Hi Marek, On 26 May 2016 at 10:53, Marek Vasut <ma...@denx.de> wrote: > On 05/26/2016 06:48 PM, Simon Glass wrote: >> Hi Marek, >> >> On 26 May 2016 at 10:47, Marek Vasut <ma...@denx.de> wrote: >>> 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? >> >> Seems like speculative complexity to me - let's worry about it when it >> happens! > > Heh, ok. But if we add Kconfig stuff, we can as well go with option 2) , > which would only show up if JZ47XX is selected. Since this bits is > specific to this lineup of SoCs , that makes sense in my head. What do > you think ?
SGTM. - Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
