On Fri, Oct 31, 2025 at 10:24:55AM +0800, Peng Fan wrote:
> i.MX95 features a Cortex-M33 core, six Cortex-A55 cores, and
> one Cortex-M7 core. The System Control Management Interface(SCMI)
> firmware runs on the M33 core. The i.MX95 SCMI firmware named System
> Manager(SM) includes vendor extension protocols, Logical Machine
> Management(LMM) protocol and CPU protocol and etc.
>
> There are three cases for M7:
> (1) M7 in a separate Logical Machine(LM) that Linux can't control it.
> (2) M7 in a separate Logical Machine that Linux can control it using
> LMM protocol
> (3) M7 runs in same Logical Machine as A55, so Linux can control it
> using CPU protocol
>
> So extend the driver to using LMM and CPU protocol to manage the M7 core.
> - Compare linux LM ID(got using scmi_imx_lmm_info) and M7 LM ID(the ID
> is fixed as 1 in SM firmware if M7 is in a seprate LM),
> if Linux LM ID equals M7 LM ID(linux and M7 in same LM), use CPU
> protocol to start/stop. Otherwise, use LMM protocol to start/stop.
> Whether using CPU or LMM protocol to start/stop, the M7 status
> detection could use CPU protocol to detect started or not. So
> in imx_rproc_detect_mode, use scmi_imx_cpu_started to check the
> status of M7.
> - For above case (1) and (2), Use SCMI_IMX_LMM_POWER_ON to detect whether
> the M7 LM is under control of A55 LM.
> - For above case , after using SCMI_IMX_LMM_POWER_ON to check
> permission, SCMI_IMX_LMM_SHUTDOWN API should be called to shutdown
> the M7 LM to save power only when M7 LM is going to be started by
> remoteproc framework. Otherwise bypass SCMI_IMX_LMM_SHUTDOWN API if
> M7 LM is started before booting Linux.
>
> Current setup relies on pre-Linux software(U-Boot) to do M7 TCM ECC
> initialization. In future, we could add the support in Linux to decouple
> U-Boot and Linux.
>
> Signed-off-by: Peng Fan <[email protected]>
> ---
> drivers/remoteproc/Kconfig | 2 +
> drivers/remoteproc/imx_rproc.c | 192
> +++++++++++++++++++++++++++++++++++++++++
> drivers/remoteproc/imx_rproc.h | 3 +
> 3 files changed, 197 insertions(+)
>
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index
> 48a0d3a69ed08057716f1e7ea950899f60bbe0cf..ee54436fea5ad08a9c198ce74d44ce7a9aa206de
> 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -27,6 +27,8 @@ config IMX_REMOTEPROC
> tristate "i.MX remoteproc support"
> depends on ARCH_MXC
> depends on HAVE_ARM_SMCCC
> + depends on IMX_SCMI_CPU_DRV || !IMX_SCMI_CPU_DRV
> + depends on IMX_SCMI_LMM_DRV || !IMX_SCMI_LMM_DRV
> select MAILBOX
> help
> Say y here to support iMX's remote processors via the remote
> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> index
> 232eb91e0b5dc2432131b1c140d6688b073fea1d..1fb17701964ca4ee4b73d343b5ec1be8e2ee5fda
> 100644
> --- a/drivers/remoteproc/imx_rproc.c
> +++ b/drivers/remoteproc/imx_rproc.c
> @@ -8,6 +8,7 @@
...
> +
> +static int imx_rproc_sm_lmm_check(struct rproc *rproc, bool started)
> +{
> + struct imx_rproc *priv = rproc->priv;
> + const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> + struct device *dev = priv->dev;
> + int ret;
> +
> + /*
> + * Use power on to do permission check. If rproc is in different LM,
> + * and linux has permission to handle the LM, set
> IMX_RPROC_FLAGS_SM_LMM_AVAIL.
> + */
> + ret = scmi_imx_lmm_operation(dcfg->lmid, SCMI_IMX_LMM_POWER_ON, 0);
> + if (ret != 0) {
if (!ret)
> + if (ret == -EACCES) {
> + /* Not under Linux Control, so only do IPC between
> rproc and Linux */
> + dev_info(dev, "lmm(%d) not under Linux Control\n",
> dcfg->lmid);
> + return 0;
> + }
> +
> + dev_info(dev, "power on lmm(%d) failed: %d\n", dcfg->lmid, ret);
dev_err()? because it is "... failed"
> + return ret;
> + }
> +
> + priv->flags |= IMX_RPROC_FLAGS_SM_LMM_AVAIL;
> +
> + /* rproc was started before boot Linux and under control of Linux,
> directly return */
> + if (started)
> + return 0;
> +
> + /* else shutdown the LM to save power */
> + ret = scmi_imx_lmm_operation(dcfg->lmid, SCMI_IMX_LMM_SHUTDOWN, 0);
> + if (ret) {
> + dev_err(dev, "shutdown lmm(%d) failed: %d\n", dcfg->lmid, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int imx_rproc_sm_detect_mode(struct rproc *rproc)
> +{
> + struct imx_rproc *priv = rproc->priv;
> + const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> + struct device *dev = priv->dev;
> + struct scmi_imx_lmm_info info;
> + bool started = false;
> + bool is_cpu_ops;
> + int ret;
> +
> + ret = scmi_imx_cpu_started(dcfg->cpuid, &started);
> + if (ret) {
> + dev_err(dev, "Failed to detect cpu(%d) status: %d\n",
> dcfg->cpuid, ret);
> + return ret;
> + }
> +
> + if (started)
> + priv->rproc->state = RPROC_DETACHED;
> +
> + /* Get current Linux Logical Machine ID */
> + ret = scmi_imx_lmm_info(LMM_ID_DISCOVER, &info);
> + if (ret) {
> + dev_err(dev, "Failed to get current LMM ID err: %d\n", ret);
> + return ret;
> + }
> +
> + /*
> + * Check whether remote processor is in same Logical Machine as Linux.
> + * If yes, use CPU protocol API to manage remote processor.
> + * If no, use Logical Machine API to manage remote processor.
> + */
> + is_cpu_ops = dcfg->lmid == info.lmid;
> +
> + if (is_cpu_ops) {
> + priv->ops = &imx_rproc_ops_sm_cpu;
> + dev_info(dev, "Using CPU Protocol OPS\n");
> + return 0;
> + }
does need else branch to set priv->ops?
Frank
> +
> + dev_info(dev, "Using LMM Protocol OPS\n");
> +
> + return imx_rproc_sm_lmm_check(rproc, started);
> +}
> +
> static int imx_rproc_detect_mode(struct imx_rproc *priv)
> {
> /*
> diff --git a/drivers/remoteproc/imx_rproc.h b/drivers/remoteproc/imx_rproc.h
> index
> e4b9ede656506142b260aa7515823f489a168ba4..c05bfc4528f3b7518d4f2272d15fdeab1a68c2a3
> 100644
> --- a/drivers/remoteproc/imx_rproc.h
> +++ b/drivers/remoteproc/imx_rproc.h
> @@ -52,6 +52,9 @@ struct imx_rproc_dcfg {
> enum imx_rproc_method method;
> u32 flags;
> const struct imx_rproc_plat_ops *ops;
> + /* For System Manager(SM) based SoCs, the IDs are from SM firmware */
> + u32 cpuid;
> + u32 lmid;
> };
>
> #endif /* _IMX_RPROC_H */
>
> --
> 2.37.1
>
