On Wed, Dec 29, 2010 at 11:52:53AM +0100, Gregory CLEMENT wrote:
> 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 restore context when device is not used.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).
>
merged, thanks.
g.
> Changelog:
> * Change from v1 to v2:
> - Rebase on linus/master (after 2.6.37-rc1)
> - Do some clean-up and fix indentation on both patches
> - Add more explanations for patch 2
>
> * Change from v2 to v3:
> - Use directly resume function of spi_master instead of using function
> - from spi_device as Grant Likely pointed it out.
> - Force this transition explicitly for each CS used by a device.
>
> * Change from v3 to v4:
> - Patch clean-up according to Kevin Hilman and checkpatch.
> - Now force CS to be in inactive state only if it was inactive when it was
> suspended.
>
> * Change from v4 to v5:
> - Rebase on linus/master (after 2.6.37-rc3)
> - Collapse some lines as pointed by Grant Likely
> - Fix a spelling
>
> * Change from v5 to v6:
> - Rebase on linus/master (after 2.6.37-rc7)
> - Use CONFIG_SUSPEND instead of CONFIG_PM
> - Didn't use legacy PM methods anymore. Instead, add a struct dev_pm_ops and
> add the resume method there.
> - Fix multi-line comment style
>
> * Change from v6 to v7:
> - Rebase on linus/master (after 2.6.37-rc8)
> - Drop an extra line
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> Acked-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
>
> ---
> drivers/spi/omap2_mcspi.c | 39 +++++++++++++++++++++++++++++++++++++++
> 1 files changed, 39 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
> index 2a651e6..951a160 100644
> --- a/drivers/spi/omap2_mcspi.c
> +++ b/drivers/spi/omap2_mcspi.c
> @@ -1305,10 +1305,49 @@ static int __exit omap2_mcspi_remove(struct platform_device *pdev)
> /* work with hotplug and coldplug */
> MODULE_ALIAS("platform:omap2_mcspi");
>
> +#ifdef CONFIG_SUSPEND
> +/*
> + * When SPI wake up from off-mode, CS is in activate state. If it was in
> + * unactive state when driver was suspend, then force it to unactive state at
> + * wake up.
> + */
> +static int omap2_mcspi_resume(struct device *dev)
> +{
> + struct spi_master *master = dev_get_drvdata(dev);
> + struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
> + struct omap2_mcspi_cs *cs;
> +
> + omap2_mcspi_enable_clocks(mcspi);
> + list_for_each_entry(cs, &omap2_mcspi_ctx[master->bus_num - 1].cs,
> + node) {
> + if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
> +
> + /*
> + * We need to toggle CS state for OMAP take this
> + * change in account.
> + */
> + 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);
> + }
> + }
> + omap2_mcspi_disable_clocks(mcspi);
> + return 0;
> +}
> +#else
> +#define omap2_mcspi_resume NULL
> +#endif
> +
> +static const struct dev_pm_ops omap2_mcspi_pm_ops = {
> + .resume = omap2_mcspi_resume,
> +};
> +
> static struct platform_driver omap2_mcspi_driver = {
> .driver = {
> .name = "omap2_mcspi",
> .owner = THIS_MODULE,
> + .pm = &omap2_mcspi_pm_ops
> },
> .remove = __exit_p(omap2_mcspi_remove),
> };
> --
> 1.7.0.4
>
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