Am 2020-04-16 11:20, schrieb Linus Walleij:
On Tue, Apr 14, 2020 at 9:57 PM Michael Walle <michael@xxxxxxxx> 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
