Commit id 2bd16e3e23d9df41592c6b257c59b6860a9cc3ea
(spi: omap2-mcspi: Do not configure the controller
on each transfer unless needed) does its job too
well so omap2_mcspi_setup_transfer() isn't called
even when an SPI slave driver changes 'spi->mode'.
The result is that the mode requested by the SPI
slave driver never takes effect.
Fix this by adding the 'mode' member to the
omap2_mcspi_cs structure which holds the mode
value that the hardware is configured for.
When the SPI slave driver changes 'spi->mode'
it will be different than the value of this new
member and the SPI master driver will know that
the hardware must be reconfigured (by calling
omap2_mcspi_setup_transfer()).
CC: Stefan Sørensen <stefan.sorensen@xxxxxxxxxxxxxxx>
Signed-off-by: Mark A. Greer <mgreer@xxxxxxxxxxxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 4dc77df..68441fa 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -149,6 +149,7 @@ struct omap2_mcspi_cs {
void __iomem *base;
unsigned long phys;
int word_len;
+ u16 mode;
struct list_head node;
/* Context save and restore shadow register */
u32 chconf0, chctrl0;
@@ -926,6 +927,8 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
mcspi_write_chconf0(spi, l);
+ cs->mode = spi->mode;
+
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
speed_hz,
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
@@ -998,6 +1001,7 @@ static int omap2_mcspi_setup(struct spi_device *spi)
return -ENOMEM;
cs->base = mcspi->base + spi->chip_select * 0x14;
cs->phys = mcspi->phys + spi->chip_select * 0x14;
+ cs->mode = 0;
cs->chconf0 = 0;
cs->chctrl0 = 0;
spi->controller_state = cs;
@@ -1079,6 +1083,16 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
cs = spi->controller_state;
cd = spi->controller_data;
+ /*
+ * The slave driver could have changed spi->mode in which case
+ * it will be different from cs->mode (the current hardware setup).
+ * If so, set par_override (even though its not a parity issue) so
+ * omap2_mcspi_setup_transfer will be called to configure the hardware
+ * with the correct mode on the first iteration of the loop below.
+ */
+ if (spi->mode != cs->mode)
+ par_override = 1;
+
omap2_mcspi_set_enable(spi, 0);
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
--
1.9.0
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