GPIO driver refactor - polling, multiple instance fixes, remove default Kconfigs #640
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* Actually allow defaulting yes in other places.
* Add easier macros for conditional polling/interrupt code. * Properly continue polling on intervals, without extra enable/disable code for pins that is superfluous when not trying to deal with interupts firing. * Fix to allow multiple GPIO drivers when doing splits w/ IO expanders
joelspadin
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joelspadin
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I'm not sure I fully understand how the kscan driver works, but everything I see changing here looks reasonable to me.
| (int err = kscan_gpio_enable_interrupts_##n(dev); \ | ||
| if (err) { return err; } return kscan_gpio_read_##n(dev);)) \ | ||
| COND_POLL_OR_INTERRUPTS((struct kscan_gpio_data_##n *data = dev->data; \ | ||
| k_timer_start(&data->poll_timer, K_MSEC(10), K_MSEC(10)); \ |
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Am I correctly interpreting this that when polling is enabled, we poll at a constant 100 Hz? It might be useful to make that configurable, for example if someone wanted to make a wired keyboard that polls as fast as possible.
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Yeah, I hadn't remembered hardcoding.this, but it does seem so, yeah. Good item to move into Kconfig soon, yeah.
| COND_POLL_OR_INTERRUPTS( \ | ||
| (k_timer_init(&data->poll_timer, kscan_gpio_timer_handler_##n, NULL); \ | ||
| kscan_gpio_set_output_state_##n(dev, 0);), \ | ||
| (kscan_gpio_set_output_state_##n(dev, 1);)) \ |
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Would I be correct in guessing that the interrupt behavior is different here because it sets all the outputs active, waits for an interrupt to happen on any input, and then does a regular scan?
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Correct. We want to drive all outputs to active when "idle", so that any key press will trigger an interrupt. Then we keep polling/scanning until all keys are released again.
petejohanson
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petejohanson
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Self approving, been using this extensively for several days on Ferris and on other interrupt based boards like Corne.
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This refactor is needed for my upcoming Ferris board work. In particular, the Ferris:
While there, I took the opportunity to add some more useful macros to make the conditional code a little bit easier to read.
There's also a small commit in here as well that removes some
default nsettings from some Kconfig settings to allow them to be defaulted yes elsewhere as needed.