From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabio Estevam Subject: Re: [PATCH] spi-imx: Add loopback mode support Date: Sat, 5 Dec 2015 15:32:31 -0200 Message-ID: References: <1449192204-24877-1-git-send-email-festevam@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: "linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Fabio Estevam , anton.bondarenko.sama-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org To: Mark Brown Return-path: In-Reply-To: <1449192204-24877-1-git-send-email-festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Thu, Dec 3, 2015 at 11:23 PM, Fabio Estevam wrote: > From: Fabio Estevam > > Loopback mode can be activated by setting bit LBC (LoopBack > Control) of register ECSPI_TESTREG. > > Add support for it. > > Signed-off-by: Fabio Estevam > --- > drivers/spi/spi-imx.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c > index 0e5723a..e7e4f0c 100644 > --- a/drivers/spi/spi-imx.c > +++ b/drivers/spi/spi-imx.c > @@ -244,6 +244,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, > #define MX51_ECSPI_STAT 0x18 > #define MX51_ECSPI_STAT_RR (1 << 3) > > +#define MX51_ECSPI_TESTREG 0x20 > +#define MX51_ECSPI_TESTREG_LBC BIT(31) > + > /* MX51 eCSPI */ > static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi, > unsigned int *fres) > @@ -313,7 +316,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, > { > u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0; > u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg; > - u32 clk = config->speed_hz, delay; > + u32 clk = config->speed_hz, delay, reg; > > /* > * The hardware seems to have a race condition when changing modes. The > @@ -351,6 +354,13 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, > else > cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs); > > + reg = readl(spi_imx->base + MX51_ECSPI_TESTREG); > + if (config->mode & SPI_LOOP) > + reg |= MX51_ECSPI_TESTREG_LBC; > + else > + reg &= ~MX51_ECSPI_TESTREG_LBC; > + writel(reg, spi_imx->base + MX51_ECSPI_TESTREG); > + > writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); > writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG); > > @@ -1141,7 +1151,8 @@ 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 | > + SPI_LOOP; The SPI_LOOP should not be added to all spi versions, only for the mx51/mx53/mx6q type. Just realized that Anton sent the loopback support as part of his series, so please discard this one. -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html