[U-Boot] [PATCH 03/20] cros_ec: Handle the single duplex requirement in cros_ec

Simon Glass
2015-02-17T22:29:37Z

With several chips using the SPI protocol it seems better to put the single
duplex functionality in the EC rather than the SPI driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

drivers/misc/cros_ec_spi.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/cros_ec_spi.c b/drivers/misc/cros_ec_spi.c
index 9359c56..5f37947 100644
--- a/drivers/misc/cros_ec_spi.c
+++ b/drivers/misc/cros_ec_spi.c
@@ -25,6 +25,8 @@ int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
{
struct cros_ec_dev *dev = udev->uclass_priv;
struct spi_slave *slave = dev_get_parentdata(dev->dev);
+ ulong start;
+ uint8_t byte;
int rv;

/* Do the transfer */
@@ -33,10 +35,25 @@ int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
return -1;
}

- rv = spi_xfer(slave, max(out_bytes, in_bytes) * 8,
- dev->dout, dev->din,
- SPI_XFER_BEGIN | SPI_XFER_END);
+ rv = spi_xfer(slave, out_bytes * 8, dev->dout, NULL, SPI_XFER_BEGIN);
+ if (rv)
+ goto done;
+ start = get_timer(0);
+ while (1) {
+ rv = spi_xfer(slave, 8, NULL, &byte, 0);
+ if (byte == SPI_PREAMBLE_END_BYTE)
+ break;
+ if (rv)
+ goto done;
+ if (get_timer(start) > 100) {
+ rv = -ETIMEDOUT;
+ goto done;
+ }
+ }

+ rv = spi_xfer(slave, in_bytes * 8, NULL, dev->din, 0);
+done:
+ spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END);
spi_release_bus(slave);

if (rv) {
--
2.2.0.rc0.207.ga3a616c