spi/spi_mpc8xxx: Fix QE mode Litte Endian
QE mode uses Little Endian so words > 8 bits are byte swapped.
Workaround this by always enforcing wordsize 8 for words
> 8 bits. Unfortunately this will not work for LSB transfers
where wordsize is > 8 bits so disable these for now.
Also move the different quirks into its own function to keep
mpc8xxx_spi_setup_transfer() sane.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c
index 0dfc482..66517ce7 100644
--- a/drivers/spi/spi_mpc8xxx.c
+++ b/drivers/spi/spi_mpc8xxx.c
@@ -286,11 +286,75 @@
}
}
+static int
+mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
+ struct spi_device *spi,
+ struct mpc8xxx_spi *mpc8xxx_spi,
+ int bits_per_word)
+{
+ cs->rx_shift = 0;
+ cs->tx_shift = 0;
+ if (bits_per_word <= 8) {
+ cs->get_rx = mpc8xxx_spi_rx_buf_u8;
+ cs->get_tx = mpc8xxx_spi_tx_buf_u8;
+ if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
+ cs->rx_shift = 16;
+ cs->tx_shift = 24;
+ }
+ } else if (bits_per_word <= 16) {
+ cs->get_rx = mpc8xxx_spi_rx_buf_u16;
+ cs->get_tx = mpc8xxx_spi_tx_buf_u16;
+ if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
+ cs->rx_shift = 16;
+ cs->tx_shift = 16;
+ }
+ } else if (bits_per_word <= 32) {
+ cs->get_rx = mpc8xxx_spi_rx_buf_u32;
+ cs->get_tx = mpc8xxx_spi_tx_buf_u32;
+ } else
+ return -EINVAL;
+
+ if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE &&
+ spi->mode & SPI_LSB_FIRST) {
+ cs->tx_shift = 0;
+ if (bits_per_word <= 8)
+ cs->rx_shift = 8;
+ else
+ cs->rx_shift = 0;
+ }
+ mpc8xxx_spi->rx_shift = cs->rx_shift;
+ mpc8xxx_spi->tx_shift = cs->tx_shift;
+ mpc8xxx_spi->get_rx = cs->get_rx;
+ mpc8xxx_spi->get_tx = cs->get_tx;
+
+ return bits_per_word;
+}
+
+static int
+mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
+ struct spi_device *spi,
+ int bits_per_word)
+{
+ /* QE uses Little Endian for words > 8
+ * so transform all words > 8 into 8 bits
+ * Unfortnatly that doesn't work for LSB so
+ * reject these for now */
+ /* Note: 32 bits word, LSB works iff
+ * tfcr/rfcr is set to CPMFCR_GBL */
+ if (spi->mode & SPI_LSB_FIRST &&
+ bits_per_word > 8)
+ return -EINVAL;
+ if (bits_per_word > 8)
+ return 8; /* pretend its 8 bits */
+ return bits_per_word;
+}
+
static
int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
{
struct mpc8xxx_spi *mpc8xxx_spi;
- u8 bits_per_word, pm;
+ int bits_per_word;
+ u8 pm;
u32 hz;
struct spi_mpc8xxx_cs *cs = spi->controller_state;
@@ -316,41 +380,16 @@
if (!hz)
hz = spi->max_speed_hz;
- cs->rx_shift = 0;
- cs->tx_shift = 0;
- if (bits_per_word <= 8) {
- cs->get_rx = mpc8xxx_spi_rx_buf_u8;
- cs->get_tx = mpc8xxx_spi_tx_buf_u8;
- if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
- cs->rx_shift = 16;
- cs->tx_shift = 24;
- }
- } else if (bits_per_word <= 16) {
- cs->get_rx = mpc8xxx_spi_rx_buf_u16;
- cs->get_tx = mpc8xxx_spi_tx_buf_u16;
- if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
- cs->rx_shift = 16;
- cs->tx_shift = 16;
- }
- } else if (bits_per_word <= 32) {
- cs->get_rx = mpc8xxx_spi_rx_buf_u32;
- cs->get_tx = mpc8xxx_spi_tx_buf_u32;
- } else
- return -EINVAL;
+ if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
+ bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
+ mpc8xxx_spi,
+ bits_per_word);
+ else if (mpc8xxx_spi->flags & SPI_QE)
+ bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
+ bits_per_word);
- if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE &&
- spi->mode & SPI_LSB_FIRST) {
- cs->tx_shift = 0;
- if (bits_per_word <= 8)
- cs->rx_shift = 8;
- else
- cs->rx_shift = 0;
- }
-
- mpc8xxx_spi->rx_shift = cs->rx_shift;
- mpc8xxx_spi->tx_shift = cs->tx_shift;
- mpc8xxx_spi->get_rx = cs->get_rx;
- mpc8xxx_spi->get_tx = cs->get_tx;
+ if (bits_per_word < 0)
+ return bits_per_word;
if (bits_per_word == 32)
bits_per_word = 0;