Before switching to DT pinctrl states of OMAP IPs have been handled by hwmod framework. After switching to DT-boot the pinctrl handling was dropped from hwmod framework and, as it was recommended, OMAP IP's drivers have to be updated to handle pinctrl states by itself using pinctrl_pm_select_xx() helpers (see http://lists.infradead.org/pipermail/linux-arm-kernel/2013-June/173514.html) But this is not right for OMAP2+ SoC where real IPs state is controlled by omap_device core which enables/disables modules & clocks actually. For example, if OMAP I2C driver will handle pinctrl state during system wide suspend the following issue may occure: - suspend_noirq - I2C device can be still active because of PM auto-suspend |-_od_suspend_noirq |- omap_i2c_suspend_noirq |- PINs state set to SLEEP |- pm_generic_runtime_suspend |- omap_i2c_runtime_suspend() |- PINs state set to IDLE <--- *oops* PINs state is IDLE and not SLEEP |- omap_device_idle() |- omap_hwmod_idle() |- _idle() |- disbale module (sysc&clocks) - resume_noirq - I2C was active before suspend |-_od_resume_noirq |- omap_hwmod_enable() |- _enable() |- enable module (sysc&clocks) |- pm_generic_runtime_resume |- omap_i2c_runtime_resume() |- PINs state set to DEFAULT <--- !!!! |- omap_i2c_resume_noirq |- PINs state set to DEFAULT |- PINs state set to IDLE <--- *big oops* we have active module and its PINs state is IDLE (see https://patchwork.kernel.org/patch/2642101/) Of course, everything can be handled by adding a tons of code in ecah driver to check PM state of device and override default behavior of omap_device core, but this not good. Hence, add pinctrl handling in omap_device core as shown below: + | | .probe() | +-----v--------+ | | | default | | | +----+--+------+ | | pm_runtime_get()| | pm_runtime_put() +----------------+ +------------+ | | +------v------+ pm_runtime_put()+-------v-----+ | +-----------------> | +-----------> Active |pm_runtime_get() | Idle <----------+ | | <-----------------+ | | | +-------+-----+ +-------+-----+ | | |.suspend_noirq() |.suspend_noirq()| | | | | | | | | | | | | | | | | | +-------v-----+ +-------v-----+ | | | | | | | +-----------+ Sleep ------+ | Sleep +----------+ .resume_noirq() | | | | |.resume_noirq() +-------|-----+ | +-------------+ | Idle | +-----------+ 1) on PM runtime resume - switch pinctrl state to "active" 2) on PM runtime suspend - switch pinctrl state to "idle" 3) during system wide suspend - switch pinctrl state to "sleep" or "idle" if omap_device core disables device - switch pinctrl state to "sleep" if device has been disabled already 4) during system wide resume - switch pinctrl state to "active" if omap_device core has disabled device during suspend - switch pinctrl state to "idle" if device was already disabled before suspend This will enable pinctrl for all OMAP2+ IP's drivers by default - no changes in code is needed and only DT data will need to be updated (add "default", "active", "idle", "sleep" states). Related discussions: - [3/3] i2c: nomadik: use pinctrl PM helpers https://patchwork.kernel.org/patch/2670291/ - mmc: omap_hsmmc: Remux pins to support SDIO interrupt and PM runtime https://patchwork.kernel.org/patch/2690191/ - [PATCH 00/11] drivers: Add Pinctrl PM support https://lkml.org/lkml/2013/5/31/210 CC: Linus Walleij <linus.walleij@xxxxxxxxxx> Cc: Stephen Warren <swarren@xxxxxxxxxxxxx> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> --- arch/arm/mach-omap2/omap_device.c | 40 +++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c index 5cc9287..4ebdbd7 100644 --- a/arch/arm/mach-omap2/omap_device.c +++ b/arch/arm/mach-omap2/omap_device.c @@ -39,6 +39,7 @@ #include "soc.h" #include "omap_device.h" #include "omap_hwmod.h" +#include "iomap.h" /* Private functions */ @@ -582,8 +583,10 @@ static int _od_runtime_suspend(struct device *dev) ret = pm_generic_runtime_suspend(dev); - if (!ret) + if (!ret) { omap_device_idle(pdev); + pinctrl_pm_select_idle_state(dev); + } return ret; } @@ -592,12 +595,25 @@ static int _od_runtime_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); + pinctrl_pm_select_active_state(dev); + omap_device_enable(pdev); return pm_generic_runtime_resume(dev); } #endif +void _od_suspend_sel_pinctrl_state(struct device *dev) +{ + if (!dev->pins) + return; + /* try to select *deepest* pinctrl state */ + if (IS_ERR(dev->pins->sleep_state)) + pinctrl_pm_select_idle_state(dev); + else + pinctrl_pm_select_sleep_state(dev); +} + #ifdef CONFIG_SUSPEND static int _od_suspend_noirq(struct device *dev) { @@ -610,11 +626,19 @@ static int _od_suspend_noirq(struct device *dev) return 0; ret = pm_generic_suspend_noirq(dev); - - if (!ret && !pm_runtime_status_suspended(dev)) { - if (pm_generic_runtime_suspend(dev) == 0) { - omap_device_idle(pdev); - od->flags |= OMAP_DEVICE_SUSPENDED; + if (!ret) { + if (!pm_runtime_status_suspended(dev)) { + if (pm_generic_runtime_suspend(dev) == 0) { + omap_device_idle(pdev); + od->flags |= OMAP_DEVICE_SUSPENDED; + _od_suspend_sel_pinctrl_state(dev); + } + } else { + /* + * "idle" pinctrl state already applied - + * try to set "sleep" state + */ + pinctrl_pm_select_sleep_state(dev); } } @@ -630,7 +654,11 @@ static int _od_resume_noirq(struct device *dev) !pm_runtime_status_suspended(dev)) { od->flags &= ~OMAP_DEVICE_SUSPENDED; omap_device_enable(pdev); + pinctrl_pm_select_active_state(dev); pm_generic_runtime_resume(dev); + } else if (pm_runtime_status_suspended(dev)) { + /* switch back to "idle" pinctrl state */ + pinctrl_pm_select_idle_state(dev); } return pm_generic_resume_noirq(dev); -- 1.7.9.5 -- 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
