From 06a7a3cff042a36fb7e6af71039a17c6d1a6d90f Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Date: Fri, 24 Jan 2014 09:44:00 +0100 Subject: [PATCH] spi: rspi: Add support for loopback mode Add support for specifying loopback mode. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org> --- drivers/spi/spi-rspi.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index 0c7556978d2e..28db8770aaf3 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -183,8 +183,9 @@ struct rspi_data { struct spi_master *master; wait_queue_head_t wait; struct clk *clk; - u8 spsr; u16 spcmd; + u8 spsr; + u8 sppcr; int rx_irq, tx_irq; const struct spi_ops *ops; @@ -252,8 +253,8 @@ static int rspi_set_config_register(struct rspi_data *rspi, int access_size) { int spbr; - /* Sets output mode(CMOS) and MOSI signal(from previous transfer) */ - rspi_write8(rspi, 0x00, RSPI_SPPCR); + /* Sets output mode, MOSI signal, and (optionally) loopback */ + rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1; @@ -288,8 +289,8 @@ static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size) { int spbr; - /* Sets output mode */ - rspi_write8(rspi, 0x00, RSPI_SPPCR); + /* Sets output mode, MOSI signal, and (optionally) loopback */ + rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1; @@ -322,8 +323,8 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) u16 spcmd; int spbr; - /* Sets output mode(CMOS) and MOSI signal(from previous transfer) */ - rspi_write8(rspi, 0x00, RSPI_SPPCR); + /* Sets output mode, MOSI signal, and (optionally) loopback */ + rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz); @@ -829,6 +830,11 @@ static int rspi_setup(struct spi_device *spi) if (spi->mode & SPI_CPHA) rspi->spcmd |= SPCMD_CPHA; + /* CMOS output mode and MOSI signal from previous transfer */ + rspi->sppcr = 0; + if (spi->mode & SPI_LOOP) + rspi->sppcr |= SPPCR_SPLP; + set_config_register(rspi, 8); return 0; @@ -1050,7 +1056,7 @@ static int rspi_probe(struct platform_device *pdev) master->cleanup = rspi_cleanup; master->prepare_message = rspi_prepare_message; master->unprepare_message = rspi_unprepare_message; - master->mode_bits = SPI_CPHA | SPI_CPOL; + master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP; ret = platform_get_irq_byname(pdev, "rx"); if (ret < 0) {