Subject: [PATCH v2 5/8] spi: imx: Add support for loopback for ECSPI controllers

From: [email-masked] (Robin Gong)
Date: Thu, 8 Oct 2015 17:28:28 +0800

On Thu, Oct 01, 2015 at 12:16:49AM +0000, Bondarenko, Anton wrote:
> On 30.09.2015 10:42, Robin Gong wrote:
> > On Fri, Sep 25, 2015 at 07:57:12PM +0200, Anton Bondarenko wrote:
> >> @@ -370,8 +374,12 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
> >>  	if (config->mode & SPI_CS_HIGH)
> >>  		cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
> >>  
> >> +	if (config->mode & SPI_LOOP)
> >> +		lpb |= MX51_ECSPI_LOOP;
> >> +
> >>  	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
> >>  	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
> >> +	writel(lpb, spi_imx->base + MX51_ECSPI_TEST);
> > It's better write this MX51_ECSPI_TEST only in LOOP mode.
> LOOP mode can be set dynamically. This mean we should be able to set and clear the flag.
> Currently only LOOP flag is used. I did not find any problems with writing 0 in the rest
> fields of TEST register.
Yes, I know writing 0 is harmless, but we never need to touch this register if
SPI_LOOP flags not set, I'd like below:
	if (config->mode & SPI_LOOP) {
		lpb |= MX51_ECSPI_LOOP;
		writel(lgb, spi_imx->base + MX51_ECSPI_TEST);
	}

> >>  
> >>  	/*
> >>  	 * Wait until the changes in the configuration register CONFIGREG
> >> @@ -1276,12 +1287,13 @@ static int spi_imx_probe(struct platform_device *pdev)
> >>  	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
> >>  	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
> >>  	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
> >> -	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> >> +	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA |
> >> +				SPI_CS_HIGH;
> > Any change?
> Will be fixed in V3
> >>  
> >> -	init_completion(&spi_imx->xfer_done);
> >> +	if (is_imx5x_ecspi(spi_imx))
> >> +		spi_imx->bitbang.master->mode_bits |= SPI_LOOP;
> >>  
> >> -	spi_imx->devtype_data = of_id ? of_id->data :
> >> -		(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
> >> +	init_completion(&spi_imx->xfer_done);
> >>  
> >>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>  	spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
> >> -- 
> >> 2.5.2
> >>
>