Re: [PATCH v4 3/5] remoteproc: Add prepare/unprepare callbacks

Bjorn Andersson
2019-12-21T20:20:42Z

On Tue 10 Dec 08:40 PST 2019, Paul Cercueil wrote:

> The .prepare() callback is called before the firmware is loaded to
> memory. This is useful for instance in the case where some setup is
> required for the memory to be accessible.
>

Would it make sense to somehow tie this prepare/unprepare to the actual
struct rproc_mem_entry that needs the resource enabled?

Regards,
Bjorn

> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
>
> Notes:
> v2-v4: No change
>
> drivers/remoteproc/remoteproc_core.c | 16 +++++++++++++++-
> include/linux/remoteproc.h | 4 ++++
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 0a9fc7fdd1c3..3ea5f675a148 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1299,11 +1299,19 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> struct device *dev = &rproc->dev;
> int ret;
>
> + if (rproc->ops->prepare) {
> + ret = rproc->ops->prepare(rproc);
> + if (ret) {
> + dev_err(dev, "Failed to prepare rproc: %d\n", ret);
> + return ret;
> + }
> + }
> +
> /* load the ELF segments to memory */
> ret = rproc_load_segments(rproc, fw);
> if (ret) {
> dev_err(dev, "Failed to load program segments: %d\n", ret);
> - return ret;
> + goto unprepare_rproc;
> }
>
> /*
> @@ -1354,6 +1362,9 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> rproc_unprepare_subdevices(rproc);
> reset_table_ptr:
> rproc->table_ptr = rproc->cached_table;
> +unprepare_rproc:
> + if (rproc->ops->unprepare)
> + rproc->ops->unprepare(rproc);
>
> return ret;
> }
> @@ -1483,6 +1494,9 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
>
> rproc->state = RPROC_OFFLINE;
>
> + if (rproc->ops->unprepare)
> + rproc->ops->unprepare(rproc);
> +
> dev_info(dev, "stopped remote processor %s\n", rproc->name);
>
> return 0;
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 5f201f0c86c3..a6272d1ba384 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -355,6 +355,8 @@ enum rsc_handling_status {
>
> /**
> * struct rproc_ops - platform-specific device handlers
> + * @prepare: prepare the device for power up (before the firmware is loaded)
> + * @unprepare: unprepare the device after it is stopped
> * @start: power on the device and boot it
> * @stop: power off the device
> * @kick: kick a virtqueue (virtqueue id given as a parameter)
> @@ -371,6 +373,8 @@ enum rsc_handling_status {
> * @get_boot_addr: get boot address to entry point specified in firmware
> */
> struct rproc_ops {
> + int (*prepare)(struct rproc *rproc);
> + void (*unprepare)(struct rproc *rproc);
> int (*start)(struct rproc *rproc);
> int (*stop)(struct rproc *rproc);
> void (*kick)(struct rproc *rproc, int vqid);
> --
> 2.24.0
>