spi: spi_sh_msiof: Fixed data sampling on the correct edge

The spi_sh_msiof.c driver presently misconfigures REDG and TEDG. TEDG==0
outputs data at the **rising edge** of the clock and REDG==0 samples data
at the **falling edge** of the clock. Therefore for SPI, TEDG must be
equal to REDG, otherwise the last byte received is not sampled in SPI
mode 3.

This brings the driver in line with the SH7723 HW Reference Manual
settings documented in Figures 20.20 and 20.21 ("SPI Clock and data
timing").

Signed-off-by: Markus Pietrek <Markus.Pietrek@emtrion.de>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/spi/spi_sh_msiof.c b/drivers/spi/spi_sh_msiof.c
index 51e5e1dfa6e5..30973ec16a93 100644
--- a/drivers/spi/spi_sh_msiof.c
+++ b/drivers/spi/spi_sh_msiof.c
@@ -173,15 +173,12 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
         int edge;
 
         /*
-         * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG(!)
-         *    0    0         10     10    1    0
-         *    0    1         10     10    0    1
-         *    1    0         11     11    0    1
-         *    1    1         11     11    1    0
-         *
-         * (!) Note: REDG is inverted recommended data sheet setting
+         * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
+         *    0    0         10     10    1    1
+         *    0    1         10     10    0    0
+         *    1    0         11     11    0    0
+         *    1    1         11     11    1    1
          */
-
         sh_msiof_write(p, FCTR, 0);
         sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
         sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
@@ -193,7 +190,7 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
         edge = cpol ? cpha : !cpha;
 
         tmp |= edge << 27; /* TEDG */
-        tmp |= !edge << 26; /* REDG */
+        tmp |= edge << 26; /* REDG */
         tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
         sh_msiof_write(p, CTR, tmp);
 }