Use software emulated RS485 direction control to provide RS485 API
Currently it is not possible to use rs485 as pointer to
rs485_config struct in struct uart_port is NULL in case we
configure the port through device tree.
Signed-off-by: Heiko Schocher <[email protected]>
---
Patch is based on:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
commit:
505a8ec7e11a - Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()"
checkpatch output:
$ ./scripts/checkpatch.pl 0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch
total: 0 errors, 0 warnings, 43 lines checked
0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch has no obvious style problems and is ready for submission.
drivers/tty/serial/8250/8250_of.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 0826cfdbd4063..92fbf46ce3bd9 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -48,6 +48,36 @@ static inline void tegra_serial_handle_break(struct uart_port *port)
}
#endif
+static int of_8250_rs485_config(struct uart_port *port,
+ struct serial_rs485 *rs485)
+{
+ struct uart_8250_port *up = up_to_u8250p(port);
+
+ /* Clamp the delays to [0, 100ms] */
+ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
+ rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
+
+ port->rs485 = *rs485;
+
+ /*
+ * Both serial8250_em485_init and serial8250_em485_destroy
+ * are idempotent
+ */
+ if (rs485->flags & SER_RS485_ENABLED) {
+ int ret = serial8250_em485_init(up);
+
+ if (ret) {
+ rs485->flags &= ~SER_RS485_ENABLED;
+ port->rs485.flags &= ~SER_RS485_ENABLED;
+ }
+ return ret;
+ }
+
+ serial8250_em485_destroy(up);
+
+ return 0;
+}
+
/*
* Fill a struct uart_port for a given device node
*/
@@ -178,6 +208,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
port->flags |= UPF_SKIP_TEST;
port->dev = &ofdev->dev;
+ port->rs485_config = of_8250_rs485_config;
switch (type) {
case PORT_TEGRA:
--
2.21.0
On Fri, Sep 13, 2019 at 07:01:05AM +0200, Heiko Schocher wrote:
> Use software emulated RS485 direction control to provide RS485 API
>
> Currently it is not possible to use rs485 as pointer to
> rs485_config struct in struct uart_port is NULL in case we
> configure the port through device tree.
Thank you for the patch, few recommendations for the future submissions.
> Patch is based on:
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> commit:
> 505a8ec7e11a - Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()"
More reliably is to base on corresponding subsystem tree, i.e. tty-next for
this case.
> checkpatch output:
> $ ./scripts/checkpatch.pl 0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch
> total: 0 errors, 0 warnings, 43 lines checked
>
> 0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch has no obvious style problems and is ready for submission.
There is no need to mention this. It's supposed that submitter did that
themselves.
When you gather people to send the patch to, I recommend to use some threshold,
e.g. `scripts/get_maintainer.pl --git --git-min-percent=67 ...`
--
With Best Regards,
Andy Shevchenko
On Fri, Sep 13, 2019 at 04:51:30PM +0200, Heiko Schocher wrote:
> Am 13.09.2019 um 12:24 schrieb Andy Shevchenko:
> > On Fri, Sep 13, 2019 at 07:01:05AM +0200, Heiko Schocher wrote:
> > > Patch is based on:
> > > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > commit:
> > > 505a8ec7e11a - Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()"
> >
> > More reliably is to base on corresponding subsystem tree, i.e. tty-next for
> > this case.
>
> Ok, should I send a rebased v2 (I tend to wait for other comments)?
I didn't give any comments WRT patch itself, so, I don't see any needs to send
v2 right now.
--
With Best Regards,
Andy Shevchenko
Hello Andy,
Am 13.09.2019 um 12:24 schrieb Andy Shevchenko:
> On Fri, Sep 13, 2019 at 07:01:05AM +0200, Heiko Schocher wrote:
>> Use software emulated RS485 direction control to provide RS485 API
>>
>> Currently it is not possible to use rs485 as pointer to
>> rs485_config struct in struct uart_port is NULL in case we
>> configure the port through device tree.
>
> Thank you for the patch, few recommendations for the future submissions.
>
>> Patch is based on:
>> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>> commit:
>> 505a8ec7e11a - Revert "drm/i915/userptr: Acquire the page lock around set_page_dirty()"
>
> More reliably is to base on corresponding subsystem tree, i.e. tty-next for
> this case.
Ok, should I send a rebased v2 (I tend to wait for other comments)?
>> checkpatch output:
>> $ ./scripts/checkpatch.pl 0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch
>> total: 0 errors, 0 warnings, 43 lines checked
>>
>> 0001-tty-8250_of-Use-software-emulated-RS485-direction-co.patch has no obvious style problems and is ready for submission.
>
> There is no need to mention this. It's supposed that submitter did that
> themselves.
Hmm... ok.
> When you gather people to send the patch to, I recommend to use some threshold,
> e.g. `scripts/get_maintainer.pl --git --git-min-percent=67 ...`
Ah, good tip, thanks!
bye,
Heiko
--
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