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Code Issues Releases Wiki Activity

spi: davinci: consolidate setup of SPIFMTn in one function

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Consolidate the setup of SPIFMTn register under
davinci_spi_setup_transfer() simplifying the code
and avoiding unnecessary reads and writes to the
register.

The two inline functions {set|clear}_fmt_bits() can
be eliminated because of this.

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 12:15:22 +05:30 committed by Sekhar Nori
parent 53a31b07c5
commit 25f33512f6
1 changed files with 49 additions and 105 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

154
drivers/spi/davinci_spi.c
View file

@ -52,7 +52,6 @@
#define SPIFMT_ODD_PARITY_MASK BIT(23)
#define SPIFMT_WDELAY_MASK 0x3f000000u
#define SPIFMT_WDELAY_SHIFT 24
#define SPIFMT_CHARLEN_MASK 0x0000001Fu
#define SPIFMT_PRESCALE_SHIFT 8
@ -212,16 +211,6 @@ static inline void clear_io_bits(void __iomem *addr, u32 bits)
iowrite32(v, addr);
}
static inline void set_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
{
set_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
}
static inline void clear_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
{
clear_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
}
static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable)
{
struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
@ -306,10 +295,14 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
{
struct davinci_spi *davinci_spi;
struct davinci_spi_config *spicfg;
u8 bits_per_word = 0;
u32 hz = 0, prescale = 0;
u32 hz = 0, spifmt = 0, prescale = 0;
davinci_spi = spi_master_get_devdata(spi->master);
spicfg = (struct davinci_spi_config *)spi->controller_data;
if (!spicfg)
spicfg = &davinci_spi_default_cfg;
if (t) {
bits_per_word = t->bits_per_word;
@ -338,18 +331,55 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
if (!hz)
hz = spi->max_speed_hz;
/* Set up SPIFMTn register, unique to this chipselect. */
prescale = davinci_spi_get_prescale(davinci_spi, hz);
if (prescale < 0)
return prescale;
clear_fmt_bits(davinci_spi->base, SPIFMT_CHARLEN_MASK,
spi->chip_select);
set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f,
spi->chip_select);
spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select);
set_fmt_bits(davinci_spi->base,
prescale << SPIFMT_PRESCALE_SHIFT, spi->chip_select);
if (spi->mode & SPI_LSB_FIRST)
spifmt |= SPIFMT_SHIFTDIR_MASK;
if (spi->mode & SPI_CPOL)
spifmt |= SPIFMT_POLARITY_MASK;
if (!(spi->mode & SPI_CPHA))
spifmt |= SPIFMT_PHASE_MASK;
/*
* Version 1 hardware supports two basic SPI modes:
* - Standard SPI mode uses 4 pins, with chipselect
* - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
* (distinct from SPI_3WIRE, with just one data wire;
* or similar variants without MOSI or without MISO)
*
* Version 2 hardware supports an optional handshaking signal,
* so it can support two more modes:
* - 5 pin SPI variant is standard SPI plus SPI_READY
* - 4 pin with enable is (SPI_READY | SPI_NO_CS)
*/
if (davinci_spi->version == SPI_VERSION_2) {
spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
& SPIFMT_WDELAY_MASK);
if (spicfg->odd_parity)
spifmt |= SPIFMT_ODD_PARITY_MASK;
if (spicfg->parity_enable)
spifmt |= SPIFMT_PARITYENA_MASK;
if (spicfg->timer_disable)
spifmt |= SPIFMT_DISTIMER_MASK;
if (spi->mode & SPI_READY)
spifmt |= SPIFMT_WAITENA_MASK;
}
iowrite32(spifmt, davinci_spi->base + SPIFMT0);
return 0;
}
@ -436,12 +466,8 @@ static int davinci_spi_setup(struct spi_device *spi)
int retval;
struct davinci_spi *davinci_spi;
struct davinci_spi_dma *davinci_spi_dma;
struct davinci_spi_config *spicfg;
davinci_spi = spi_master_get_devdata(spi->master);
spicfg = (struct davinci_spi_config *)spi->controller_data;
if (!spicfg)
spicfg = &davinci_spi_default_cfg;
/* if bits per word length is zero then set it default 8 */
if (!spi->bits_per_word)
@ -460,88 +486,6 @@ static int davinci_spi_setup(struct spi_device *spi)
}
}
/*
* Set up SPIFMTn register, unique to this chipselect.
*
* NOTE: we could do all of these with one write. Also, some
* of the "version 2" features are found in chips that don't
* support all of them...
*/
if (spi->mode & SPI_LSB_FIRST)
set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
spi->chip_select);
if (spi->mode & SPI_CPOL)
set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
spi->chip_select);
if (!(spi->mode & SPI_CPHA))
set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
spi->chip_select);
/*
* Version 1 hardware supports two basic SPI modes:
* - Standard SPI mode uses 4 pins, with chipselect
* - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
* (distinct from SPI_3WIRE, with just one data wire;
* or similar variants without MOSI or without MISO)
*
* Version 2 hardware supports an optional handshaking signal,
* so it can support two more modes:
* - 5 pin SPI variant is standard SPI plus SPI_READY
* - 4 pin with enable is (SPI_READY | SPI_NO_CS)
*/
if (davinci_spi->version == SPI_VERSION_2) {
clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
spi->chip_select);
set_fmt_bits(davinci_spi->base,
(spicfg->wdelay << SPIFMT_WDELAY_SHIFT) &
SPIFMT_WDELAY_MASK, spi->chip_select);
if (spicfg->odd_parity)
set_fmt_bits(davinci_spi->base, SPIFMT_ODD_PARITY_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_ODD_PARITY_MASK,
spi->chip_select);
if (spicfg->parity_enable)
set_fmt_bits(davinci_spi->base, SPIFMT_PARITYENA_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_PARITYENA_MASK,
spi->chip_select);
if (spicfg->timer_disable)
set_fmt_bits(davinci_spi->base, SPIFMT_DISTIMER_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_DISTIMER_MASK,
spi->chip_select);
if (spi->mode & SPI_READY)
set_fmt_bits(davinci_spi->base,
SPIFMT_WAITENA_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_WAITENA_MASK,
spi->chip_select);
}
retval = davinci_spi_setup_transfer(spi, NULL);
return retval;