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: wangyuhang <wangyuhang2014@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 2a20c32..39d3875 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -869,6 +869,51 @@
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 @@
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 @@
/**
* 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 @@
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;
}