[PATCH v4 10/18] soc: imx: add i.MX8M blk-ctrl driver
Lucas Stach
l.stach at pengutronix.de
Mon Nov 8 00:35:11 PST 2021
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.
>
> 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.
>
> > +
> > + 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?
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
> >
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