Commit f477b7fb authored by wangyuhang's avatar wangyuhang Committed by Mark Brown
Browse files

spi: DUAL and QUAD support 



fix the previous patch some mistake below:
1. DT in slave node, use "spi-tx-nbits = <1/2/4>" in place of using
   "spi-tx-dual, spi-tx-quad" directly, same to rx. So correct the
   previous way to get the property in @of_register_spi_devices().
2. Change the value of transfer bit macro(SPI_NBITS_SINGLE, SPI_NBITS_DUAL
   SPI_NBITS_QUAD) to 0x01, 0x02 and 0x04 to match the actual wires.
3. Add the following check
   (1)keep the tx_nbits and rx_nbits in spi_transfer is not beyond the
      single, dual and quad.
   (2)keep tx_nbits and rx_nbits are contained by @spi_device->mode
      example: if @spi_device->mode = DUAL, then tx/rx_nbits can not be set
               to QUAD(SPI_NBITS_QUAD)
   (3)if "@spi_device->mode & SPI_3WIRE", then tx/rx_nbits should be in
      single(SPI_NBITS_SINGLE)

Signed-off-by: default avatarwangyuhang <wangyuhang2014@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent 56ede94a

drivers/spi/spi.c

+96 −0
Original line number Diff line number Diff line
@@ -869,6 +869,51 @@ static void of_register_spi_devices(struct spi_master *master) 
		if (of_find_property(nc, "spi-3wire", NULL))

			spi->mode |= SPI_3WIRE;



		/* Device DUAL/QUAD mode */

		prop = of_get_property(nc, "spi-tx-nbits", &len);

		if (!prop || len < sizeof(*prop)) {

			dev_err(&master->dev, "%s has no 'spi-tx-nbits' property\n",

				nc->full_name);

			spi_dev_put(spi);

			continue;

		}

		switch (be32_to_cpup(prop)) {

		case SPI_NBITS_SINGLE:

			break;

		case SPI_NBITS_DUAL:

			spi->mode |= SPI_TX_DUAL;

			break;

		case SPI_NBITS_QUAD:

			spi->mode |= SPI_TX_QUAD;

			break;

		default:

			dev_err(&master->dev, "spi-tx-nbits value is not supported\n");

			spi_dev_put(spi);

			continue;

		}



		prop = of_get_property(nc, "spi-rx-nbits", &len);

		if (!prop || len < sizeof(*prop)) {

			dev_err(&master->dev, "%s has no 'spi-rx-nbits' property\n",

				nc->full_name);

			spi_dev_put(spi);

			continue;

		}

		switch (be32_to_cpup(prop)) {

		case SPI_NBITS_SINGLE:

			break;

		case SPI_NBITS_DUAL:

			spi->mode |= SPI_RX_DUAL;

			break;

		case SPI_NBITS_QUAD:

			spi->mode |= SPI_RX_QUAD;

			break;

		default:

			dev_err(&master->dev, "spi-rx-nbits value is not supported\n");

			spi_dev_put(spi);

			continue;

		}



		/* Device speed */

		prop = of_get_property(nc, "spi-max-frequency", &len);

		if (!prop || len < sizeof(*prop)) {
@@ -1316,6 +1361,19 @@ int spi_setup(struct spi_device *spi) 
	unsigned	bad_bits;

	int		status = 0;



	/* check mode to prevent that DUAL and QUAD set at the same time

	 */

	if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||

		((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {

		dev_err(&spi->dev,

		"setup: can not select dual and quad at the same time\n");

		return -EINVAL;

	}

	/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden

	 */

	if ((spi->mode & SPI_3WIRE) && (spi->mode &

		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))

		return -EINVAL;

	/* help drivers fail *cleanly* when they need options

	 * that aren't supported with their current master

	 */
@@ -1378,6 +1436,8 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) 
	/**

	 * Set transfer bits_per_word and max speed as spi device default if

	 * it is not set for this transfer.

	 * Set transfer tx_nbits and rx_nbits as single transfer default

	 * (SPI_NBITS_SINGLE) if it is not set for this transfer.

	 */

	list_for_each_entry(xfer, &message->transfers, transfer_list) {

		if (!xfer->bits_per_word)
@@ -1403,6 +1463,42 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) 
			return -EINVAL;

		if (xfer->speed_hz && master->max_speed_hz &&

		    xfer->speed_hz > master->max_speed_hz)



		if (xfer->tx_buf && !xfer->tx_nbits)

			xfer->tx_nbits = SPI_NBITS_SINGLE;

		if (xfer->rx_buf && !xfer->rx_nbits)

			xfer->rx_nbits = SPI_NBITS_SINGLE;

		/* check transfer tx/rx_nbits:

		 * 1. keep the value is not out of single, dual and quad

		 * 2. keep tx/rx_nbits is contained by mode in spi_device

		 * 3. if SPI_3WIRE, tx/rx_nbits should be in single

		 */

		if (xfer->tx_nbits != SPI_NBITS_SINGLE &&

			xfer->tx_nbits != SPI_NBITS_DUAL &&

			xfer->tx_nbits != SPI_NBITS_QUAD)

			return -EINVAL;

		if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&

			!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))

			return -EINVAL;

		if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&

			!(spi->mode & SPI_TX_QUAD))

			return -EINVAL;

		if ((spi->mode & SPI_3WIRE) &&

			(xfer->tx_nbits != SPI_NBITS_SINGLE))

			return -EINVAL;

		/* check transfer rx_nbits */

		if (xfer->rx_nbits != SPI_NBITS_SINGLE &&

			xfer->rx_nbits != SPI_NBITS_DUAL &&

			xfer->rx_nbits != SPI_NBITS_QUAD)

			return -EINVAL;

		if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&

			!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))

			return -EINVAL;

		if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&

			!(spi->mode & SPI_RX_QUAD))

			return -EINVAL;

		if ((spi->mode & SPI_3WIRE) &&

			(xfer->rx_nbits != SPI_NBITS_SINGLE))

			return -EINVAL;

	}

include/linux/spi/spi.h

+20 −2
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ struct spi_device { 
	struct spi_master	*master;

	u32			max_speed_hz;

	u8			chip_select;

	u8			mode;

	u16			mode;

#define	SPI_CPHA	0x01			/* clock phase */

#define	SPI_CPOL	0x02			/* clock polarity */

#define	SPI_MODE_0	(0|0)			/* (original MicroWire) */
@@ -87,6 +87,10 @@ struct spi_device { 
#define	SPI_LOOP	0x20			/* loopback mode */

#define	SPI_NO_CS	0x40			/* 1 dev/bus, no chipselect */

#define	SPI_READY	0x80			/* slave pulls low to pause */

#define	SPI_TX_DUAL	0x100			/* transmit with 2 wires */

#define	SPI_TX_QUAD	0x200			/* transmit with 4 wires */

#define	SPI_RX_DUAL	0x400			/* receive with 2 wires */

#define	SPI_RX_QUAD	0x800			/* receive with 4 wires */

	u8			bits_per_word;

	int			irq;

	void			*controller_state;
@@ -454,6 +458,10 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); 
 * @rx_buf: data to be read (dma-safe memory), or NULL

 * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped

 * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped

 * @tx_nbits: number of bits used for writting. If 0 the default

 *      (SPI_NBITS_SINGLE) is used.

 * @rx_nbits: number of bits used for reading. If 0 the default

 *      (SPI_NBITS_SINGLE) is used.

 * @len: size of rx and tx buffers (in bytes)

 * @speed_hz: Select a speed other than the device default for this

 *      transfer. If 0 the default (from @spi_device) is used.
@@ -508,6 +516,11 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); 
 * by the results of previous messages and where the whole transaction

 * ends when the chipselect goes intactive.

 *

 * When SPI can transfer in 1x,2x or 4x. It can get this tranfer information

 * from device through @tx_nbits and @rx_nbits. In Bi-direction, these

 * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)

 * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.

 *

 * The code that submits an spi_message (and its spi_transfers)

 * to the lower layers is responsible for managing its memory.

 * Zero-initialize every field you don't set up explicitly, to
@@ -528,6 +541,11 @@ struct spi_transfer { 
	dma_addr_t	rx_dma;



	unsigned	cs_change:1;

	u8		tx_nbits;

	u8		rx_nbits;

#define	SPI_NBITS_SINGLE	0x01 /* 1bit transfer */

#define	SPI_NBITS_DUAL		0x02 /* 2bits transfer */

#define	SPI_NBITS_QUAD		0x04 /* 4bits transfer */

	u8		bits_per_word;

	u16		delay_usecs;

	u32		speed_hz;
@@ -875,7 +893,7 @@ struct spi_board_info { 
	/* mode becomes spi_device.mode, and is essential for chips

	 * where the default of SPI_CS_HIGH = 0 is wrong.

	 */

	u8		mode;

	u16		mode;



	/* ... may need additional spi_device chip config data here.

	 * avoid stuff protocol drivers can set; but include stuff

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