Currently only the MSIOF_SYNC signal can be used as a native chip
select. Extend support to up to 3 native chipselects using the
MSIOF_SS1 and MSIOF_SS2 signals.
Inspired by a patch in the BSP by Hiromitsu Yamasaki.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
Documentation/devicetree/bindings/spi/sh-msiof.txt | 6 +++++-
drivers/spi/spi-sh-msiof.c | 18 +++++++++++++-----
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt
index bdd83959019c7883..bc8c16a6cfc82685 100644
--- a/Documentation/devicetree/bindings/spi/sh-msiof.txt
+++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt
@@ -36,7 +36,11 @@ Required properties:
Optional properties:
- clocks : Must contain a reference to the functional clock.
-- num-cs : Total number of chip-selects (default is 1)
+- num-cs : Total number of chip selects (default is 1).
+ Up to 3 native chip selects are supported:
+ 0: MSIOF_SYNC
+ 1: MSIOF_SS1
+ 2: MSIOF_SS2
- dmas : Must contain a list of two references to DMA
specifiers, one for transmission, and one for
reception.
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 2704abb11ea41fd0..9bdc292aa050cb16 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -60,6 +60,8 @@ struct sh_msiof_spi_priv {
bool slave_aborted;
};
+#define MAX_SS 3 /* Maximum number of native chip selects */
+
#define TMDR1 0x00 /* Transmit Mode Register 1 */
#define TMDR2 0x04 /* Transmit Mode Register 2 */
#define TMDR3 0x08 /* Transmit Mode Register 3 */
@@ -93,6 +95,8 @@ struct sh_msiof_spi_priv {
#define MDR1_XXSTP 0x00000001 /* Transmission/Reception Stop on FIFO */
/* TMDR1 */
#define TMDR1_PCON 0x40000000 /* Transfer Signal Connection */
+#define TMDR1_SYNCCH_MASK 0xc000000 /* Synchronization Signal Channel Select */
+#define TMDR1_SYNCCH_SHIFT 26 /* 0=MSIOF_SYNC, 1=MSIOF_SS1, 2=MSIOF_SS2 */
/* TMDR2 and RMDR2 */
#define MDR2_BITLEN1(i) (((i) - 1) << 24) /* Data Size (8-32 bits) */
@@ -326,7 +330,7 @@ static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
return val;
}
-static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
+static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p, u32 ss,
u32 cpol, u32 cpha,
u32 tx_hi_z, u32 lsb_first, u32 cs_high)
{
@@ -344,10 +348,13 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
tmp |= lsb_first << MDR1_BITLSB_SHIFT;
tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
- if (spi_controller_is_slave(p->master))
+ if (spi_controller_is_slave(p->master)) {
sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
- else
- sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
+ } else {
+ sh_msiof_write(p, TMDR1,
+ tmp | MDR1_TRMD | TMDR1_PCON |
+ (ss < MAX_SS ? ss : 0) << TMDR1_SYNCCH_SHIFT);
+ }
if (p->master->flags & SPI_MASTER_MUST_TX) {
/* These bits are reserved if RX needs TX */
tmp &= ~0x0000ffff;
@@ -575,7 +582,8 @@ static int sh_msiof_prepare_message(struct spi_master *master,
const struct spi_device *spi = msg->spi;
/* Configure pins before asserting CS */
- sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
+ sh_msiof_spi_set_pin_regs(p, spi->chip_select,
+ !!(spi->mode & SPI_CPOL),
!!(spi->mode & SPI_CPHA),
!!(spi->mode & SPI_3WIRE),
!!(spi->mode & SPI_LSB_FIRST),
--
2.7.4
--
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