Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 610 insertions, 0 deletions

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
new file mode 100644
index 0000000000..974c5bd923
--- /dev/null
+++ b/drivers/iio/adc/mcp3911.c
@@ -0,0 +1,610 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Microchip MCP3911, Two-channel Analog Front End
+ *
+ * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
+ * Copyright (C) 2018 Kent Gustavsson <kent@minoris.se>
+ */
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/trigger.h>
+
+#include <asm/unaligned.h>
+
+#define MCP3911_REG_CHANNEL0		0x00
+#define MCP3911_REG_CHANNEL1		0x03
+#define MCP3911_REG_MOD			0x06
+#define MCP3911_REG_PHASE		0x07
+#define MCP3911_REG_GAIN		0x09
+#define MCP3911_GAIN_MASK(ch)		(GENMASK(2, 0) << 3 * ch)
+#define MCP3911_GAIN_VAL(ch, val)      ((val << 3 * ch) & MCP3911_GAIN_MASK(ch))
+
+#define MCP3911_REG_STATUSCOM		0x0a
+#define MCP3911_STATUSCOM_DRHIZ         BIT(12)
+#define MCP3911_STATUSCOM_READ		GENMASK(7, 6)
+#define MCP3911_STATUSCOM_CH1_24WIDTH	BIT(4)
+#define MCP3911_STATUSCOM_CH0_24WIDTH	BIT(3)
+#define MCP3911_STATUSCOM_EN_OFFCAL	BIT(2)
+#define MCP3911_STATUSCOM_EN_GAINCAL	BIT(1)
+
+#define MCP3911_REG_CONFIG		0x0c
+#define MCP3911_CONFIG_CLKEXT		BIT(1)
+#define MCP3911_CONFIG_VREFEXT		BIT(2)
+#define MCP3911_CONFIG_OSR		GENMASK(13, 11)
+
+#define MCP3911_REG_OFFCAL_CH0		0x0e
+#define MCP3911_REG_GAINCAL_CH0		0x11
+#define MCP3911_REG_OFFCAL_CH1		0x14
+#define MCP3911_REG_GAINCAL_CH1		0x17
+#define MCP3911_REG_VREFCAL		0x1a
+
+#define MCP3911_CHANNEL(x)		(MCP3911_REG_CHANNEL0 + x * 3)
+#define MCP3911_OFFCAL(x)		(MCP3911_REG_OFFCAL_CH0 + x * 6)
+
+/* Internal voltage reference in mV */
+#define MCP3911_INT_VREF_MV		1200
+
+#define MCP3911_REG_READ(reg, id)	((((reg) << 1) | ((id) << 6) | (1 << 0)) & 0xff)
+#define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 6) | (0 << 0)) & 0xff)
+#define MCP3911_REG_MASK		GENMASK(4, 1)
+
+#define MCP3911_NUM_CHANNELS		2
+#define MCP3911_NUM_SCALES		6
+
+static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
+static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2];
+
+struct mcp3911 {
+	struct spi_device *spi;
+	struct mutex lock;
+	struct regulator *vref;
+	struct clk *clki;
+	u32 dev_addr;
+	struct iio_trigger *trig;
+	u32 gain[MCP3911_NUM_CHANNELS];
+	struct {
+		u32 channels[MCP3911_NUM_CHANNELS];
+		s64 ts __aligned(8);
+	} scan;
+
+	u8 tx_buf __aligned(IIO_DMA_MINALIGN);
+	u8 rx_buf[MCP3911_NUM_CHANNELS * 3];
+};
+
+static int mcp3911_read(struct mcp3911 *adc, u8 reg, u32 *val, u8 len)
+{
+	int ret;
+
+	reg = MCP3911_REG_READ(reg, adc->dev_addr);
+	ret = spi_write_then_read(adc->spi, &reg, 1, val, len);
+	if (ret < 0)
+		return ret;
+
+	be32_to_cpus(val);
+	*val >>= ((4 - len) * 8);
+	dev_dbg(&adc->spi->dev, "reading 0x%x from register 0x%lx\n", *val,
+		FIELD_GET(MCP3911_REG_MASK, reg));
+	return ret;
+}
+
+static int mcp3911_write(struct mcp3911 *adc, u8 reg, u32 val, u8 len)
+{
+	dev_dbg(&adc->spi->dev, "writing 0x%x to register 0x%x\n", val, reg);
+
+	val <<= (3 - len) * 8;
+	cpu_to_be32s(&val);
+	val |= MCP3911_REG_WRITE(reg, adc->dev_addr);
+
+	return spi_write(adc->spi, &val, len + 1);
+}
+
+static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
+		u32 val, u8 len)
+{
+	u32 tmp;
+	int ret;
+
+	ret = mcp3911_read(adc, reg, &tmp, len);
+	if (ret)
+		return ret;
+
+	val &= mask;
+	val |= tmp & ~mask;
+	return mcp3911_write(adc, reg, val, len);
+}
+
+static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
+					struct iio_chan_spec const *chan,
+					long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		return IIO_VAL_INT;
+	default:
+		return IIO_VAL_INT_PLUS_NANO;
+	}
+}
+
+static int mcp3911_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		*type = IIO_VAL_INT;
+		*vals = mcp3911_osr_table;
+		*length = ARRAY_SIZE(mcp3911_osr_table);
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SCALE:
+		*type = IIO_VAL_INT_PLUS_NANO;
+		*vals = (int *)mcp3911_scale_table;
+		*length = ARRAY_SIZE(mcp3911_scale_table) * 2;
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mcp3911_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long mask)
+{
+	struct mcp3911 *adc = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&adc->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = mcp3911_read(adc,
+				   MCP3911_CHANNEL(channel->channel), val, 3);
+		if (ret)
+			goto out;
+
+		*val = sign_extend32(*val, 23);
+
+		ret = IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_OFFSET:
+		ret = mcp3911_read(adc,
+				   MCP3911_OFFCAL(channel->channel), val, 3);
+		if (ret)
+			goto out;
+
+		ret = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		ret = mcp3911_read(adc, MCP3911_REG_CONFIG, val, 2);
+		if (ret)
+			goto out;
+
+		*val = FIELD_GET(MCP3911_CONFIG_OSR, *val);
+		*val = 32 << *val;
+		ret = IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0];
+		*val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1];
+		ret = IIO_VAL_INT_PLUS_NANO;
+		break;
+	}
+
+out:
+	mutex_unlock(&adc->lock);
+	return ret;
+}
+
+static int mcp3911_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int val,
+			    int val2, long mask)
+{
+	struct mcp3911 *adc = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&adc->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+			if (val == mcp3911_scale_table[i][0] &&
+				val2 == mcp3911_scale_table[i][1]) {
+
+				adc->gain[channel->channel] = BIT(i);
+				ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+						MCP3911_GAIN_MASK(channel->channel),
+						MCP3911_GAIN_VAL(channel->channel, i), 1);
+			}
+		}
+		break;
+	case IIO_CHAN_INFO_OFFSET:
+		if (val2 != 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/* Write offset */
+		ret = mcp3911_write(adc, MCP3911_OFFCAL(channel->channel), val,
+				    3);
+		if (ret)
+			goto out;
+
+		/* Enable offset*/
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM,
+				MCP3911_STATUSCOM_EN_OFFCAL,
+				MCP3911_STATUSCOM_EN_OFFCAL, 2);
+		break;
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		for (int i = 0; i < ARRAY_SIZE(mcp3911_osr_table); i++) {
+			if (val == mcp3911_osr_table[i]) {
+				val = FIELD_PREP(MCP3911_CONFIG_OSR, i);
+				ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR,
+						val, 2);
+				break;
+			}
+		}
+		break;
+	}
+
+out:
+	mutex_unlock(&adc->lock);
+	return ret;
+}
+
+static int mcp3911_calc_scale_table(struct mcp3911 *adc)
+{
+	u32 ref = MCP3911_INT_VREF_MV;
+	u32 div;
+	int ret;
+	u64 tmp;
+
+	if (adc->vref) {
+		ret = regulator_get_voltage(adc->vref);
+		if (ret < 0) {
+			dev_err(&adc->spi->dev,
+				"failed to get vref voltage: %d\n",
+			       ret);
+			return ret;
+		}
+
+		ref = ret / 1000;
+	}
+
+	/*
+	 * For 24-bit Conversion
+	 * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
+	 * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
+	 *
+	 * ref = Reference voltage
+	 * div = (2^23 * 1.5 * gain) = 12582912 * gain
+	 */
+	for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+		div = 12582912 * BIT(i);
+		tmp = div_s64((s64)ref * 1000000000LL, div);
+
+		mcp3911_scale_table[i][0] = 0;
+		mcp3911_scale_table[i][1] = tmp;
+	}
+
+	return 0;
+}
+
+#define MCP3911_CHAN(idx) {					\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = idx,					\
+		.scan_index = idx,				\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+			BIT(IIO_CHAN_INFO_OFFSET) |		\
+			BIT(IIO_CHAN_INFO_SCALE),		\
+		.info_mask_shared_by_type_available =           \
+			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		.info_mask_separate_available =			\
+			BIT(IIO_CHAN_INFO_SCALE),		\
+		.scan_type = {					\
+			.sign = 's',				\
+			.realbits = 24,				\
+			.storagebits = 32,			\
+			.endianness = IIO_BE,			\
+		},						\
+}
+
+static const struct iio_chan_spec mcp3911_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct mcp3911 *adc = iio_priv(indio_dev);
+	struct spi_transfer xfer[] = {
+		{
+			.tx_buf = &adc->tx_buf,
+			.len = 1,
+		}, {
+			.rx_buf = adc->rx_buf,
+			.len = sizeof(adc->rx_buf),
+		},
+	};
+	int scan_index;
+	int i = 0;
+	int ret;
+
+	mutex_lock(&adc->lock);
+	adc->tx_buf = MCP3911_REG_READ(MCP3911_CHANNEL(0), adc->dev_addr);
+	ret = spi_sync_transfer(adc->spi, xfer, ARRAY_SIZE(xfer));
+	if (ret < 0) {
+		dev_warn(&adc->spi->dev,
+				"failed to get conversion data\n");
+		goto out;
+	}
+
+	for_each_set_bit(scan_index, indio_dev->active_scan_mask, indio_dev->masklength) {
+		const struct iio_chan_spec *scan_chan = &indio_dev->channels[scan_index];
+
+		adc->scan.channels[i] = get_unaligned_be24(&adc->rx_buf[scan_chan->channel * 3]);
+		i++;
+	}
+	iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan,
+					   iio_get_time_ns(indio_dev));
+out:
+	mutex_unlock(&adc->lock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info mcp3911_info = {
+	.read_raw = mcp3911_read_raw,
+	.write_raw = mcp3911_write_raw,
+	.read_avail = mcp3911_read_avail,
+	.write_raw_get_fmt = mcp3911_write_raw_get_fmt,
+};
+
+static int mcp3911_config(struct mcp3911 *adc)
+{
+	struct device *dev = &adc->spi->dev;
+	u32 regval;
+	int ret;
+
+	ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
+
+	/*
+	 * Fallback to "device-addr" due to historical mismatch between
+	 * dt-bindings and implementation
+	 */
+	if (ret)
+		device_property_read_u32(dev, "device-addr", &adc->dev_addr);
+	if (adc->dev_addr > 3) {
+		dev_err(&adc->spi->dev,
+			"invalid device address (%i). Must be in range 0-3.\n",
+			adc->dev_addr);
+		return -EINVAL;
+	}
+	dev_dbg(&adc->spi->dev, "use device address %i\n", adc->dev_addr);
+
+	ret = mcp3911_read(adc, MCP3911_REG_CONFIG, &regval, 2);
+	if (ret)
+		return ret;
+
+	regval &= ~MCP3911_CONFIG_VREFEXT;
+	if (adc->vref) {
+		dev_dbg(&adc->spi->dev, "use external voltage reference\n");
+		regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 1);
+	} else {
+		dev_dbg(&adc->spi->dev,
+			"use internal voltage reference (1.2V)\n");
+		regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 0);
+	}
+
+	regval &= ~MCP3911_CONFIG_CLKEXT;
+	if (adc->clki) {
+		dev_dbg(&adc->spi->dev, "use external clock as clocksource\n");
+		regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 1);
+	} else {
+		dev_dbg(&adc->spi->dev,
+			"use crystal oscillator as clocksource\n");
+		regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 0);
+	}
+
+	ret = mcp3911_write(adc, MCP3911_REG_CONFIG, regval, 2);
+	if (ret)
+		return ret;
+
+	ret = mcp3911_read(adc, MCP3911_REG_STATUSCOM, &regval, 2);
+	if (ret)
+		return ret;
+
+	/* Address counter incremented, cycle through register types */
+	regval &= ~MCP3911_STATUSCOM_READ;
+	regval |= FIELD_PREP(MCP3911_STATUSCOM_READ, 0x02);
+
+	return  mcp3911_write(adc, MCP3911_REG_STATUSCOM, regval, 2);
+}
+
+static void mcp3911_cleanup_regulator(void *vref)
+{
+	regulator_disable(vref);
+}
+
+static int mcp3911_set_trigger_state(struct iio_trigger *trig, bool enable)
+{
+	struct mcp3911 *adc = iio_trigger_get_drvdata(trig);
+
+	if (enable)
+		enable_irq(adc->spi->irq);
+	else
+		disable_irq(adc->spi->irq);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops mcp3911_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+	.set_trigger_state = mcp3911_set_trigger_state,
+};
+
+static int mcp3911_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct mcp3911 *adc;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	adc = iio_priv(indio_dev);
+	adc->spi = spi;
+
+	adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
+	if (IS_ERR(adc->vref)) {
+		if (PTR_ERR(adc->vref) == -ENODEV) {
+			adc->vref = NULL;
+		} else {
+			dev_err(&adc->spi->dev,
+				"failed to get regulator (%ld)\n",
+				PTR_ERR(adc->vref));
+			return PTR_ERR(adc->vref);
+		}
+
+	} else {
+		ret = regulator_enable(adc->vref);
+		if (ret)
+			return ret;
+
+		ret = devm_add_action_or_reset(&spi->dev,
+				mcp3911_cleanup_regulator, adc->vref);
+		if (ret)
+			return ret;
+	}
+
+	adc->clki = devm_clk_get_enabled(&adc->spi->dev, NULL);
+	if (IS_ERR(adc->clki)) {
+		if (PTR_ERR(adc->clki) == -ENOENT) {
+			adc->clki = NULL;
+		} else {
+			dev_err(&adc->spi->dev,
+				"failed to get adc clk (%ld)\n",
+				PTR_ERR(adc->clki));
+			return PTR_ERR(adc->clki);
+		}
+	}
+
+	ret = mcp3911_config(adc);
+	if (ret)
+		return ret;
+
+	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				0, 2);
+	else
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				MCP3911_STATUSCOM_DRHIZ, 2);
+	if (ret)
+		return ret;
+
+	ret = mcp3911_calc_scale_table(adc);
+	if (ret)
+		return ret;
+
+       /* Set gain to 1 for all channels */
+	for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
+		adc->gain[i] = 1;
+		ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+				MCP3911_GAIN_MASK(i),
+				MCP3911_GAIN_VAL(i, 0), 1);
+		if (ret)
+			return ret;
+	}
+
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mcp3911_info;
+	spi_set_drvdata(spi, indio_dev);
+
+	indio_dev->channels = mcp3911_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mcp3911_channels);
+
+	mutex_init(&adc->lock);
+
+	if (spi->irq > 0) {
+		adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+				indio_dev->name,
+				iio_device_id(indio_dev));
+		if (!adc->trig)
+			return -ENOMEM;
+
+		adc->trig->ops = &mcp3911_trigger_ops;
+		iio_trigger_set_drvdata(adc->trig, adc);
+		ret = devm_iio_trigger_register(&spi->dev, adc->trig);
+		if (ret)
+			return ret;
+
+		/*
+		 * The device generates interrupts as long as it is powered up.
+		 * Some platforms might not allow the option to power it down so
+		 * don't enable the interrupt to avoid extra load on the system.
+		 */
+		ret = devm_request_irq(&spi->dev, spi->irq,
+				&iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT,
+				indio_dev->name, adc->trig);
+		if (ret)
+			return ret;
+	}
+
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+			NULL,
+			mcp3911_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&adc->spi->dev, indio_dev);
+}
+
+static const struct of_device_id mcp3911_dt_ids[] = {
+	{ .compatible = "microchip,mcp3911" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mcp3911_dt_ids);
+
+static const struct spi_device_id mcp3911_id[] = {
+	{ "mcp3911", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, mcp3911_id);
+
+static struct spi_driver mcp3911_driver = {
+	.driver = {
+		.name = "mcp3911",
+		.of_match_table = mcp3911_dt_ids,
+	},
+	.probe = mcp3911_probe,
+	.id_table = mcp3911_id,
+};
+module_spi_driver(mcp3911_driver);
+
+MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
+MODULE_AUTHOR("Kent Gustavsson <kent@minoris.se>");
+MODULE_DESCRIPTION("Microchip Technology MCP3911");
+MODULE_LICENSE("GPL v2");