Re: [Device-drivers-devel] [PATCH 04/24] staging:iio:gyro:adxrs450 make more use of spi_read and spi_write.

[Michael Hennerich <michael.hennerich@analog.com>]

On 06/29/2011 01:51 PM, Jonathan Cameron wrote:
> This needs confirmation that the devices is happy if another part is
> talked to in between the request for a register and the read back.
I don't see a reason why this could break.

Acked-by: Michael Hennerich <michael.hennerich@analog.com>

> Signed-off-by: Jonathan Cameron<jic23@cam.ac.uk>
> ---
>   drivers/staging/iio/gyro/adxrs450_core.c |   63 ++++++++----------------------
>   1 files changed, 17 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adxrs450_core.c b/drivers/staging/iio/gyro/adxrs450_core.c
> index a756262..2d2916c 100644
> --- a/drivers/staging/iio/gyro/adxrs450_core.c
> +++ b/drivers/staging/iio/gyro/adxrs450_core.c
> @@ -35,21 +35,8 @@ static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev,
>   				    u8 reg_address,
>   				    u16 *val)
>   {
> -	struct spi_message msg;
>   	struct adxrs450_state *st = iio_priv(indio_dev);
>   	int ret;
> -	struct spi_transfer xfers[] = {
> -		{
> -			.tx_buf = st->tx,
> -			.bits_per_word = 8,
> -			.len = 4,
> -			.cs_change = 1,
> -		}, {
> -			.rx_buf = st->rx,
> -			.bits_per_word = 8,
> -			.len = 4,
> -		},
> -	};
>
>   	mutex_lock(&st->buf_lock);
>   	st->tx[0] = ADXRS450_READ_DATA | (reg_address>>  7);
> @@ -60,10 +47,13 @@ static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev,
>   	if (!(hweight32(be32_to_cpu(*(u32 *)st->tx))&  1))
>   		st->tx[3]  |= ADXRS450_P;
>
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfers[0],&msg);
> -	spi_message_add_tail(&xfers[1],&msg);
> -	ret = spi_sync(st->us,&msg);
> +	ret = spi_write(st->us, st->tx, 4);
> +	if (ret) {
> +		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
> +			reg_address);
> +		goto error_ret;
> +	}
> +	ret = spi_read(st->us, st->rx, 4);
>   	if (ret) {
>   		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
>   				reg_address);
> @@ -88,15 +78,8 @@ static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev,
>   				     u8 reg_address,
>   				     u16 val)
>   {
> -	struct spi_message msg;
>   	struct adxrs450_state *st = iio_priv(indio_dev);
>   	int ret;
> -	struct spi_transfer xfers = {
> -		.tx_buf = st->tx,
> -		.rx_buf = st->rx,
> -		.bits_per_word = 8,
> -		.len = 4,
> -	};
>
>   	mutex_lock(&st->buf_lock);
>   	st->tx[0] = ADXRS450_WRITE_DATA | reg_address>>  7;
> @@ -105,14 +88,12 @@ static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev,
>   	st->tx[3] = val<<  1;
>
>   	if (!(hweight32(be32_to_cpu(*(u32 *)st->tx))&  1))
> -		st->tx[3]  |= ADXRS450_P;
> +		st->tx[3] |= ADXRS450_P;
>
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfers,&msg);
> -	ret = spi_sync(st->us,&msg);
> +	ret = spi_write(st->us, st->tx, 4);
>   	if (ret)
>   		dev_err(&st->us->dev, "problem while writing 16 bit register 0x%02x\n",
> -				reg_address);
> +			reg_address);
>   	msleep(1); /* enforce sequential transfer delay 0.1ms */
>   	mutex_unlock(&st->buf_lock);
>   	return ret;
> @@ -125,21 +106,8 @@ static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev,
>    **/
>   static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val)
>   {
> -	struct spi_message msg;
>   	struct adxrs450_state *st = iio_priv(indio_dev);
>   	int ret;
> -	struct spi_transfer xfers[] = {
> -		{
> -			.tx_buf = st->tx,
> -			.bits_per_word = 8,
> -			.len = 4,
> -			.cs_change = 1,
> -		}, {
> -			.rx_buf = st->rx,
> -			.bits_per_word = 8,
> -			.len = 4,
> -		},
> -	};
>
>   	mutex_lock(&st->buf_lock);
>   	st->tx[0] = ADXRS450_SENSOR_DATA;
> @@ -147,10 +115,13 @@ static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val)
>   	st->tx[2] = 0;
>   	st->tx[3] = 0;
>
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfers[0],&msg);
> -	spi_message_add_tail(&xfers[1],&msg);
> -	ret = spi_sync(st->us,&msg);
> +	ret = spi_write(st->us, st->tx, 4);
> +	if (ret) {
> +		dev_err(&st->us->dev, "Problem while reading sensor data\n");
> +		goto error_ret;
> +	}
> +
> +	ret = spi_read(st->us, st->rx, 4);
>   	if (ret) {
>   		dev_err(&st->us->dev, "Problem while reading sensor data\n");
>   		goto error_ret;


-- 
Greetings,
Michael

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