[PATCH v4 1/2] spi: implemented driver for Cirrus EP93xx SPI controller

[H Hartley Sweeten]

On Tuesday, April 20, 2010 8:12 AM, Mika Westerberg wrote:
> This patch adds an SPI master driver for the Cirrus EP93xx SPI controller found
> in EP93xx chips (EP9301, EP9302, EP9307, EP9312 and EP9315).
> 
> Signed-off-by: Mika Westerberg <mika.westerberg at iki.fi>

Mika,

I'm still looking this over but I have one quick comment.

> +/**
> + * ep93xx_spi_select_device() - select given SPI device
> + * @espi: ep93xx SPI controller struct
> + * @spi: SPI device to select
> + *
> + * Function asserts chipselect line as specified in @spi->chip_select in board
> + * specific manner.
> + *
> + * Note that this function is called from a thread context and can sleep.
> + */
> +static inline void ep93xx_spi_select_device(const struct ep93xx_spi *espi,
> +					    struct spi_device *spi)
> +{
> +	if (espi->cs_control)
> +		espi->cs_control(spi, !!(spi->mode & SPI_CS_HIGH));
> +}
> +
> +/**
> + * ep93xx_spi_deselect_device() - deselects given SPI device
> + * @espi: ep93xx SPI controller struct
> + * @spi: SPI device to deselect
> + *
> + * Function deasserts chipselect line as specified in @spi->chip_select in board
> + * specific manner.
> + *
> + * Note that this function is called from a thread context and can sleep.
> + */
> +static inline void ep93xx_spi_deselect_device(const struct ep93xx_spi *espi,
> +					      struct spi_device *spi)
> +{
> +	if (espi->cs_control)
> +		espi->cs_control(spi, !(spi->mode & SPI_CS_HIGH));
> +}

These two functions can be combined.

/**
 * ep93xx_spi_chip_select() - select/deselect a given SPI device
 * @espi: ep93xx SPI controller struct
 * @spi: SPI device to select
 * @assert: flag to assert the chip select line
 *
 * Note that this function is called from a thread context and can sleep.
 */
static void ep93xx_spi_chip_select(const struct ep93xx_spi *espi,
					     struct spi_device *spi, int assert)
{
	int value = (spi->mode & SPI_CS_HIGH) ? !!assert : !assert;

	if (espi->cs_control)
		espi->cs_control(spi, value);
}

Then just do:

ep93xx_spi_select_device(espi, msg->spi, 1);	/* assert the spi chip select */

ep93xx_spi_select_device(espi, msg->spi, 0);	/* deassert the spi chip select */

Regards,
Hartley