diff mbox series

[06/10] staging: greybus: spilib: use 'spi_delay_to_ns' for getting xfer delay

Message ID 20210308145502.1075689-7-aardelean@deviqon.com
State New
Headers show
Series spi: finalize 'delay_usecs' removal/transition | expand

Commit Message

Alexandru Ardelean March 8, 2021, 2:54 p.m. UTC
The intent is the removal of the 'delay_usecs' field from the
spi_transfer struct, as there is a 'delay' field that does the same
thing.

The spi_delay_to_ns() can be used to get the transfer delay. It works by
using the 'delay_usecs' field first (if it is non-zero), and finally
uses the 'delay' field.

Since the 'delay_usecs' field is going away, this change makes use of the
spi_delay_to_ns() function. This also means dividing the return value of
the function by 1000, to convert it to microseconds.
To prevent any potential faults when converting to microseconds and since
the result of spi_delay_to_ns() is int, the delay is being computed in 32
bits and then clamped between 0 & U16_MAX.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---
 drivers/staging/greybus/spilib.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Viresh Kumar March 9, 2021, 4:28 a.m. UTC | #1
On 08-03-21, 16:54, Alexandru Ardelean wrote:
> The intent is the removal of the 'delay_usecs' field from the
> spi_transfer struct, as there is a 'delay' field that does the same
> thing.
> 
> The spi_delay_to_ns() can be used to get the transfer delay. It works by
> using the 'delay_usecs' field first (if it is non-zero), and finally
> uses the 'delay' field.
> 
> Since the 'delay_usecs' field is going away, this change makes use of the
> spi_delay_to_ns() function. This also means dividing the return value of
> the function by 1000, to convert it to microseconds.
> To prevent any potential faults when converting to microseconds and since
> the result of spi_delay_to_ns() is int, the delay is being computed in 32
> bits and then clamped between 0 & U16_MAX.
> 
> Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
> ---
>  drivers/staging/greybus/spilib.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c
> index 672d540d3365..30655153df6a 100644
> --- a/drivers/staging/greybus/spilib.c
> +++ b/drivers/staging/greybus/spilib.c
> @@ -245,6 +245,7 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
>  	/* Fill in the transfers array */
>  	xfer = spi->first_xfer;
>  	while (msg->state != GB_SPI_STATE_OP_DONE) {
> +		int xfer_delay;
>  		if (xfer == spi->last_xfer)
>  			xfer_len = spi->last_xfer_size;
>  		else
> @@ -259,7 +260,9 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
>  
>  		gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
>  		gb_xfer->len = cpu_to_le32(xfer_len);
> -		gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
> +		xfer_delay = spi_delay_to_ns(&xfer->delay, xfer) / 1000;
> +		xfer_delay = clamp_t(u16, xfer_delay, 0, U16_MAX);
> +		gb_xfer->delay_usecs = cpu_to_le16(xfer_delay);
>  		gb_xfer->cs_change = xfer->cs_change;
>  		gb_xfer->bits_per_word = xfer->bits_per_word;

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Rui Miguel Silva March 9, 2021, 9:29 a.m. UTC | #2
Hi,
On Tue, Mar 09, 2021 at 09:58:09AM +0530, Viresh Kumar wrote:
> On 08-03-21, 16:54, Alexandru Ardelean wrote:
> > The intent is the removal of the 'delay_usecs' field from the
> > spi_transfer struct, as there is a 'delay' field that does the same
> > thing.
> > 
> > The spi_delay_to_ns() can be used to get the transfer delay. It works by
> > using the 'delay_usecs' field first (if it is non-zero), and finally
> > uses the 'delay' field.
> > 
> > Since the 'delay_usecs' field is going away, this change makes use of the
> > spi_delay_to_ns() function. This also means dividing the return value of
> > the function by 1000, to convert it to microseconds.
> > To prevent any potential faults when converting to microseconds and since
> > the result of spi_delay_to_ns() is int, the delay is being computed in 32
> > bits and then clamped between 0 & U16_MAX.
> > 
> > Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
> > ---
> >  drivers/staging/greybus/spilib.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c
> > index 672d540d3365..30655153df6a 100644
> > --- a/drivers/staging/greybus/spilib.c
> > +++ b/drivers/staging/greybus/spilib.c
> > @@ -245,6 +245,7 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
> >  	/* Fill in the transfers array */
> >  	xfer = spi->first_xfer;
> >  	while (msg->state != GB_SPI_STATE_OP_DONE) {
> > +		int xfer_delay;
> >  		if (xfer == spi->last_xfer)
> >  			xfer_len = spi->last_xfer_size;
> >  		else
> > @@ -259,7 +260,9 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
> >  
> >  		gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
> >  		gb_xfer->len = cpu_to_le32(xfer_len);
> > -		gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
> > +		xfer_delay = spi_delay_to_ns(&xfer->delay, xfer) / 1000;
> > +		xfer_delay = clamp_t(u16, xfer_delay, 0, U16_MAX);
> > +		gb_xfer->delay_usecs = cpu_to_le16(xfer_delay);
> >  		gb_xfer->cs_change = xfer->cs_change;
> >  		gb_xfer->bits_per_word = xfer->bits_per_word;
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>

------
Cheers,
     Rui
Greg Kroah-Hartman March 9, 2021, 1:05 p.m. UTC | #3
On Mon, Mar 08, 2021 at 04:54:58PM +0200, Alexandru Ardelean wrote:
> The intent is the removal of the 'delay_usecs' field from the
> spi_transfer struct, as there is a 'delay' field that does the same
> thing.
> 
> The spi_delay_to_ns() can be used to get the transfer delay. It works by
> using the 'delay_usecs' field first (if it is non-zero), and finally
> uses the 'delay' field.
> 
> Since the 'delay_usecs' field is going away, this change makes use of the
> spi_delay_to_ns() function. This also means dividing the return value of
> the function by 1000, to convert it to microseconds.
> To prevent any potential faults when converting to microseconds and since
> the result of spi_delay_to_ns() is int, the delay is being computed in 32
> bits and then clamped between 0 & U16_MAX.
> 
> Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
> ---
>  drivers/staging/greybus/spilib.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c
> index 672d540d3365..30655153df6a 100644
> --- a/drivers/staging/greybus/spilib.c
> +++ b/drivers/staging/greybus/spilib.c
> @@ -245,6 +245,7 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
>  	/* Fill in the transfers array */
>  	xfer = spi->first_xfer;
>  	while (msg->state != GB_SPI_STATE_OP_DONE) {
> +		int xfer_delay;
>  		if (xfer == spi->last_xfer)
>  			xfer_len = spi->last_xfer_size;
>  		else
> @@ -259,7 +260,9 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
>  
>  		gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
>  		gb_xfer->len = cpu_to_le32(xfer_len);
> -		gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
> +		xfer_delay = spi_delay_to_ns(&xfer->delay, xfer) / 1000;
> +		xfer_delay = clamp_t(u16, xfer_delay, 0, U16_MAX);
> +		gb_xfer->delay_usecs = cpu_to_le16(xfer_delay);
>  		gb_xfer->cs_change = xfer->cs_change;
>  		gb_xfer->bits_per_word = xfer->bits_per_word;
>  

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff mbox series

Patch

diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c
index 672d540d3365..30655153df6a 100644
--- a/drivers/staging/greybus/spilib.c
+++ b/drivers/staging/greybus/spilib.c
@@ -245,6 +245,7 @@  static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
 	/* Fill in the transfers array */
 	xfer = spi->first_xfer;
 	while (msg->state != GB_SPI_STATE_OP_DONE) {
+		int xfer_delay;
 		if (xfer == spi->last_xfer)
 			xfer_len = spi->last_xfer_size;
 		else
@@ -259,7 +260,9 @@  static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
 
 		gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
 		gb_xfer->len = cpu_to_le32(xfer_len);
-		gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
+		xfer_delay = spi_delay_to_ns(&xfer->delay, xfer) / 1000;
+		xfer_delay = clamp_t(u16, xfer_delay, 0, U16_MAX);
+		gb_xfer->delay_usecs = cpu_to_le16(xfer_delay);
 		gb_xfer->cs_change = xfer->cs_change;
 		gb_xfer->bits_per_word = xfer->bits_per_word;