On 05/26/2016 06:44 PM, Simon Glass wrote: > Hi Marek, > > On 26 May 2016 at 10:34, Marek Vasut <ma...@denx.de> wrote: >> On 05/26/2016 03:29 PM, Simon Glass wrote: >>> Hi Marek, >>> >>> On 25 May 2016 at 16:35, Marek Vasut <ma...@denx.de> wrote: >>>> On 05/26/2016 12:31 AM, Daniel Schwierzeck wrote: >>>>> >>>>> >>>>> Am 26.05.2016 um 00:21 schrieb Marek Vasut: >>>>>> On 05/26/2016 12:17 AM, Daniel Schwierzeck wrote: >>>>>>> >>>>>>> >>>>>>> Am 25.05.2016 um 02:19 schrieb Marek Vasut: >>>>>>>> The Ingenic JZ47xx requires special bit (UART_EN) set in FCR register >>>>>>>> in order to work at all. Add this special case handling into the >>>>>>>> driver. >>>>>>>> >>>>>>>> Signed-off-by: Marek Vasut <ma...@denx.de> >>>>>>>> Cc: Tom Rini <tr...@konsulko.com> >>>>>>>> Cc: Simon Glass <s...@chromium.org> >>>>>>>> Cc: Daniel Schwierzeck <daniel.schwierz...@gmail.com> >>>>>>>> Cc: Paul Burton <paul.bur...@imgtec.com> >>>>>>>> --- >>>>>>>> drivers/serial/ns16550.c | 8 ++++++++ >>>>>>>> 1 file changed, 8 insertions(+) >>>>>>>> >>>>>>>> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c >>>>>>>> index 30ba0aa..1323881 100644 >>>>>>>> --- a/drivers/serial/ns16550.c >>>>>>>> +++ b/drivers/serial/ns16550.c >>>>>>>> @@ -50,6 +50,14 @@ DECLARE_GLOBAL_DATA_PTR; >>>>>>>> #endif >>>>>>>> #endif >>>>>>>> >>>>>>>> +#ifdef CONFIG_ARCH_JZ47XX >>>>>>>> +#undef UART_FCRVAL >>>>>>>> +/* Ingenic JZ47xx SoCs require that a 'UART Module Enable' bit be set >>>>>>>> */ >>>>>>>> +#define UART_FCR_UME 0x10 >>>>>>>> +#define UART_FCRVAL (UART_FCR_FIFO_EN | UART_FCR_RXSR | \ >>>>>>>> + UART_FCR_TXSR | UART_FCR_UME) >>>>>>>> +#endif >>>>>>> >>>>>>> I think this could be added as DT property >>>>>> >>>>>> Not for SPL, which has 14 kiB size limit and it is itching to overflow. >>>>>> I am literally counting bytes in the SPL and removing slop from >>>>>> structures to make it fit, just barely. With the USB loader, I can >>>>>> brutalize the SPL into having extremely rudimentary UART support now >>>>>> (like printch() being the most advanced output mechanism, but you can >>>>>> only use it three times, otherwise the code won't fit and the board is >>>>>> eaten by demons) and this is where this patch comes into play. >>>>>> >>>>>> So yes, for full u-boot, this _should_ be part of DT. For SPL, please >>>>>> apply. >>>>>> >>>>> >>>>> ok, but wouldn't it be better to introduce an option like >>>>> CONFIG_SYS_NS16550_UME instead of using the SoC-specific >>>>> CONFIG_ARCH_JZ47XX. This driver is messed up enough ;) >>>> >>>> I was undecided between this (like the IER) and adding new ifdef (like >>>> SOC_KEYSTONE). Whichever way is fine with me. Yeah, the driver is >>>> repugnant for sure. >>>> >>>>>>>> + >>>>>>>> #ifndef CONFIG_SYS_NS16550_IER >>>>>>>> #define CONFIG_SYS_NS16550_IER 0x00 >>>>>>>> #endif /* CONFIG_SYS_NS16550_IER */ >>>>>>>> >>> >>> That way seems better to me. You should be able to add your UME flag >>> as a Kconfig for this driver, in drivers/serial/Kconfig, which >>> defaults to 0. It would be good to keep out board-specific stuff from >>> this file, as you did with OMAP1510. >> >> I'm not really sure I want to expose the CONFIG_SYS_NS16550_FCR override >> via Kconfig. The extra bits should be set via DT props >> unless there is some really good reason why that cannot be done >> (like size limitation in SPL or DT not available). >> >> I tried these approaches: >> 1) Add Kconfig option for CONFIG_SYS_NS16550_FCR , where you >> set specific byte value. This makes it hard to figure out >> which bits are set in the FCR just by looking at the value. >> 2) Add Kconfig option selected if ARCH_JZ47XX is selected and >> use that in the driver to add the extra UME bit. >> 3) Define CONFIG_SYS_NS16550_FCR in include/configs/board.h >> using the macros from ns16550.h . This makes it obvious >> which bits are set. >> >> I am undecided between 2 and 3, but inclined to go with 3. >> What do you think ? > > How about making your feature an option, like CONFIG_SYS_NS16550_UEN, > which defaults to 0, but in your case is 0x10. You can OR it into the > value.
That's quite close to 1) , but then what if someone comes and wants to remove some bits from the FCR instead of adding some? -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
