From 4d676fc5c39a677aa72148debd47029d8d8f0634 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Tue, 11 Jan 2011 11:19:07 -0500 Subject: [PATCH] spi/bfin_spi: support for multiples of 8bits with hardware CS We can do multiples of 8bit transfers when using the hardware CS and a little bit of magic, so make it work. Signed-off-by: Bob Liu Signed-off-by: Mike Frysinger Signed-off-by: Grant Likely --- drivers/spi/spi_bfin5xx.c | 103 ++++++++++++++++++++++++++------------ 1 file changed, 71 insertions(+), 32 deletions(-) diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index 3f223511127b..e8d68b79e98f 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -425,6 +425,7 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) struct bfin_spi_slave_data *chip = drv_data->cur_chip; struct spi_message *msg = drv_data->cur_msg; int n_bytes = drv_data->n_bytes; + int loop = 0; /* wait until transfer finished. */ while (!(read_STAT(drv_data) & BIT_STAT_RXS)) @@ -435,10 +436,15 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) /* last read */ if (drv_data->rx) { dev_dbg(&drv_data->pdev->dev, "last read\n"); - if (n_bytes == 2) - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); - else if (n_bytes == 1) - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); + if (n_bytes % 2) { + u16 *buf = (u16 *)drv_data->rx; + for (loop = 0; loop < n_bytes / 2; loop++) + *buf++ = read_RDBR(drv_data); + } else { + u8 *buf = (u8 *)drv_data->rx; + for (loop = 0; loop < n_bytes; loop++) + *buf++ = read_RDBR(drv_data); + } drv_data->rx += n_bytes; } @@ -458,29 +464,53 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) if (drv_data->rx && drv_data->tx) { /* duplex */ dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n"); - if (drv_data->n_bytes == 2) { - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); - } else if (drv_data->n_bytes == 1) { - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); + if (n_bytes % 2) { + u16 *buf = (u16 *)drv_data->rx; + u16 *buf2 = (u16 *)drv_data->tx; + for (loop = 0; loop < n_bytes / 2; loop++) { + *buf++ = read_RDBR(drv_data); + write_TDBR(drv_data, *buf2++); + } + } else { + u8 *buf = (u8 *)drv_data->rx; + u8 *buf2 = (u8 *)drv_data->tx; + for (loop = 0; loop < n_bytes; loop++) { + *buf++ = read_RDBR(drv_data); + write_TDBR(drv_data, *buf2++); + } } } else if (drv_data->rx) { /* read */ dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n"); - if (drv_data->n_bytes == 2) - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); - else if (drv_data->n_bytes == 1) - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); - write_TDBR(drv_data, chip->idle_tx_val); + if (n_bytes % 2) { + u16 *buf = (u16 *)drv_data->rx; + for (loop = 0; loop < n_bytes / 2; loop++) { + *buf++ = read_RDBR(drv_data); + write_TDBR(drv_data, chip->idle_tx_val); + } + } else { + u8 *buf = (u8 *)drv_data->rx; + for (loop = 0; loop < n_bytes; loop++) { + *buf++ = read_RDBR(drv_data); + write_TDBR(drv_data, chip->idle_tx_val); + } + } } else if (drv_data->tx) { /* write */ dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n"); - bfin_spi_dummy_read(drv_data); - if (drv_data->n_bytes == 2) - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); - else if (drv_data->n_bytes == 1) - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); + if (n_bytes % 2) { + u16 *buf = (u16 *)drv_data->tx; + for (loop = 0; loop < n_bytes / 2; loop++) { + read_RDBR(drv_data); + write_TDBR(drv_data, *buf++); + } + } else { + u8 *buf = (u8 *)drv_data->tx; + for (loop = 0; loop < n_bytes; loop++) { + read_RDBR(drv_data); + write_TDBR(drv_data, *buf++); + } + } } if (drv_data->tx) @@ -651,16 +681,16 @@ static void bfin_spi_pump_transfers(unsigned long data) /* Bits per word setup */ bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word; - if (bits_per_word == 8) { - drv_data->n_bytes = 1; - drv_data->len = transfer->len; - cr_width = 0; - drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; - } else if (bits_per_word == 16) { - drv_data->n_bytes = 2; + if ((bits_per_word > 0) && (bits_per_word % 16 == 0)) { + drv_data->n_bytes = bits_per_word/8; drv_data->len = (transfer->len) >> 1; cr_width = BIT_CTL_WORDSIZE; drv_data->ops = &bfin_bfin_spi_transfer_ops_u16; + } else if ((bits_per_word > 0) && (bits_per_word % 8 == 0)) { + drv_data->n_bytes = bits_per_word/8; + drv_data->len = transfer->len; + cr_width = 0; + drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; } else { dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n"); message->status = -EINVAL; @@ -815,10 +845,19 @@ static void bfin_spi_pump_transfers(unsigned long data) if (drv_data->tx == NULL) write_TDBR(drv_data, chip->idle_tx_val); else { - if (bits_per_word == 8) - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); - else - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); + int loop; + if (bits_per_word % 16 == 0) { + u16 *buf = (u16 *)drv_data->tx; + for (loop = 0; loop < bits_per_word / 16; + loop++) { + write_TDBR(drv_data, *buf++); + } + } else if (bits_per_word % 8 == 0) { + u8 *buf = (u8 *)drv_data->tx; + for (loop = 0; loop < bits_per_word / 8; loop++) + write_TDBR(drv_data, *buf++); + } + drv_data->tx += drv_data->n_bytes; } @@ -1031,7 +1070,7 @@ static int bfin_spi_setup(struct spi_device *spi) chip->ctl_reg &= bfin_ctl_reg; } - if (spi->bits_per_word != 8 && spi->bits_per_word != 16) { + if (spi->bits_per_word % 8) { dev_err(&spi->dev, "%d bits_per_word is not supported\n", spi->bits_per_word); goto error; -- 2.20.1