On Wed 20 May 17:10 PDT 2020, Suman Anna wrote: > The resets for the DSP processors on K3 SoCs are managed through the > Power and Sleep Controller (PSC) module. Each DSP typically has two > resets - a global module reset for powering on the device, and a local > reset that affects only the CPU while allowing access to the other > sub-modules within the DSP processor sub-systems. > > The C66x DSPs have two levels of internal RAMs that can be used to > boot from, and the firmware loading into these RAMs require the > local reset to be asserted with the device powered on/enabled using > the module reset. Enhance the K3 DSP remoteproc driver to add support > for loading into the internal RAMs. The local reset is deasserted on > SoC power-on-reset, so logic has to be added in probe in remoteproc > mode to balance the remoteproc state-machine. > > Note that the local resets are a no-op on C71x cores, and the hardware > does not supporting loading into its internal RAMs. > > Signed-off-by: Suman Anna <s-anna@xxxxxx> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Regards, Bjorn > --- > v2: > - Dropped the local-reset no-op checks from k3_dsp_rproc_prepare/unprepare() > callbacks. The logic will be adjusted back in the C71 patch series. > - The C71 local reset references are also removed from the comments for the > k3_dsp_rproc_prepare() function. > v1: https://patchwork.kernel.org/patch/11458579/ > > drivers/remoteproc/ti_k3_dsp_remoteproc.c | 72 +++++++++++++++++++++++ > 1 file changed, 72 insertions(+) > > diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c b/drivers/remoteproc/ti_k3_dsp_remoteproc.c > index e4036f5992fe..610fbbf85ee6 100644 > --- a/drivers/remoteproc/ti_k3_dsp_remoteproc.c > +++ b/drivers/remoteproc/ti_k3_dsp_remoteproc.c > @@ -174,6 +174,9 @@ static int k3_dsp_rproc_reset(struct k3_dsp_rproc *kproc) > return ret; > } > > + if (kproc->data->uses_lreset) > + return ret; > + > ret = kproc->ti_sci->ops.dev_ops.put_device(kproc->ti_sci, > kproc->ti_sci_id); > if (ret) { > @@ -191,6 +194,9 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) > struct device *dev = kproc->dev; > int ret; > > + if (kproc->data->uses_lreset) > + goto lreset; > + > ret = kproc->ti_sci->ops.dev_ops.get_device(kproc->ti_sci, > kproc->ti_sci_id); > if (ret) { > @@ -198,6 +204,7 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) > return ret; > } > > +lreset: > ret = reset_control_deassert(kproc->reset); > if (ret) { > dev_err(dev, "local-reset deassert failed, ret = %d\n", ret); > @@ -209,6 +216,53 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) > return ret; > } > > +/* > + * The C66x DSP cores have a local reset that affects only the CPU, and a > + * generic module reset that powers on the device and allows the DSP internal > + * memories to be accessed while the local reset is asserted. This function is > + * used to release the global reset on C66x DSPs to allow loading into the DSP > + * internal RAMs. The .prepare() ops is invoked by remoteproc core before any > + * firmware loading, and is followed by the .start() ops after loading to > + * actually let the C66x DSP cores run. > + */ > +static int k3_dsp_rproc_prepare(struct rproc *rproc) > +{ > + struct k3_dsp_rproc *kproc = rproc->priv; > + struct device *dev = kproc->dev; > + int ret; > + > + ret = kproc->ti_sci->ops.dev_ops.get_device(kproc->ti_sci, > + kproc->ti_sci_id); > + if (ret) > + dev_err(dev, "module-reset deassert failed, cannot enable internal RAM loading, ret = %d\n", > + ret); > + > + return ret; > +} > + > +/* > + * This function implements the .unprepare() ops and performs the complimentary > + * operations to that of the .prepare() ops. The function is used to assert the > + * global reset on applicable C66x cores. This completes the second portion of > + * powering down the C66x DSP cores. The cores themselves are only halted in the > + * .stop() callback through the local reset, and the .unprepare() ops is invoked > + * by the remoteproc core after the remoteproc is stopped to balance the global > + * reset. > + */ > +static int k3_dsp_rproc_unprepare(struct rproc *rproc) > +{ > + struct k3_dsp_rproc *kproc = rproc->priv; > + struct device *dev = kproc->dev; > + int ret; > + > + ret = kproc->ti_sci->ops.dev_ops.put_device(kproc->ti_sci, > + kproc->ti_sci_id); > + if (ret) > + dev_err(dev, "module-reset assert failed, ret = %d\n", ret); > + > + return ret; > +} > + > /* > * Power up the DSP remote processor. > * > @@ -352,6 +406,8 @@ static void *k3_dsp_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len) > } > > static const struct rproc_ops k3_dsp_rproc_ops = { > + .prepare = k3_dsp_rproc_prepare, > + .unprepare = k3_dsp_rproc_unprepare, > .start = k3_dsp_rproc_start, > .stop = k3_dsp_rproc_stop, > .kick = k3_dsp_rproc_kick, > @@ -614,6 +670,22 @@ static int k3_dsp_rproc_probe(struct platform_device *pdev) > goto release_tsp; > } > > + /* > + * ensure the DSP local reset is asserted to ensure the DSP doesn't > + * execute bogus code in .prepare() when the module reset is released. > + */ > + if (data->uses_lreset) { > + ret = reset_control_status(kproc->reset); > + if (ret < 0) { > + dev_err(dev, "failed to get reset status, status = %d\n", > + ret); > + goto release_mem; > + } else if (ret == 0) { > + dev_warn(dev, "local reset is deasserted for device\n"); > + k3_dsp_rproc_reset(kproc); > + } > + } > + > ret = rproc_add(rproc); > if (ret) { > dev_err(dev, "failed to add register device with remoteproc core, status = %d\n", > -- > 2.26.0 >
