On Fri, Jan 31, 2020 at 4:34 AM Chris Packham
<chris.packham@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Add a SPI device driver that sits in-band and provides a SPI controller
> which supports chip selects via a mux-control. This enables extra SPI
> devices to be connected with limited native chip selects.
Thanks for an update, my comments below.
...
> #
> # Add new SPI master controllers in alphabetical order above this line
> #
> +#
Redundant line.
...
> +/*
> + * General Purpose SPI multiplexer
> + */
I think Mark wants to have this in one line with C++ style of comments.
...
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +#include <linux/spi/spi.h>
> +#include <linux/mux/consumer.h>
Perhaps sorted?
...
> + /* do the transfer */
> + ret = spi_async(priv->spi, m);
> + return ret;
return spi_async(...);
...
> + priv->mux = devm_mux_control_get(&spi->dev, NULL);
> + ret = PTR_ERR_OR_ZERO(priv->mux);
This is a bit complicated.
> + if (ret) {
Why not simple do
if (IS_ERR(priv->mux)) {
ret = PTR_ERR(...);
...
}
?
> + if (ret != -EPROBE_DEFER)
> + dev_err(&spi->dev, "failed to get control-mux\n");
> + goto err_put_ctlr;
> + }
> + ctlr->dev.of_node = spi->dev.of_node;
I'm wondering why SPI core can't handle this by default (like GPIO
subsystem does).
> + ret = devm_spi_register_controller(&spi->dev, ctlr);
> + if (ret)
> + goto err_put_ctlr;
> +
> + return ret;
return 0;
...
> +static const struct of_device_id spi_mux_of_match[] = {
> + { .compatible = "spi-mux" },
> + { },
Comma is not needed in terminator line.
> +};
--
With Best Regards,
Andy Shevchenko
