[v1,1/2] iio: adc: ti-adc128s052: Use get_unaligned_beXX()
Commit Message
This makes the driver code slightly easier to read.
While at it, use GENMASK() as well.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/iio/adc/ti-adc128s052.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
Comments
On Wed, 14 Dec 2022 14:02:01 +0200
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> This makes the driver code slightly easier to read.
> While at it, use GENMASK() as well.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Hi Andy,
Patch looks good, but it got me thinking. Why not just flip this driver
over to using spi_write_then_read(). Would let us drop the DMA safety
protections and simplify the code + use a __be16 as the read buffer
and this would then be the slightly nicer aligned form.
Worth doing whilst you are here?
Jonathan
> ---
> drivers/iio/adc/ti-adc128s052.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/ti-adc128s052.c b/drivers/iio/adc/ti-adc128s052.c
> index fc09ee6bb174..7c4e8025861c 100644
> --- a/drivers/iio/adc/ti-adc128s052.c
> +++ b/drivers/iio/adc/ti-adc128s052.c
> @@ -9,6 +9,7 @@
> * https://www.ti.com/lit/ds/symlink/adc124s021.pdf
> */
>
> +#include <linux/bits.h>
> #include <linux/err.h>
> #include <linux/spi/spi.h>
> #include <linux/module.h>
> @@ -17,6 +18,8 @@
> #include <linux/property.h>
> #include <linux/regulator/consumer.h>
>
> +#include <asm/unaligned.h>
> +
> struct adc128_configuration {
> const struct iio_chan_spec *channels;
> u8 num_channels;
> @@ -33,6 +36,7 @@ struct adc128 {
>
> static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
> {
> + u16 value;
> int ret;
>
> mutex_lock(&adc->lock);
> @@ -53,7 +57,8 @@ static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
> if (ret < 0)
> return ret;
>
> - return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
> + value = get_unaligned_be16(&adc->buffer);
> + return value & GENMASK(11, 0);
> }
>
> static int adc128_read_raw(struct iio_dev *indio_dev,
On Fri, Dec 23, 2022 at 03:17:50PM +0000, Jonathan Cameron wrote:
> On Wed, 14 Dec 2022 14:02:01 +0200
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
>
> > This makes the driver code slightly easier to read.
> > While at it, use GENMASK() as well.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Hi Andy,
>
> Patch looks good, but it got me thinking. Why not just flip this driver
> over to using spi_write_then_read(). Would let us drop the DMA safety
> protections and simplify the code + use a __be16 as the read buffer
> and this would then be the slightly nicer aligned form.
>
> Worth doing whilst you are here?
OK, I will consider when I have time for this.
@@ -9,6 +9,7 @@
* https://www.ti.com/lit/ds/symlink/adc124s021.pdf
*/
+#include <linux/bits.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
@@ -17,6 +18,8 @@
#include <linux/property.h>
#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+
struct adc128_configuration {
const struct iio_chan_spec *channels;
u8 num_channels;
@@ -33,6 +36,7 @@ struct adc128 {
static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
{
+ u16 value;
int ret;
mutex_lock(&adc->lock);
@@ -53,7 +57,8 @@ static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
if (ret < 0)
return ret;
- return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
+ value = get_unaligned_be16(&adc->buffer);
+ return value & GENMASK(11, 0);
}
static int adc128_read_raw(struct iio_dev *indio_dev,