Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 537 insertions, 0 deletions

diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
new file mode 100644
index 000000000..a04856d8a
--- /dev/null
+++ b/drivers/iio/adc/mcp320x.c
@@ -0,0 +1,537 @@
+/*
+ * Copyright (C) 2013 Oskar Andero <oskar.andero@gmail.com>
+ * Copyright (C) 2014 Rose Technology
+ * 	   Allan Bendorff Jensen <abj@rosetechnology.dk>
+ *	   Soren Andersen <san@rosetechnology.dk>
+ *
+ * Driver for following ADC chips from Microchip Technology's:
+ * 10 Bit converter
+ * MCP3001
+ * MCP3002
+ * MCP3004
+ * MCP3008
+ * ------------
+ * 12 bit converter
+ * MCP3201
+ * MCP3202
+ * MCP3204
+ * MCP3208
+ * ------------
+ * 13 bit converter
+ * MCP3301
+ * ------------
+ * 22 bit converter
+ * MCP3550
+ * MCP3551
+ * MCP3553
+ *
+ * Datasheet can be found here:
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf  mcp3002
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf  mcp3004/08
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf  mcp3201
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf  mcp3202
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf  mcp3204/08
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf  mcp3301
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf  mcp3550/1/3
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/regulator/consumer.h>
+
+enum {
+	mcp3001,
+	mcp3002,
+	mcp3004,
+	mcp3008,
+	mcp3201,
+	mcp3202,
+	mcp3204,
+	mcp3208,
+	mcp3301,
+	mcp3550_50,
+	mcp3550_60,
+	mcp3551,
+	mcp3553,
+};
+
+struct mcp320x_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+	unsigned int resolution;
+	unsigned int conv_time; /* usec */
+};
+
+/**
+ * struct mcp320x - Microchip SPI ADC instance
+ * @spi: SPI slave (parent of the IIO device)
+ * @msg: SPI message to select a channel and receive a value from the ADC
+ * @transfer: SPI transfers used by @msg
+ * @start_conv_msg: SPI message to start a conversion by briefly asserting CS
+ * @start_conv_transfer: SPI transfer used by @start_conv_msg
+ * @reg: regulator generating Vref
+ * @lock: protects read sequences
+ * @chip_info: ADC properties
+ * @tx_buf: buffer for @transfer[0] (not used on single-channel converters)
+ * @rx_buf: buffer for @transfer[1]
+ */
+struct mcp320x {
+	struct spi_device *spi;
+	struct spi_message msg;
+	struct spi_transfer transfer[2];
+	struct spi_message start_conv_msg;
+	struct spi_transfer start_conv_transfer;
+
+	struct regulator *reg;
+	struct mutex lock;
+	const struct mcp320x_chip_info *chip_info;
+
+	u8 tx_buf ____cacheline_aligned;
+	u8 rx_buf[4];
+};
+
+static int mcp320x_channel_to_tx_data(int device_index,
+			const unsigned int channel, bool differential)
+{
+	int start_bit = 1;
+
+	switch (device_index) {
+	case mcp3002:
+	case mcp3202:
+		return ((start_bit << 4) | (!differential << 3) |
+							(channel << 2));
+	case mcp3004:
+	case mcp3204:
+	case mcp3008:
+	case mcp3208:
+		return ((start_bit << 6) | (!differential << 5) |
+							(channel << 2));
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
+				  bool differential, int device_index, int *val)
+{
+	int ret;
+
+	if (adc->chip_info->conv_time) {
+		ret = spi_sync(adc->spi, &adc->start_conv_msg);
+		if (ret < 0)
+			return ret;
+
+		usleep_range(adc->chip_info->conv_time,
+			     adc->chip_info->conv_time + 100);
+	}
+
+	memset(&adc->rx_buf, 0, sizeof(adc->rx_buf));
+	if (adc->chip_info->num_channels > 1)
+		adc->tx_buf = mcp320x_channel_to_tx_data(device_index, channel,
+							 differential);
+
+	ret = spi_sync(adc->spi, &adc->msg);
+	if (ret < 0)
+		return ret;
+
+	switch (device_index) {
+	case mcp3001:
+		*val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+		return 0;
+	case mcp3002:
+	case mcp3004:
+	case mcp3008:
+		*val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+		return 0;
+	case mcp3201:
+		*val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+		return 0;
+	case mcp3202:
+	case mcp3204:
+	case mcp3208:
+		*val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+		return 0;
+	case mcp3301:
+		*val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8
+				    | adc->rx_buf[1], 12);
+		return 0;
+	case mcp3550_50:
+	case mcp3550_60:
+	case mcp3551:
+	case mcp3553: {
+		u32 raw = be32_to_cpup((u32 *)adc->rx_buf);
+
+		if (!(adc->spi->mode & SPI_CPOL))
+			raw <<= 1; /* strip Data Ready bit in SPI mode 0,0 */
+
+		/*
+		 * If the input is within -vref and vref, bit 21 is the sign.
+		 * Up to 12% overrange or underrange are allowed, in which case
+		 * bit 23 is the sign and bit 0 to 21 is the value.
+		 */
+		raw >>= 8;
+		if (raw & BIT(22) && raw & BIT(23))
+			return -EIO; /* cannot have overrange AND underrange */
+		else if (raw & BIT(22))
+			raw &= ~BIT(22); /* overrange */
+		else if (raw & BIT(23) || raw & BIT(21))
+			raw |= GENMASK(31, 22); /* underrange or negative */
+
+		*val = (s32)raw;
+		return 0;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mcp320x_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long mask)
+{
+	struct mcp320x *adc = iio_priv(indio_dev);
+	int ret = -EINVAL;
+	int device_index = 0;
+
+	mutex_lock(&adc->lock);
+
+	device_index = spi_get_device_id(adc->spi)->driver_data;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = mcp320x_adc_conversion(adc, channel->address,
+			channel->differential, device_index, val);
+		if (ret < 0)
+			goto out;
+
+		ret = IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_SCALE:
+		ret = regulator_get_voltage(adc->reg);
+		if (ret < 0)
+			goto out;
+
+		/* convert regulator output voltage to mV */
+		*val = ret / 1000;
+		*val2 = adc->chip_info->resolution;
+		ret = IIO_VAL_FRACTIONAL_LOG2;
+		break;
+	}
+
+out:
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
+#define MCP320X_VOLTAGE_CHANNEL(num)				\
+	{							\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = (num),				\
+		.address = (num),				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+	}
+
+#define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2)		\
+	{							\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = (chan1),				\
+		.channel2 = (chan2),				\
+		.address = (chan1),				\
+		.differential = 1,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+	}
+
+static const struct iio_chan_spec mcp3201_channels[] = {
+	MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
+};
+
+static const struct iio_chan_spec mcp3202_channels[] = {
+	MCP320X_VOLTAGE_CHANNEL(0),
+	MCP320X_VOLTAGE_CHANNEL(1),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
+};
+
+static const struct iio_chan_spec mcp3204_channels[] = {
+	MCP320X_VOLTAGE_CHANNEL(0),
+	MCP320X_VOLTAGE_CHANNEL(1),
+	MCP320X_VOLTAGE_CHANNEL(2),
+	MCP320X_VOLTAGE_CHANNEL(3),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
+};
+
+static const struct iio_chan_spec mcp3208_channels[] = {
+	MCP320X_VOLTAGE_CHANNEL(0),
+	MCP320X_VOLTAGE_CHANNEL(1),
+	MCP320X_VOLTAGE_CHANNEL(2),
+	MCP320X_VOLTAGE_CHANNEL(3),
+	MCP320X_VOLTAGE_CHANNEL(4),
+	MCP320X_VOLTAGE_CHANNEL(5),
+	MCP320X_VOLTAGE_CHANNEL(6),
+	MCP320X_VOLTAGE_CHANNEL(7),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7),
+	MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6),
+};
+
+static const struct iio_info mcp320x_info = {
+	.read_raw = mcp320x_read_raw,
+};
+
+static const struct mcp320x_chip_info mcp320x_chip_infos[] = {
+	[mcp3001] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 10
+	},
+	[mcp3002] = {
+		.channels = mcp3202_channels,
+		.num_channels = ARRAY_SIZE(mcp3202_channels),
+		.resolution = 10
+	},
+	[mcp3004] = {
+		.channels = mcp3204_channels,
+		.num_channels = ARRAY_SIZE(mcp3204_channels),
+		.resolution = 10
+	},
+	[mcp3008] = {
+		.channels = mcp3208_channels,
+		.num_channels = ARRAY_SIZE(mcp3208_channels),
+		.resolution = 10
+	},
+	[mcp3201] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 12
+	},
+	[mcp3202] = {
+		.channels = mcp3202_channels,
+		.num_channels = ARRAY_SIZE(mcp3202_channels),
+		.resolution = 12
+	},
+	[mcp3204] = {
+		.channels = mcp3204_channels,
+		.num_channels = ARRAY_SIZE(mcp3204_channels),
+		.resolution = 12
+	},
+	[mcp3208] = {
+		.channels = mcp3208_channels,
+		.num_channels = ARRAY_SIZE(mcp3208_channels),
+		.resolution = 12
+	},
+	[mcp3301] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 13
+	},
+	[mcp3550_50] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 21,
+		/* 2% max deviation + 144 clock periods to exit shutdown */
+		.conv_time = 80000 * 1.02 + 144000 / 102.4,
+	},
+	[mcp3550_60] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 21,
+		.conv_time = 66670 * 1.02 + 144000 / 122.88,
+	},
+	[mcp3551] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 21,
+		.conv_time = 73100 * 1.02 + 144000 / 112.64,
+	},
+	[mcp3553] = {
+		.channels = mcp3201_channels,
+		.num_channels = ARRAY_SIZE(mcp3201_channels),
+		.resolution = 21,
+		.conv_time = 16670 * 1.02 + 144000 / 122.88,
+	},
+};
+
+static int mcp320x_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct mcp320x *adc;
+	const struct mcp320x_chip_info *chip_info;
+	int ret, device_index;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	adc = iio_priv(indio_dev);
+	adc->spi = spi;
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->dev.of_node = spi->dev.of_node;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mcp320x_info;
+	spi_set_drvdata(spi, indio_dev);
+
+	device_index = spi_get_device_id(spi)->driver_data;
+	chip_info = &mcp320x_chip_infos[device_index];
+	indio_dev->channels = chip_info->channels;
+	indio_dev->num_channels = chip_info->num_channels;
+
+	adc->chip_info = chip_info;
+
+	adc->transfer[0].tx_buf = &adc->tx_buf;
+	adc->transfer[0].len = sizeof(adc->tx_buf);
+	adc->transfer[1].rx_buf = adc->rx_buf;
+	adc->transfer[1].len = DIV_ROUND_UP(chip_info->resolution, 8);
+
+	if (chip_info->num_channels == 1)
+		/* single-channel converters are rx only (no MOSI pin) */
+		spi_message_init_with_transfers(&adc->msg,
+						&adc->transfer[1], 1);
+	else
+		spi_message_init_with_transfers(&adc->msg, adc->transfer,
+						ARRAY_SIZE(adc->transfer));
+
+	switch (device_index) {
+	case mcp3550_50:
+	case mcp3550_60:
+	case mcp3551:
+	case mcp3553:
+		/* rx len increases from 24 to 25 bit in SPI mode 0,0 */
+		if (!(spi->mode & SPI_CPOL))
+			adc->transfer[1].len++;
+
+		/* conversions are started by asserting CS pin for 8 usec */
+		adc->start_conv_transfer.delay_usecs = 8;
+		spi_message_init_with_transfers(&adc->start_conv_msg,
+						&adc->start_conv_transfer, 1);
+
+		/*
+		 * If CS was previously kept low (continuous conversion mode)
+		 * and then changed to high, the chip is in shutdown.
+		 * Sometimes it fails to wake from shutdown and clocks out
+		 * only 0xffffff.  The magic sequence of performing two
+		 * conversions without delay between them resets the chip
+		 * and ensures all subsequent conversions succeed.
+		 */
+		mcp320x_adc_conversion(adc, 0, 1, device_index, &ret);
+		mcp320x_adc_conversion(adc, 0, 1, device_index, &ret);
+	}
+
+	adc->reg = devm_regulator_get(&spi->dev, "vref");
+	if (IS_ERR(adc->reg))
+		return PTR_ERR(adc->reg);
+
+	ret = regulator_enable(adc->reg);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&adc->lock);
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto reg_disable;
+
+	return 0;
+
+reg_disable:
+	regulator_disable(adc->reg);
+
+	return ret;
+}
+
+static int mcp320x_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct mcp320x *adc = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	regulator_disable(adc->reg);
+
+	return 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id mcp320x_dt_ids[] = {
+	/* NOTE: The use of compatibles with no vendor prefix is deprecated. */
+	{ .compatible = "mcp3001" },
+	{ .compatible = "mcp3002" },
+	{ .compatible = "mcp3004" },
+	{ .compatible = "mcp3008" },
+	{ .compatible = "mcp3201" },
+	{ .compatible = "mcp3202" },
+	{ .compatible = "mcp3204" },
+	{ .compatible = "mcp3208" },
+	{ .compatible = "mcp3301" },
+	{ .compatible = "microchip,mcp3001" },
+	{ .compatible = "microchip,mcp3002" },
+	{ .compatible = "microchip,mcp3004" },
+	{ .compatible = "microchip,mcp3008" },
+	{ .compatible = "microchip,mcp3201" },
+	{ .compatible = "microchip,mcp3202" },
+	{ .compatible = "microchip,mcp3204" },
+	{ .compatible = "microchip,mcp3208" },
+	{ .compatible = "microchip,mcp3301" },
+	{ .compatible = "microchip,mcp3550-50" },
+	{ .compatible = "microchip,mcp3550-60" },
+	{ .compatible = "microchip,mcp3551" },
+	{ .compatible = "microchip,mcp3553" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);
+#endif
+
+static const struct spi_device_id mcp320x_id[] = {
+	{ "mcp3001", mcp3001 },
+	{ "mcp3002", mcp3002 },
+	{ "mcp3004", mcp3004 },
+	{ "mcp3008", mcp3008 },
+	{ "mcp3201", mcp3201 },
+	{ "mcp3202", mcp3202 },
+	{ "mcp3204", mcp3204 },
+	{ "mcp3208", mcp3208 },
+	{ "mcp3301", mcp3301 },
+	{ "mcp3550-50", mcp3550_50 },
+	{ "mcp3550-60", mcp3550_60 },
+	{ "mcp3551", mcp3551 },
+	{ "mcp3553", mcp3553 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, mcp320x_id);
+
+static struct spi_driver mcp320x_driver = {
+	.driver = {
+		.name = "mcp320x",
+		.of_match_table = of_match_ptr(mcp320x_dt_ids),
+	},
+	.probe = mcp320x_probe,
+	.remove = mcp320x_remove,
+	.id_table = mcp320x_id,
+};
+module_spi_driver(mcp320x_driver);
+
+MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
+MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08 and MCP3550/1/3");
+MODULE_LICENSE("GPL v2");