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

On Thu, Oct 01, 2015 at 12:16:49AM +0000, Bondarenko, Anton wrote:

On 30.09.2015 10:42, Robin Gong wrote:

quoted

On Fri, Sep 25, 2015 at 07:57:12PM +0200, Anton Bondarenko wrote:

quoted

@@ -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);
	}

quoted

quoted

 
 	/*
 	 * 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

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-	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