Re: [PATCH 04/15 v2] iio: accel: kxsd9: Split out SPI transport

[Jonathan Cameron <jic23@kernel.org>]

On 03/09/16 20:24, Jonathan Cameron wrote:
> On 01/09/16 10:44, Linus Walleij wrote:
>> This moves the KXSD9 SPI transport out to its own file and Kconfig
>> entry, so that we will be able to add another transport method.
>> We export the common probe and add a local header file for the
>> functionality shared between the main driver and the transport
>> driver.
>>
>> We make the SPI transport the default for the driver if SPI is
>> available and the KXSD9 driver was selected, so the oldconfig
>> upgrade path will be clear.
>>
>> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> Applied to the togreg branch of iio.git
> 
Backed out due to later mess against the fixes.

Jonathan
> Thanks
>> ---
>> ChangeLog v1->v2:
>> - Preserve MODULE_* macros as the compilation complains about
>>   tainting etc.
>> - Rebased to account for the common .remove() function, make sure
>>   this is also exported etc.
>> ---
>>  drivers/iio/accel/Kconfig     |  10 ++-
>>  drivers/iio/accel/Makefile    |   1 +
>>  drivers/iio/accel/kxsd9-spi.c | 110 +++++++++++++++++++++++++++++++
>>  drivers/iio/accel/kxsd9.c     | 147 ++++++------------------------------------
>>  drivers/iio/accel/kxsd9.h     |  32 +++++++++
>>  5 files changed, 173 insertions(+), 127 deletions(-)
>>  create mode 100644 drivers/iio/accel/kxsd9-spi.c
>>  create mode 100644 drivers/iio/accel/kxsd9.h
>>
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 89d78208de3f..95e3fc09f640 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -96,7 +96,6 @@ config IIO_ST_ACCEL_SPI_3AXIS
>>  
>>  config KXSD9
>>  	tristate "Kionix KXSD9 Accelerometer Driver"
>> -	depends on SPI
>>  	help
>>  	  Say yes here to build support for the Kionix KXSD9 accelerometer.
>>  	  Currently this only supports the device via an SPI interface.
>> @@ -104,6 +103,15 @@ config KXSD9
>>  	  To compile this driver as a module, choose M here: the module
>>  	  will be called kxsd9.
>>  
>> +config KXSD9_SPI
>> +	tristate "Kionix KXSD9 SPI transport"
>> +	depends on KXSD9
>> +	depends on SPI
>> +	default KXSD9
>> +	help
>> +	  Say yes here to enable the Kionix KXSD9 accelerometer
>> +	  SPI transport channel.
>> +
>>  config KXCJK1013
>>  	tristate "Kionix 3-Axis Accelerometer Driver"
>>  	depends on I2C
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 6cedbecca2ee..22a5770f62a9 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -11,6 +11,7 @@ obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>  obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
>>  obj-$(CONFIG_KXSD9)	+= kxsd9.o
>> +obj-$(CONFIG_KXSD9_SPI)	+= kxsd9-spi.o
>>  
>>  obj-$(CONFIG_MMA7455)		+= mma7455_core.o
>>  obj-$(CONFIG_MMA7455_I2C)	+= mma7455_i2c.o
>> diff --git a/drivers/iio/accel/kxsd9-spi.c b/drivers/iio/accel/kxsd9-spi.c
>> new file mode 100644
>> index 000000000000..ec9d00d5340f
>> --- /dev/null
>> +++ b/drivers/iio/accel/kxsd9-spi.c
>> @@ -0,0 +1,110 @@
>> +#include <linux/device.h>
>> +#include <linux/kernel.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +
>> +#include "kxsd9.h"
>> +
>> +#define KXSD9_READ(a) (0x80 | (a))
>> +#define KXSD9_WRITE(a) (a)
>> +
>> +static int kxsd9_spi_readreg(struct kxsd9_transport *tr, u8 address)
>> +{
>> +	struct spi_device *spi = tr->trdev;
>> +
>> +	return spi_w8r8(spi, KXSD9_READ(address));
>> +}
>> +
>> +static int kxsd9_spi_writereg(struct kxsd9_transport *tr, u8 address, u8 val)
>> +{
>> +	struct spi_device *spi = tr->trdev;
>> +
>> +	tr->tx[0] = KXSD9_WRITE(address),
>> +	tr->tx[1] = val;
>> +	return spi_write(spi, tr->tx, 2);
>> +}
>> +
>> +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] = KXSD9_READ(address);
>> +	ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
>> +	if (!ret)
>> +		ret = (((u16)(tr->rx[0])) << 8) | (tr->rx[1]);
>> +	return ret;
>> +}
>> +
>> +static int kxsd9_spi_probe(struct spi_device *spi)
>> +{
>> +	struct kxsd9_transport *transport;
>> +	int ret;
>> +
>> +	transport = devm_kzalloc(&spi->dev, sizeof(*transport), GFP_KERNEL);
>> +	if (!transport)
>> +		return -ENOMEM;
>> +
>> +	transport->trdev = spi;
>> +	transport->readreg = kxsd9_spi_readreg;
>> +	transport->writereg = kxsd9_spi_writereg;
>> +	transport->write2 = kxsd9_spi_write2;
>> +	transport->readval = kxsd9_spi_readval;
>> +	spi->mode = SPI_MODE_0;
>> +	spi_setup(spi);
>> +
>> +	ret = kxsd9_common_probe(&spi->dev,
>> +				 transport,
>> +				 spi_get_device_id(spi)->name);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>> +static int kxsd9_spi_remove(struct spi_device *spi)
>> +{
>> +	return kxsd9_common_remove(&spi->dev);
>> +}
>> +
>> +static const struct spi_device_id kxsd9_spi_id[] = {
>> +	{"kxsd9", 0},
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(spi, kxsd9_spi_id);
>> +
>> +static struct spi_driver kxsd9_spi_driver = {
>> +	.driver = {
>> +		.name = "kxsd9",
>> +	},
>> +	.probe = kxsd9_spi_probe,
>> +	.remove = kxsd9_spi_remove,
>> +	.id_table = kxsd9_spi_id,
>> +};
>> +module_spi_driver(kxsd9_spi_driver);
>> +
>> +MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
>> +MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
>> index 1f9e9a867f34..e2033374bfef 100644
>> --- a/drivers/iio/accel/kxsd9.c
>> +++ b/drivers/iio/accel/kxsd9.c
>> @@ -18,7 +18,6 @@
>>  
>>  #include <linux/device.h>
>>  #include <linux/kernel.h>
>> -#include <linux/spi/spi.h>
>>  #include <linux/sysfs.h>
>>  #include <linux/slab.h>
>>  #include <linux/module.h>
>> @@ -26,6 +25,8 @@
>>  #include <linux/iio/iio.h>
>>  #include <linux/iio/sysfs.h>
>>  
>> +#include "kxsd9.h"
>> +
>>  #define KXSD9_REG_X		0x00
>>  #define KXSD9_REG_Y		0x02
>>  #define KXSD9_REG_Z		0x04
>> @@ -38,32 +39,6 @@
>>  #define KXSD9_REG_CTRL_B	0x0d
>>  #define KXSD9_REG_CTRL_A	0x0e
>>  
>> -#define KXSD9_READ(a) (0x80 | (a))
>> -#define KXSD9_WRITE(a) (a)
>> -
>> -#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
>> @@ -98,12 +73,13 @@ static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
>>  		return -EINVAL;
>>  
>>  	mutex_lock(&st->buf_lock);
>> -	ret = st->transport->write1(st->transport, KXSD9_READ(KXSD9_REG_CTRL_C));
>> -	if (ret)
>> +	ret = st->transport->readreg(st->transport,
>> +				     KXSD9_REG_CTRL_C);
>> +	if (ret < 0)
>>  		goto error_ret;
>> -	ret = st->transport->write2(st->transport,
>> -				    KXSD9_WRITE(KXSD9_REG_CTRL_C),
>> -				    (ret & ~KXSD9_FS_MASK) | i);
>> +	ret = st->transport->writereg(st->transport,
>> +				      KXSD9_REG_CTRL_C,
>> +				      (ret & ~KXSD9_FS_MASK) | i);
>>  error_ret:
>>  	mutex_unlock(&st->buf_lock);
>>  	return ret;
>> @@ -115,7 +91,9 @@ static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
>>  	struct kxsd9_state *st = iio_priv(indio_dev);
>>  
>>  	mutex_lock(&st->buf_lock);
>> -	ret = st->transport->readval(st->transport, KXSD9_READ(address));
>> +	ret = st->transport->readval(st->transport, address);
>> +	/* Only 12 bits are valid */
>> +	ret &= 0xfff0;
>>  	mutex_unlock(&st->buf_lock);
>>  	return ret;
>>  }
>> @@ -165,8 +143,9 @@ static int kxsd9_read_raw(struct iio_dev *indio_dev,
>>  		ret = IIO_VAL_INT;
>>  		break;
>>  	case IIO_CHAN_INFO_SCALE:
>> -		ret = st->transport->write1(st->transport, KXSD9_READ(KXSD9_REG_CTRL_C));
>> -		if (ret)
>> +		ret = st->transport->readreg(st->transport,
>> +					     KXSD9_REG_CTRL_C);
>> +		if (ret < 0)
>>  			goto error_ret;
>>  		*val = 0;
>>  		*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
>> @@ -218,9 +197,9 @@ static const struct iio_info kxsd9_info = {
>>  	.driver_module = THIS_MODULE,
>>  };
>>  
>> -static int kxsd9_common_probe(struct device *parent,
>> -			      struct kxsd9_transport *transport,
>> -			      const char *name)
>> +int kxsd9_common_probe(struct device *parent,
>> +		       struct kxsd9_transport *transport,
>> +		       const char *name)
>>  {
>>  	struct iio_dev *indio_dev;
>>  	struct kxsd9_state *st;
>> @@ -251,8 +230,9 @@ static int kxsd9_common_probe(struct device *parent,
>>  
>>  	return 0;
>>  }
>> +EXPORT_SYMBOL(kxsd9_common_probe);
>>  
>> -static int kxsd9_common_remove(struct device *parent)
>> +int kxsd9_common_remove(struct device *parent)
>>  {
>>  	struct iio_dev *indio_dev = dev_get_drvdata(parent);
>>  
>> @@ -260,93 +240,8 @@ static int kxsd9_common_remove(struct device *parent)
>>  
>>  	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;
>> -	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);
>> -
>> -	ret = kxsd9_common_probe(&spi->dev,
>> -				 transport,
>> -				 spi_get_device_id(spi)->name);
>> -	if (ret)
>> -		return ret;
>> -
>> -	return 0;
>> -}
>> -
>> -static int kxsd9_spi_remove(struct spi_device *spi)
>> -{
>> -	return kxsd9_common_remove(&spi->dev);
>> -}
>> -
>> -static const struct spi_device_id kxsd9_spi_id[] = {
>> -	{"kxsd9", 0},
>> -	{ },
>> -};
>> -MODULE_DEVICE_TABLE(spi, kxsd9_spi_id);
>> -
>> -static struct spi_driver kxsd9_spi_driver = {
>> -	.driver = {
>> -		.name = "kxsd9",
>> -	},
>> -	.probe = kxsd9_spi_probe,
>> -	.remove = kxsd9_spi_remove,
>> -	.id_table = kxsd9_spi_id,
>> -};
>> -module_spi_driver(kxsd9_spi_driver);
>> +EXPORT_SYMBOL(kxsd9_common_remove);
>>  
>>  MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
>> -MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
>> +MODULE_DESCRIPTION("Kionix KXSD9 driver");
>>  MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/iio/accel/kxsd9.h b/drivers/iio/accel/kxsd9.h
>> new file mode 100644
>> index 000000000000..28845c3440e9
>> --- /dev/null
>> +++ b/drivers/iio/accel/kxsd9.h
>> @@ -0,0 +1,32 @@
>> +#include <linux/device.h>
>> +#include <linux/kernel.h>
>> +
>> +#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
>> + * @readreg(): function to read a byte from an address in the device
>> + * @writereg(): function to write a byte to an address in 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 (*readreg) (struct kxsd9_transport *tr, u8 address);
>> +	int (*writereg) (struct kxsd9_transport *tr, u8 address, u8 val);
>> +	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];
>> +};
>> +
>> +int kxsd9_common_probe(struct device *parent,
>> +		       struct kxsd9_transport *transport,
>> +		       const char *name);
>> +int kxsd9_common_remove(struct device *parent);
>>
> 
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