Commit 9f907972 authored by Linus Walleij's avatar Linus Walleij Committed by Jonathan Cameron
Browse files

iio: accel: kxsd9: Split out transport mechanism 



Split off a transport mechanism struct that will deal with the SPI
traffic in preparation for adding I2C support.

Tested-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 6841b2a0

drivers/iio/accel/kxsd9.c

+123 −52
Original line number Diff line number Diff line
@@ -43,18 +43,36 @@ 


#define KXSD9_STATE_RX_SIZE 2

#define KXSD9_STATE_TX_SIZE 2



struct kxsd9_transport;



/**

 * struct kxsd9_transport - transport adapter for SPI or I2C

 * @trdev: transport device such as SPI or I2C

 * @write1(): function to write a byte to the device

 * @write2(): function to write two consecutive bytes to the device

 * @readval(): function to read a 16bit value from the device

 * @rx: cache aligned read buffer

 * @tx: cache aligned write buffer

 */

struct kxsd9_transport {

	void *trdev;

	int (*write1) (struct kxsd9_transport *tr, u8 byte);

	int (*write2) (struct kxsd9_transport *tr, u8 b1, u8 b2);

	int (*readval) (struct kxsd9_transport *tr, u8 address);

	u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;

	u8 tx[KXSD9_STATE_TX_SIZE];

};



/**

 * struct kxsd9_state - device related storage

 * @transport:	transport for the KXSD9

 * @buf_lock:	protect the rx and tx buffers.

 * @us:		spi device

 * @rx:		single rx buffer storage

 * @tx:		single tx buffer storage

 **/

struct kxsd9_state {

	struct kxsd9_transport *transport;

	struct mutex buf_lock;

	struct spi_device *us;

	u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;

	u8 tx[KXSD9_STATE_TX_SIZE];

};



#define KXSD9_SCALE_2G "0.011978"
@@ -80,13 +98,12 @@ static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro) 
		return -EINVAL;



	mutex_lock(&st->buf_lock);

	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));

	if (ret < 0)

	ret = st->transport->write1(st->transport, KXSD9_READ(KXSD9_REG_CTRL_C));

	if (ret)

		goto error_ret;

	st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);

	st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;



	ret = spi_write(st->us, st->tx, 2);

	ret = st->transport->write2(st->transport,

				    KXSD9_WRITE(KXSD9_REG_CTRL_C),

				    (ret & ~KXSD9_FS_MASK) | i);

error_ret:

	mutex_unlock(&st->buf_lock);

	return ret;
@@ -96,24 +113,9 @@ static int kxsd9_read(struct iio_dev *indio_dev, u8 address) 
{

	int ret;

	struct kxsd9_state *st = iio_priv(indio_dev);

	struct spi_transfer xfers[] = {

		{

			.bits_per_word = 8,

			.len = 1,

			.delay_usecs = 200,

			.tx_buf = st->tx,

		}, {

			.bits_per_word = 8,

			.len = 2,

			.rx_buf = st->rx,

		},

	};



	mutex_lock(&st->buf_lock);

	st->tx[0] = KXSD9_READ(address);

	ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));

	if (!ret)

		ret = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);

	ret = st->transport->readval(st->transport, KXSD9_READ(address));

	mutex_unlock(&st->buf_lock);

	return ret;

}
@@ -163,8 +165,8 @@ static int kxsd9_read_raw(struct iio_dev *indio_dev, 
		ret = IIO_VAL_INT;

		break;

	case IIO_CHAN_INFO_SCALE:

		ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));

		if (ret < 0)

		ret = st->transport->write1(st->transport, KXSD9_READ(KXSD9_REG_CTRL_C));

		if (ret)

			goto error_ret;

		*val = 0;

		*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
@@ -203,15 +205,10 @@ static int kxsd9_power_up(struct kxsd9_state *st) 
{

	int ret;



	st->tx[0] = 0x0d;

	st->tx[1] = 0x40;

	ret = spi_write(st->us, st->tx, 2);

	ret = st->transport->write2(st->transport, 0x0d, 0x40);

	if (ret)

		return ret;



	st->tx[0] = 0x0c;

	st->tx[1] = 0x9b;

	return spi_write(st->us, st->tx, 2);

	return st->transport->write2(st->transport, 0x0c, 0x9b);

};



static const struct iio_info kxsd9_info = {
@@ -221,56 +218,130 @@ static const struct iio_info kxsd9_info = { 
	.driver_module = THIS_MODULE,

};



static int kxsd9_probe(struct spi_device *spi)

static int kxsd9_common_probe(struct device *parent,

			      struct kxsd9_transport *transport,

			      const char *name,

			      struct iio_dev **retdev)

{

	struct iio_dev *indio_dev;

	struct kxsd9_state *st;

	int ret;



	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));

	indio_dev = devm_iio_device_alloc(parent, sizeof(*st));

	if (!indio_dev)

		return -ENOMEM;



	st = iio_priv(indio_dev);

	spi_set_drvdata(spi, indio_dev);

	st->transport = transport;



	st->us = spi;

	mutex_init(&st->buf_lock);

	indio_dev->channels = kxsd9_channels;

	indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);

	indio_dev->name = spi_get_device_id(spi)->name;

	indio_dev->dev.parent = &spi->dev;

	indio_dev->name = name;

	indio_dev->dev.parent = parent;

	indio_dev->info = &kxsd9_info;

	indio_dev->modes = INDIO_DIRECT_MODE;



	kxsd9_power_up(st);



	ret = iio_device_register(indio_dev);

	if (ret)

		return ret;



	*retdev = indio_dev;

	return 0;

}



static int kxsd9_spi_write1(struct kxsd9_transport *tr, u8 byte)

{

	struct spi_device *spi = tr->trdev;



	return spi_w8r8(spi, byte);

}



static int kxsd9_spi_write2(struct kxsd9_transport *tr, u8 b1, u8 b2)

{

	struct spi_device *spi = tr->trdev;



	tr->tx[0] = b1;

	tr->tx[1] = b2;

	return spi_write(spi, tr->tx, 2);

}



static int kxsd9_spi_readval(struct kxsd9_transport *tr, u8 address)

{

	struct spi_device *spi = tr->trdev;

	struct spi_transfer xfers[] = {

		{

			.bits_per_word = 8,

			.len = 1,

			.delay_usecs = 200,

			.tx_buf = tr->tx,

		}, {

			.bits_per_word = 8,

			.len = 2,

			.rx_buf = tr->rx,

		},

	};

	int ret;



	tr->tx[0] = address;

	ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));

	if (!ret)

		ret = (((u16)(tr->rx[0])) << 8) | (tr->rx[1] & 0xF0);

	return ret;

}



static int kxsd9_spi_probe(struct spi_device *spi)

{

	struct kxsd9_transport *transport;

	struct iio_dev *indio_dev;

	int ret;



	transport = devm_kzalloc(&spi->dev, sizeof(*transport), GFP_KERNEL);

	if (!transport)

		return -ENOMEM;



	transport->trdev = spi;

	transport->write1 = kxsd9_spi_write1;

	transport->write2 = kxsd9_spi_write2;

	transport->readval = kxsd9_spi_readval;

	spi->mode = SPI_MODE_0;

	spi_setup(spi);

	kxsd9_power_up(st);



	return iio_device_register(indio_dev);

	ret = kxsd9_common_probe(&spi->dev,

				 transport,

				 spi_get_device_id(spi)->name,

				 &indio_dev);

	if (ret)

		return ret;



	spi_set_drvdata(spi, indio_dev);

	return 0;

}



static int kxsd9_remove(struct spi_device *spi)

static int kxsd9_spi_remove(struct spi_device *spi)

{

	iio_device_unregister(spi_get_drvdata(spi));



	return 0;

}



static const struct spi_device_id kxsd9_id[] = {

static const struct spi_device_id kxsd9_spi_id[] = {

	{"kxsd9", 0},

	{ },

};

MODULE_DEVICE_TABLE(spi, kxsd9_id);

MODULE_DEVICE_TABLE(spi, kxsd9_spi_id);



static struct spi_driver kxsd9_driver = {

static struct spi_driver kxsd9_spi_driver = {

	.driver = {

		.name = "kxsd9",

	},

	.probe = kxsd9_probe,

	.remove = kxsd9_remove,

	.id_table = kxsd9_id,

	.probe = kxsd9_spi_probe,

	.remove = kxsd9_spi_remove,

	.id_table = kxsd9_spi_id,

};

module_spi_driver(kxsd9_driver);

module_spi_driver(kxsd9_spi_driver);



MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");

MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");