示例#1
0
static int davinci_spi_setup(struct spi_device *spi)
{
	int retval;
	struct davinci_spi *davinci_spi;
	struct davinci_spi_dma *davinci_spi_dma;

	davinci_spi = spi_master_get_devdata(spi->master);

	/* if bits per word length is zero then set it default 8 */
	if (!spi->bits_per_word)
		spi->bits_per_word = 8;

	davinci_spi->slave[spi->chip_select].cmd_to_write = 0;

	if (use_dma && davinci_spi->dma_channels) {
		davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];

		if ((davinci_spi_dma->dma_rx_channel == -1)
				|| (davinci_spi_dma->dma_tx_channel == -1)) {
			retval = davinci_spi_request_dma(spi);
			if (retval < 0)
				return retval;
		}
	}

	retval = davinci_spi_setup_transfer(spi, NULL);

	return retval;
}
示例#2
0
static int davinci_spi_setup(struct spi_device *spi)
{
	int retval;
	struct davinci_spi *davinci_spi;
	struct davinci_spi_dma *davinci_spi_dma;
	struct device *sdev;

	davinci_spi = spi_master_get_devdata(spi->master);
	sdev = davinci_spi->bitbang.master->dev.parent;

	/* if bits per word length is zero then set it default 8 */
	if (!spi->bits_per_word)
		spi->bits_per_word = 8;

	davinci_spi->slave[spi->chip_select].cmd_to_write = 0;

	if (use_dma && davinci_spi->dma_channels) {
		davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];

		if ((davinci_spi_dma->dma_rx_channel == -1)
				|| (davinci_spi_dma->dma_tx_channel == -1)) {
			retval = davinci_spi_request_dma(spi);
			if (retval < 0)
				return retval;
		}
	}

	/*
	 * SPI in DaVinci and DA8xx operate between
	 * 600 KHz and 50 MHz
	 */
	if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000) {
		dev_dbg(sdev, "Operating frequency is not in acceptable "
				"range\n");
		return -EINVAL;
	}

	/*
	 * Set up SPIFMTn register, unique to this chipselect.
	 *
	 * NOTE: we could do all of these with one write.  Also, some
	 * of the "version 2" features are found in chips that don't
	 * support all of them...
	 */
	if (spi->mode & SPI_LSB_FIRST)
		set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
				spi->chip_select);
	else
		clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
				spi->chip_select);

	if (spi->mode & SPI_CPOL)
		set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
				spi->chip_select);
	else
		clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
				spi->chip_select);

	if (!(spi->mode & SPI_CPHA))
		set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
				spi->chip_select);
	else
		clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
				spi->chip_select);

	/*
	 * Version 1 hardware supports two basic SPI modes:
	 *  - Standard SPI mode uses 4 pins, with chipselect
	 *  - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
	 *	(distinct from SPI_3WIRE, with just one data wire;
	 *	or similar variants without MOSI or without MISO)
	 *
	 * Version 2 hardware supports an optional handshaking signal,
	 * so it can support two more modes:
	 *  - 5 pin SPI variant is standard SPI plus SPI_READY
	 *  - 4 pin with enable is (SPI_READY | SPI_NO_CS)
	 */

	if (davinci_spi->version == SPI_VERSION_2) {
		clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
				spi->chip_select);
		set_fmt_bits(davinci_spi->base,
				(davinci_spi->pdata->wdelay
						<< SPIFMT_WDELAY_SHIFT)
					& SPIFMT_WDELAY_MASK,
				spi->chip_select);

		if (davinci_spi->pdata->odd_parity)
			set_fmt_bits(davinci_spi->base,
					SPIFMT_ODD_PARITY_MASK,
					spi->chip_select);
		else
			clear_fmt_bits(davinci_spi->base,
					SPIFMT_ODD_PARITY_MASK,
					spi->chip_select);

		if (davinci_spi->pdata->parity_enable)
			set_fmt_bits(davinci_spi->base,
					SPIFMT_PARITYENA_MASK,
					spi->chip_select);
		else
			clear_fmt_bits(davinci_spi->base,
					SPIFMT_PARITYENA_MASK,
					spi->chip_select);

		if (davinci_spi->pdata->wait_enable)
			set_fmt_bits(davinci_spi->base,
					SPIFMT_WAITENA_MASK,
					spi->chip_select);
		else
			clear_fmt_bits(davinci_spi->base,
					SPIFMT_WAITENA_MASK,
					spi->chip_select);

		if (davinci_spi->pdata->timer_disable)
			set_fmt_bits(davinci_spi->base,
					SPIFMT_DISTIMER_MASK,
					spi->chip_select);
		else
			clear_fmt_bits(davinci_spi->base,
					SPIFMT_DISTIMER_MASK,
					spi->chip_select);
	}

	retval = davinci_spi_setup_transfer(spi, NULL);

	return retval;
}