From: Brian Niebuhr <[email protected]> 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 <[email protected]> Tested-By: Michael Williamson <[email protected]> Signed-off-by: Sekhar Nori <[email protected]> --- arch/arm/mach-davinci/include/mach/spi.h | 32 ++++++++++++++++++++++++++++++ drivers/spi/davinci_spi.c | 7 ++++++ 2 files changed, 39 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; diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index 2ec5fd2..f40f1be 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -787,6 +787,13 @@ rx_dma_failed: /** * davinci_spi_probe - probe function for SPI Master Controller * @pdev: platform_device structure which contains plateform specific data + * + * According to Linux Device Model this function will be invoked by Linux + * with platform_device struct which contains the device specific info. + * This function will map the SPI controller's memory, register IRQ, + * Reset SPI controller and setting its registers to default value. + * It will invoke spi_bitbang_start to create work queue so that client driver + * can register transfer method to work queue. */ static int davinci_spi_probe(struct platform_device *pdev) { -- 1.7.3.2 ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
