Messages in this thread | | | Date | Fri, 28 May 2021 12:09:34 +0800 | From | Steven Lee <> | Subject | Re: [PATCH v2 1/4] dt-bindings: aspeed-sgpio: Convert txt bindings to yaml. |
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The 05/28/2021 07:51, Linus Walleij wrote: > On Thu, May 27, 2021 at 2:55 AM Steven Lee <steven_lee@aspeedtech.com> wrote: > > > SGPIO bindings should be converted as yaml format. > > In addition to the file conversion, a new property max-ngpios is > > added in the yaml file as well. > > The new property is required by the enhanced sgpio driver for > > making the configuration of the max number of gpio pins more flexible. > > > > Signed-off-by: Steven Lee <steven_lee@aspeedtech.com> > (...) > > + max-ngpios: > > + description: > > + represents the number of actual hardware-supported GPIOs (ie, > > + slots within the clocked serial GPIO data). Since each HW GPIO is both an > > + input and an output, we provide max_ngpios * 2 lines on our gpiochip > > + device. We also use it to define the split between the inputs and > > + outputs; the inputs start at line 0, the outputs start at max_ngpios. > > + minimum: 0 > > + maximum: 128 > > Why can this not be derived from the compatible value? > > Normally there should be one compatible per hardware variant > of the block. And this should be aligned with that, should it not? > > If this is not the case, maybe more detailed compatible strings > are needed, maybe double compatibles with compatible per > family and SoC? >
Thanks for your suggestion. I add max-ngpios in dt-bindings as there is ngpios defined in dt-bindings, users can get the both max-ngpios and ngpios information from dtsi without digging sgpio driver.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed-g5.dtsi#n354
If adding more detailed compatibles is better, I will add them to sgpio driver in V3 patch and remove max-ngpios from dt-bindings.
Since AST2600 has 2 sgpio controller one with 128 pins and another one with 80 pins. For supporting max-ngpios in compatibles, 2 platform data for each ast2600 sgpio controller as follows are necessary.
``` static const struct aspeed_sgpio_pdata ast2600_sgpiom1_pdata = { .max_ngpios = 128; }; static const struct aspeed_sgpio_pdata ast2600_sgpiom2_pdata = { .max_ngpios = 80; };
{ .compatible = "aspeed,ast2500-sgpio" , .data = &ast2400_sgpio_pdata, }, { .compatible = "aspeed,ast2600-sgpiom1", .data = &ast2600_sgpiom1_pdata, }, { .compatible = "aspeed,ast2600-sgpiom2", .data = &ast2600_sgpiom2_pdata, }, ```
Thanks, Steven
> Yours, > Linus Walleij
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