On Mon, 15 May 2023 20:52:23 -0600 Sam Edwards cfsworks@gmail.com wrote:
Hi Sam,
On 12/5/22 17:45, Andre Przywara wrote:
diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c index 3763ec3d2e4..33331cda5e2 100644 --- a/arch/arm/mach-sunxi/board.c +++ b/arch/arm/mach-sunxi/board.c @@ -148,6 +148,10 @@ static int gpio_init(void) sunxi_gpio_set_cfgpin(SUNXI_GPH(12), SUN9I_GPH_UART0); sunxi_gpio_set_cfgpin(SUNXI_GPH(13), SUN9I_GPH_UART0); sunxi_gpio_set_pull(SUNXI_GPH(13), SUNXI_GPIO_PULL_UP); +#elif CONFIG_CONS_INDEX == 1 && defined(CONFIG_MACH_SUN8I_R528)
- sunxi_gpio_set_cfgpin(SUNXI_GPE(2), 6);
- sunxi_gpio_set_cfgpin(SUNXI_GPE(3), 6);
- sunxi_gpio_set_pull(SUNXI_GPE(3), SUNXI_GPIO_PULL_UP); #elif CONFIG_CONS_INDEX == 2 && defined(CONFIG_MACH_SUNIV) sunxi_gpio_set_cfgpin(SUNXI_GPA(2), SUNIV_GPE_UART0); sunxi_gpio_set_cfgpin(SUNXI_GPA(3), SUNIV_GPE_UART0);
I'm a relative outsider to sunxi, but it does look like the NCAT2 generation's MUX is a lot more flexible in its UART assignments: e.g. while H3's UART1-3 only had one set of pins each UART could use, the T113 (my target) supports anywhere from 2-6 (typically 4) different options for each of its UARTs. It is not as simple as configuring which UART is the serial console anymore, because different boards might wire the console header to different pins. My particular target uses UART3 on pins PB6/PB7, for example.
Well, theoretically there are indeed quite some options, but in reality we find that most boards follow some reference design, and the *debug* UART is only ever using a very few of the possible settings. For the later (ARMv8) SoCs this is mostly UART0, but for the T113 it's apparently indeed UART3. I also changed that in the Github version, to use the very same PB6/7 UART3 mux as you.
Since this patchset is updating the PIO driver anyway, maybe it's worth updating the (preprocessor, not runtime) logic in gpio_init to support getting the UART TX/RX pins from Kconfig, validating that the CONFIG_CONS_INDEX and pin selection are compatible, and setting the correct MUX function for those pins with a value pulled from a table?
Mmmh, that's an idea one could follow, as this function is indeed insane. I actually rewrote gpio_init() already, to replace the hard to read #ifdef's with actual C if statements, though that's still following the same idea as the current code. Let me have a look how this would look like.
Cheers, Andre