| Message ID | 20200221101936.16833-12-t-kristo@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | remoteproc: updates for omap remoteproc support | expand |
On Fri, Feb 21, 2020 at 12:19:32PM +0200, Tero Kristo wrote: > From: Suman Anna <s-anna@ti.com> > > This patch adds the support for system suspend/resume to the > OMAP remoteproc driver so that the OMAP remoteproc devices can > be suspended/resumed during a system suspend/resume. The support > is added through the driver PM .suspend/.resume callbacks, and > requires appropriate support from the OS running on the remote > processors. > > The IPU & DSP remote processors typically have their own private > modules like registers, internal memories, caches etc. The context > of these modules need to be saved and restored properly for a > suspend/resume to work. These are in general not accessible from > the MPU, so the remote processors themselves have to implement > the logic for the context save & restore of these modules. > > The OMAP remoteproc driver initiates a suspend by sending a mailbox > message requesting the remote processor to save its context and > enter into an idle/standby state. The remote processor should > usually stop whatever processing it is doing to switch to a context > save mode. The OMAP remoteproc driver detects the completion of > the context save by checking the module standby status for the > remoteproc device. It also stops any resources used by the remote > processors like the timers. The timers need to be running only > when the processor is active and executing, and need to be stopped > otherwise to allow the timer driver to reach low-power states. The > IOMMUs are automatically suspended by the PM core during the late > suspend stage, after the remoteproc suspend process is completed by > putting the remote processor cores into reset. Thereafter, the Linux > kernel can put the domain into further lower power states as possible. > > The resume sequence undoes the operations performed in the PM suspend > callback, by starting the timers and finally releasing the processors > from reset. This requires that the remote processor side OS be able to > distinguish a power-resume boot from a power-on/cold boot, restore the > context of its private modules saved during the suspend phase, and > resume executing code from where it was suspended. The IOMMUs would > have been resumed by the PM core during early resume, so they are > already enabled by the time remoteproc resume callback gets invoked. > > The remote processors should save their context into System RAM (DDR), > as any internal memories are not guaranteed to retain context as it > depends on the lowest power domain that the remote processor device > is put into. The management of the DDR contents will be managed by > the Linux kernel. > > Signed-off-by: Suman Anna <s-anna@ti.com> > [t-kristo@ti.com: converted to use ti-sysc instead of hwmod] > Signed-off-by: Tero Kristo <t-kristo@ti.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > v7: couple of cosmetic fixes > > drivers/remoteproc/omap_remoteproc.c | 191 +++++++++++++++++++++++++++ > drivers/remoteproc/omap_remoteproc.h | 18 ++- > 2 files changed, 207 insertions(+), 2 deletions(-) > > diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c > index b44b470d570b..0d45af1fb0e3 100644 > --- a/drivers/remoteproc/omap_remoteproc.c > +++ b/drivers/remoteproc/omap_remoteproc.c > @@ -15,13 +15,17 @@ > > #include <linux/kernel.h> > #include <linux/module.h> > +#include <linux/clk.h> > +#include <linux/clk/ti.h> > #include <linux/err.h> > +#include <linux/io.h> > #include <linux/of_device.h> > #include <linux/of_reserved_mem.h> > #include <linux/platform_device.h> > #include <linux/dma-mapping.h> > #include <linux/remoteproc.h> > #include <linux/mailbox_client.h> > +#include <linux/omap-iommu.h> > #include <linux/omap-mailbox.h> > #include <linux/regmap.h> > #include <linux/mfd/syscon.h> > @@ -81,6 +85,9 @@ struct omap_rproc_timer { > * @timers: timer(s) info used by rproc > * @rproc: rproc handle > * @reset: reset handle > + * @pm_comp: completion primitive to sync for suspend response > + * @fck: functional clock for the remoteproc > + * @suspend_acked: state machine flag to store the suspend request ack > */ > struct omap_rproc { > struct mbox_chan *mbox; > @@ -92,6 +99,9 @@ struct omap_rproc { > struct omap_rproc_timer *timers; > struct rproc *rproc; > struct reset_control *reset; > + struct completion pm_comp; > + struct clk *fck; > + bool suspend_acked; > }; > > /** > @@ -371,6 +381,12 @@ static void omap_rproc_mbox_callback(struct mbox_client *client, void *data) > case RP_MBOX_ECHO_REPLY: > dev_info(dev, "received echo reply from %s\n", name); > break; > + case RP_MBOX_SUSPEND_ACK: > + /* Fall through */ > + case RP_MBOX_SUSPEND_CANCEL: > + oproc->suspend_acked = msg == RP_MBOX_SUSPEND_ACK; > + complete(&oproc->pm_comp); > + break; > default: > if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG) > return; > @@ -562,6 +578,168 @@ static const struct rproc_ops omap_rproc_ops = { > .da_to_va = omap_rproc_da_to_va, > }; > > +#ifdef CONFIG_PM > +static bool _is_rproc_in_standby(struct omap_rproc *oproc) > +{ > + return ti_clk_is_in_standby(oproc->fck); > +} > + > +/* 1 sec is long enough time to let the remoteproc side suspend the device */ > +#define DEF_SUSPEND_TIMEOUT 1000 > +static int _omap_rproc_suspend(struct rproc *rproc) > +{ > + struct device *dev = rproc->dev.parent; > + struct omap_rproc *oproc = rproc->priv; > + unsigned long to = msecs_to_jiffies(DEF_SUSPEND_TIMEOUT); > + unsigned long ta = jiffies + to; > + int ret; > + > + reinit_completion(&oproc->pm_comp); > + oproc->suspend_acked = false; > + ret = mbox_send_message(oproc->mbox, (void *)RP_MBOX_SUSPEND_SYSTEM); > + if (ret < 0) { > + dev_err(dev, "PM mbox_send_message failed: %d\n", ret); > + return ret; > + } > + > + ret = wait_for_completion_timeout(&oproc->pm_comp, to); > + if (!oproc->suspend_acked) > + return -EBUSY; > + > + /* > + * The remoteproc side is returning the ACK message before saving the > + * context, because the context saving is performed within a SYS/BIOS > + * function, and it cannot have any inter-dependencies against the IPC > + * layer. Also, as the SYS/BIOS needs to preserve properly the processor > + * register set, sending this ACK or signalling the completion of the > + * context save through a shared memory variable can never be the > + * absolute last thing to be executed on the remoteproc side, and the > + * MPU cannot use the ACK message as a sync point to put the remoteproc > + * into reset. The only way to ensure that the remote processor has > + * completed saving the context is to check that the module has reached > + * STANDBY state (after saving the context, the SYS/BIOS executes the > + * appropriate target-specific WFI instruction causing the module to > + * enter STANDBY). > + */ > + while (!_is_rproc_in_standby(oproc)) { > + if (time_after(jiffies, ta)) > + return -ETIME; > + schedule(); > + } > + > + ret = reset_control_assert(oproc->reset); > + if (ret) { > + dev_err(dev, "reset assert during suspend failed %d\n", ret); > + return ret; > + } > + > + ret = omap_rproc_disable_timers(rproc, false); > + if (ret) { > + dev_err(dev, "disabling timers during suspend failed %d\n", > + ret); > + goto enable_device; > + } > + > + return 0; > + > +enable_device: > + reset_control_deassert(oproc->reset); > + return ret; > +} > + > +static int _omap_rproc_resume(struct rproc *rproc) > +{ > + struct device *dev = rproc->dev.parent; > + struct omap_rproc *oproc = rproc->priv; > + int ret; > + > + /* boot address could be lost after suspend, so restore it */ > + if (oproc->boot_data) { > + ret = omap_rproc_write_dsp_boot_addr(rproc); > + if (ret) { > + dev_err(dev, "boot address restore failed %d\n", ret); > + goto out; > + } > + } > + > + ret = omap_rproc_enable_timers(rproc, false); > + if (ret) { > + dev_err(dev, "enabling timers during resume failed %d\n", ret); > + goto out; > + } > + > + ret = reset_control_deassert(oproc->reset); > + if (ret) { > + dev_err(dev, "reset deassert during resume failed %d\n", ret); > + goto disable_timers; > + } > + > + return 0; > + > +disable_timers: > + omap_rproc_disable_timers(rproc, false); > +out: > + return ret; > +} > + > +static int __maybe_unused omap_rproc_suspend(struct device *dev) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct rproc *rproc = platform_get_drvdata(pdev); > + int ret = 0; > + > + mutex_lock(&rproc->lock); > + if (rproc->state == RPROC_OFFLINE) > + goto out; > + > + if (rproc->state == RPROC_SUSPENDED) > + goto out; > + > + if (rproc->state != RPROC_RUNNING) { > + ret = -EBUSY; > + goto out; > + } > + > + ret = _omap_rproc_suspend(rproc); > + if (ret) { > + dev_err(dev, "suspend failed %d\n", ret); > + goto out; > + } > + > + rproc->state = RPROC_SUSPENDED; > +out: > + mutex_unlock(&rproc->lock); > + return ret; > +} > + > +static int __maybe_unused omap_rproc_resume(struct device *dev) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct rproc *rproc = platform_get_drvdata(pdev); > + int ret = 0; > + > + mutex_lock(&rproc->lock); > + if (rproc->state == RPROC_OFFLINE) > + goto out; > + > + if (rproc->state != RPROC_SUSPENDED) { > + ret = -EBUSY; > + goto out; > + } > + > + ret = _omap_rproc_resume(rproc); > + if (ret) { > + dev_err(dev, "resume failed %d\n", ret); > + goto out; > + } > + > + rproc->state = RPROC_RUNNING; > +out: > + mutex_unlock(&rproc->lock); > + return ret; > +} > +#endif /* CONFIG_PM */ > + > static const struct omap_rproc_mem_data ipu_mems[] = { > { .name = "l2ram", .dev_addr = 0x20000000 }, > { }, > @@ -804,6 +982,14 @@ static int omap_rproc_probe(struct platform_device *pdev) > oproc->num_timers); > } > > + init_completion(&oproc->pm_comp); > + > + oproc->fck = devm_clk_get(&pdev->dev, 0); > + if (IS_ERR(oproc->fck)) { > + ret = PTR_ERR(oproc->fck); > + goto free_rproc; > + } > + > ret = of_reserved_mem_device_init(&pdev->dev); > if (ret) { > dev_warn(&pdev->dev, "device does not have specific CMA pool.\n"); > @@ -837,11 +1023,16 @@ static int omap_rproc_remove(struct platform_device *pdev) > return 0; > } > > +static const struct dev_pm_ops omap_rproc_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(omap_rproc_suspend, omap_rproc_resume) > +}; > + > static struct platform_driver omap_rproc_driver = { > .probe = omap_rproc_probe, > .remove = omap_rproc_remove, > .driver = { > .name = "omap-rproc", > + .pm = &omap_rproc_pm_ops, > .of_match_table = omap_rproc_of_match, > }, > }; > diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h > index 72f656c93caa..13f17d9135c0 100644 > --- a/drivers/remoteproc/omap_remoteproc.h > +++ b/drivers/remoteproc/omap_remoteproc.h > @@ -1,7 +1,7 @@ > /* > * Remote processor messaging > * > - * Copyright (C) 2011 Texas Instruments, Inc. > + * Copyright (C) 2011-2020 Texas Instruments, Inc. > * Copyright (C) 2011 Google, Inc. > * All rights reserved. > * > @@ -57,6 +57,16 @@ > * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the > * recovery mechanism (to some extent). > * > + * @RP_MBOX_SUSPEND_AUTO: auto suspend request for the remote processor > + * > + * @RP_MBOX_SUSPEND_SYSTEM: system suspend request for the remote processor > + * > + * @RP_MBOX_SUSPEND_ACK: successful response from remote processor for a > + * suspend request > + * > + * @RP_MBOX_SUSPEND_CANCEL: a cancel suspend response from a remote processor > + * on a suspend request > + * > * Introduce new message definitions if any here. > * > * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote core > @@ -70,7 +80,11 @@ enum omap_rp_mbox_messages { > RP_MBOX_ECHO_REQUEST = 0xFFFFFF03, > RP_MBOX_ECHO_REPLY = 0xFFFFFF04, > RP_MBOX_ABORT_REQUEST = 0xFFFFFF05, > - RP_MBOX_END_MSG = 0xFFFFFF06, > + RP_MBOX_SUSPEND_AUTO = 0xFFFFFF10, > + RP_MBOX_SUSPEND_SYSTEM = 0xFFFFFF11, > + RP_MBOX_SUSPEND_ACK = 0xFFFFFF12, > + RP_MBOX_SUSPEND_CANCEL = 0xFFFFFF13, > + RP_MBOX_END_MSG = 0xFFFFFF14, > }; > > #endif /* _OMAP_RPMSG_H */ > -- > 2.17.1 > > -- > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c index b44b470d570b..0d45af1fb0e3 100644 --- a/drivers/remoteproc/omap_remoteproc.c +++ b/drivers/remoteproc/omap_remoteproc.c @@ -15,13 +15,17 @@ #include <linux/kernel.h> #include <linux/module.h> +#include <linux/clk.h> +#include <linux/clk/ti.h> #include <linux/err.h> +#include <linux/io.h> #include <linux/of_device.h> #include <linux/of_reserved_mem.h> #include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/remoteproc.h> #include <linux/mailbox_client.h> +#include <linux/omap-iommu.h> #include <linux/omap-mailbox.h> #include <linux/regmap.h> #include <linux/mfd/syscon.h> @@ -81,6 +85,9 @@ struct omap_rproc_timer { * @timers: timer(s) info used by rproc * @rproc: rproc handle * @reset: reset handle + * @pm_comp: completion primitive to sync for suspend response + * @fck: functional clock for the remoteproc + * @suspend_acked: state machine flag to store the suspend request ack */ struct omap_rproc { struct mbox_chan *mbox; @@ -92,6 +99,9 @@ struct omap_rproc { struct omap_rproc_timer *timers; struct rproc *rproc; struct reset_control *reset; + struct completion pm_comp; + struct clk *fck; + bool suspend_acked; }; /** @@ -371,6 +381,12 @@ static void omap_rproc_mbox_callback(struct mbox_client *client, void *data) case RP_MBOX_ECHO_REPLY: dev_info(dev, "received echo reply from %s\n", name); break; + case RP_MBOX_SUSPEND_ACK: + /* Fall through */ + case RP_MBOX_SUSPEND_CANCEL: + oproc->suspend_acked = msg == RP_MBOX_SUSPEND_ACK; + complete(&oproc->pm_comp); + break; default: if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG) return; @@ -562,6 +578,168 @@ static const struct rproc_ops omap_rproc_ops = { .da_to_va = omap_rproc_da_to_va, }; +#ifdef CONFIG_PM +static bool _is_rproc_in_standby(struct omap_rproc *oproc) +{ + return ti_clk_is_in_standby(oproc->fck); +} + +/* 1 sec is long enough time to let the remoteproc side suspend the device */ +#define DEF_SUSPEND_TIMEOUT 1000 +static int _omap_rproc_suspend(struct rproc *rproc) +{ + struct device *dev = rproc->dev.parent; + struct omap_rproc *oproc = rproc->priv; + unsigned long to = msecs_to_jiffies(DEF_SUSPEND_TIMEOUT); + unsigned long ta = jiffies + to; + int ret; + + reinit_completion(&oproc->pm_comp); + oproc->suspend_acked = false; + ret = mbox_send_message(oproc->mbox, (void *)RP_MBOX_SUSPEND_SYSTEM); + if (ret < 0) { + dev_err(dev, "PM mbox_send_message failed: %d\n", ret); + return ret; + } + + ret = wait_for_completion_timeout(&oproc->pm_comp, to); + if (!oproc->suspend_acked) + return -EBUSY; + + /* + * The remoteproc side is returning the ACK message before saving the + * context, because the context saving is performed within a SYS/BIOS + * function, and it cannot have any inter-dependencies against the IPC + * layer. Also, as the SYS/BIOS needs to preserve properly the processor + * register set, sending this ACK or signalling the completion of the + * context save through a shared memory variable can never be the + * absolute last thing to be executed on the remoteproc side, and the + * MPU cannot use the ACK message as a sync point to put the remoteproc + * into reset. The only way to ensure that the remote processor has + * completed saving the context is to check that the module has reached + * STANDBY state (after saving the context, the SYS/BIOS executes the + * appropriate target-specific WFI instruction causing the module to + * enter STANDBY). + */ + while (!_is_rproc_in_standby(oproc)) { + if (time_after(jiffies, ta)) + return -ETIME; + schedule(); + } + + ret = reset_control_assert(oproc->reset); + if (ret) { + dev_err(dev, "reset assert during suspend failed %d\n", ret); + return ret; + } + + ret = omap_rproc_disable_timers(rproc, false); + if (ret) { + dev_err(dev, "disabling timers during suspend failed %d\n", + ret); + goto enable_device; + } + + return 0; + +enable_device: + reset_control_deassert(oproc->reset); + return ret; +} + +static int _omap_rproc_resume(struct rproc *rproc) +{ + struct device *dev = rproc->dev.parent; + struct omap_rproc *oproc = rproc->priv; + int ret; + + /* boot address could be lost after suspend, so restore it */ + if (oproc->boot_data) { + ret = omap_rproc_write_dsp_boot_addr(rproc); + if (ret) { + dev_err(dev, "boot address restore failed %d\n", ret); + goto out; + } + } + + ret = omap_rproc_enable_timers(rproc, false); + if (ret) { + dev_err(dev, "enabling timers during resume failed %d\n", ret); + goto out; + } + + ret = reset_control_deassert(oproc->reset); + if (ret) { + dev_err(dev, "reset deassert during resume failed %d\n", ret); + goto disable_timers; + } + + return 0; + +disable_timers: + omap_rproc_disable_timers(rproc, false); +out: + return ret; +} + +static int __maybe_unused omap_rproc_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rproc *rproc = platform_get_drvdata(pdev); + int ret = 0; + + mutex_lock(&rproc->lock); + if (rproc->state == RPROC_OFFLINE) + goto out; + + if (rproc->state == RPROC_SUSPENDED) + goto out; + + if (rproc->state != RPROC_RUNNING) { + ret = -EBUSY; + goto out; + } + + ret = _omap_rproc_suspend(rproc); + if (ret) { + dev_err(dev, "suspend failed %d\n", ret); + goto out; + } + + rproc->state = RPROC_SUSPENDED; +out: + mutex_unlock(&rproc->lock); + return ret; +} + +static int __maybe_unused omap_rproc_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct rproc *rproc = platform_get_drvdata(pdev); + int ret = 0; + + mutex_lock(&rproc->lock); + if (rproc->state == RPROC_OFFLINE) + goto out; + + if (rproc->state != RPROC_SUSPENDED) { + ret = -EBUSY; + goto out; + } + + ret = _omap_rproc_resume(rproc); + if (ret) { + dev_err(dev, "resume failed %d\n", ret); + goto out; + } + + rproc->state = RPROC_RUNNING; +out: + mutex_unlock(&rproc->lock); + return ret; +} +#endif /* CONFIG_PM */ + static const struct omap_rproc_mem_data ipu_mems[] = { { .name = "l2ram", .dev_addr = 0x20000000 }, { }, @@ -804,6 +982,14 @@ static int omap_rproc_probe(struct platform_device *pdev) oproc->num_timers); } + init_completion(&oproc->pm_comp); + + oproc->fck = devm_clk_get(&pdev->dev, 0); + if (IS_ERR(oproc->fck)) { + ret = PTR_ERR(oproc->fck); + goto free_rproc; + } + ret = of_reserved_mem_device_init(&pdev->dev); if (ret) { dev_warn(&pdev->dev, "device does not have specific CMA pool.\n"); @@ -837,11 +1023,16 @@ static int omap_rproc_remove(struct platform_device *pdev) return 0; } +static const struct dev_pm_ops omap_rproc_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(omap_rproc_suspend, omap_rproc_resume) +}; + static struct platform_driver omap_rproc_driver = { .probe = omap_rproc_probe, .remove = omap_rproc_remove, .driver = { .name = "omap-rproc", + .pm = &omap_rproc_pm_ops, .of_match_table = omap_rproc_of_match, }, }; diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h index 72f656c93caa..13f17d9135c0 100644 --- a/drivers/remoteproc/omap_remoteproc.h +++ b/drivers/remoteproc/omap_remoteproc.h @@ -1,7 +1,7 @@ /* * Remote processor messaging * - * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011-2020 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * All rights reserved. * @@ -57,6 +57,16 @@ * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the * recovery mechanism (to some extent). * + * @RP_MBOX_SUSPEND_AUTO: auto suspend request for the remote processor + * + * @RP_MBOX_SUSPEND_SYSTEM: system suspend request for the remote processor + * + * @RP_MBOX_SUSPEND_ACK: successful response from remote processor for a + * suspend request + * + * @RP_MBOX_SUSPEND_CANCEL: a cancel suspend response from a remote processor + * on a suspend request + * * Introduce new message definitions if any here. * * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote core @@ -70,7 +80,11 @@ enum omap_rp_mbox_messages { RP_MBOX_ECHO_REQUEST = 0xFFFFFF03, RP_MBOX_ECHO_REPLY = 0xFFFFFF04, RP_MBOX_ABORT_REQUEST = 0xFFFFFF05, - RP_MBOX_END_MSG = 0xFFFFFF06, + RP_MBOX_SUSPEND_AUTO = 0xFFFFFF10, + RP_MBOX_SUSPEND_SYSTEM = 0xFFFFFF11, + RP_MBOX_SUSPEND_ACK = 0xFFFFFF12, + RP_MBOX_SUSPEND_CANCEL = 0xFFFFFF13, + RP_MBOX_END_MSG = 0xFFFFFF14, }; #endif /* _OMAP_RPMSG_H */