[PATCH v2 5/8] spi: imx: Add support for loopback for ECSPI controllers
From: Anton Bondarenko <hidden>
Date: 2015-10-20 23:08:24
Also in:
linux-spi, lkml
On 08.10.2015 11:28, Robin Gong wrote:
On Thu, Oct 01, 2015 at 12:16:49AM +0000, Bondarenko, Anton wrote:quoted
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); }
Proposed code not able to clear LOOP mode in TEST register. What about something like this: if (config->mode & SPI_LOOP) lpb |= MX51_ECSPI_LOOP; if ((readl(spi_imx->base + MX51_ECSPI_TEST) & MX51_ECSPI_LOOP) != lpb) writel(lpb, spi_imx->base + MX51_ECSPI_TEST); In this case driver will write TEST register only if needed.
quoted
quoted
quoted
/* * Wait until the changes in the configuration register CONFIGREG
Regards, Anton