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author | Brian Niebuhr <bniebuhr@efjohnson.com> | 2010-10-06 18:32:40 +0530 |
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committer | Sekhar Nori <nsekhar@ti.com> | 2010-11-18 18:38:37 +0530 |
commit | 035540f6ea2394bdd9675552d31e1125cd0e402e (patch) | |
tree | 2e8673d2920cd473aef270e05f4520456d5c3090 /arch/arm/mach-davinci/include | |
parent | d8c174cdeb6511aa307e6058468b68a9cc3990e4 (diff) | |
download | op-kernel-dev-035540f6ea2394bdd9675552d31e1125cd0e402e.zip op-kernel-dev-035540f6ea2394bdd9675552d31e1125cd0e402e.tar.gz |
spi: davinci: add additional comments
Add comments describing the platform data members
and per-chip-select SPI configuration structure.
Also, add some comments describing the what happens
during the driver probe.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Diffstat (limited to 'arch/arm/mach-davinci/include')
-rw-r--r-- | arch/arm/mach-davinci/include/mach/spi.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/include/mach/spi.h b/arch/arm/mach-davinci/include/mach/spi.h index 1f8b786..38f4da5 100644 --- a/arch/arm/mach-davinci/include/mach/spi.h +++ b/arch/arm/mach-davinci/include/mach/spi.h @@ -26,6 +26,20 @@ enum { SPI_VERSION_2, /* For DA8xx */ }; +/** + * davinci_spi_platform_data - Platform data for SPI master device on DaVinci + * + * @version: version of the SPI IP. Different DaVinci devices have slightly + * varying versions of the same IP. + * @num_chipselect: number of chipselects supported by this SPI master + * @intr_line: interrupt line used to connect the SPI IP to the ARM interrupt + * controller withn the SoC. Possible values are 0 and 1. + * @chip_sel: list of GPIOs which can act as chip-selects for the SPI. + * SPI_INTERN_CS denotes internal SPI chip-select. Not necessary + * to populate if all chip-selects are internal. + * @cshold_bug: set this to true if the SPI controller on your chip requires + * a write to CSHOLD bit in between transfers (like in DM355). + */ struct davinci_spi_platform_data { u8 version; u8 num_chipselect; @@ -34,6 +48,24 @@ struct davinci_spi_platform_data { bool cshold_bug; }; +/** + * davinci_spi_config - Per-chip-select configuration for SPI slave devices + * + * @wdelay: amount of delay between transmissions. Measured in number of + * SPI module clocks. + * @odd_parity: polarity of parity flag at the end of transmit data stream. + * 0 - odd parity, 1 - even parity. + * @parity_enable: enable transmission of parity at end of each transmit + * data stream. + * @io_type: type of IO transfer. Choose between polled, interrupt and DMA. + * @timer_disable: disable chip-select timers (setup and hold) + * @c2tdelay: chip-select setup time. Measured in number of SPI module clocks. + * @t2cdelay: chip-select hold time. Measured in number of SPI module clocks. + * @t2edelay: transmit data finished to SPI ENAn pin inactive time. Measured + * in number of SPI clocks. + * @c2edelay: chip-select active to SPI ENAn signal active time. Measured in + * number of SPI clocks. + */ struct davinci_spi_config { u8 wdelay; u8 odd_parity; |