diff options
| author | Fabio Estevam <fabio.estevam@freescale.com> | 2015-12-04 02:23:24 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-12-04 13:13:02 +0100 |
| commit | 9f6aa42bbbb23d2115704c5044da951a7e685cc5 (patch) | |
| tree | f2fe81d06fbca90f22abfbdb570ea0c5efb820b8 /drivers/spi | |
| parent | Linux 4.4-rc1 (diff) | |
| download | linux-9f6aa42bbbb23d2115704c5044da951a7e685cc5.tar.xz linux-9f6aa42bbbb23d2115704c5044da951a7e685cc5.zip | |
spi: imx: Add loopback mode support
Loopback mode can be activated by setting bit LBC (LoopBack
Control) of register ECSPI_TESTREG.
Add support for it.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-imx.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 0e5723ab47f0..e7e4f0c0f14d 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; init_completion(&spi_imx->xfer_done); |