On Sun, Jul 23, 2023 at 09:16:40PM +0000, jon@elytron.openbsd.amsterdam wrote:
> If I'm not mistaken, all wskbd_{get,set}_backlight uses are in the
> following drivers: acpicbkbd, acpithinkpad, asmc, pwmleds, and now
> my implementation in adb. It is my impression that they are roughly
> the same code, I have collected them below to ease their inspection.
This doesn't look too bad actually but I am not quite sure about pwm.
A common way to solve this is adding a task to do the heavy lifiting and
then invoking that from interrupt context.
In wskbd.c there is a wskbd_brightness_task() which you could use as a
reference for a new wskbd_kbd_backlight_task().
>
> I would also like to acknowledge the kind help of jcs@, whom I
> approached back when I made my first post on this matter (before
> the key shortcuts, wsconsctl only) upon coming across his acpicbkbd(4).
>
> (installed in dev/acpi/amsc.c:319)
>
> int
> asmc_get_backlight(struct wskbd_backlight *kbl)
> {
> struct asmc_softc *sc = asmc_cd.cd_devs[0];
>
> KASSERT(sc != NULL);
> kbl->min = 0;
> kbl->max = 0xff;
> kbl->curval = sc->sc_backlight;
> return 0;
> }
>
> int
> asmc_set_backlight(struct wskbd_backlight *kbl)
> {
> struct asmc_softc *sc = asmc_cd.cd_devs[0];
>
> KASSERT(sc != NULL);
> if (kbl->curval > 0xff)
> return EINVAL;
> sc->sc_backlight = kbl->curval;
> task_add(systq, &sc->sc_task_backlight);
> return 0;
> }
>
> (installed in dev/acpi/acpicbkbd.c:94)
>
> int
> acpicbkbd_get_backlight(struct wskbd_backlight *kbl)
> {
> struct acpicbkbd_softc *sc = acpicbkbd_cd.cd_devs[0];
>
> KASSERT(sc != NULL);
>
> kbl->min = 0;
> kbl->max = ACPICBKBD_MAX_BACKLIGHT;
> kbl->curval = sc->sc_backlight;
>
> return 0;
> }
>
> int
> acpicbkbd_set_backlight(struct wskbd_backlight *kbl)
> {
> struct acpicbkbd_softc *sc = acpicbkbd_cd.cd_devs[0];
>
> KASSERT(sc != NULL);
>
> if (kbl->curval > ACPICBKBD_MAX_BACKLIGHT)
> return EINVAL;
>
> sc->sc_backlight = kbl->curval;
>
> acpi_addtask(sc->sc_acpi, acpicbkbd_write_backlight, sc, 0);
> acpi_wakeup(sc->sc_acpi);
>
> return 0;
> }
>
> (installed in dev/acpi/acpithinkpad.c:347)
>
> int
> thinkpad_get_kbd_backlight(struct wskbd_backlight *kbl)
> {
> struct acpithinkpad_softc *sc = acpithinkpad_cd.cd_devs[0];
>
> KASSERT(sc != NULL);
>
> kbl->min = 0;
> kbl->max = (sc->sc_thinklight >> 8) & 0x0f;
> kbl->curval = sc->sc_thinklight & 0x0f;
>
> if (kbl->max == 0)
> return (ENOTTY);
>
> return 0;
> }
>
> int
> thinkpad_set_kbd_backlight(struct wskbd_backlight *kbl)
> {
> struct acpithinkpad_softc *sc = acpithinkpad_cd.cd_devs[0];
> int maxval;
>
> KASSERT(sc != NULL);
>
> maxval = (sc->sc_thinklight >> 8) & 0x0f;
>
> if (maxval == 0)
> return (ENOTTY);
>
> if (kbl->curval > maxval)
> return EINVAL;
>
> sc->sc_thinklight &= ~0xff;
> sc->sc_thinklight |= kbl->curval;
> acpi_addtask(sc->sc_acpi, thinkpad_set_thinklight, sc, 0);
> acpi_wakeup(sc->sc_acpi);
> return 0;
> }
>
> (installed in pwmleds.c:102)
> int
> pwmleds_get_kbd_backlight(struct wskbd_backlight *kbl)
> {
> struct pwmleds_softc *sc;
> struct pwm_state ps;
> int error;
>
> sc = pwmleds_kbd_backlight();
> if (sc == NULL)
> return ENOTTY;
>
> error = pwm_get_state(sc->sc_pwm, &ps);
> if (error)
> return error;
>
> kbl->min = 0;
> kbl->max = sc->sc_max_brightness;
> kbl->curval = (ps.ps_enabled) ?
> ((uint64_t)ps.ps_pulse_width * kbl->max) / ps.ps_period : 0;
> return 0;
> }
>
> int
> pwmleds_set_kbd_backlight(struct wskbd_backlight *kbl)
> {
> struct pwmleds_softc *sc;
> struct pwm_state ps;
>
> sc = pwmleds_kbd_backlight();
> if (sc == NULL)
> return ENOTTY;
>
> if (kbl->curval < 0 || kbl->curval > sc->sc_max_brightness)
> return EINVAL;
>
> pwm_init_state(sc->sc_pwm, &ps);
> ps.ps_pulse_width =
> ((uint64_t)kbl->curval * ps.ps_period) / sc->sc_max_brightness;
> ps.ps_enabled = (ps.ps_pulse_width > 0);
> return pwm_set_state(sc->sc_pwm, &ps);
> }
