From 5753d09b1064a669e3be8f27e0f1fd008b96934a Mon Sep 17 00:00:00 2001 From: Nikita Kiryanov Date: Wed, 16 Oct 2013 17:23:25 +0300 Subject: [PATCH] spi: omap3: add support for more word lengths Current implementation only supports 8 bit word lengths, even though omap3 can handle anything between 4 and 32. Update the spi interface to support changing the SPI word length, and implement it in omap3_spi driver to support the full range of possible word lengths. This implementation is backwards compatible by defaulting to the old behavior of 8 bit word lengths. Also, it required a change to the omap3_spi non static I/O functions, but since they are not used anywhere else, no collateral changes are required. Cc: Tom Rini Cc: Jagannadha Sutradharudu Teki Cc: Igor Grinberg Signed-off-by: Nikita Kiryanov --- drivers/spi/omap3_spi.c | 69 +++++++++++++++++++++++++++++------------ drivers/spi/omap3_spi.h | 8 ++--- drivers/spi/spi.c | 13 ++++++++ include/spi.h | 16 ++++++++++ 4 files changed, 82 insertions(+), 24 deletions(-) diff --git a/drivers/spi/omap3_spi.c b/drivers/spi/omap3_spi.c index 116276c000..a3ad056473 100644 --- a/drivers/spi/omap3_spi.c +++ b/drivers/spi/omap3_spi.c @@ -20,7 +20,6 @@ #include #include "omap3_spi.h" -#define WORD_LEN 8 #define SPI_WAIT_TIMEOUT 3000000 static void spi_reset(struct omap3_spi_slave *ds) @@ -185,7 +184,7 @@ int spi_claim_bus(struct spi_slave *slave) /* wordlength */ conf &= ~OMAP3_MCSPI_CHCONF_WL_MASK; - conf |= (WORD_LEN - 1) << 7; + conf |= (ds->slave.wordlen - 1) << 7; /* set chipselect polarity; manage with FORCE */ if (!(ds->mode & SPI_CS_HIGH)) @@ -223,7 +222,7 @@ void spi_release_bus(struct spi_slave *slave) spi_reset(ds); } -int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp, +int omap3_spi_write(struct spi_slave *slave, unsigned int len, const void *txp, unsigned long flags) { struct omap3_spi_slave *ds = to_omap3_spi(slave); @@ -234,7 +233,8 @@ int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp, /* Enable the channel */ omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN); - chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK; + chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK); + chconf |= (ds->slave.wordlen - 1) << 7; chconf |= OMAP3_MCSPI_CHCONF_TRM_TX_ONLY; chconf |= OMAP3_MCSPI_CHCONF_FORCE; omap3_spi_write_chconf(ds,chconf); @@ -250,7 +250,13 @@ int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp, } } /* Write the data */ - writel(txp[i], &ds->regs->channel[ds->slave.cs].tx); + unsigned int *tx = &ds->regs->channel[ds->slave.cs].tx; + if (ds->slave.wordlen > 16) + writel(((u32 *)txp)[i], tx); + else if (ds->slave.wordlen > 8) + writel(((u16 *)txp)[i], tx); + else + writel(((u8 *)txp)[i], tx); } /* wait to finish of transfer */ @@ -268,7 +274,7 @@ int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp, return 0; } -int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp, +int omap3_spi_read(struct spi_slave *slave, unsigned int len, void *rxp, unsigned long flags) { struct omap3_spi_slave *ds = to_omap3_spi(slave); @@ -279,7 +285,8 @@ int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp, /* Enable the channel */ omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN); - chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK; + chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK); + chconf |= (ds->slave.wordlen - 1) << 7; chconf |= OMAP3_MCSPI_CHCONF_TRM_RX_ONLY; chconf |= OMAP3_MCSPI_CHCONF_FORCE; omap3_spi_write_chconf(ds,chconf); @@ -302,7 +309,13 @@ int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp, omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS); /* Read the data */ - rxp[i] = readl(&ds->regs->channel[ds->slave.cs].rx); + unsigned int *rx = &ds->regs->channel[ds->slave.cs].rx; + if (ds->slave.wordlen > 16) + ((u32 *)rxp)[i] = readl(rx); + else if (ds->slave.wordlen > 8) + ((u16 *)rxp)[i] = (u16)readl(rx); + else + ((u8 *)rxp)[i] = (u8)readl(rx); } if (flags & SPI_XFER_END) { @@ -314,8 +327,8 @@ int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp, } /*McSPI Transmit Receive Mode*/ -int omap3_spi_txrx(struct spi_slave *slave, - unsigned int len, const u8 *txp, u8 *rxp, unsigned long flags) +int omap3_spi_txrx(struct spi_slave *slave, unsigned int len, + const void *txp, void *rxp, unsigned long flags) { struct omap3_spi_slave *ds = to_omap3_spi(slave); int timeout = SPI_WAIT_TIMEOUT; @@ -327,7 +340,8 @@ int omap3_spi_txrx(struct spi_slave *slave, omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN); /*set TRANSMIT-RECEIVE Mode*/ - chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK; + chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK); + chconf |= (ds->slave.wordlen - 1) << 7; chconf |= OMAP3_MCSPI_CHCONF_FORCE; omap3_spi_write_chconf(ds,chconf); @@ -344,7 +358,13 @@ int omap3_spi_txrx(struct spi_slave *slave, } } /* Write the data */ - writel(txp[i], &ds->regs->channel[ds->slave.cs].tx); + unsigned int *tx = &ds->regs->channel[ds->slave.cs].tx; + if (ds->slave.wordlen > 16) + writel(((u32 *)txp)[i], tx); + else if (ds->slave.wordlen > 8) + writel(((u16 *)txp)[i], tx); + else + writel(((u8 *)txp)[i], tx); /*Read: wait for RX containing data (RXS == 1)*/ while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) & @@ -356,7 +376,13 @@ int omap3_spi_txrx(struct spi_slave *slave, } } /* Read the data */ - rxp[i] = readl(&ds->regs->channel[ds->slave.cs].rx); + unsigned int *rx = &ds->regs->channel[ds->slave.cs].rx; + if (ds->slave.wordlen > 16) + ((u32 *)rxp)[i] = readl(rx); + else if (ds->slave.wordlen > 8) + ((u16 *)rxp)[i] = (u16)readl(rx); + else + ((u8 *)rxp)[i] = (u8)readl(rx); } /* Disable the channel */ omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS); @@ -375,14 +401,17 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, { struct omap3_spi_slave *ds = to_omap3_spi(slave); unsigned int len; - const u8 *txp = dout; - u8 *rxp = din; int ret = -1; - if (bitlen % 8) + if (ds->slave.wordlen < 4 || ds->slave.wordlen > 32) { + printf("omap3_spi: invalid wordlen %d\n", ds->slave.wordlen); + return -1; + } + + if (bitlen % ds->slave.wordlen) return -1; - len = bitlen / 8; + len = bitlen / ds->slave.wordlen; if (bitlen == 0) { /* only change CS */ int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf); @@ -400,11 +429,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, ret = 0; } else { if (dout != NULL && din != NULL) - ret = omap3_spi_txrx(slave, len, txp, rxp, flags); + ret = omap3_spi_txrx(slave, len, dout, din, flags); else if (dout != NULL) - ret = omap3_spi_write(slave, len, txp, flags); + ret = omap3_spi_write(slave, len, dout, flags); else if (din != NULL) - ret = omap3_spi_read(slave, len, rxp, flags); + ret = omap3_spi_read(slave, len, din, flags); } return ret; } diff --git a/drivers/spi/omap3_spi.h b/drivers/spi/omap3_spi.h index 01537b6246..ab7cd84448 100644 --- a/drivers/spi/omap3_spi.h +++ b/drivers/spi/omap3_spi.h @@ -99,11 +99,11 @@ static inline struct omap3_spi_slave *to_omap3_spi(struct spi_slave *slave) return container_of(slave, struct omap3_spi_slave, slave); } -int omap3_spi_txrx(struct spi_slave *slave, unsigned int len, const u8 *txp, - u8 *rxp, unsigned long flags); -int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp, +int omap3_spi_txrx(struct spi_slave *slave, unsigned int len, const void *txp, + void *rxp, unsigned long flags); +int omap3_spi_write(struct spi_slave *slave, unsigned int len, const void *txp, unsigned long flags); -int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp, +int omap3_spi_read(struct spi_slave *slave, unsigned int len, void *rxp, unsigned long flags); #endif /* _OMAP3_SPI_H_ */ diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ea39d1a1ee..b76a26cef0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -8,6 +8,18 @@ #include #include +int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen) +{ + if (wordlen == 0 || wordlen > 32) { + printf("spi: invalid wordlen %d\n", wordlen); + return -1; + } + + slave->wordlen = wordlen; + + return 0; +} + void *spi_do_alloc_slave(int offset, int size, unsigned int bus, unsigned int cs) { @@ -20,6 +32,7 @@ void *spi_do_alloc_slave(int offset, int size, unsigned int bus, slave = (struct spi_slave *)(ptr + offset); slave->bus = bus; slave->cs = cs; + slave->wordlen = SPI_DEFAULT_WORDLEN; } return ptr; diff --git a/include/spi.h b/include/spi.h index ad9248bee0..67da75cb59 100644 --- a/include/spi.h +++ b/include/spi.h @@ -33,6 +33,8 @@ /* Header byte that marks the start of the message */ #define SPI_PREAMBLE_END_BYTE 0xec +#define SPI_DEFAULT_WORDLEN 8 + /** * struct spi_slave - Representation of a SPI slave * @@ -40,6 +42,7 @@ * * @bus: ID of the bus that the slave is attached to. * @cs: ID of the chip select connected to the slave. + * @wordlen: Size of SPI word in number of bits * @max_write_size: If non-zero, the maximum number of bytes which can * be written at once, excluding command bytes. * @memory_map: Address of read-only SPI flash access. @@ -47,6 +50,7 @@ struct spi_slave { unsigned int bus; unsigned int cs; + unsigned int wordlen; unsigned int max_write_size; void *memory_map; }; @@ -152,6 +156,18 @@ int spi_claim_bus(struct spi_slave *slave); */ void spi_release_bus(struct spi_slave *slave); +/** + * Set the word length for SPI transactions + * + * Set the word length (number of bits per word) for SPI transactions. + * + * @slave: The SPI slave + * @wordlen: The number of bits in a word + * + * Returns: 0 on success, -1 on failure. + */ +int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen); + /** * SPI transfer * -- 2.30.2