Messages in this thread | | | Date | Thu, 16 Apr 2020 11:34:26 +0200 | From | Michael Walle <> | Subject | Re: [PATCH v2 10/16] gpio: add a reusable generic gpio_chip using regmap |
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Am 2020-04-16 11:20, schrieb Linus Walleij: > On Tue, Apr 14, 2020 at 9:57 PM Michael Walle <michael@walle.cc> wrote: > >> So what about the following: >> >> #define GPIO_REGMAP_ADDR_ZERO (unsigned int)(-1) > > Yeah with regmap explicitly using int I guess we can't use > S32_MAX, so that is fair. > >> So this way the user might assign the base addresses the normal way >> except when he wants to use zero, in that case he has to use >> >> ->base_adr = GPIO_REGMAP_ADDR_ZERO; >> >> gpio-regmap.c could use then: >> >> if (base_addr) >> something_useful(gpio_regmap_addr(base_addr)); >> >> unsigned int gpio_regmap_addr(unsigned int addr) >> { >> return (addr == GPIO_REGMAP_ADDR_ZERO) ? 0 : addr; >> } > > That's reasonably clean.
Ok, at least on that side. For my sl28 gpio driver I then have the problem that depending on 'base' I might have to use GPIO_REGMAP_ADDR_ZERO:
#define GPIO_REG_DIR 0 config.reg_dir_out_base = base + GPIO_REG_DIR;
So there is still a convenience macro: #define GPIO_REGMAP_ADDR(addr) ((addr) ? addr : GPIO_REGMAP_ADDR_ZERO)
which you can use if you can't be sure that the address is not non-zero. So the code in my sl28 gpio driver looks like:
config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
I'll respin the patch with the current remarks.
-michael
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