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spi: sh-msiof: Extend support to 3 native chip selects

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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>
This commit is contained in:
Geert Uytterhoeven 2017-12-13 20:05:11 +01:00 committed by Mark Brown
parent 7ff0b53c40
commit 9cce882bed
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GPG key ID: 24D68B725D5487D0
2 changed files with 18 additions and 6 deletions
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6
Documentation/devicetree/bindings/spi/sh-msiof.txt
View file

@ -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.

18
drivers/spi/spi-sh-msiof.c
View file

@ -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),