From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Gong Subject: Re: [PATCH v2 5/8] spi: imx: Add support for loopback for ECSPI controllers Date: Wed, 30 Sep 2015 16:42:20 +0800 Message-ID: <20150930084219.GE2709@shlinux2> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: muzaffar_mahmood@relay1.mentorg.com, jiada_wang@mentor.com, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, broonie@kernel.org, vladimir_zapolskiy@mentor.com, linux-arm-kernel@lists.infradead.org To: Anton Bondarenko Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org On Fri, Sep 25, 2015 at 07:57:12PM +0200, Anton Bondarenko wrote: > Support for ECSPI loopback for IMX51,IMX53 and IMX6Q using TEST register. > > Signed-off-by: Mohsin Kazmi > Signed-off-by: Anton Bondarenko > --- > drivers/spi/spi-imx.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c > index 41c9cef..4b3c16e 100644 > --- a/drivers/spi/spi-imx.c > +++ b/drivers/spi/spi-imx.c > @@ -265,6 +265,9 @@ 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_TEST 0x20 > +#define MX51_ECSPI_LOOP BIT(31) > + > /* MX51 eCSPI */ > static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi, > unsigned int *fres) > @@ -338,6 +341,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, > u32 ctrl = MX51_ECSPI_CTRL_ENABLE, dma = 0; > u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG); > u32 delay; > + u32 lpb = 0; > > /* > * The hardware seems to have a race condition when changing modes. The > @@ -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. > > /* > * Wait until the changes in the configuration register CONFIGREG > @@ -1252,6 +1260,9 @@ static int spi_imx_probe(struct platform_device *pdev) > spi_imx = spi_master_get_devdata(master); > spi_imx->bitbang.master = master; > > + spi_imx->devtype_data = of_id ? of_id->data : > + (struct spi_imx_devtype_data *)pdev->id_entry->driver_data; > + > for (i = 0; i < master->num_chipselect; i++) { > int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); > if (!gpio_is_valid(cs_gpio) && mxc_platform_info) > @@ -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? > > - 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 >