Re: [PATCH 7/9] remoteproc: imx_rproc: support kicking Mcore from Linux for i.MX8QXP

From: Mathieu Poirier
Date: Wed Jan 19 2022 - 13:59:02 EST


On Tue, Jan 11, 2022 at 11:33:31AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
>
> When M4 is in the same hardware partition with Cortex-A, it
> could be start/stop by Linux.
>
> Added power domain to make sure M4 could run, it requires several power
> domains to work. Make clk always optional for i.MX8QXP, because
> SCFW handles it when power up M4 core.
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/remoteproc/imx_rproc.c | 64 +++++++++++++++++++++++++++++++++-
> 1 file changed, 63 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> index 5f04aea2f6a1..09d2a06e5ed6 100644
> --- a/drivers/remoteproc/imx_rproc.c
> +++ b/drivers/remoteproc/imx_rproc.c
> @@ -16,6 +16,7 @@
> #include <linux/of_reserved_mem.h>
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> #include <linux/regmap.h>
> #include <linux/remoteproc.h>
> #include <linux/workqueue.h>
> @@ -97,6 +98,9 @@ struct imx_rproc {
> struct notifier_block proc_nb;
> u32 rproc_pt;
> u32 rsrc;
> + int num_pd;
> + struct device **pd_dev;
> + struct device_link **pd_dev_link;
> };
>
> static const struct imx_rproc_att imx_rproc_att_imx8qxp[] = {
> @@ -305,6 +309,9 @@ static int imx_rproc_start(struct rproc *rproc)
> arm_smccc_smc(IMX_SIP_RPROC, IMX_SIP_RPROC_START, 0, 0, 0, 0, 0, 0, &res);
> ret = res.a0;
> break;
> + case IMX_RPROC_SCU_API:
> + ret = imx_sc_pm_cpu_start(priv->ipc_handle, priv->rsrc, true, 0x34fe0000);

Where does the 0x34fe0000 comes from and what happens when the boot address
changes? This should come from the device tree or some HW register somewhere.

> + break;
> default:
> return -EOPNOTSUPP;
> }
> @@ -334,6 +341,9 @@ static int imx_rproc_stop(struct rproc *rproc)
> if (res.a1)
> dev_info(dev, "Not in wfi, force stopped\n");
> break;
> + case IMX_RPROC_SCU_API:
> + ret = imx_sc_pm_cpu_start(priv->ipc_handle, priv->rsrc, false, 0x34fe0000);
> + break;

Same as above.

> default:
> return -EOPNOTSUPP;
> }
> @@ -719,6 +729,56 @@ static int imx_rproc_partition_notify(struct notifier_block *nb,
> return 0;
> }
>
> +static int imx_rproc_attach_pd(struct imx_rproc *priv)
> +{
> + struct device *dev = priv->dev;
> + int ret, i;
> +
> + priv->num_pd = of_count_phandle_with_args(dev->of_node, "power-domains",
> + "#power-domain-cells");
> + if (priv->num_pd < 0)
> + return priv->num_pd;
> +
> + if (!priv->num_pd)
> + return 0;
> +
> + priv->pd_dev = devm_kmalloc_array(dev, priv->num_pd, sizeof(*priv->pd_dev), GFP_KERNEL);
> + if (!priv->pd_dev)
> + return -ENOMEM;
> +
> + priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_pd, sizeof(*priv->pd_dev_link),
> + GFP_KERNEL);
> +
> + if (!priv->pd_dev_link)
> + return -ENOMEM;
> +
> + for (i = 0; i < priv->num_pd; i++) {
> + priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
> + if (IS_ERR(priv->pd_dev[i])) {
> + ret = PTR_ERR(priv->pd_dev[i]);
> + goto detach_pd;
> + }
> +
> + priv->pd_dev_link[i] = device_link_add(dev, priv->pd_dev[i], DL_FLAG_STATELESS |
> + DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE);
> + if (!priv->pd_dev_link[i]) {
> + dev_pm_domain_detach(priv->pd_dev[i], false);
> + ret = -EINVAL;
> + goto detach_pd;
> + }
> + }
> +
> + return 0;
> +
> +detach_pd:
> + while (--i >= 0) {
> + device_link_del(priv->pd_dev_link[i]);
> + dev_pm_domain_detach(priv->pd_dev[i], false);
> + }
> +
> + return ret;
> +}
> +
> static int imx_rproc_detect_mode(struct imx_rproc *priv)
> {
> struct regmap_config config = { .name = "imx-rproc" };
> @@ -749,13 +809,13 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv)
> return ret;
> }
>
> + priv->has_clk = false;

This statement seems to imply that for imx8qxq processors, which is the only one
to use the IMX_RPROC_SCU_API, priv->has_clk is always false. If so then why
bother with a flag at all?

More comments tomorrow...

> /*
> * If Mcore resource is not owned by Acore partition, It is kicked by ROM,
> * and Linux could only do IPC with Mcore and nothing else.
> */
> if (!imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc)) {
>
> - priv->has_clk = false;
> priv->rproc->self_recovery = true;
> priv->rproc->state = RPROC_DETACHED;
>
> @@ -782,6 +842,8 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv)
> dev_warn(dev, "Enable irq failed.\n");
> return ret;
> }
> + } else {
> + return imx_rproc_attach_pd(priv);
> }
>
> return 0;
> --
> 2.25.1
>