On Tue, Sep 27, 2022 at 01:32:28PM +0200, Bert Vermeulen wrote:
>
> +config SPI_AIROHA_EN7523
> + bool "Airoha EN7523 SPI controller support"
Why not tristate?
> + depends on ARCH_AIROHA
I don't see a reason we couldn't have an || COMPILE_TEST here to improve
coverage?
> + default ARCH_AIROHA
It's unusual to default a SPI controller on, they tend not to be ultra
critical like a clock driver or similar can be?
> +static void __iomem *iobase;
This should be driver data rather than a global, your current SoC might
only have one controller but some other model might build two and it's
fairly trivial to do.
> +static void opfifo_write(u32 cmd, u32 len)
> +{
> + u32 tmp = ((cmd & 0x1f) << 9) | (len & 0x1ff);
> +
> + writel(tmp, REG(ENSPI_MANUAL_OPFIFO_WDATA));
> +
> + /* Wait for room in OPFIFO */
> + while (readl(REG(ENSPI_MANUAL_OPFIFO_FULL)))
> + cpu_relax();
> +
Some sort of timeout would be good with these loops, if things go wrong
we'll just lock up which isn't good.
> + ret = clk_prepare_enable(clk);
> + if (ret)
> + return ret;
Nothing ever reverses this unless clk_set_rate() fails.
> + ret = clk_set_rate(clk, 40000000);
> + if (ret) {
> + clk_disable_unprepare(clk);
> + return ret;
> + }
Could this be pushed into DT via the clock bindings? The hard coded
number might need to vary by SoC.
> +static int xfer_read(struct spi_transfer *xfer)
> +{
> + int opcode;
> + uint8_t *buf = xfer->rx_buf;
> +
> + switch (xfer->rx_nbits) {
> + case SPI_NBITS_SINGLE:
> + opcode = OP_INS;
> + break;
> + case SPI_NBITS_DUAL:
> + opcode = OP_IND;
> + break;
> + }
This should have a default case that returns an error.
> +static int transfer_one_message(struct spi_controller *ctrl, struct spi_message *msg)
> +{
> + struct spi_transfer *xfer;
> + int next_xfer_is_rx = 0;
> +
> + manual_begin_cmd();
> + set_cs(0);
The driver should not be setting chip select itself, it should just
provide the set_cs() operation to the core and let the core worry about
when to call it.
> + ctrl->transfer_one_message = transfer_one_message;
> + err = devm_spi_register_controller(&pdev->dev, ctrl);
> + if (err) {
> + dev_err(&pdev->dev, "Could not register SPI controller\n");
> + return -ENODEV;
> + }
Don't discard the error code that registeration returned, include it in
the log message and pass it back to the caller.
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