2018-08-08 07:15:50

by Simon Goldschmidt

[permalink] [raw]
Subject: [PATCH] spi: dw: support 4-16 bits per word

The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.

Signed-off-by: Simon Goldschmidt <[email protected]>
---
drivers/spi/spi-dw.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index f693bfe95ab9..2ecbb6b19cea 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -307,14 +307,14 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
+ if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
+ return -EINVAL;
+ if (transfer->bits_per_word <= 8) {
dws->n_bytes = 1;
dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
+ } else {
dws->n_bytes = 2;
dws->dma_width = 2;
- } else {
- return -EINVAL;
}
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
@@ -493,7 +493,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}

master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
--
2.17.1



2018-08-08 09:46:39

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH] spi: dw: support 4-16 bits per word

On Wed, Aug 8, 2018 at 10:14 AM, Simon Goldschmidt
<[email protected]> wrote:
> The spi-dw driver currently only supports 8 or 16 bits per word.
>
> Since the hardware supports 4-16 bits per word, adapt the driver
> to also support this.
>
> Tested on socfpga cyclone5 with a 9-bit SPI display.

> + if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
> + return -EINVAL;

> + if (transfer->bits_per_word <= 8) {
> dws->n_bytes = 1;
> dws->dma_width = 1;
> - } else if (transfer->bits_per_word == 16) {
> + } else {
> dws->n_bytes = 2;
> dws->dma_width = 2;
> }

Now these can be just

n_bytes = round_up(8);
dma_width = round_up(8);

--
With Best Regards,
Andy Shevchenko

2018-08-08 12:00:18

by Simon Goldschmidt

[permalink] [raw]
Subject: Re: [PATCH] spi: dw: support 4-16 bits per word

On Wed, Aug 8, 2018 at 11:45 AM Andy Shevchenko
<[email protected]> wrote:
>
> On Wed, Aug 8, 2018 at 10:14 AM, Simon Goldschmidt
> <[email protected]> wrote:
> > The spi-dw driver currently only supports 8 or 16 bits per word.
> >
> > Since the hardware supports 4-16 bits per word, adapt the driver
> > to also support this.
> >
> > Tested on socfpga cyclone5 with a 9-bit SPI display.
>
> > + if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
> > + return -EINVAL;
>
> > + if (transfer->bits_per_word <= 8) {
> > dws->n_bytes = 1;
> > dws->dma_width = 1;
> > - } else if (transfer->bits_per_word == 16) {
> > + } else {
> > dws->n_bytes = 2;
> > dws->dma_width = 2;
> > }
>
> Now these can be just
>
> n_bytes = round_up(8);
> dma_width = round_up(8);

I guess you mean:

n_bytes = round_up(transfer->bits_per_word, 8);

But that would yield 8 or 16 where we need 1 or 2.

Reading spi-imx.c, this might work:

n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);


Simon

2018-08-08 12:27:09

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH] spi: dw: support 4-16 bits per word

On Wed, Aug 8, 2018 at 2:58 PM, Simon Goldschmidt
<[email protected]> wrote:
> On Wed, Aug 8, 2018 at 11:45 AM Andy Shevchenko
> <[email protected]> wrote:
>> On Wed, Aug 8, 2018 at 10:14 AM, Simon Goldschmidt
>> <[email protected]> wrote:

>> n_bytes = round_up(8);
>> dma_width = round_up(8);
>
> I guess you mean:
>
> n_bytes = round_up(transfer->bits_per_word, 8);
>
> But that would yield 8 or 16 where we need 1 or 2.

Indeed.

> Reading spi-imx.c, this might work:
>
> n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);

Yes.

--
With Best Regards,
Andy Shevchenko

2018-08-17 07:03:59

by Simon Goldschmidt

[permalink] [raw]
Subject: [PATCH v2] spi: dw: support 4-16 bits per word

The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.

Signed-off-by: Simon Goldschmidt <[email protected]>
---

Changes in v2:
- use DIV_ROUND_UP to calculate number of bytes per word instead of
if/else range checks

drivers/spi/spi-dw.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index f693bfe95ab9..58a7caf31d59 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -307,15 +307,13 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
- dws->n_bytes = 1;
- dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
- dws->n_bytes = 2;
- dws->dma_width = 2;
- } else {
+
+ if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
return -EINVAL;
- }
+
+ dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+ dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
@@ -493,7 +491,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}

master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
--
2.17.1


2018-08-17 11:18:49

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2] spi: dw: support 4-16 bits per word

On Fri, Aug 17, 2018 at 10:01 AM, Simon Goldschmidt
<[email protected]> wrote:
> The spi-dw driver currently only supports 8 or 16 bits per word.
>
> Since the hardware supports 4-16 bits per word, adapt the driver
> to also support this.
>
> Tested on socfpga cyclone5 with a 9-bit SPI display.
>

LGTM,
Reviewed-by: Andy Shevchenko <[email protected]>

> Signed-off-by: Simon Goldschmidt <[email protected]>
> ---
>
> Changes in v2:
> - use DIV_ROUND_UP to calculate number of bytes per word instead of
> if/else range checks
>
> drivers/spi/spi-dw.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
> index f693bfe95ab9..58a7caf31d59 100644
> --- a/drivers/spi/spi-dw.c
> +++ b/drivers/spi/spi-dw.c
> @@ -307,15 +307,13 @@ static int dw_spi_transfer_one(struct spi_controller *master,
> dws->current_freq = transfer->speed_hz;
> spi_set_clk(dws, chip->clk_div);
> }
> - if (transfer->bits_per_word == 8) {
> - dws->n_bytes = 1;
> - dws->dma_width = 1;
> - } else if (transfer->bits_per_word == 16) {
> - dws->n_bytes = 2;
> - dws->dma_width = 2;
> - } else {
> +
> + if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
> return -EINVAL;
> - }
> +
> + dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
> + dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
> +
> /* Default SPI mode is SCPOL = 0, SCPH = 0 */
> cr0 = (transfer->bits_per_word - 1)
> | (chip->type << SPI_FRF_OFFSET)
> @@ -493,7 +491,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
> }
>
> master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
> - master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
> + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
> master->bus_num = dws->bus_num;
> master->num_chipselect = dws->num_cs;
> master->setup = dw_spi_setup;
> --
> 2.17.1
>



--
With Best Regards,
Andy Shevchenko

2018-08-17 16:34:51

by Trent Piepho

[permalink] [raw]
Subject: Re: [PATCH v2] spi: dw: support 4-16 bits per word

On Fri, 2018-08-17 at 09:01 +0200, Simon Goldschmidt wrote:
> The spi-dw driver currently only supports 8 or 16 bits per word.
>
> Since the hardware supports 4-16 bits per word, adapt the driver
> to also support this.
>
>

> @@ -307,15 +307,13 @@ static int dw_spi_transfer_one(struct spi_controller *master,
> +
> + if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
> return -EINVAL;
> - }

You don't need this check as the spi core validates the transfer
against master->bits_per_word_mask.

> master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
> - master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
> + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
> master->bus_num = dws->bus_num;
>

2018-08-18 08:40:45

by Simon Goldschmidt

[permalink] [raw]
Subject: Re: [PATCH v2] spi: dw: support 4-16 bits per word

On Fri, Aug 17, 2018 at 6:32 PM Trent Piepho <[email protected]> wrote:
>
> On Fri, 2018-08-17 at 09:01 +0200, Simon Goldschmidt wrote:
> > The spi-dw driver currently only supports 8 or 16 bits per word.
> >
> > Since the hardware supports 4-16 bits per word, adapt the driver
> > to also support this.
> >
> >
>
> > @@ -307,15 +307,13 @@ static int dw_spi_transfer_one(struct spi_controller *master,
> > +
> > + if ((transfer->bits_per_word < 4) || (transfer->bits_per_word > 16))
> > return -EINVAL;
> > - }
>
> You don't need this check as the spi core validates the transfer
> against master->bits_per_word_mask.

Ok.

>
> > master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
> > - master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
> > + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
> > master->bus_num = dws->bus_num;
> >

2018-09-04 19:51:49

by Simon Goldschmidt

[permalink] [raw]
Subject: [PATCH v3] spi: dw: support 4-16 bits per word

The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.

Signed-off-by: Simon Goldschmidt <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
Changes in v3
- remove the check for valid 'bits_per_word' from dw_spi_transfer_one()
- add reviewed-by tag

Changes in v2:
- use DIV_ROUND_UP to calculate number of bytes per word instead of
if/else range checks

drivers/spi/spi-dw.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index f693bfe95ab9..58a7caf31d59 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -307,15 +307,10 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
- dws->n_bytes = 1;
- dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
- dws->n_bytes = 2;
- dws->dma_width = 2;
- } else {
- return -EINVAL;
- }
+
+ dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+ dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
@@ -493,7 +491,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}

master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
--
2.17.1


2018-09-06 11:26:34

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH v3] spi: dw: support 4-16 bits per word

On Tue, Sep 04, 2018 at 09:49:44PM +0200, Simon Goldschmidt wrote:
> The spi-dw driver currently only supports 8 or 16 bits per word.
>
> Since the hardware supports 4-16 bits per word, adapt the driver
> to also support this.

Please don't send new patches in reply to old patch serieses, it makes
it harder to follow what the current version of things is and makes it
much easier for the patches to get lost in the old threads.


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2018-09-06 11:27:04

by Mark Brown

[permalink] [raw]
Subject: Applied "spi: dw: support 4-16 bits per word" to the spi tree

The patch

spi: dw: support 4-16 bits per word

has been applied to the spi tree at

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From af060b3f72b801962033f75a2fda25fff992796d Mon Sep 17 00:00:00 2001
From: Simon Goldschmidt <[email protected]>
Date: Tue, 4 Sep 2018 21:49:44 +0200
Subject: [PATCH] spi: dw: support 4-16 bits per word

The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.

Signed-off-by: Simon Goldschmidt <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
---
drivers/spi/spi-dw.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 1736612ee86b..3e205ab60cd4 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -308,15 +308,10 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->current_freq = transfer->speed_hz;
spi_set_clk(dws, chip->clk_div);
}
- if (transfer->bits_per_word == 8) {
- dws->n_bytes = 1;
- dws->dma_width = 1;
- } else if (transfer->bits_per_word == 16) {
- dws->n_bytes = 2;
- dws->dma_width = 2;
- } else {
- return -EINVAL;
- }
+
+ dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+ dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE);
+
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
@@ -496,7 +491,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}

master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
- master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
--
2.19.0.rc1


2018-09-06 11:32:23

by Simon Goldschmidt

[permalink] [raw]
Subject: Re: [PATCH v3] spi: dw: support 4-16 bits per word

On Thu, Sep 6, 2018 at 1:09 PM Mark Brown <[email protected]> wrote:
>
> On Tue, Sep 04, 2018 at 09:49:44PM +0200, Simon Goldschmidt wrote:
> > The spi-dw driver currently only supports 8 or 16 bits per word.
> >
> > Since the hardware supports 4-16 bits per word, adapt the driver
> > to also support this.
>
> Please don't send new patches in reply to old patch serieses, it makes
> it harder to follow what the current version of things is and makes it
> much easier for the patches to get lost in the old threads.

Ok, no problem and thanks for the hint! Where does this requirement
come from? Patchwork or mail sorting habits?

Anyway, how does this continue, will you pick the patch or do I need
to somehow collect yet more reviews?

Regards,
Simon

2018-09-06 13:40:09

by Simon Goldschmidt

[permalink] [raw]
Subject: Re: [PATCH v3] spi: dw: support 4-16 bits per word

On Thu, Sep 6, 2018 at 3:23 PM Mark Brown <[email protected]> wrote:
>
> On Thu, Sep 06, 2018 at 01:23:34PM +0200, Simon Goldschmidt wrote:
> > On Thu, Sep 6, 2018 at 1:09 PM Mark Brown <[email protected]> wrote:
>
> > > Please don't send new patches in reply to old patch serieses, it makes
> > > it harder to follow what the current version of things is and makes it
> > > much easier for the patches to get lost in the old threads.
>
> > Ok, no problem and thanks for the hint! Where does this requirement
> > come from? Patchwork or mail sorting habits?
>
> Mail sorting. It can mean that you get things like someone deleting a
> thread and the new patch getting caught up in a thread delete command
> and hence missed.
>
> > Anyway, how does this continue, will you pick the patch or do I need
> > to somehow collect yet more reviews?
>
> You should've got a mail at about the same time saying it's been
> applied.

Right, got it. Thanks again.

2018-09-06 19:58:02

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH v3] spi: dw: support 4-16 bits per word

On Thu, Sep 06, 2018 at 01:23:34PM +0200, Simon Goldschmidt wrote:
> On Thu, Sep 6, 2018 at 1:09 PM Mark Brown <[email protected]> wrote:

> > Please don't send new patches in reply to old patch serieses, it makes
> > it harder to follow what the current version of things is and makes it
> > much easier for the patches to get lost in the old threads.

> Ok, no problem and thanks for the hint! Where does this requirement
> come from? Patchwork or mail sorting habits?

Mail sorting. It can mean that you get things like someone deleting a
thread and the new patch getting caught up in a thread delete command
and hence missed.

> Anyway, how does this continue, will you pick the patch or do I need
> to somehow collect yet more reviews?

You should've got a mail at about the same time saying it's been
applied.


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