[v2 PATCH 10/14] spi/atmel_spi: correct 16 bits transfers using PIO
From: Wenyou Yang <hidden>
Date: 2012-12-04 07:59:44
Also in:
linux-arm-kernel, lkml
Subsystem:
microchip spi driver, spi subsystem, the rest · Maintainers:
Ryan Wanner, Mark Brown, Linus Torvalds
From: Richard Genoud <redacted> Signed-off-by: Richard Genoud <redacted> Cc: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org --- drivers/spi/spi-atmel.c | 46 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 9 deletions(-)
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 7f624b6..9616fab 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c@@ -573,13 +573,17 @@ static void atmel_spi_next_xfer_pio(struct spi_master *master, } if (xfer->tx_buf) - spi_writel(as, TDR, *(u8 *)(xfer->tx_buf)); + if (xfer->bits_per_word > 8) + spi_writel(as, TDR, *(u16 *)(xfer->tx_buf)); + else + spi_writel(as, TDR, *(u8 *)(xfer->tx_buf)); else spi_writel(as, TDR, 0); dev_dbg(master->dev.parent, - " start pio xfer %p: len %u tx %p rx %p\n", - xfer, xfer->len, xfer->tx_buf, xfer->rx_buf); + " start pio xfer %p: len %u tx %p rx %p bitpw %d\n", + xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, + xfer->bits_per_word); /* Enable relevant interrupts */ spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
@@ -997,21 +1001,39 @@ atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer) { u8 *txp; u8 *rxp; + u16 *txp16; + u16 *rxp16; unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; if (xfer->rx_buf) { - rxp = ((u8 *)xfer->rx_buf) + xfer_pos; - *rxp = spi_readl(as, RDR); + if (xfer->bits_per_word > 8) { + rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); + *rxp16 = spi_readl(as, RDR); + } else { + rxp = ((u8 *)xfer->rx_buf) + xfer_pos; + *rxp = spi_readl(as, RDR); + } } else { spi_readl(as, RDR); } - - as->current_remaining_bytes--; + if (xfer->bits_per_word > 8) { + as->current_remaining_bytes -= 2; + if (as->current_remaining_bytes < 0) + as->current_remaining_bytes = 0; + } else { + as->current_remaining_bytes--; + } if (as->current_remaining_bytes) { if (xfer->tx_buf) { - txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1; - spi_writel(as, TDR, *txp); + if (xfer->bits_per_word > 8) { + txp16 = (u16 *)(((u8 *)xfer->tx_buf) + + xfer_pos + 2); + spi_writel(as, TDR, *txp16); + } else { + txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1; + spi_writel(as, TDR, *txp); + } } else { spi_writel(as, TDR, 0); }
@@ -1431,6 +1453,12 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) return -ENOPROTOOPT; } } + if (xfer->bits_per_word > 8) { + if (xfer->len % 2) { + dev_dbg(&spi->dev, "buffer len should be 16 bits aligned\n"); + return -EINVAL; + } + } /* FIXME implement these protocol options!! */ if (xfer->speed_hz) {
--
1.7.9.5
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