[U-Boot] [PATCH 07/15 V2] iMX28: Add SPI driver

Mike Frysinger vapier at gentoo.org
Wed Sep 14 04:50:09 CEST 2011


On Tuesday, September 13, 2011 18:26:19 Marek Vasut wrote:
> +int spi_claim_bus(struct spi_slave *slave)
> +{
> +	struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
> +	struct mx28_ssp_regs *ssp_regs = mxs_slave->regs;
> +	uint32_t reg = 0;
> +
> +	mx28_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
> +
> +	writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
> +
> +	reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
> +	reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
> +	reg |= (mxs_slave->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0;
> +	writel(reg, &ssp_regs->hw_ssp_ctrl1);
> +
> +	writel(0, &ssp_regs->hw_ssp_cmd0);
> +
> +	mx28_set_ssp_busclock(slave->bus, mxs_slave->max_khz);

this turns on the hardware ...

> +void spi_release_bus(struct spi_slave *slave)
> +{
> +}

... so shouldn't this turn it off ?

i dont have the datasheet for the controller, so i have no idea :)
-mike
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