Hi Geert,
Just in case you were wondering...
On Monday, November 12, 2018, Geert Uytterhoeven wrote:
> > + "PJ_0", "PJ_1", "PJ_2", "PJ_3", "PJ_4", "PJ_5", "PJ_6", "PJ_7",
> > + "PK_0", "PK_1", "PK_2", "PK_3", "PK_4", "PK_5", "PK_6", "PK_7",
> > + "PL_0", "PL_1", "PL_2", "PL_3", "PL_4", "PL_5", "PL_6", "PL_7",
> > + "PM_0", "PM_1", "PM_2", "PM_3", "PM_4", "PM_5", "PM_6", "PM_7",
> > +};
> > +
> > +static struct gpio_chip chip = {
> > + .names = rza2_gpio_names,
>
> BTW, is their much value in filling gpio_chip.names[]?
> I had never seen that before.
On Tuesday, November 13, 2018, Geert Uytterhoeven wrote:
> 2. Userspace library libgpiod, incl. a few tools like
> gpioinfo/gpioset/gpioget.
> These accept whatever reference to identify a GPIO.
> As your driver fills in pins[i].name, I expect you can pass names
> like P5_6.
Actually, just filling in pins[i].name is not enough. You really need to
pass an array of strings to gpio_chip.name.
When struct gpio_chip.names = NULL, you get this:
$ gpioinfo
gpiochip0 - 176 lines:
line 0: unnamed unused input active-high
line 1: unnamed unused input active-high
line 2: unnamed unused input active-high
line 3: unnamed unused input active-high
line 4: unnamed unused input active-high
line 5: unnamed unused input active-high
line 6: unnamed unused input active-high
line 7: unnamed unused input active-high
line 8: unnamed unused input active-high
line 9: unnamed unused input active-high
line 10: unnamed unused input active-high
line 11: unnamed unused input active-high
line 12: unnamed unused input active-high
When struct gpio_chip.names = rza2_gpio_names, you get this:
$ gpioinfo
gpiochip0 - 176 lines:
line 0: "P0_0" unused input active-high
line 1: "P0_1" unused input active-high
line 2: "P0_2" unused input active-high
line 3: "P0_3" unused input active-high
line 4: "P0_4" unused input active-high
line 5: "P0_5" unused input active-high
line 6: "P0_6" unused input active-high
line 7: "P0_7" unused input active-high
line 8: "P1_0" unused input active-high
line 9: "P1_1" unused input active-high
line 10: "P1_2" unused input active-high
line 11: "P1_3" unused input active-high
line 12: "P1_4" unused input active-high
Then you can use gpiofind to convert a name into an ID.
$ gpiofind P6_0
gpiochip0 48
But to your point, libgpiod is way better than using /sys directly.
Chris
