[PATCH v4 10/18] soc: imx: add i.MX8M blk-ctrl driver
Adam Ford
aford173 at gmail.com
Mon Nov 8 05:13:24 PST 2021
On Mon, Nov 8, 2021 at 2:35 AM Lucas Stach <l.stach at pengutronix.de> wrote:
>
> Hi Adam,
>
> Am Sonntag, dem 07.11.2021 um 15:08 -0600 schrieb Adam Ford:
> > On Fri, Sep 10, 2021 at 3:26 PM Lucas Stach <l.stach at pengutronix.de> wrote:
> > >
> > > This adds a driver for the blk-ctrl blocks found in the i.MX8M* line of
> > > SoCs. The blk-ctrl is a top-level peripheral located in the various *MIX
> > > power domains and interacts with the GPC power controller to provide the
> > > peripherals in the power domain access to the NoC and ensures that those
> > > peripherals are properly reset when their respective power domain is
> > > brought back to life.
> > >
> > > Software needs to do different things to make the bus handshake happen
> > > after the GPC *MIX domain is powered up and before it is powered down.
> > > As the requirements are quite different between the various blk-ctrls
> > > there is a callback function provided to hook in the proper sequence.
> > >
> > > The peripheral domains are quite uniform, they handle the soft clock
> > > enables and resets in the blk-ctrl address space and sequencing with the
> > > upstream GPC power domains.
> > >
> > Sorry to resurrect an old thread, but I'm running into issues enabling
> > new peripherals, and I think it's related to this, but I am not
> > certain.
> >
> > I have attempted to enable the various VPU's, and in doing so, I
> > referenced the vpu_blk_ctrl for the respective power-domains reference
> > [1].
> >
> > The various VPU devices enumerate, and I can see the various VPU power
> > domains turn on and off a boot.
> >
> > [ 1.968565] genpd genpd:0:38330000.blk-ctrl: adding to PM domain vpumix
> > [ 1.981208] genpd genpd:1:38330000.blk-ctrl: adding to PM domain vpu-g1
> > [ 1.993838] genpd genpd:2:38330000.blk-ctrl: adding to PM domain vpu-g2
> > [ 2.006455] genpd genpd:3:38330000.blk-ctrl: adding to PM domain vpu-h1
> > [ 8.922661] hantro_vpu: module is from the staging directory, the
> > quality is unknown, you have been warned.
> > [ 9.008147] hantro_vpu: module is from the staging directory, the
> > quality is unknown, you have been warned.
> > [ 9.044041] hantro-vpu 38300000.video-codec: adding to PM domain vpublk-g1
> > [ 9.050959] hantro-vpu 38300000.video-codec: genpd_add_device()
> > [ 9.063349] PM: vpumix: Power-on latency exceeded, new value 50875 ns
> > [ 9.083437] PM: vpu-g1: Power-on latency exceeded, new value 26125 ns
> > [ 9.104778] PM: vpublk-g1: Power-on latency exceeded, new value 47819250 ns
> > [ 9.211988] hantro-vpu 38300000.video-codec: registered
> > nxp,imx8mm-vpu-dec as /dev/video0
> > [ 9.259680] hantro-vpu 38300000.video-codec: genpd_runtime_resume()
> > [ 9.297395] hantro-vpu 38300000.video-codec: resume latency exceeded, 2750 ns
> > [ 9.307767] hantro-vpu 38310000.video-codec: adding to PM domain vpublk-g2
> > [ 9.316462] hantro-vpu 38310000.video-codec: genpd_add_device()
> > [ 9.328807] PM: vpu-g2: Power-on latency exceeded, new value 26625 ns
> > [ 9.342401] PM: vpublk-g2: Power-on latency exceeded, new value 19965125 ns
> > [ 9.430254] hantro-vpu 38300000.video-codec: genpd_runtime_suspend()
> > [ 9.436683] hantro-vpu 38300000.video-codec: suspend latency
> > exceeded, 1625 ns
> > [ 9.443984] PM: vpublk-g1: Power-off latency exceeded, new value 16625 ns
> > [ 9.462361] hantro-vpu 38310000.video-codec: registered
> > nxp,imx8mm-vpu-g2-dec as /dev/video2
> > [ 9.491848] PM: vpu-g1: Power-off latency exceeded, new value 17125 ns
> > [ 9.506353] hantro-vpu 38310000.video-codec: genpd_runtime_resume()
> > [ 9.512735] hantro-vpu 38310000.video-codec: resume latency exceeded, 2750 ns
> > [ 9.520306] hantro-vpu 38320000.video-codec: adding to PM domain vpublk-h1
> > [ 9.527268] hantro-vpu 38320000.video-codec: genpd_add_device()
> > [ 9.539632] PM: vpu-h1: Power-on latency exceeded, new value 27750 ns
> > [ 9.553358] PM: vpublk-h1: Power-on latency exceeded, new value 20112125 ns
> > [ 9.605800] hantro_vpu: module is from the staging directory, the
> > quality is unknown, you have been warned.
> > [ 9.642194] hantro-vpu 38310000.video-codec: genpd_runtime_suspend()
> > [ 9.648634] hantro-vpu 38310000.video-codec: suspend latency
> > exceeded, 1500 ns
> > [ 9.655974] PM: vpublk-g2: Power-off latency exceeded, new value 12625 ns
> > [ 9.703863] PM: vpu-g2: Power-off latency exceeded, new value 16750 ns
> > [ 9.754527] hantro-vpu 38320000.video-codec: registered
> > nxp,imx8mm-vpu-h1-enc as /dev/video3
> > [ 9.785424] hantro-vpu 38320000.video-codec: genpd_runtime_resume()
> > [ 9.796034] hantro-vpu 38320000.video-codec: resume latency exceeded, 2000 ns
> > [ 9.934247] hantro-vpu 38320000.video-codec: genpd_runtime_suspend()
> > [ 9.940707] hantro-vpu 38320000.video-codec: suspend latency
> > exceeded, 1500 ns
> > [ 9.948042] PM: vpublk-h1: Power-off latency exceeded, new value 18875 ns
> > [ 9.975951] PM: vpu-h1: Power-off latency exceeded, new value 17625 ns
> > [ 9.999970] PM: vpumix: Power-off latency exceeded, new value 25750 ns
> >
> > However, because the vpumix is disabled here, I think it might be
> > what's causing a hang when I attempt to read the regmap registers with
> >
> > cat /sys/kernel/debug/regmap/38330000.blk-ctrl/registers
>
> That is expected, as regmap doesn't tie into the runtime PM and is the
> same behavior as on other devices when you try to read the registers
> via regmap while the peripheral clock is gated.
Ok. That makes sense. I think I was so focussed on getting the regmap
working, I assumed something was wrong with the blk-ctrl.
>
> >
> > I was looking at the ATF code that NXP has, and it doesn't appear that
> > the VPUMIX ever shuts down, and for that matter, I don't think the g1,
> > g2, and h1 domains shutdown either.
> >
> > I think it makes sense to have the domains turned off when not in use,
> > but I have a few comments / questions below....
> >
> > > Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> > > Acked-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> > > Reviewed-by: Philipp Zabel <p.zabel at pengutronix.de>
> > > ---
> > > This commit includes the full code to drive the VPUMIX domain on the
> > > i.MX8MM, as the skeleton driver would probably be harder to review
> > > without the context provided by one blk-ctrl implementation. Other
> > > blk-ctrl implementations will follow, based on this overall structure.
> > >
> > > v4:
> > > - fix commit message typos
> > > - fix superfluous whitespace
> > > - constify clk_names more
> > > ---
> > > drivers/soc/imx/Makefile | 1 +
> > > drivers/soc/imx/imx8m-blk-ctrl.c | 453 +++++++++++++++++++++++++++++++
> > > 2 files changed, 454 insertions(+)
> > > create mode 100644 drivers/soc/imx/imx8m-blk-ctrl.c
> > >
> > > diff --git a/drivers/soc/imx/Makefile b/drivers/soc/imx/Makefile
> > > index 078dc918f4f3..8a707077914c 100644
> > > --- a/drivers/soc/imx/Makefile
> > > +++ b/drivers/soc/imx/Makefile
> > > @@ -5,3 +5,4 @@ endif
> > > obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
> > > obj-$(CONFIG_IMX_GPCV2_PM_DOMAINS) += gpcv2.o
> > > obj-$(CONFIG_SOC_IMX8M) += soc-imx8m.o
> > > +obj-$(CONFIG_SOC_IMX8M) += imx8m-blk-ctrl.o
> > > diff --git a/drivers/soc/imx/imx8m-blk-ctrl.c b/drivers/soc/imx/imx8m-blk-ctrl.c
> > > new file mode 100644
> > > index 000000000000..f2d74669d683
> > > --- /dev/null
> > > +++ b/drivers/soc/imx/imx8m-blk-ctrl.c
> > > @@ -0,0 +1,453 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +
> > > +/*
> > > + * Copyright 2021 Pengutronix, Lucas Stach <kernel at pengutronix.de>
> > > + */
> > > +
> > > +#include <linux/device.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of_device.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/pm_domain.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/clk.h>
> > > +
> > > +#include <dt-bindings/power/imx8mm-power.h>
> > > +
> > > +#define BLK_SFT_RSTN 0x0
> > > +#define BLK_CLK_EN 0x4
> > > +
> > > +struct imx8m_blk_ctrl_domain;
> > > +
> > > +struct imx8m_blk_ctrl {
> > > + struct device *dev;
> > > + struct notifier_block power_nb;
> > > + struct device *bus_power_dev;
> > > + struct regmap *regmap;
> > > + struct imx8m_blk_ctrl_domain *domains;
> > > + struct genpd_onecell_data onecell_data;
> > > +};
> > > +
> > > +struct imx8m_blk_ctrl_domain_data {
> > > + const char *name;
> > > + const char * const *clk_names;
> > > + int num_clks;
> > > + const char *gpc_name;
> > > + u32 rst_mask;
> > > + u32 clk_mask;
> > > +};
> > > +
> > > +#define DOMAIN_MAX_CLKS 3
> > > +
> > > +struct imx8m_blk_ctrl_domain {
> > > + struct generic_pm_domain genpd;
> > > + const struct imx8m_blk_ctrl_domain_data *data;
> > > + struct clk_bulk_data clks[DOMAIN_MAX_CLKS];
> > > + struct device *power_dev;
> > > + struct imx8m_blk_ctrl *bc;
> > > +};
> > > +
> > > +struct imx8m_blk_ctrl_data {
> > > + int max_reg;
> > > + notifier_fn_t power_notifier_fn;
> > > + const struct imx8m_blk_ctrl_domain_data *domains;
> > > + int num_domains;
> > > +};
> > > +
> > > +static inline struct imx8m_blk_ctrl_domain *
> > > +to_imx8m_blk_ctrl_domain(struct generic_pm_domain *genpd)
> > > +{
> > > + return container_of(genpd, struct imx8m_blk_ctrl_domain, genpd);
> > > +}
> > > +
> > > +static int imx8m_blk_ctrl_power_on(struct generic_pm_domain *genpd)
> > > +{
> > > + struct imx8m_blk_ctrl_domain *domain = to_imx8m_blk_ctrl_domain(genpd);
> > > + const struct imx8m_blk_ctrl_domain_data *data = domain->data;
> > > + struct imx8m_blk_ctrl *bc = domain->bc;
> > > + int ret;
> > > +
> > > + /* make sure bus domain is awake */
> > > + ret = pm_runtime_get_sync(bc->bus_power_dev);
> > > + if (ret < 0) {
> > > + pm_runtime_put_noidle(bc->bus_power_dev);
> > > + dev_err(bc->dev, "failed to power up bus domain\n");
> > > + return ret;
> > > + }
> > > +
> > > + /* put devices into reset */
> > > + regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
> > > +
> > > + /* enable upstream and blk-ctrl clocks to allow reset to propagate */
> > > + ret = clk_bulk_prepare_enable(data->num_clks, domain->clks);
> > > + if (ret) {
> > > + dev_err(bc->dev, "failed to enable clocks\n");
> > > + goto bus_put;
> > > + }
> > > + regmap_set_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
> > > +
> > > + /* power up upstream GPC domain */
> > > + ret = pm_runtime_get_sync(domain->power_dev);
> > > + if (ret < 0) {
> > > + dev_err(bc->dev, "failed to power up peripheral domain\n");
> > > + goto clk_disable;
> > > + }
> > > +
> > > + /* wait for reset to propagate */
> > > + udelay(5);
> > > +
> > > + /* release reset */
> > > + regmap_set_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
> > > +
> > > + /* disable upstream clocks */
> > > + clk_bulk_disable_unprepare(data->num_clks, domain->clks);
> > > +
> > > + return 0;
> > > +
> > > +clk_disable:
> > > + clk_bulk_disable_unprepare(data->num_clks, domain->clks);
> > > +bus_put:
> > > + pm_runtime_put(bc->bus_power_dev);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static int imx8m_blk_ctrl_power_off(struct generic_pm_domain *genpd)
> > > +{
> > > + struct imx8m_blk_ctrl_domain *domain = to_imx8m_blk_ctrl_domain(genpd);
> > > + const struct imx8m_blk_ctrl_domain_data *data = domain->data;
> > > + struct imx8m_blk_ctrl *bc = domain->bc;
> > > +
> > > + /* put devices into reset and disable clocks */
> > > + regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, data->rst_mask);
> > > + regmap_clear_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
> > > +
> > > + /* power down upstream GPC domain */
> > > + pm_runtime_put(domain->power_dev);
> > > +
> > > + /* allow bus domain to suspend */
> > > + pm_runtime_put(bc->bus_power_dev);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static struct generic_pm_domain *
> > > +imx8m_blk_ctrl_xlate(struct of_phandle_args *args, void *data)
> > > +{
> > > + struct genpd_onecell_data *onecell_data = data;
> > > + unsigned int index = args->args[0];
> > > +
> > > + if (args->args_count != 1 ||
> > > + index > onecell_data->num_domains)
> > > + return ERR_PTR(-EINVAL);
> > > +
> > > + return onecell_data->domains[index];
> > > +}
> > > +
> > > +static struct lock_class_key blk_ctrl_genpd_lock_class;
> > > +
> > > +static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
> > > +{
> > > + const struct imx8m_blk_ctrl_data *bc_data;
> > > + struct device *dev = &pdev->dev;
> > > + struct imx8m_blk_ctrl *bc;
> > > + void __iomem *base;
> > > + int i, ret;
> > > +
> > > + struct regmap_config regmap_config = {
> > > + .reg_bits = 32,
> > > + .val_bits = 32,
> > > + .reg_stride = 4,
> > > + };
> > > +
> > > + bc = devm_kzalloc(dev, sizeof(*bc), GFP_KERNEL);
> > > + if (!bc)
> > > + return -ENOMEM;
> > > +
> > > + bc->dev = dev;
> > > +
> > > + bc_data = of_device_get_match_data(dev);
> > > +
> > > + base = devm_platform_ioremap_resource(pdev, 0);
> > > + if (IS_ERR(base))
> > > + return PTR_ERR(base);
> > > +
> > > + regmap_config.max_register = bc_data->max_reg;
> > > + bc->regmap = devm_regmap_init_mmio(dev, base, ®map_config);
> > > + if (IS_ERR(bc->regmap))
> > > + return dev_err_probe(dev, PTR_ERR(bc->regmap),
> > > + "failed to init regmap\n");
> > > +
> > > + bc->domains = devm_kcalloc(dev, bc_data->num_domains,
> > > + sizeof(struct imx8m_blk_ctrl_domain),
> > > + GFP_KERNEL);
> > > + if (!bc->domains)
> > > + return -ENOMEM;
> > > +
> > > + bc->onecell_data.num_domains = bc_data->num_domains;
> > > + bc->onecell_data.xlate = imx8m_blk_ctrl_xlate;
> > > + bc->onecell_data.domains =
> > > + devm_kcalloc(dev, bc_data->num_domains,
> > > + sizeof(struct generic_pm_domain *), GFP_KERNEL);
> > > + if (!bc->onecell_data.domains)
> > > + return -ENOMEM;
> > > +
> > > + bc->bus_power_dev = genpd_dev_pm_attach_by_name(dev, "bus");
> > > + if (IS_ERR(bc->bus_power_dev))
> > > + return dev_err_probe(dev, PTR_ERR(bc->bus_power_dev),
> > > + "failed to attach power domain\n");
> > > +
> > > + for (i = 0; i < bc_data->num_domains; i++) {
> > > + const struct imx8m_blk_ctrl_domain_data *data = &bc_data->domains[i];
> > > + struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
> > > + int j;
> > > +
> > > + domain->data = data;
> > > +
> > > + for (j = 0; j < data->num_clks; j++)
> > > + domain->clks[j].id = data->clk_names[j];
> > > +
> > > + ret = devm_clk_bulk_get(dev, data->num_clks, domain->clks);
> > > + if (ret) {
> > > + dev_err_probe(dev, ret, "failed to get clock\n");
> > > + goto cleanup_pds;
> > > + }
> > > +
> > > + domain->power_dev =
> > > + dev_pm_domain_attach_by_name(dev, data->gpc_name);
> > > + if (IS_ERR(domain->power_dev)) {
> > > + dev_err_probe(dev, PTR_ERR(domain->power_dev),
> > > + "failed to attach power domain\n");
> > > + ret = PTR_ERR(domain->power_dev);
> > > + goto cleanup_pds;
> > > + }
> > > +
> > > + domain->genpd.name = data->name;
> > > + domain->genpd.power_on = imx8m_blk_ctrl_power_on;
> > > + domain->genpd.power_off = imx8m_blk_ctrl_power_off;
> > > + domain->bc = bc;
> > > +
> > > + ret = pm_genpd_init(&domain->genpd, NULL, true);
> > > + if (ret) {
> > > + dev_err_probe(dev, ret, "failed to init power domain\n");
> > > + dev_pm_domain_detach(domain->power_dev, true);
> > > + goto cleanup_pds;
> > > + }
> > > +
> > > + /*
> > > + * We use runtime PM to trigger power on/off of the upstream GPC
> > > + * domain, as a strict hierarchical parent/child power domain
> > > + * setup doesn't allow us to meet the sequencing requirements.
> > > + * This means we have nested locking of genpd locks, without the
> > > + * nesting being visible at the genpd level, so we need a
> > > + * separate lock class to make lockdep aware of the fact that
> > > + * this are separate domain locks that can be nested without a
> > > + * self-deadlock.
> > > + */
> > > + lockdep_set_class(&domain->genpd.mlock,
> > > + &blk_ctrl_genpd_lock_class);
> > > +
> > > + bc->onecell_data.domains[i] = &domain->genpd;
> > > + }
> > > +
> > > + ret = of_genpd_add_provider_onecell(dev->of_node, &bc->onecell_data);
> > > + if (ret) {
> > > + dev_err_probe(dev, ret, "failed to add power domain provider\n");
> > > + goto cleanup_pds;
> > > + }
> > > +
> > > + bc->power_nb.notifier_call = bc_data->power_notifier_fn;
> > > + ret = dev_pm_genpd_add_notifier(bc->bus_power_dev, &bc->power_nb);
> > > + if (ret) {
> > > + dev_err_probe(dev, ret, "failed to add power notifier\n");
> > > + goto cleanup_provider;
> > > + }
> > > +
> > > + dev_set_drvdata(dev, bc);
> > > +
> > > + return 0;
> > > +
> > > +cleanup_provider:
> > > + of_genpd_del_provider(dev->of_node);
> > > +cleanup_pds:
> > > + for (i--; i >= 0; i--) {
> > > + pm_genpd_remove(&bc->domains[i].genpd);
> > > + dev_pm_domain_detach(bc->domains[i].power_dev, true);
> > > + }
> > > +
> > > + dev_pm_domain_detach(bc->bus_power_dev, true);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static int imx8m_blk_ctrl_remove(struct platform_device *pdev)
> > > +{
> > > + struct imx8m_blk_ctrl *bc = dev_get_drvdata(&pdev->dev);
> > > + int i;
> > > +
> > > + of_genpd_del_provider(pdev->dev.of_node);
> > > +
> > > + for (i = 0; bc->onecell_data.num_domains; i++) {
> > > + struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
> > > +
> > > + pm_genpd_remove(&domain->genpd);
> > > + dev_pm_domain_detach(domain->power_dev, true);
> > > + }
> > > +
> > > + dev_pm_genpd_remove_notifier(bc->bus_power_dev);
> > > +
> > > + dev_pm_domain_detach(bc->bus_power_dev, true);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +#ifdef CONFIG_PM_SLEEP
> > > +static int imx8m_blk_ctrl_suspend(struct device *dev)
> > > +{
> > > + struct imx8m_blk_ctrl *bc = dev_get_drvdata(dev);
> > > + int ret, i;
> > > +
> > > + /*
> > > + * This may look strange, but is done so the generic PM_SLEEP code
> > > + * can power down our domains and more importantly power them up again
> > > + * after resume, without tripping over our usage of runtime PM to
> > > + * control the upstream GPC domains. Things happen in the right order
> > > + * in the system suspend/resume paths due to the device parent/child
> > > + * hierarchy.
> > > + */
> > > + ret = pm_runtime_get_sync(bc->bus_power_dev);
> > > + if (ret < 0) {
> > > + pm_runtime_put_noidle(bc->bus_power_dev);
> > > + return ret;
> > > + }
> > > +
> > > + for (i = 0; i < bc->onecell_data.num_domains; i++) {
> > > + struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
> > > +
> > > + ret = pm_runtime_get_sync(domain->power_dev);
> > > + if (ret < 0) {
> > > + pm_runtime_put_noidle(domain->power_dev);
> > > + goto out_fail;
> > > + }
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +out_fail:
> > > + for (i--; i >= 0; i--)
> > > + pm_runtime_put(bc->domains[i].power_dev);
> > > +
> > > + pm_runtime_put(bc->bus_power_dev);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static int imx8m_blk_ctrl_resume(struct device *dev)
> > > +{
> > > + struct imx8m_blk_ctrl *bc = dev_get_drvdata(dev);
> > > + int i;
> > > +
> > > + for (i = 0; i < bc->onecell_data.num_domains; i++)
> > > + pm_runtime_put(bc->domains[i].power_dev);
> > > +
> > > + pm_runtime_put(bc->bus_power_dev);
> > > +
> > > + return 0;
> > > +}
> > > +#endif
> > > +
> > > +static const struct dev_pm_ops imx8m_blk_ctrl_pm_ops = {
> > > + SET_SYSTEM_SLEEP_PM_OPS(imx8m_blk_ctrl_suspend, imx8m_blk_ctrl_resume)
> > > +};
> > > +
> > > +static int imx8mm_vpu_power_notifier(struct notifier_block *nb,
> > > + unsigned long action, void *data)
> > > +{
> > > + struct imx8m_blk_ctrl *bc = container_of(nb, struct imx8m_blk_ctrl,
> > > + power_nb);
> > > +
> > > + if (action != GENPD_NOTIFY_ON && action != GENPD_NOTIFY_PRE_OFF)
> > > + return NOTIFY_OK;
> > > +
> > > + /*
> > > + * The ADB in the VPUMIX domain has no separate reset and clock
> > > + * enable bits, but is ungated together with the VPU clocks. To
> > > + * allow the handshake with the GPC to progress we put the VPUs
> > > + * in reset and ungate the clocks.
> > > + */
> > > + regmap_clear_bits(bc->regmap, BLK_SFT_RSTN, BIT(0) | BIT(1)
> > > BIT(2));
> >
> > > + regmap_set_bits(bc->regmap, BLK_CLK_EN, BIT(0) | BIT(1) | BIT(2));
> >
> > The individual VPU's (IMX8MM_VPUBLK_PD_G1, G2, and H1) have clk_mask
> > values that set these bits when used and clear them when disabled. If
> > the VPUMix needs them set, shouldn't the IMX8MM_VPUBLK_PD_xx leave
> > them on until they are cleared by the VPUMIX?
>
> No, VPUMIX only need those clocks to be running for the ADB handshake
> to work. The handshake is only executed when powering up/down a GPC
> domain. So we can clockgate the individual Hantro cores when not in use
> while the power domain is up.
Ok, that makes sense.
>
> >
> > > +
> > > + if (action == GENPD_NOTIFY_ON) {
> >
> >
> > > + /*
> > > + * On power up we have no software backchannel to the GPC to
> > > + * wait for the ADB handshake to happen, so we just delay for a
> > > + * bit. On power down the GPC driver waits for the handshake.
> > > + */
> > > + udelay(5);
> > > +
> > > + /* set "fuse" bits to enable the VPUs */
> > > + regmap_set_bits(bc->regmap, 0x8, 0xffffffff);
> > > + regmap_set_bits(bc->regmap, 0xc, 0xffffffff);
> > > + regmap_set_bits(bc->regmap, 0x10, 0xffffffff);
> > > + regmap_set_bits(bc->regmap, 0x14, 0xffffffff);
> >
> > Should these registers ever get turned off when we disable the VPUMIX?
> > These registers don't have good descriptions in the TRM describing how
> > they interact with the VPU's, and it's unclear to me what happens if
> > they are set and the VPUMIX and various VPU's are disabled.
> >
> Those registers lose their state when the VPUMIX power collapses, thus
> we need to re-initialize them when powering up the domain. As far as I
> understand it those registers just carry some strap bits for the
> decoders/encoder to let them know which features should be enabled.
>
> > I am
> > curious to know if they should get enabled/disabled with their
> > respective IMX8MM_VPUBLK_PD_xx domain. The Example Code 5 in the TRM
> > doesn't set these bits in their VPUMIX example, so it makes me think
> > they're OK to leave with the individual IMX8MM_VPUBLK_PD_xx domains.
> >
> > I ask, because if I run v4l2-compliance on the H1 encoder, it also
> > appears to hang, but the power-domains appear to be attempting to
> > start, and the vpumix is the last thing to start, and I would expect
> > the pgc_vpu_h1 domain to follow, then end with the
> > vpublk-h1 starting.
> >
> > # v4l2-compliance -d3
> > [ 271.001098] hantro-vpu 38320000.video-codec: genpd_runtime_resume()
> > [ 271.007447] genpd genpd:0:38330000.blk-ctrl: genpd_runtime_resume()
> > [ 271.013796] PM: vpumix: Power-on latency exceeded, new value 40623 ns
> > [ 271.020314] genpd genpd:3:38330000.blk-ctrl: genpd_runtime_resume()
> >
> This looks correct to me. genpd:0:38330000.blk-ctrl is the VPU blk-ctrl
> bus domain, which should start the GPC vpumix domain,
> genpd:3:38330000.blk-ctrl is the blk-ctrl H1 domain, which should in
> turn power up the GPC h1 domain.
>
> Do you know where exactly things are hanging?
I added more debugging and it appears to be hanging in the VPU code
itself and not the power domain like I originally thought.
I was focussed on the power domain because the regmap was hanging that
I didn't even consider the possibility it was the VPU code itself.
[ 377.840195] hantro-vpu 38320000.video-codec: genpd_runtime_resume():
[ 377.846675] hantro-vpu 38320000.video-codec: vpublk-h1()
[ 377.852115] genpd genpd:0:38330000.blk-ctrl: genpd_runtime_resume():
[ 377.858581] genpd genpd:0:38330000.blk-ctrl: vpumix()
[ 377.863658] imx_pgc_power_up(): vpumix
[ 377.867468] imx_pgc_power_up(): Success
[ 377.871351] genpd genpd:3:38330000.blk-ctrl: genpd_runtime_resume():
[ 377.877810] genpd genpd:3:38330000.blk-ctrl: vpu-h1()
[ 377.882891] imx_pgc_power_up(): vpu-h1
[ 377.886679] imx_pgc_power_up(): Success
[ 377.890540] genpd genpd:3:38330000.blk-ctrl: resume latency exceeded, 750 ns
[ 377.897636] PM: vpublk-h1: Power-on latency exceeded, new value 45528719 ns
[ 377.904635] hantro_h1_jpeg_enc_run()
Thanks for your help. I think we're good. I'll focus my work on the
VPU encoder.
Sorry for the noise. I think I better understand the blk-ctrl now too.
adam
>
> Regards,
> Lucas
>
> > adam
> >
> > [1] - https://patchwork.kernel.org/project/linux-arm-kernel/list/?series=576435
> > > + }
> > > +
> > > + return NOTIFY_OK;
> > > +}
> > > +
> > > +static const struct imx8m_blk_ctrl_domain_data imx8m_vpu_blk_ctl_domain_data[] = {
> > > + [IMX8MM_VPUBLK_PD_G1] = {
> > > + .name = "vpublk-g1",
> > > + .clk_names = (const char *[]){ "g1", },
> > > + .num_clks = 1,
> > > + .gpc_name = "g1",
> > > + .rst_mask = BIT(1),
> > > + .clk_mask = BIT(1),
> > > + },
> > > + [IMX8MM_VPUBLK_PD_G2] = {
> > > + .name = "vpublk-g2",
> > > + .clk_names = (const char *[]){ "g2", },
> > > + .num_clks = 1,
> > > + .gpc_name = "g2",
> > > + .rst_mask = BIT(0),
> > > + .clk_mask = BIT(0),
> > > + },
> > > + [IMX8MM_VPUBLK_PD_H1] = {
> > > + .name = "vpublk-h1",
> > > + .clk_names = (const char *[]){ "h1", },
> > > + .num_clks = 1,
> > > + .gpc_name = "h1",
> > > + .rst_mask = BIT(2),
> > > + .clk_mask = BIT(2),
> > > + },
> > > +};
> > > +
> > > +static const struct imx8m_blk_ctrl_data imx8m_vpu_blk_ctl_dev_data = {
> > > + .max_reg = 0x18,
> > > + .power_notifier_fn = imx8mm_vpu_power_notifier,
> > > + .domains = imx8m_vpu_blk_ctl_domain_data,
> > > + .num_domains = ARRAY_SIZE(imx8m_vpu_blk_ctl_domain_data),
> > > +};
> > > +
> > > +static const struct of_device_id imx8m_blk_ctrl_of_match[] = {
> > > + {
> > > + .compatible = "fsl,imx8mm-vpu-blk-ctrl",
> > > + .data = &imx8m_vpu_blk_ctl_dev_data
> > > + }, {
> > > + /* Sentinel */
> > > + }
> > > +};
> > > +MODULE_DEVICE_TABLE(of, imx8m_blk_ctrl_of_match);
> > > +
> > > +static struct platform_driver imx8m_blk_ctrl_driver = {
> > > + .probe = imx8m_blk_ctrl_probe,
> > > + .remove = imx8m_blk_ctrl_remove,
> > > + .driver = {
> > > + .name = "imx8m-blk-ctrl",
> > > + .pm = &imx8m_blk_ctrl_pm_ops,
> > > + .of_match_table = imx8m_blk_ctrl_of_match,
> > > + },
> > > +};
> > > +module_platform_driver(imx8m_blk_ctrl_driver);
> > > --
> > > 2.30.2
> > >
>
>
More information about the linux-arm-kernel
mailing list