Re: [PATCH v4 09/13] firmware: arm_scmi: Add Power notifications support

From: Jonathan Cameron
Date: Mon Mar 09 2020 - 08:28:59 EST

On Wed, 4 Mar 2020 16:25:54 +0000
Cristian Marussi <cristian.marussi@xxxxxxx> wrote:

> Make SCMI Power protocol register with the notification core.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>

One comment inline on an unusual code construct, otherwise fine.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

> ---
> V3 --> V4
> - scmi_event field renamed
> V2 --> V3
> - added handle awareness
> V1 --> V2
> - simplified .set_notify_enabled() implementation moving the ALL_SRCIDs
> logic out of protocol. ALL_SRCIDs logic is now in charge of the
> notification core, together with proper reference counting of enables
> - switched to devres protocol-registration
> ---
> drivers/firmware/arm_scmi/power.c | 123 ++++++++++++++++++++++++++++++
> include/linux/scmi_protocol.h | 15 ++++
> 2 files changed, 138 insertions(+)
>
> diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
> index cf7f0312381b..281da7e7e33a 100644
> --- a/drivers/firmware/arm_scmi/power.c
> +++ b/drivers/firmware/arm_scmi/power.c
> @@ -6,6 +6,7 @@
> */
>
> #include "common.h"
> +#include "notify.h"
>
> enum scmi_power_protocol_cmd {
> POWER_DOMAIN_ATTRIBUTES = 0x3,
> @@ -48,6 +49,12 @@ struct scmi_power_state_notify {
> __le32 notify_enable;
> };
>
> +struct scmi_power_state_notify_payld {
> + __le32 agent_id;
> + __le32 domain_id;
> + __le32 power_state;
> +};
> +
> struct power_dom_info {
> bool state_set_sync;
> bool state_set_async;
> @@ -63,6 +70,11 @@ struct scmi_power_info {
> struct power_dom_info *dom_info;
> };
>
> +static enum scmi_power_protocol_cmd evt_2_cmd[] = {
> + POWER_STATE_NOTIFY,
> + POWER_STATE_CHANGE_REQUESTED_NOTIFY,
> +};
> +
> static int scmi_power_attributes_get(const struct scmi_handle *handle,
> struct scmi_power_info *pi)
> {
> @@ -186,6 +198,111 @@ static struct scmi_power_ops power_ops = {
> .state_get = scmi_power_state_get,
> };
>
> +static int scmi_power_request_notify(const struct scmi_handle *handle,
> + u32 domain, int message_id, bool enable)
> +{
> + int ret;
> + struct scmi_xfer *t;
> + struct scmi_power_state_notify *notify;
> +
> + ret = scmi_xfer_get_init(handle, message_id, SCMI_PROTOCOL_POWER,
> + sizeof(*notify), 0, &t);
> + if (ret)
> + return ret;
> +
> + notify = t->tx.buf;
> + notify->domain = cpu_to_le32(domain);
> + notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
> +
> + ret = scmi_do_xfer(handle, t);
> +
> + scmi_xfer_put(handle, t);
> + return ret;
> +}
> +
> +static bool scmi_power_set_notify_enabled(const struct scmi_handle *handle,
> + u8 evt_id, u32 src_id, bool enable)
> +{
> + int ret, cmd_id;
> +
> + cmd_id = MAP_EVT_TO_ENABLE_CMD(evt_id, evt_2_cmd);
> + if (cmd_id < 0)
> + return false;
> +
> + ret = scmi_power_request_notify(handle, src_id, cmd_id, enable);
> + if (ret)
> + pr_warn("SCMI Notifications - Proto:%X - FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
> + SCMI_PROTOCOL_POWER, evt_id, src_id, ret);
> +
> + return !ret ? true : false;

return !ret;

Is the same thing...

> +}
> +
> +static void *scmi_power_fill_custom_report(u8 evt_id, u64 timestamp,
> + const void *payld, size_t payld_sz,
> + void *report, u32 *src_id)
> +{
> + void *rep = NULL;
> +
> + switch (evt_id) {
> + case POWER_STATE_CHANGED:
> + {
> + const struct scmi_power_state_notify_payld *p = payld;
> + struct scmi_power_state_changed_report *r = report;
> +
> + if (sizeof(*p) != payld_sz)
> + break;
> +
> + r->timestamp = timestamp;
> + r->agent_id = le32_to_cpu(p->agent_id);
> + r->domain_id = le32_to_cpu(p->domain_id);
> + r->power_state = le32_to_cpu(p->power_state);
> + *src_id = r->domain_id;
> + rep = r;
> + break;
> + }
> + case POWER_STATE_CHANGE_REQUESTED:
> + {
> + const struct scmi_power_state_notify_payld *p = payld;
> + struct scmi_power_state_change_requested_report *r = report;
> +
> + if (sizeof(*p) != payld_sz)
> + break;
> +
> + r->timestamp = timestamp;
> + r->agent_id = le32_to_cpu(p->agent_id);
> + r->domain_id = le32_to_cpu(p->domain_id);
> + r->power_state = le32_to_cpu(p->power_state);
> + *src_id = r->domain_id;
> + rep = r;
> + break;
> + }
> + default:
> + break;
> + }
> +
> + return rep;
> +}
> +
> +static const struct scmi_event power_events[] = {
> + {
> + .id = POWER_STATE_CHANGED,
> + .max_payld_sz = 12,
> + .max_report_sz =
> + sizeof(struct scmi_power_state_changed_report),
> + },
> + {
> + .id = POWER_STATE_CHANGE_REQUESTED,
> + .max_payld_sz = 12,
> + .max_report_sz =
> + sizeof(struct scmi_power_state_change_requested_report),
> + },
> +};
> +
> +static const struct scmi_protocol_event_ops power_event_ops = {
> + .set_notify_enabled = scmi_power_set_notify_enabled,
> + .fill_custom_report = scmi_power_fill_custom_report,
> +};
> +
> static int scmi_power_protocol_init(struct scmi_handle *handle)
> {
> int domain;
> @@ -214,6 +331,12 @@ static int scmi_power_protocol_init(struct scmi_handle *handle)
> scmi_power_domain_attributes_get(handle, domain, dom);
> }
>
> + scmi_register_protocol_events(handle,
> + SCMI_PROTOCOL_POWER, PAGE_SIZE,
> + &power_event_ops, power_events,
> + ARRAY_SIZE(power_events),
> + pinfo->num_domains);
> +
> pinfo->version = version;
> handle->power_ops = &power_ops;
> handle->power_priv = pinfo;
> diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> index 797e1e03ae52..baa117f9eda3 100644
> --- a/include/linux/scmi_protocol.h
> +++ b/include/linux/scmi_protocol.h
> @@ -377,4 +377,19 @@ typedef int (*scmi_prot_init_fn_t)(struct scmi_handle *);
> int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn);
> void scmi_protocol_unregister(int protocol_id);
>
> +/* SCMI Notification API - Custom Event Reports */
> +struct scmi_power_state_changed_report {
> + ktime_t timestamp;
> + u32 agent_id;
> + u32 domain_id;
> + u32 power_state;
> +};
> +
> +struct scmi_power_state_change_requested_report {
> + ktime_t timestamp;
> + u32 agent_id;
> + u32 domain_id;
> + u32 power_state;
> +};
> +
> #endif /* _LINUX_SCMI_PROTOCOL_H */