spi: Add spi_write_then_read

[oweals/u-boot.git] / drivers / spi / spi-uclass.c

diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index 88cb2a126227156d18342796d4022f25c3aefbba..76c4b53c165c764e496a40c101e6e34c65b8a887 100644 (file)
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -108,6 +108,30 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
        return dm_spi_xfer(slave->dev, bitlen, dout, din, flags);
 }
 
+int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
+                       size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
+                       size_t n_buf)
+{
+       unsigned long flags = SPI_XFER_BEGIN;
+       int ret;
+
+       if (n_buf == 0)
+               flags |= SPI_XFER_END;
+
+       ret = spi_xfer(slave, n_opcode * 8, opcode, NULL, flags);
+       if (ret) {
+               debug("spi: failed to send command (%zu bytes): %d\n",
+                     n_opcode, ret);
+       } else if (n_buf != 0) {
+               ret = spi_xfer(slave, n_buf * 8, txbuf, rxbuf, SPI_XFER_END);
+               if (ret)
+                       debug("spi: failed to transfer %zu bytes of data: %d\n",
+                             n_buf, ret);
+       }
+
+       return ret;
+}
+
 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
 static int spi_child_post_bind(struct udevice *dev)
 {