Messages in this thread |  | | Date | Mon, 04 Jul 2022 14:28:21 +0200 | From | Michael Walle <> | Subject | Re: [PATCH 1/3] gpio: regmap: Support registers with more than one bit per GPIO |
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Am 2022-07-03 13:10, schrieb Aidan MacDonald: > Some devices use a multi-bit register field to change the GPIO > input/output direction. Add the ->reg_field_xlate() callback to > support such devices in gpio-regmap. > > ->reg_field_xlate() builds on ->reg_mask_xlate() by allowing the > driver to return a mask and values to describe a register field. > gpio-regmap will use the mask to isolate the field and compare or > update it using the values to implement GPIO level and direction > get and set ops.
Thanks for working on this. Here are my thoughts on how to improve it: - I'm wary on the value translation of the set and get, you don't need that at the moment, correct? I'd concentrate on the direction for now. - I'd add a xlate_direction(), see below for an example - because we can then handle the value too, we don't need the invert handling in the {set,get}_direction. drop it there and handle it in a simple_xlat. In gpio_regmap, store "reg_dir_base" and "invert_direction", derived from config->reg_dir_in_base and config->reg_dir_out_base.
static int gpio_regmap_simple_xlat_direction(struct gpio_regmap *gpio unsigend int base, unsigned int offset, unsigned int *dir_out, unsigned int *dir_in) { unsigned int line = offset % gpio->ngpio_per_reg; unsigned int mask = BIT(line);
if (!gpio->invert_direction) { *dir_out = mask; *dir_in = 0; } else { *dir_out = 0; *dir_in = mask; }
return 0; }
And in the {set,get}_direction() you can then check both values and convert it from or to GPIO_LINE_DIRECTION_{OUT,IN}.
Thoughts?
-michael
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