Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 035540f6 authored by Brian Niebuhr's avatar Brian Niebuhr Committed by Sekhar Nori
Browse files

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: default avatarBrian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: default avatarMichael Williamson <michael.williamson@criticallink.com>
Signed-off-by: default avatarSekhar Nori <nsekhar@ti.com>
parent d8c174cd

arch/arm/mach-davinci/include/mach/spi.h

+32 −0
Original line number Original line Diff line number Diff line
@@ -26,6 +26,20 @@ enum { 
	SPI_VERSION_2, /* For DA8xx */

	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 {

struct davinci_spi_platform_data {

	u8	version;

	u8	version;

	u8	num_chipselect;

	u8	num_chipselect;
@@ -34,6 +48,24 @@ struct davinci_spi_platform_data { 
	bool	cshold_bug;

	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 {

struct davinci_spi_config {

	u8	wdelay;

	u8	wdelay;

	u8	odd_parity;

	u8	odd_parity;

drivers/spi/davinci_spi.c

+7 −0
Original line number Original line Diff line number Diff line
@@ -787,6 +787,13 @@ static int davinci_spi_request_dma(struct davinci_spi *davinci_spi) 
/**

/**

 * davinci_spi_probe - probe function for SPI Master Controller

 * davinci_spi_probe - probe function for SPI Master Controller

 * @pdev: platform_device structure which contains plateform specific data

 * @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)

static int davinci_spi_probe(struct platform_device *pdev)

{

{