[PATCH v4 0/3] remoteproc: imx_rproc: allow attaching to running core kicked by the bootloader

[Hiago De Franco <hiagofranco@gmail.com>]

From: Hiago De Franco <hiago.franco@toradex.com>

This patch series depends on Ulf's patches that are currently under review,
"pmdomain: Add generic ->sync_state() support to genpd" [1]. Without them,
this series is not going to work.

For the i.MX8X and i.MX8 family SoCs, currently when the remotecore is
started by the bootloader and the M core and A core are in the same
partition, the driver is not capable to detect the remote core and
report the correct state of it.

This patch series implement a new function, dev_pm_genpd_is_on(), which
returns the power status of a given power domain (M core power domains
IMX_SC_R_M4_0_PID0 and IMX_SC_R_M4_0_MU_1A in this case). If it is already
powered on, the driver will attach to it.

Finally, the imx_rproc_clk_enable() function was also changed to make it
return before dev_clk_get() is called, as it currently generates an SCU
fault reset if the remote core is already running and the kernel tries
to enable the clock again. These changes are a follow up from a v1 sent
to imx_rproc [2] and from a reported regression [3].

[1] https://lore.kernel.org/all/20250523134025.75130-1-ulf.hansson@linaro.org/
[2] https://lore.kernel.org/lkml/20250423155131.101473-1-hiagofranco@gmail.com/
[3] https://lore.kernel.org/lkml/20250404141713.ac2ntcsjsf7epdfa@hiago-nb/

v4:
- dev_pm_genpd_is_on() introduced to drivers/pmdomain/core.c
- imx_rproc.c updated to use the generic power domains instead of the
  SCU API call, which depends on Ulf's patch series.

v3:
- https://lore.kernel.org/all/20250519171514.61974-1-hiagofranco@gmail.com/

v2:
- https://lore.kernel.org/lkml/20250507160056.11876-1-hiagofranco@gmail.com/

v1:
- https://lore.kernel.org/lkml/20250505154849.64889-1-hiagofranco@gmail.com/

Hiago De Franco (3):
  pmdomain: core: introduce dev_pm_genpd_is_on
  remoteproc: imx_rproc: skip clock enable when M-core is managed by the
    SCU
  remoteproc: imx_rproc: detect and attach to pre-booted remote cores

 drivers/pmdomain/core.c        | 27 +++++++++++++++++++++++++++
 drivers/remoteproc/imx_rproc.c | 33 ++++++++++++++++++++++++++-------
 include/linux/pm_domain.h      |  6 ++++++
 3 files changed, 59 insertions(+), 7 deletions(-)

-- 
2.39.5