Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx> writes:
> When SPI wake up from OFF mode, CS is in the wrong state: force it to
> the inactive state.
>
> During the system life, I monitored the CS behavior using a
> oscilloscope. I also activated debug in omap2_mcspi, so I saw when
> driver disable the clocks and
> Each time the CS was in the correct state.
> It was only when system was put suspend to ram with off-mode activated
> that on resume the CS was in wrong state( ie activated).
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
Lots of whitespace issues in this patch, please run through checkpatch.
> ---
> drivers/spi/omap2_mcspi.c | 29 +++++++++++++++++++++++++++++
> 1 files changed, 29 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
> index 2a651e6..708990e 100644
> --- a/drivers/spi/omap2_mcspi.c
> +++ b/drivers/spi/omap2_mcspi.c
> @@ -1305,11 +1305,40 @@ static int __exit omap2_mcspi_remove(struct
> platform_device *pdev)
> /* work with hotplug and coldplug */
> MODULE_ALIAS("platform:omap2_mcspi");
> +#ifdef CONFIG_PM
> +/* When SPI wake up, CS is in wrong state: force it to unactive state*/
This comment should be more specific that only this condition happens
only on off-mode wakeups
> +static int omap2_mcspi_resume(struct platform_device *pdev)
> +{
> + struct spi_master *master;
> + struct omap2_mcspi *mcspi;
> + struct omap2_mcspi_cs *cs;
> +
> + master = dev_get_drvdata(&pdev->dev);
> + mcspi = spi_master_get_devdata(master);
> + omap2_mcspi_enable_clocks(master);
insert blank line here
> + /* We need to togle CS state for OMAP take this chang in account*/
> +
remove blank line here
> + list_for_each_entry(cs, &omap2_mcspi_ctx[master->bus_num - 1].cs,
> + node)
> + {
this '{' belongs on like above
> + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 1);
> + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
> + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 0);
> + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
> + }
Rather than force the state to a hard-coded value, it seems better if
the driver instead restore the previous state, which could be saved
during suspend.
> + omap2_mcspi_disable_clocks(master);
> + return 0;
> +}
> +#else
> +#define omap2_mcspi_resume NULL
> +#endif
> +
> static struct platform_driver omap2_mcspi_driver = {
> .driver = {
> .name = "omap2_mcspi",
> .owner = THIS_MODULE,
> },
> + .resume = omap2_mcspi_resume,
> .remove = __exit_p(omap2_mcspi_remove),
> };
> -- 1.7.0.4
Kevin
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
