From: Magnus Damm <[email protected]>
This patch modifies the shared spi bitbanging code
to allow using spi_bitbang_setup() even though the
txrx_word[] callbacks are unset. Useful for drivers
that want to make use of spi_bitbang_setup() but
have their own txrx_bufs() callback.
While at it, drop the MSIOF driver workaround.
Signed-off-by: Magnus Damm <[email protected]>
---
Depends on the MSIOF driver.
drivers/spi/spi_bitbang.c | 25 ++++++++++++++-----------
drivers/spi/spi_sh_msiof.c | 11 -----------
2 files changed, 14 insertions(+), 22 deletions(-)
--- 0001/drivers/spi/spi_bitbang.c
+++ work/drivers/spi/spi_bitbang.c 2009-11-25 15:30:45.000000000 +0900
@@ -176,6 +176,14 @@ int spi_bitbang_setup_transfer(struct sp
}
EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
+static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct spi_bitbang_cs *cs = spi->controller_state;
+ unsigned nsecs = cs->nsecs;
+
+ return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
+}
+
/**
* spi_bitbang_setup - default setup for per-word I/O loops
*/
@@ -183,6 +191,7 @@ int spi_bitbang_setup(struct spi_device
{
struct spi_bitbang_cs *cs = spi->controller_state;
struct spi_bitbang *bitbang;
+ int mode_mask = SPI_CPOL | SPI_CPHA;
int retval;
unsigned long flags;
@@ -196,9 +205,11 @@ int spi_bitbang_setup(struct spi_device
}
/* per-word shift register access, in hardware or bitbanging */
- cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
- if (!cs->txrx_word)
- return -EINVAL;
+ if (bitbang->txrx_bufs == spi_bitbang_bufs) {
+ cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
+ if (!cs->txrx_word)
+ return -EINVAL;
+ }
retval = bitbang->setup_transfer(spi, NULL);
if (retval < 0)
@@ -232,14 +243,6 @@ void spi_bitbang_cleanup(struct spi_devi
}
EXPORT_SYMBOL_GPL(spi_bitbang_cleanup);
-static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
-{
- struct spi_bitbang_cs *cs = spi->controller_state;
- unsigned nsecs = cs->nsecs;
-
- return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
-}
-
/*----------------------------------------------------------------------*/
/*
--- 0002/drivers/spi/spi_sh_msiof.c
+++ work/drivers/spi/spi_sh_msiof.c 2009-11-25 15:25:32.000000000 +0900
@@ -510,13 +510,6 @@ static int sh_msiof_spi_txrx(struct spi_
return bytes_done;
}
-static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
- u32 word, u8 bits)
-{
- BUG_ON(1); /* unused but needed by bitbang code */
- return 0;
-}
-
static int sh_msiof_spi_probe(struct platform_device *pdev)
{
struct resource *r;
@@ -594,10 +587,6 @@ static int sh_msiof_spi_probe(struct pla
p->bitbang.chipselect = sh_msiof_spi_chipselect;
p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
- p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
- p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
- p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
- p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
ret = spi_bitbang_start(&p->bitbang);
if (ret == 0)
On Wed, Nov 25, 2009 at 1:26 AM, Magnus Damm <[email protected]> wrote:
> From: Magnus Damm <[email protected]>
>
> This patch modifies the shared spi bitbanging code
> to allow using spi_bitbang_setup() even though the
> txrx_word[] callbacks are unset. Useful for drivers
> that want to make use of spi_bitbang_setup() but
> have their own txrx_bufs() callback.
>
> While at it, drop the MSIOF driver workaround.
>
> Signed-off-by: Magnus Damm <[email protected]>
> ---
>
> ?Depends on the MSIOF driver.
>
> ?drivers/spi/spi_bitbang.c ?| ? 25 ++++++++++++++-----------
> ?drivers/spi/spi_sh_msiof.c | ? 11 -----------
> ?2 files changed, 14 insertions(+), 22 deletions(-)
>
> --- 0001/drivers/spi/spi_bitbang.c
> +++ work/drivers/spi/spi_bitbang.c ? ? ?2009-11-25 15:30:45.000000000 +0900
> @@ -176,6 +176,14 @@ int spi_bitbang_setup_transfer(struct sp
> ?}
> ?EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
>
> +static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
> +{
> + ? ? ? struct spi_bitbang_cs ? *cs = spi->controller_state;
> + ? ? ? unsigned ? ? ? ? ? ? ? ?nsecs = cs->nsecs;
> +
> + ? ? ? return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
> +}
> +
> ?/**
> ?* spi_bitbang_setup - default setup for per-word I/O loops
> ?*/
> @@ -183,6 +191,7 @@ int spi_bitbang_setup(struct spi_device
> ?{
> ? ? ? ?struct spi_bitbang_cs ? *cs = spi->controller_state;
> ? ? ? ?struct spi_bitbang ? ? ?*bitbang;
> + ? ? ? int ? ? ? ? ? ? ? ? ? ? mode_mask = SPI_CPOL | SPI_CPHA;
> ? ? ? ?int ? ? ? ? ? ? ? ? ? ? retval;
> ? ? ? ?unsigned long ? ? ? ? ? flags;
>
> @@ -196,9 +205,11 @@ int spi_bitbang_setup(struct spi_device
> ? ? ? ?}
>
> ? ? ? ?/* per-word shift register access, in hardware or bitbanging */
> - ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
> - ? ? ? if (!cs->txrx_word)
> - ? ? ? ? ? ? ? return -EINVAL;
> + ? ? ? if (bitbang->txrx_bufs == spi_bitbang_bufs) {
> + ? ? ? ? ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
> + ? ? ? ? ? ? ? if (!cs->txrx_word)
> + ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;
> + ? ? ? }
Hmmm... this smells like an ugly hack to me. It seems to me that if
some bitbang backend drivers don't want this code, then it should be
encoded into a callback so it can be overridden. Thoughts.
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
Hi Grant,
On Thu, Nov 26, 2009 at 7:15 AM, Grant Likely <[email protected]> wrote:
> On Wed, Nov 25, 2009 at 1:26 AM, Magnus Damm <[email protected]> wrote:
>> This patch modifies the shared spi bitbanging code
>> to allow using spi_bitbang_setup() even though the
>> txrx_word[] callbacks are unset. Useful for drivers
>> that want to make use of spi_bitbang_setup() but
>> have their own txrx_bufs() callback.
>> @@ -196,9 +205,11 @@ int spi_bitbang_setup(struct spi_device
>> ? ? ? ?}
>>
>> ? ? ? ?/* per-word shift register access, in hardware or bitbanging */
>> - ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
>> - ? ? ? if (!cs->txrx_word)
>> - ? ? ? ? ? ? ? return -EINVAL;
>> + ? ? ? if (bitbang->txrx_bufs == spi_bitbang_bufs) {
>> + ? ? ? ? ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
>> + ? ? ? ? ? ? ? if (!cs->txrx_word)
>> + ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;
>> + ? ? ? }
>
> Hmmm... this smells like an ugly hack to me. ?It seems to me that if
> some bitbang backend drivers don't want this code, then it should be
> encoded into a callback so it can be overridden. ?Thoughts.
Yeah, it's far from clean. I want to make use of spi_bitbang_setup()
in my MSIOF driver, but I want to avoid dummy txtx_word[] callbacks
that will be unused since i'm using a driver specific
bitbang->txrx_bufs function.
I guess the attached patch is slightly cleaner? I like the idea of
letting bitbang drivers use shared code for
spi_bitbang_setup()/spi_bitbang_cleanup() with their private
setup_transfer() function which in turn calls
spi_bitbang_setup_transfer(). My impression is that there's quite a
bit of duplicated setup()/cleanup() code.
/ magnus
On Wed, Nov 25, 2009 at 11:47 PM, Magnus Damm <[email protected]> wrote:
> Hi Grant,
>
> On Thu, Nov 26, 2009 at 7:15 AM, Grant Likely <[email protected]> wrote:
>> On Wed, Nov 25, 2009 at 1:26 AM, Magnus Damm <[email protected]> wrote:
>>> ? ? ? ?/* per-word shift register access, in hardware or bitbanging */
>>> - ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
>>> - ? ? ? if (!cs->txrx_word)
>>> - ? ? ? ? ? ? ? return -EINVAL;
>>> + ? ? ? if (bitbang->txrx_bufs == spi_bitbang_bufs) {
>>> + ? ? ? ? ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
>>> + ? ? ? ? ? ? ? if (!cs->txrx_word)
>>> + ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;
>>> + ? ? ? }
>>
>> Hmmm... this smells like an ugly hack to me. ?It seems to me that if
>> some bitbang backend drivers don't want this code, then it should be
>> encoded into a callback so it can be overridden. ?Thoughts.
>
> Yeah, it's far from clean. I want to make use of spi_bitbang_setup()
> in my MSIOF driver, but I want to avoid dummy txtx_word[] callbacks
> that will be unused since i'm using a driver specific
> bitbang->txrx_bufs function.
>
> I guess the attached patch is slightly cleaner? I like the idea of
> letting bitbang drivers use shared code for
> spi_bitbang_setup()/spi_bitbang_cleanup() with their private
> setup_transfer() function which in turn calls
> spi_bitbang_setup_transfer(). My impression is that there's quite a
> bit of duplicated setup()/cleanup() code.
This is certainly less ugly. But with the points brought up in the
other thread, I want to have a close look at spi-bitbang before I
start applying stuff. It seems nasty. Give me a few days.
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
On Thu, Nov 26, 2009 at 4:21 PM, Grant Likely <[email protected]> wrote:
> On Wed, Nov 25, 2009 at 11:47 PM, Magnus Damm <[email protected]> wrote:
>> On Thu, Nov 26, 2009 at 7:15 AM, Grant Likely <[email protected]> wrote:
>>> On Wed, Nov 25, 2009 at 1:26 AM, Magnus Damm <[email protected]> wrote:
>>>> ? ? ? ?/* per-word shift register access, in hardware or bitbanging */
>>>> - ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
>>>> - ? ? ? if (!cs->txrx_word)
>>>> - ? ? ? ? ? ? ? return -EINVAL;
>>>> + ? ? ? if (bitbang->txrx_bufs == spi_bitbang_bufs) {
>>>> + ? ? ? ? ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
>>>> + ? ? ? ? ? ? ? if (!cs->txrx_word)
>>>> + ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;
>>>> + ? ? ? }
>>>
>>> Hmmm... this smells like an ugly hack to me. ?It seems to me that if
>>> some bitbang backend drivers don't want this code, then it should be
>>> encoded into a callback so it can be overridden. ?Thoughts.
>>
>> Yeah, it's far from clean. I want to make use of spi_bitbang_setup()
>> in my MSIOF driver, but I want to avoid dummy txtx_word[] callbacks
>> that will be unused since i'm using a driver specific
>> bitbang->txrx_bufs function.
>>
>> I guess the attached patch is slightly cleaner? I like the idea of
>> letting bitbang drivers use shared code for
>> spi_bitbang_setup()/spi_bitbang_cleanup() with their private
>> setup_transfer() function which in turn calls
>> spi_bitbang_setup_transfer(). My impression is that there's quite a
>> bit of duplicated setup()/cleanup() code.
>
> This is certainly less ugly. ?But with the points brought up in the
> other thread, I want to have a close look at spi-bitbang before I
> start applying stuff. ?It seems nasty. ?Give me a few days.
Sure, I plan on posting a V2 of the MSIOF driver. I plan to keep the
dummy txrx_word() function for now - this to disconnect the cleanup
from the driver integration, hope that sounds like a good plan.
Cheers,
/ magnus
On Thu, Nov 26, 2009 at 12:50 AM, Magnus Damm <[email protected]> wrote:
> On Thu, Nov 26, 2009 at 4:21 PM, Grant Likely <[email protected]> wrote:
>> On Wed, Nov 25, 2009 at 11:47 PM, Magnus Damm <[email protected]> wrote:
>>> On Thu, Nov 26, 2009 at 7:15 AM, Grant Likely <[email protected]> wrote:
>>>> On Wed, Nov 25, 2009 at 1:26 AM, Magnus Damm <[email protected]> wrote:
>>>>> ? ? ? ?/* per-word shift register access, in hardware or bitbanging */
>>>>> - ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
>>>>> - ? ? ? if (!cs->txrx_word)
>>>>> - ? ? ? ? ? ? ? return -EINVAL;
>>>>> + ? ? ? if (bitbang->txrx_bufs == spi_bitbang_bufs) {
>>>>> + ? ? ? ? ? ? ? cs->txrx_word = bitbang->txrx_word[spi->mode & mode_mask];
>>>>> + ? ? ? ? ? ? ? if (!cs->txrx_word)
>>>>> + ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;
>>>>> + ? ? ? }
>>>>
>>>> Hmmm... this smells like an ugly hack to me. ?It seems to me that if
>>>> some bitbang backend drivers don't want this code, then it should be
>>>> encoded into a callback so it can be overridden. ?Thoughts.
>>>
>>> Yeah, it's far from clean. I want to make use of spi_bitbang_setup()
>>> in my MSIOF driver, but I want to avoid dummy txtx_word[] callbacks
>>> that will be unused since i'm using a driver specific
>>> bitbang->txrx_bufs function.
>>>
>>> I guess the attached patch is slightly cleaner? I like the idea of
>>> letting bitbang drivers use shared code for
>>> spi_bitbang_setup()/spi_bitbang_cleanup() with their private
>>> setup_transfer() function which in turn calls
>>> spi_bitbang_setup_transfer(). My impression is that there's quite a
>>> bit of duplicated setup()/cleanup() code.
>>
>> This is certainly less ugly. ?But with the points brought up in the
>> other thread, I want to have a close look at spi-bitbang before I
>> start applying stuff. ?It seems nasty. ?Give me a few days.
>
> Sure, I plan on posting a V2 of the MSIOF driver. I plan to keep the
> dummy txrx_word() function for now - this to disconnect the cleanup
> from the driver integration, hope that sounds like a good plan.
Works for me. Now I just need to find someone with the time to
refactor spi-bitbang. :-)
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.