On Thu, 2016-06-16 at 11:37 +0100, Sudeep Holla wrote: > SCPI protocol supports device power state management. This deals with > power states of various peripheral devices in the system other than the > core compute subsystem. > > This patch adds support for the power state management of those > peripheral devices. > > Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
Reviewed-by: Jon Medhurst <t...@linaro.org> Tested-by: Jon Medhurst <t...@linaro.org> I've also tested this series on Juno r2 together with the coresight changes [1], to the extent that enabling various kernel configs gets the kernel log showing several lines like: coresight-etm4x 22040000.etm: ETM 4.0 initialized and if I omit the power domain entries from device-tree then boot hangs as you indicated it would be expected due to coresight hardware being powered off. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-June/433769.html > --- > drivers/firmware/arm_scpi.c | 30 ++++++++++++++++++++++++++++++ > include/linux/scpi_protocol.h | 2 ++ > 2 files changed, 32 insertions(+) > > diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c > index 51c6db0774cc..438893762076 100644 > --- a/drivers/firmware/arm_scpi.c > +++ b/drivers/firmware/arm_scpi.c > @@ -231,6 +231,11 @@ struct sensor_value { > __le32 hi_val; > } __packed; > > +struct dev_pstate_set { > + u16 dev_id; > + u8 pstate; > +} __packed; > + > static struct scpi_drvinfo *scpi_info; > > static int scpi_linux_errmap[SCPI_ERR_MAX] = { > @@ -537,6 +542,29 @@ static int scpi_sensor_get_value(u16 sensor, u64 *val) > return ret; > } > > +static int scpi_device_get_power_state(u16 dev_id) > +{ > + int ret; > + u8 pstate; > + __le16 id = cpu_to_le16(dev_id); > + > + ret = scpi_send_message(SCPI_CMD_GET_DEVICE_PWR_STATE, &id, > + sizeof(id), &pstate, sizeof(pstate)); > + return ret ? ret : pstate; > +} > + > +static int scpi_device_set_power_state(u16 dev_id, u8 pstate) > +{ > + int stat; > + struct dev_pstate_set dev_set = { > + .dev_id = cpu_to_le16(dev_id), > + .pstate = pstate, > + }; > + > + return scpi_send_message(SCPI_CMD_SET_DEVICE_PWR_STATE, &dev_set, > + sizeof(dev_set), &stat, sizeof(stat)); > +} > + > static struct scpi_ops scpi_ops = { > .get_version = scpi_get_version, > .clk_get_range = scpi_clk_get_range, > @@ -548,6 +576,8 @@ static struct scpi_ops scpi_ops = { > .sensor_get_capability = scpi_sensor_get_capability, > .sensor_get_info = scpi_sensor_get_info, > .sensor_get_value = scpi_sensor_get_value, > + .device_get_power_state = scpi_device_get_power_state, > + .device_set_power_state = scpi_device_set_power_state, > }; > > struct scpi_ops *get_scpi_ops(void) > diff --git a/include/linux/scpi_protocol.h b/include/linux/scpi_protocol.h > index 35de50a65665..dc5f989be226 100644 > --- a/include/linux/scpi_protocol.h > +++ b/include/linux/scpi_protocol.h > @@ -70,6 +70,8 @@ struct scpi_ops { > int (*sensor_get_capability)(u16 *sensors); > int (*sensor_get_info)(u16 sensor_id, struct scpi_sensor_info *); > int (*sensor_get_value)(u16, u64 *); > + int (*device_get_power_state)(u16); > + int (*device_set_power_state)(u16, u8); > }; > > #if IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL) > -- > 2.7.4 >
