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authorGeert Uytterhoeven <geert+renesas@glider.be>2017-12-13 20:05:11 +0100
committerMark Brown <broonie@kernel.org>2017-12-14 11:46:07 +0000
commit9cce882bedd2768dc251b73f2ad86a9bfcfd9fc7 (patch)
tree4cad033f301cd7628aea3ba08923b6f8e1500232 /drivers/spi/spi-sh-msiof.c
parent7ff0b53c4051145d1cf992d2f60987e6447eed4f (diff)
downloadlinux-9cce882bedd2768dc251b73f2ad86a9bfcfd9fc7.tar.bz2
spi: sh-msiof: Extend support to 3 native chip selects
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@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-sh-msiof.c')
-rw-r--r--drivers/spi/spi-sh-msiof.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 2704abb11ea4..9bdc292aa050 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),