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spi: davinci: add support for wait enable timeouts

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Just enabling WAITENA in SPIFMTn register waits for the
enable signal from the slave indefinitely. Allow support
for finite waiting by adding support for c2e delay
(maximum time for addressed slave to respond) and t2e
delay (maximum time for slave to respond after transmit
data finished).

While at it, modify the T2C and C2T defines by prepending
the register name as is the convention followed for other
register field elsewhere in the driver.

Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
This commit is contained in:
Brian Niebuhr 2010-08-19 15:07:38 +05:30 committed by Sekhar Nori
parent fd764463fe
commit 7abbf23c59
2 changed files with 29 additions and 9 deletions
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2
arch/arm/mach-davinci/include/mach/spi.h
View file

@ -43,6 +43,8 @@ struct davinci_spi_config {
u8 timer_disable;
u8 c2tdelay;
u8 t2cdelay;
u8 t2edelay;
u8 c2edelay;
};
#endif /* __ARCH_ARM_DAVINCI_SPI_H */

36
drivers/spi/davinci_spi.c
View file

@ -78,6 +78,16 @@
#define SPIBUF_TXFULL_MASK BIT(29)
#define SPIBUF_RXEMPTY_MASK BIT(31)
/* SPIDELAY */
#define SPIDELAY_C2TDELAY_SHIFT 24
#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
#define SPIDELAY_T2CDELAY_SHIFT 16
#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
#define SPIDELAY_T2EDELAY_SHIFT 8
#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
#define SPIDELAY_C2EDELAY_SHIFT 0
#define SPIDELAY_C2EDELAY_MASK 0xFF
/* Error Masks */
#define SPIFLG_DLEN_ERR_MASK BIT(0)
#define SPIFLG_TIMEOUT_MASK BIT(1)
@ -95,9 +105,6 @@
#define SPIINT_TX_INTR BIT(9)
#define SPIINT_DMA_REQ_EN BIT(16)
#define SPI_T2CDELAY_SHIFT 16
#define SPI_C2TDELAY_SHIFT 24
/* SPI Controller registers */
#define SPIGCR0 0x00
#define SPIGCR1 0x04
@ -363,6 +370,8 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
if (davinci_spi->version == SPI_VERSION_2) {
u32 delay = 0;
spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
& SPIFMT_WDELAY_MASK);
@ -372,15 +381,24 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
if (spicfg->parity_enable)
spifmt |= SPIFMT_PARITYENA_MASK;
if (spicfg->timer_disable)
if (spicfg->timer_disable) {
spifmt |= SPIFMT_DISTIMER_MASK;
else
iowrite32((spicfg->c2tdelay << SPI_C2TDELAY_SHIFT) |
(spicfg->t2cdelay << SPI_T2CDELAY_SHIFT),
davinci_spi->base + SPIDELAY);
} else {
delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
& SPIDELAY_C2TDELAY_MASK;
delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
& SPIDELAY_T2CDELAY_MASK;
}
if (spi->mode & SPI_READY)
if (spi->mode & SPI_READY) {
spifmt |= SPIFMT_WAITENA_MASK;
delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
& SPIDELAY_T2EDELAY_MASK;
delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
& SPIDELAY_C2EDELAY_MASK;
}
iowrite32(delay, davinci_spi->base + SPIDELAY);
}
iowrite32(spifmt, davinci_spi->base + SPIFMT0);