diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/bfin_spi.c | 155 |
1 files changed, 128 insertions, 27 deletions
diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c index 556b97a..d7e1474 100644 --- a/drivers/spi/bfin_spi.c +++ b/drivers/spi/bfin_spi.c @@ -1,7 +1,7 @@ /* * Driver for Blackfin On-Chip SPI device * - * Copyright (c) 2005-2008 Analog Devices Inc. + * Copyright (c) 2005-2010 Analog Devices Inc. * * Licensed under the GPL-2 or later. */ @@ -13,6 +13,7 @@ #include <spi.h> #include <asm/blackfin.h> +#include <asm/dma.h> #include <asm/gpio.h> #include <asm/portmux.h> #include <asm/mach-common/bits/spi.h> @@ -237,10 +238,131 @@ void spi_release_bus(struct spi_slave *slave) SSYNC(); } +#ifdef __ADSPBF54x__ +# define SPI_DMA_BASE DMA4_NEXT_DESC_PTR +#elif defined(__ADSPBF533__) || defined(__ADSPBF532__) || defined(__ADSPBF531__) || \ + defined(__ADSPBF538__) || defined(__ADSPBF539__) +# define SPI_DMA_BASE DMA5_NEXT_DESC_PTR +#elif defined(__ADSPBF561__) +# define SPI_DMA_BASE DMA2_4_NEXT_DESC_PTR +#elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__) || \ + defined(__ADSPBF52x__) || defined(__ADSPBF51x__) +# define SPI_DMA_BASE DMA7_NEXT_DESC_PTR +#else +# error "Please provide SPI DMA channel defines" +#endif +static volatile struct dma_register *dma = (void *)SPI_DMA_BASE; + #ifndef CONFIG_BFIN_SPI_IDLE_VAL # define CONFIG_BFIN_SPI_IDLE_VAL 0xff #endif +#ifdef CONFIG_BFIN_SPI_NO_DMA +# define SPI_DMA 0 +#else +# define SPI_DMA 1 +#endif + +static int spi_dma_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx, + uint bytes) +{ + int ret = -1; + u16 ndsize, spi_config, dma_config; + struct dmasg dmasg[2]; + const u8 *buf; + + if (tx) { + debug("%s: doing half duplex TX\n", __func__); + buf = tx; + spi_config = TDBR_DMA; + dma_config = 0; + } else { + debug("%s: doing half duplex RX\n", __func__); + buf = rx; + spi_config = RDBR_DMA; + dma_config = WNR; + } + + dmasg[0].start_addr = (unsigned long)buf; + dmasg[0].x_modify = 1; + dma_config |= WDSIZE_8 | DMAEN; + if (bytes <= 65536) { + blackfin_dcache_flush_invalidate_range(buf, buf + bytes); + ndsize = NDSIZE_5; + dmasg[0].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN; + dmasg[0].x_count = bytes; + } else { + blackfin_dcache_flush_invalidate_range(buf, buf + 65536 - 1); + ndsize = NDSIZE_7; + dmasg[0].cfg = NDSIZE_5 | dma_config | FLOW_ARRAY | DMA2D; + dmasg[0].x_count = 0; /* 2^16 */ + dmasg[0].y_count = bytes >> 16; /* count / 2^16 */ + dmasg[0].y_modify = 1; + dmasg[1].start_addr = (unsigned long)(buf + (bytes & ~0xFFFF)); + dmasg[1].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN; + dmasg[1].x_count = bytes & 0xFFFF; /* count % 2^16 */ + dmasg[1].x_modify = 1; + } + + dma->cfg = 0; + dma->irq_status = DMA_DONE | DMA_ERR; + dma->curr_desc_ptr = dmasg; + write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE)); + write_SPI_STAT(bss, -1); + SSYNC(); + + write_SPI_TDBR(bss, CONFIG_BFIN_SPI_IDLE_VAL); + dma->cfg = ndsize | FLOW_ARRAY | DMAEN; + write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE) | spi_config); + SSYNC(); + + /* + * We already invalidated the first 64k, + * now while we just wait invalidate the remaining part. + * Its not likely that the DMA is going to overtake + */ + if (bytes > 65536) + blackfin_dcache_flush_invalidate_range(buf + 65536, buf + bytes); + + while (!(dma->irq_status & DMA_DONE)) + if (ctrlc()) + goto done; + + dma->cfg = 0; + + ret = 0; + done: + write_SPI_CTL(bss, bss->ctl); + return ret; +} + +static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx, + uint bytes) +{ + /* todo: take advantage of hardware fifos */ + while (bytes--) { + u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL); + debug("%s: tx:%x ", __func__, value); + write_SPI_TDBR(bss, value); + SSYNC(); + while ((read_SPI_STAT(bss) & TXS)) + if (ctrlc()) + return -1; + while (!(read_SPI_STAT(bss) & SPIF)) + if (ctrlc()) + return -1; + while (!(read_SPI_STAT(bss) & RXS)) + if (ctrlc()) + return -1; + value = read_SPI_RDBR(bss); + if (rx) + *rx++ = value; + debug("rx:%x\n", value); + } + + return 0; +} + int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { @@ -265,32 +387,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, if (flags & SPI_XFER_BEGIN) spi_cs_activate(slave); - /* todo: take advantage of hardware fifos and setup RX dma */ - while (bytes--) { - u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL); - debug("%s: tx:%x ", __func__, value); - write_SPI_TDBR(bss, value); - SSYNC(); - while ((read_SPI_STAT(bss) & TXS)) - if (ctrlc()) { - ret = -1; - goto done; - } - while (!(read_SPI_STAT(bss) & SPIF)) - if (ctrlc()) { - ret = -1; - goto done; - } - while (!(read_SPI_STAT(bss) & RXS)) - if (ctrlc()) { - ret = -1; - goto done; - } - value = read_SPI_RDBR(bss); - if (rx) - *rx++ = value; - debug("rx:%x\n", value); - } + /* TX DMA doesn't work quite right */ + if (SPI_DMA && bytes > 6 && (!tx /*|| !rx*/)) + ret = spi_dma_xfer(bss, tx, rx, bytes); + else + ret = spi_pio_xfer(bss, tx, rx, bytes); done: if (flags & SPI_XFER_END) |