Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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:
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf  mcp3002
 * https://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
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf  mcp3301
 * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf  mcp3550/1/3
 */
 
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/mod_devicetable.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((__be32 *)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->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.value = 8;
<------><------>adc->start_conv_transfer.delay.unit = SPI_DELAY_UNIT_USECS;
<------><------>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;
}
 
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);
 
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 = 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");