diff options
author | David Brownell | 2009-06-18 01:26:03 +0200 |
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committer | Linus Torvalds | 2009-06-18 22:03:42 +0200 |
commit | 7d0771970c51e736758525dd71fb82dd036b823a (patch) | |
tree | 9ff72b89cd06cd67e0db681859606dd77f5cba80 /drivers/spi/spi.c | |
parent | spi_bfin5xx: limit reaches -1 (diff) | |
download | kernel-qcow2-linux-7d0771970c51e736758525dd71fb82dd036b823a.tar.gz kernel-qcow2-linux-7d0771970c51e736758525dd71fb82dd036b823a.tar.xz kernel-qcow2-linux-7d0771970c51e736758525dd71fb82dd036b823a.zip |
spi: move common spi_setup() functionality into core
Start moving some spi_setup() functionality into the SPI core from the
various spi_master controller drivers:
- Make that function stop being an inline;
- Move two common idioms from drivers into that new function:
* Default bits_per_word to 8 if that field isn't set
* Issue a standardized dev_dbg() message
This is a net minor source code shrink, and supports enhancments found in
some follow-up patches.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r-- | drivers/spi/spi.c | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8eba98c8ed1e..0276bc37e255 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -265,7 +265,7 @@ int spi_add_device(struct spi_device *spi) * normally rely on the device being setup. Devices * using SPI_CS_HIGH can't coexist well otherwise... */ - status = spi->master->setup(spi); + status = spi_setup(spi); if (status < 0) { dev_err(dev, "can't %s %s, status %d\n", "setup", dev_name(&spi->dev), status); @@ -583,6 +583,59 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master); /*-------------------------------------------------------------------------*/ +/* Core methods for SPI master protocol drivers. Some of the + * other core methods are currently defined as inline functions. + */ + +/** + * spi_setup - setup SPI mode and clock rate + * @spi: the device whose settings are being modified + * Context: can sleep, and no requests are queued to the device + * + * SPI protocol drivers may need to update the transfer mode if the + * device doesn't work with its default. They may likewise need + * to update clock rates or word sizes from initial values. This function + * changes those settings, and must be called from a context that can sleep. + * Except for SPI_CS_HIGH, which takes effect immediately, the changes take + * effect the next time the device is selected and data is transferred to + * or from it. When this function returns, the spi device is deselected. + * + * Note that this call will fail if the protocol driver specifies an option + * that the underlying controller or its driver does not support. For + * example, not all hardware supports wire transfers using nine bit words, + * LSB-first wire encoding, or active-high chipselects. + */ +int spi_setup(struct spi_device *spi) +{ + int status; + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + status = spi->master->setup(spi); + + dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s" + "%u bits/w, %u Hz max --> %d\n", + (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), + (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", + (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", + (spi->mode & SPI_3WIRE) ? "3wire, " : "", + (spi->mode & SPI_LOOP) ? "loopback, " : "", + spi->bits_per_word, spi->max_speed_hz, + status); + + return status; +} +EXPORT_SYMBOL_GPL(spi_setup); + + +/*-------------------------------------------------------------------------*/ + +/* Utility methods for SPI master protocol drivers, layered on + * top of the core. Some other utility methods are defined as + * inline functions. + */ + static void spi_complete(void *arg) { complete(arg); |