RE: [PATCH 2/2] spi: add SPI controller driver for UniPhier SoC

[Keiji Hayashibara]

Hi Mark,

> -----Original Message-----
> From: Mark Brown [mailto:broonie@xxxxxxxxxx]
> Sent: Friday, July 20, 2018 1:52 AM
> Subject: Re: [PATCH 2/2] spi: add SPI controller driver for UniPhier SoC
> 
> On Thu, Jul 19, 2018 at 03:51:57PM +0900, Keiji Hayashibara wrote:
> 
> This all looks good, just a small number of fairly minor things - mostly style points.
> 
> > @@ -0,0 +1,532 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * spi-uniphier.c - Socionext UniPhier SPI controller driver
> > + *
> > + * Copyright 2012      Panasonic Corporation
> > + * Copyright 2016-2018 Socionext Inc.
> > + */
> 
> Please make the entire comment a C++ one, it makes things look a bit more joined up/intentional.

OK. I will modify to C++ style.


> > +#define BYTES_PER_WORD(x)			\
> > +({						\
> > +	int __x;				\
> > +	__x = (x <= 8)  ? 1 :			\
> > +	      (x <= 16) ? 2 : 4;		\
> > +	__x;					\
> > +})
> 
> Could this be replaced with an inline function?  The usage seems fine but it's a bit big for a macro.  The end
> result should be similar.

OK. I will replace with an inline function.

> 
> > +static irqreturn_t uniphier_spi_handler(int irq, void *dev_id) {
> > +	struct uniphier_spi_priv *priv = dev_id;
> > +	u32 val, stat;
> > +
> > +	stat = readl(priv->base + SSI_IS);
> > +	val = SSI_IC_TCIC | SSI_IC_RCIC | SSI_IC_RORIC;
> > +	writel(val, priv->base + SSI_IC);
> > +
> > +	/* rx fifo overrun */
> > +	if (stat & SSI_IS_RORID) {
> > +		priv->error = -EIO;
> > +		goto done;
> > +	}
> > +
> > +	/* rx complete */
> > +	if ((stat & SSI_IS_RCID) && (stat & SSI_IS_RXRS)) {
> 
> > +	}
> > +
> > +	return IRQ_HANDLED;
> > +
> > +done:
> > +	complete(&priv->xfer_done);
> > +	return IRQ_HANDLED;
> 
> This will unconditionally report IRQ_HANDLED even if none of the flags were set by the hardware which will cause
> problems if something goes wrong - the interrupt will continually be serviced and the interrupt framework won't
> be able to mitigate or provide diagnostics.  It's better to return IRQ_NONE if nothing is detected from the hardware.

I agree. I will modify it.

> > +static const struct of_device_id uniphier_spi_match[] = {
> > +	{ .compatible = "socionext,uniphier-scssi", },
> > +	{ /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, uniphier_spi_match);
> 
> The binding document also listed socionext,uniphier-mcssi as a compatible but this driver doesn't match that.

This driver doesn't support uniphier-mcssi, and support uniphier-scssi only.
I described in the commit comment,
but I will also describe it in the binding document.

Thank you.

-----------------
Best Regards,
Keiji Hayashibara