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 | 109 ++++++++++++++++++++++++++------------ 1 file changed, 74 insertions(+), 35 deletions(-) diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c index 0dfc482bbff5..66517ce750f3 100644 --- a/drivers/spi/spi_mpc8xxx.c +++ b/drivers/spi/spi_mpc8xxx.c @@ -286,11 +286,75 @@ static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value) } } +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) +{ + cs->rx_shift = 0; + cs->tx_shift = 0; + if (bits_per_word <= 8) { + cs->get_rx = mpc8xxx_spi_rx_buf_u8; + cs->get_tx = mpc8xxx_spi_tx_buf_u8; + if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) { + cs->rx_shift = 16; + cs->tx_shift = 24; + } + } else if (bits_per_word <= 16) { + cs->get_rx = mpc8xxx_spi_rx_buf_u16; + cs->get_tx = mpc8xxx_spi_tx_buf_u16; + if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) { + cs->rx_shift = 16; + cs->tx_shift = 16; + } + } else if (bits_per_word <= 32) { + cs->get_rx = mpc8xxx_spi_rx_buf_u32; + cs->get_tx = mpc8xxx_spi_tx_buf_u32; + } else + return -EINVAL; + + if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE && + 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; - u8 bits_per_word, pm; + int bits_per_word; + u8 pm; u32 hz; struct spi_mpc8xxx_cs *cs = spi->controller_state; @@ -316,41 +380,16 @@ int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) if (!hz) hz = spi->max_speed_hz; - cs->rx_shift = 0; - cs->tx_shift = 0; - if (bits_per_word <= 8) { - cs->get_rx = mpc8xxx_spi_rx_buf_u8; - cs->get_tx = mpc8xxx_spi_tx_buf_u8; - if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) { - cs->rx_shift = 16; - cs->tx_shift = 24; - } - } else if (bits_per_word <= 16) { - cs->get_rx = mpc8xxx_spi_rx_buf_u16; - cs->get_tx = mpc8xxx_spi_tx_buf_u16; - if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) { - cs->rx_shift = 16; - cs->tx_shift = 16; - } - } else if (bits_per_word <= 32) { - cs->get_rx = mpc8xxx_spi_rx_buf_u32; - cs->get_tx = mpc8xxx_spi_tx_buf_u32; - } else - return -EINVAL; + 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 (mpc8xxx_spi->flags & SPI_QE_CPU_MODE && - 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; + if (bits_per_word < 0) + return bits_per_word; if (bits_per_word == 32) bits_per_word = 0;