[PATCH 09/24] gpio: Add ZTE ZX279128S GPIO driver

[Stefan Dösinger]

Am Samstag, 10. Oktober 2026, 14:59:47 Mitteleuropäische Sommerzeit schrieben 
Sie:
> +/*
> + * Each bank has 16 lines, one bit per line in each register. The registers
> + * at 0x04-0x10 and 0x28-0x34 control the interrupts, which are not
> supported + * yet.
> + */
> +#define ZX279128S_GPIO_DIR	0x00	/* 1: output */
> +#define ZX279128S_GPIO_DATA	0x14	/* line level */
> +#define ZX279128S_GPIO_SET	0x18	/* write 1: drive high */
> +#define ZX279128S_GPIO_CLEAR	0x1c	/* write 1: drive low */

This looks identical to mine, which itself matches the old zx29 GPIO driver 
with IRQ support etc that was removed in 89d4f98ae90d ("ARM: remove zte  zx 
platform"). This old driver had support for IRQs.

My hardware has the same register layout, but no IRQ support (related 
registers are always 0). So I wasn't planning on reviving the old driver and 
just using regmap-gpio like you do here. If your hardware has indeed working 
GPIO IRQs it would make sense to revive the old driver.

My hardware has one annoyance: There is one GPIO line (not one block of 16, 
just one single line) that has an inverted direction bit - and this line is 
necessary to run the routers on battery. I don't yet know what the nicest way 
to deal with this is. If we have a good reason to have our own zx gpio driver 
then life would be easier :-)
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