Merge tag 'spi-bpw-is-supported' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.3

spi: Add spi_is_bpw_supported()

Lets client drivers check and potentially handle issues.

include/linux/spi/spi.h

@@ -1005,6 +1005,26 @@ spi_max_transfer_size(struct spi_device *spi)
 	return min(tr_max, msg_max);
 }
 
+/**
+ * spi_is_bpw_supported - Check if bits per word is supported
+ * @spi: SPI device
+ * @bpw: Bits per word
+ *
+ * This function checks to see if the SPI controller supports @bpw.
+ *
+ * Returns:
+ * True if @bpw is supported, false otherwise.
+ */
+static inline bool spi_is_bpw_supported(struct spi_device *spi, u32 bpw)
+{
+	u32 bpw_mask = spi->master->bits_per_word_mask;
+
+	if (bpw == 8 || (bpw <= 32 && bpw_mask & SPI_BPW_MASK(bpw)))
+		return true;
+
+	return false;
+}
+
 /*---------------------------------------------------------------------------*/
 
 /* SPI transfer replacement methods which make use of spi_res */