From 0398fb70940e1f10939d6126eafb760bd48d1566 Mon Sep 17 00:00:00 2001 From: Joakim Tjernlund Date: Fri, 14 May 2010 09:14:26 +0000 Subject: [PATCH] spi/spi_mpc8xxx: Fix QE mode Litte Endian QE mode uses Little Endian so words > 8 bits are byte swapped. Workaround this by always enforcing wordsize 8 for words > 8 bits. Unfortunately this will not work for LSB transfers where wordsize is > 8 bits so disable these for now. Also move the different quirks into its own function to keep mpc8xxx_spi_setup_transfer() sane. Signed-off-by: Joakim Tjernlund Acked-by: Anton Vorontsov Signed-off-by: Grant Likely --- drivers/spi/spi_mpc8xxx.c | 101 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 70 insertions(+), 31 deletions(-) diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c index 0dfc482..66517ce7 100644 --- a/drivers/spi/spi_mpc8xxx.c +++ b/drivers/spi/spi_mpc8xxx.c @@ -286,36 +286,12 @@ static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value) } } -static -int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) +static int +mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs, + struct spi_device *spi, + struct mpc8xxx_spi *mpc8xxx_spi, + int bits_per_word) { - struct mpc8xxx_spi *mpc8xxx_spi; - u8 bits_per_word, pm; - u32 hz; - struct spi_mpc8xxx_cs *cs = spi->controller_state; - - mpc8xxx_spi = spi_master_get_devdata(spi->master); - - if (t) { - bits_per_word = t->bits_per_word; - hz = t->speed_hz; - } else { - bits_per_word = 0; - hz = 0; - } - - /* spi_transfer level calls that work per-word */ - if (!bits_per_word) - bits_per_word = spi->bits_per_word; - - /* Make sure its a bit width we support [4..16, 32] */ - if ((bits_per_word < 4) - || ((bits_per_word > 16) && (bits_per_word != 32))) - return -EINVAL; - - if (!hz) - hz = spi->max_speed_hz; - cs->rx_shift = 0; cs->tx_shift = 0; if (bits_per_word <= 8) { @@ -339,19 +315,82 @@ int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) return -EINVAL; if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE && - spi->mode & SPI_LSB_FIRST) { + spi->mode & SPI_LSB_FIRST) { cs->tx_shift = 0; if (bits_per_word <= 8) cs->rx_shift = 8; else cs->rx_shift = 0; } - mpc8xxx_spi->rx_shift = cs->rx_shift; mpc8xxx_spi->tx_shift = cs->tx_shift; mpc8xxx_spi->get_rx = cs->get_rx; mpc8xxx_spi->get_tx = cs->get_tx; + return bits_per_word; +} + +static int +mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs, + struct spi_device *spi, + int bits_per_word) +{ + /* QE uses Little Endian for words > 8 + * so transform all words > 8 into 8 bits + * Unfortnatly that doesn't work for LSB so + * reject these for now */ + /* Note: 32 bits word, LSB works iff + * tfcr/rfcr is set to CPMFCR_GBL */ + if (spi->mode & SPI_LSB_FIRST && + bits_per_word > 8) + return -EINVAL; + if (bits_per_word > 8) + return 8; /* pretend its 8 bits */ + return bits_per_word; +} + +static +int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct mpc8xxx_spi *mpc8xxx_spi; + int bits_per_word; + u8 pm; + u32 hz; + struct spi_mpc8xxx_cs *cs = spi->controller_state; + + mpc8xxx_spi = spi_master_get_devdata(spi->master); + + if (t) { + bits_per_word = t->bits_per_word; + hz = t->speed_hz; + } else { + bits_per_word = 0; + hz = 0; + } + + /* spi_transfer level calls that work per-word */ + if (!bits_per_word) + bits_per_word = spi->bits_per_word; + + /* Make sure its a bit width we support [4..16, 32] */ + if ((bits_per_word < 4) + || ((bits_per_word > 16) && (bits_per_word != 32))) + return -EINVAL; + + if (!hz) + hz = spi->max_speed_hz; + + if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) + bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi, + mpc8xxx_spi, + bits_per_word); + else if (mpc8xxx_spi->flags & SPI_QE) + bits_per_word = mspi_apply_qe_mode_quirks(cs, spi, + bits_per_word); + + if (bits_per_word < 0) + return bits_per_word; + if (bits_per_word == 32) bits_per_word = 0; else -- 1.8.2.3