),		\
+	MAX1027_V_CHAN(15, depth)
+
+static const struct iio_chan_spec max1027_channels[] = {
+	MAX1X27_CHANNELS(10),
+};
+
+static const struct iio_chan_spec max1029_channels[] = {
+	MAX1X29_CHANNELS(10),
+};
+
+static const struct iio_chan_spec max1031_channels[] = {
+	MAX1X31_CHANNELS(10),
+};
+
+static const struct iio_chan_spec max1227_channels[] = {
+	MAX1X27_CHANNELS(12),
+};
+
+static const struct iio_chan_spec max1229_channels[] = {
+	MAX1X29_CHANNELS(12),
+};
+
+static const struct iio_chan_spec max1231_channels[] = {
+	MAX1X31_CHANNELS(12),
+};
+
+/*
+ * These devices are able to scan from 0 to N, N being the highest voltage
+ * channel requested by the user. The temperature can be included or not,
+ * but cannot be retrieved alone. Based on the below
+ * ->available_scan_masks, the core will select the most appropriate
+ * ->active_scan_mask and the "minimum" number of channels will be
+ * scanned and pushed to the buffers.
+ *
+ * For example, if the user wants channels 1, 4 and 5, all channels from
+ * 0 to 5 will be scanned and pushed to the IIO buffers. The core will then
+ * filter out the unneeded samples based on the ->active_scan_mask that has
+ * been selected and only channels 1, 4 and 5 will be available to the user
+ * in the shared buffer.
+ */
+#define MAX1X27_SCAN_MASK_TEMP BIT(0)
+
+#define MAX1X27_SCAN_MASKS(temp)					\
+	GENMASK(1, 1 - (temp)), GENMASK(2, 1 - (temp)),			\
+	GENMASK(3, 1 - (temp)), GENMASK(4, 1 - (temp)),			\
+	GENMASK(5, 1 - (temp)), GENMASK(6, 1 - (temp)),			\
+	GENMASK(7, 1 - (temp)), GENMASK(8, 1 - (temp))
+
+#define MAX1X29_SCAN_MASKS(temp)					\
+	MAX1X27_SCAN_MASKS(temp),					\
+	GENMASK(9, 1 - (temp)), GENMASK(10, 1 - (temp)),		\
+	GENMASK(11, 1 - (temp)), GENMASK(12, 1 - (temp))
+
+#define MAX1X31_SCAN_MASKS(temp)					\
+	MAX1X29_SCAN_MASKS(temp),					\
+	GENMASK(13, 1 - (temp)), GENMASK(14, 1 - (temp)),		\
+	GENMASK(15, 1 - (temp)), GENMASK(16, 1 - (temp))
+
+static const unsigned long max1027_available_scan_masks[] = {
+	MAX1X27_SCAN_MASKS(0),
+	MAX1X27_SCAN_MASKS(1),
+	0x00000000,
+};
+
+static const unsigned long max1029_available_scan_masks[] = {
+	MAX1X29_SCAN_MASKS(0),
+	MAX1X29_SCAN_MASKS(1),
+	0x00000000,
+};
+
+static const unsigned long max1031_available_scan_masks[] = {
+	MAX1X31_SCAN_MASKS(0),
+	MAX1X31_SCAN_MASKS(1),
+	0x00000000,
+};
+
+struct max1027_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+	const unsigned long *available_scan_masks;
+};
+
+static const struct max1027_chip_info max1027_chip_info_tbl[] = {
+	[max1027] = {
+		.channels = max1027_channels,
+		.num_channels = ARRAY_SIZE(max1027_channels),
+		.available_scan_masks = max1027_available_scan_masks,
+	},
+	[max1029] = {
+		.channels = max1029_channels,
+		.num_channels = ARRAY_SIZE(max1029_channels),
+		.available_scan_masks = max1029_available_scan_masks,
+	},
+	[max1031] = {
+		.channels = max1031_channels,
+		.num_channels = ARRAY_SIZE(max1031_channels),
+		.available_scan_masks = max1031_available_scan_masks,
+	},
+	[max1227] = {
+		.channels = max1227_channels,
+		.num_channels = ARRAY_SIZE(max1227_channels),
+		.available_scan_masks = max1027_available_scan_masks,
+	},
+	[max1229] = {
+		.channels = max1229_channels,
+		.num_channels = ARRAY_SIZE(max1229_channels),
+		.available_scan_masks = max1029_available_scan_masks,
+	},
+	[max1231] = {
+		.channels = max1231_channels,
+		.num_channels = ARRAY_SIZE(max1231_channels),
+		.available_scan_masks = max1031_available_scan_masks,
+	},
+};
+
+struct max1027_state {
+	const struct max1027_chip_info	*info;
+	struct spi_device		*spi;
+	struct iio_trigger		*trig;
+	__be16				*buffer;
+	struct mutex			lock;
+	struct completion		complete;
+
+	u8				reg __aligned(IIO_DMA_MINALIGN);
+};
+
+static int max1027_wait_eoc(struct iio_dev *indio_dev)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+	unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+	int ret;
+
+	if (st->spi->irq) {
+		ret = wait_for_completion_timeout(&st->complete,
+						  msecs_to_jiffies(1000));
+		reinit_completion(&st->complete);
+		if (!ret)
+			return -ETIMEDOUT;
+	} else {
+		if (indio_dev->active_scan_mask)
+			conversion_time *= hweight32(*indio_dev->active_scan_mask);
+
+		usleep_range(conversion_time, conversion_time * 2);
+	}
+
+	return 0;
+}
+
+/* Scan from chan 0 to the highest requested channel. Include temperature on demand. */
+static int max1027_configure_chans_and_start(struct iio_dev *indio_dev)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N;
+	st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2);
+	if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP)
+		st->reg |= MAX1027_TEMP;
+
+	return spi_write(st->spi, &st->reg, 1);
+}
+
+static int max1027_enable_trigger(struct iio_dev *indio_dev, bool enable)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2;
+
+	/*
+	 * Start acquisition on:
+	 * MODE0: external hardware trigger wired to the cnvst input pin
+	 * MODE2: conversion register write
+	 */
+	if (enable)
+		st->reg |= MAX1027_CKS_MODE0;
+	else
+		st->reg |= MAX1027_CKS_MODE2;
+
+	return spi_write(st->spi, &st->reg, 1);
+}
+
+static int max1027_read_single_value(struct iio_dev *indio_dev,
+				     struct iio_chan_spec const *chan,
+				     int *val)
+{
+	int ret;
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
+
+	/* Configure conversion register with the requested chan */
+	st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
+		  MAX1027_NOSCAN;
+	if (chan->type == IIO_TEMP)
+		st->reg |= MAX1027_TEMP;
+	ret = spi_write(st->spi, &st->reg, 1);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev,
+			"Failed to configure conversion register\n");
+		goto release;
+	}
+
+	/*
+	 * For an unknown reason, when we use the mode "10" (write
+	 * conversion register), the interrupt doesn't occur every time.
+	 * So we just wait the maximum conversion time and deliver the value.
+	 */
+	ret = max1027_wait_eoc(indio_dev);
+	if (ret)
+		goto release;
+
+	/* Read result */
+	ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
+
+release:
+	iio_device_release_direct_mode(indio_dev);
+
+	if (ret < 0)
+		return ret;
+
+	*val = be16_to_cpu(st->buffer[0]);
+
+	return IIO_VAL_INT;
+}
+
+static int max1027_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	int ret = 0;
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	mutex_lock(&st->lock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = max1027_read_single_value(indio_dev, chan, val);
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = 1;
+			*val2 = 8;
+			ret = IIO_VAL_FRACTIONAL;
+			break;
+		case IIO_VOLTAGE:
+			*val = 2500;
+			*val2 = chan->scan_type.realbits;
+			ret = IIO_VAL_FRACTIONAL_LOG2;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
+				      unsigned int reg, unsigned int writeval,
+				      unsigned int *readval)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+	u8 *val = (u8 *)st->buffer;
+
+	if (readval) {
+		int ret = spi_read(st->spi, val, 2);
+		*readval = be16_to_cpu(st->buffer[0]);
+		return ret;
+	}
+
+	*val = (u8)writeval;
+	return spi_write(st->spi, val, 1);
+}
+
+static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	int ret;
+
+	/*
+	 * In order to disable the convst trigger, start acquisition on
+	 * conversion register write, which basically disables triggering
+	 * conversions upon cnvst changes and thus has the effect of disabling
+	 * the external hardware trigger.
+	 */
+	ret = max1027_enable_trigger(indio_dev, state);
+	if (ret)
+		return ret;
+
+	if (state) {
+		ret = max1027_configure_chans_and_start(indio_dev);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int max1027_read_scan(struct iio_dev *indio_dev)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+	unsigned int scanned_chans;
+	int ret;
+
+	scanned_chans = fls(*indio_dev->active_scan_mask) - 1;
+	if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP)
+		scanned_chans++;
+
+	/* fill buffer with all channel */
+	ret = spi_read(st->spi, st->buffer, scanned_chans * 2);
+	if (ret < 0)
+		return ret;
+
+	iio_push_to_buffers(indio_dev, st->buffer);
+
+	return 0;
+}
+
+static irqreturn_t max1027_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	/*
+	 * If buffers are disabled (raw read) or when using external triggers,
+	 * we just need to unlock the waiters which will then handle the data.
+	 *
+	 * When using the internal trigger, we must hand-off the choice of the
+	 * handler to the core which will then lookup through the interrupt tree
+	 * for the right handler registered with iio_triggered_buffer_setup()
+	 * to execute, as this trigger might very well be used in conjunction
+	 * with another device. The core will then call the relevant handler to
+	 * perform the data processing step.
+	 */
+	if (!iio_buffer_enabled(indio_dev))
+		complete(&st->complete);
+	else
+		iio_trigger_poll(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t max1027_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	int ret;
+
+	if (!iio_trigger_using_own(indio_dev)) {
+		ret = max1027_configure_chans_and_start(indio_dev);
+		if (ret)
+			goto out;
+
+		/* This is a threaded handler, it is fine to wait for an IRQ */
+		ret = max1027_wait_eoc(indio_dev);
+		if (ret)
+			goto out;
+	}
+
+	ret = max1027_read_scan(indio_dev);
+out:
+	if (ret)
+		dev_err(&indio_dev->dev,
+			"Cannot read scanned values (%d)\n", ret);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_trigger_ops max1027_trigger_ops = {
+	.validate_device = &iio_trigger_validate_own_device,
+	.set_trigger_state = &max1027_set_cnvst_trigger_state,
+};
+
+static const struct iio_info max1027_info = {
+	.read_raw = &max1027_read_raw,
+	.debugfs_reg_access = &max1027_debugfs_reg_access,
+};
+
+static int max1027_probe(struct spi_device *spi)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct max1027_state *st;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev) {
+		pr_err("Can't allocate iio device\n");
+		return -ENOMEM;
+	}
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+	st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	mutex_init(&st->lock);
+	init_completion(&st->complete);
+
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &max1027_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->info->channels;
+	indio_dev->num_channels = st->info->num_channels;
+	indio_dev->available_scan_masks = st->info->available_scan_masks;
+
+	st->buffer = devm_kmalloc_array(&indio_dev->dev,
+					indio_dev->num_channels, 2,
+					GFP_KERNEL);
+	if (!st->buffer)
+		return -ENOMEM;
+
+	/* Enable triggered buffers */
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &max1027_trigger_handler,
+					      NULL);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to setup buffer\n");
+		return ret;
+	}
+
+	/* If there is an EOC interrupt, register the cnvst hardware trigger */
+	if (spi->irq) {
+		st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
+						  indio_dev->name);
+		if (!st->trig) {
+			ret = -ENOMEM;
+			dev_err(&indio_dev->dev,
+				"Failed to allocate iio trigger\n");
+			return ret;
+		}
+
+		st->trig->ops = &max1027_trigger_ops;
+		iio_trigger_set_drvdata(st->trig, indio_dev);
+		ret = devm_iio_trigger_register(&indio_dev->dev,
+						st->trig);
+		if (ret < 0) {
+			dev_err(&indio_dev->dev,
+				"Failed to register iio trigger\n");
+			return ret;
+		}
+
+		ret = devm_request_irq(&spi->dev, spi->irq, max1027_handler,
+				       IRQF_TRIGGER_FALLING,
+				       spi->dev.driver->name, indio_dev);
+		if (ret < 0) {
+			dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
+			return ret;
+		}
+	}
+
+	/* Internal reset */
+	st->reg = MAX1027_RST_REG;
+	ret = spi_write(st->spi, &st->reg, 1);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to reset the ADC\n");
+		return ret;
+	}
+
+	/* Disable averaging */
+	st->reg = MAX1027_AVG_REG;
+	ret = spi_write(st->spi, &st->reg, 1);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to configure averaging register\n");
+		return ret;
+	}
+
+	/* Assume conversion on register write for now */
+	ret = max1027_enable_trigger(indio_dev, false);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static struct spi_driver max1027_driver = {
+	.driver = {
+		.name	= "max1027",
+		.of_match_table = max1027_adc_dt_ids,
+	},
+	.probe		= max1027_probe,
+	.id_table	= max1027_id,
+};
+module_spi_driver(max1027_driver);
+
+MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
+MODULE_DESCRIPTION("MAX1X27/MAX1X29/MAX1X31 ADC");
+MODULE_LICENSE("GPL v2");