text: /*
   * ADE7854/58/68/78 Polyphase Multifunction Energy Metering IC Driver (SPI Bus)
   *
   * Copyright 2010 Analog Devices Inc.
   *
   * Licensed under the GPL-2 or later.
   */
  
  #include <linux/device.h>
  #include <linux/kernel.h>
  #include <linux/spi/spi.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  
  #include <linux/iio/iio.h>
  #include "ade7854.h"
  
  static int ade7854_spi_write_reg_8(struct device *dev,
  		u16 reg_address,
  		u8 value)
  {
  	int ret;
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	struct spi_transfer xfer = {
  		.tx_buf = st->tx,
  		.bits_per_word = 8,
  		.len = 4,
  	};
  
  	mutex_lock(&st->buf_lock);
  	st->tx[0] = ADE7854_WRITE_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  	st->tx[3] = value & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, &xfer, 1);
  	mutex_unlock(&st->buf_lock);
  
  	return ret;
  }
  
  static int ade7854_spi_write_reg_16(struct device *dev,
  		u16 reg_address,
  		u16 value)
  {
  	int ret;
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	struct spi_transfer xfer = {
  		.tx_buf = st->tx,
  		.bits_per_word = 8,
  		.len = 5,
  	};
  
  	mutex_lock(&st->buf_lock);
  	st->tx[0] = ADE7854_WRITE_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  	st->tx[3] = (value >> 8) & 0xFF;
  	st->tx[4] = value & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, &xfer, 1);
  	mutex_unlock(&st->buf_lock);
  
  	return ret;
  }
  
  static int ade7854_spi_write_reg_24(struct device *dev,
  		u16 reg_address,
  		u32 value)
  {
  	int ret;
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	struct spi_transfer xfer = {
  		.tx_buf = st->tx,
  		.bits_per_word = 8,
  		.len = 6,
  	};
  
  	mutex_lock(&st->buf_lock);
  	st->tx[0] = ADE7854_WRITE_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  	st->tx[3] = (value >> 16) & 0xFF;
  	st->tx[4] = (value >> 8) & 0xFF;
  	st->tx[5] = value & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, &xfer, 1);
  	mutex_unlock(&st->buf_lock);
  
  	return ret;
  }
  
  static int ade7854_spi_write_reg_32(struct device *dev,
  		u16 reg_address,
  		u32 value)
  {
  	int ret;
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	struct spi_transfer xfer = {
  		.tx_buf = st->tx,
  		.bits_per_word = 8,
  		.len = 7,
  	};
  
  	mutex_lock(&st->buf_lock);
  	st->tx[0] = ADE7854_WRITE_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  	st->tx[3] = (value >> 24) & 0xFF;
  	st->tx[4] = (value >> 16) & 0xFF;
  	st->tx[5] = (value >> 8) & 0xFF;
  	st->tx[6] = value & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, &xfer, 1);
  	mutex_unlock(&st->buf_lock);
  
  	return ret;
  }
  
  static int ade7854_spi_read_reg_8(struct device *dev,
  		u16 reg_address,
  		u8 *val)
  {
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	int ret;
  	struct spi_transfer xfers[] = {
  		{
  			.tx_buf = st->tx,
  			.bits_per_word = 8,
  			.len = 3,
  		}, {
  			.rx_buf = st->rx,
  			.bits_per_word = 8,
  			.len = 1,
  		}
  	};
  
  	mutex_lock(&st->buf_lock);
  
  	st->tx[0] = ADE7854_READ_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
  	if (ret) {
  		dev_err(&st->spi->dev, "problem when reading 8 bit register 0x%02X",
  				reg_address);
  		goto error_ret;
  	}
  	*val = st->rx[0];
  
  error_ret:
  	mutex_unlock(&st->buf_lock);
  	return ret;
  }
  
  static int ade7854_spi_read_reg_16(struct device *dev,
  		u16 reg_address,
  		u16 *val)
  {
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	int ret;
  	struct spi_transfer xfers[] = {
  		{
  			.tx_buf = st->tx,
  			.bits_per_word = 8,
  			.len = 3,
  		}, {
  			.rx_buf = st->rx,
  			.bits_per_word = 8,
  			.len = 2,
  		}
  	};
  
  	mutex_lock(&st->buf_lock);
  	st->tx[0] = ADE7854_READ_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
  	if (ret) {
  		dev_err(&st->spi->dev, "problem when reading 16 bit register 0x%02X",
  				reg_address);
  		goto error_ret;
  	}
  	*val = be16_to_cpup((const __be16 *)st->rx);
  
  error_ret:
  	mutex_unlock(&st->buf_lock);
  	return ret;
  }
  
  static int ade7854_spi_read_reg_24(struct device *dev,
  		u16 reg_address,
  		u32 *val)
  {
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	int ret;
  	struct spi_transfer xfers[] = {
  		{
  			.tx_buf = st->tx,
  			.bits_per_word = 8,
  			.len = 3,
  		}, {
  			.rx_buf = st->rx,
  			.bits_per_word = 8,
  			.len = 3,
  		}
  	};
  
  	mutex_lock(&st->buf_lock);
  
  	st->tx[0] = ADE7854_READ_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
  	if (ret) {
  		dev_err(&st->spi->dev, "problem when reading 24 bit register 0x%02X",
  				reg_address);
  		goto error_ret;
  	}
  	*val = (st->rx[0] << 16) | (st->rx[1] << 8) | st->rx[2];
  
  error_ret:
  	mutex_unlock(&st->buf_lock);
  	return ret;
  }
  
  static int ade7854_spi_read_reg_32(struct device *dev,
  		u16 reg_address,
  		u32 *val)
  {
  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  	struct ade7854_state *st = iio_priv(indio_dev);
  	int ret;
  	struct spi_transfer xfers[] = {
  		{
  			.tx_buf = st->tx,
  			.bits_per_word = 8,
  			.len = 3,
  		}, {
  			.rx_buf = st->rx,
  			.bits_per_word = 8,
  			.len = 4,
  		}
  	};
  
  	mutex_lock(&st->buf_lock);
  
  	st->tx[0] = ADE7854_READ_REG;
  	st->tx[1] = (reg_address >> 8) & 0xFF;
  	st->tx[2] = reg_address & 0xFF;
  
  	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
  	if (ret) {
  		dev_err(&st->spi->dev, "problem when reading 32 bit register 0x%02X",
  				reg_address);
  		goto error_ret;
  	}
  	*val = be32_to_cpup((const __be32 *)st->rx);
  
  error_ret:
  	mutex_unlock(&st->buf_lock);
  	return ret;
  }
  
  static int ade7854_spi_probe(struct spi_device *spi)
  {
  	int ret;
  	struct ade7854_state *st;
  	struct iio_dev *indio_dev;
  
  	indio_dev = iio_device_alloc(sizeof(*st));
  	if (indio_dev == NULL)
  		return -ENOMEM;
  	st = iio_priv(indio_dev);
  	spi_set_drvdata(spi, indio_dev);
  	st->read_reg_8 = ade7854_spi_read_reg_8;
  	st->read_reg_16 = ade7854_spi_read_reg_16;
  	st->read_reg_24 = ade7854_spi_read_reg_24;
  	st->read_reg_32 = ade7854_spi_read_reg_32;
  	st->write_reg_8 = ade7854_spi_write_reg_8;
  	st->write_reg_16 = ade7854_spi_write_reg_16;
  	st->write_reg_24 = ade7854_spi_write_reg_24;
  	st->write_reg_32 = ade7854_spi_write_reg_32;
  	st->irq = spi->irq;
  	st->spi = spi;
  
  
  	ret = ade7854_probe(indio_dev, &spi->dev);
  	if (ret)
  		iio_device_free(indio_dev);
  
  	return 0;
  }
  
  static int ade7854_spi_remove(struct spi_device *spi)
  {
  	ade7854_remove(spi_get_drvdata(spi));
  
  	return 0;
  }
  static const struct spi_device_id ade7854_id[] = {
  	{ "ade7854", 0 },
  	{ "ade7858", 0 },
  	{ "ade7868", 0 },
  	{ "ade7878", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(spi, ade7854_id);
  
  static struct spi_driver ade7854_driver = {
  	.driver = {
  		.name = "ade7854",
  		.owner = THIS_MODULE,
  	},
  	.probe = ade7854_spi_probe,
  	.remove = ade7854_spi_remove,
  	.id_table = ade7854_id,
  };
  module_spi_driver(ade7854_driver);
  
  MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
  MODULE_DESCRIPTION("Analog Devices ADE7854/58/68/78 SPI Driver");
  MODULE_LICENSE("GPL v2");
  