From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 14 Dec 2019 23:30:03 +0100 From: Paul Cercueil Subject: Re: [PATCH v4 3/5] remoteproc: Add prepare/unprepare callbacks Message-Id: <1576362603.3.5@crapouillou.net> In-Reply-To: References: <20191210164014.50739-1-paul@crapouillou.net> <20191210164014.50739-3-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable To: Fabien DESSENNE Cc: Ohad Ben-Cohen , Bjorn Andersson , Rob Herring , Mark Rutland , od@zcrc.me, linux-remoteproc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: Hi Fabien, Le jeu., d=E9c. 12, 2019 at 10:03, Fabien DESSENNE=20 a =E9crit : > Hi Paul >=20 >=20 > On 10/12/2019 5:40 PM, 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. >=20 >=20 > I am trying to figure out what king of 'setup' may be required. From=20 > the > ingenic driver I understand that you need to enable clocks to allow=20 > some > memory access. >=20 > Instead of adding this new ops, why not enabling clocks in probe()? Enabling the clocks in the probe means that the clocks will be=20 unconditionally enabled until the driver is removed, even if the remote=20 processor end up being unused. That would be a waste of power. Cheers, -Paul >=20 > BR >=20 > Fabien >=20 >=20 >>=20 >> Signed-off-by: Paul Cercueil >> --- >>=20 >> Notes: >> v2-v4: No change >>=20 >> drivers/remoteproc/remoteproc_core.c | 16 +++++++++++++++- >> include/linux/remoteproc.h | 4 ++++ >> 2 files changed, 19 insertions(+), 1 deletion(-) >>=20 >> diff --git a/drivers/remoteproc/remoteproc_core.c=20 >> 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,=20 >> const struct firmware *fw) >> struct device *dev =3D &rproc->dev; >> int ret; >>=20 >> + if (rproc->ops->prepare) { >> + ret =3D 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 =3D rproc_load_segments(rproc, fw); >> if (ret) { >> dev_err(dev, "Failed to load program segments: %d\n", ret); >> - return ret; >> + goto unprepare_rproc; >> } >>=20 >> /* >> @@ -1354,6 +1362,9 @@ static int rproc_start(struct rproc *rproc,=20 >> const struct firmware *fw) >> rproc_unprepare_subdevices(rproc); >> reset_table_ptr: >> rproc->table_ptr =3D rproc->cached_table; >> +unprepare_rproc: >> + if (rproc->ops->unprepare) >> + rproc->ops->unprepare(rproc); >>=20 >> return ret; >> } >> @@ -1483,6 +1494,9 @@ static int rproc_stop(struct rproc *rproc,=20 >> bool crashed) >>=20 >> rproc->state =3D RPROC_OFFLINE; >>=20 >> + if (rproc->ops->unprepare) >> + rproc->ops->unprepare(rproc); >> + >> dev_info(dev, "stopped remote processor %s\n", rproc->name); >>=20 >> 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 { >>=20 >> /** >> * struct rproc_ops - platform-specific device handlers >> + * @prepare: prepare the device for power up (before the firmware=20 >> 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=20 >> 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); =