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

[Jonathan Cameron <jic23@kernel.org>]

On 03/09/16 20:29, Jonathan Cameron wrote:
> 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.
Applied again.

Jonathan
> 
> 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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