firmware: arm_scmi: Use common iterators in the voltage protocol

Make SCMI voltage protocol use the common iterator protocol helpers for
issuing the multi-part commands.

Link: https://lore.kernel.org/r/20220330150551.2573938-18-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c
index 5d58ba7..e1bdce5 100644 (file)
--- a/drivers/firmware/arm_scmi/voltage.c
+++ b/drivers/firmware/arm_scmi/voltage.c
@@ -112,14 +112,100 @@ static int scmi_init_voltage_levels(struct device *dev,
        return 0;
 }
 
+struct scmi_volt_ipriv {
+       struct device *dev;
+       struct scmi_voltage_info *v;
+};
+
+static void iter_volt_levels_prepare_message(void *message,
+                                            unsigned int desc_index,
+                                            const void *priv)
+{
+       struct scmi_msg_cmd_describe_levels *msg = message;
+       const struct scmi_volt_ipriv *p = priv;
+
+       msg->domain_id = cpu_to_le32(p->v->id);
+       msg->level_index = cpu_to_le32(desc_index);
+}
+
+static int iter_volt_levels_update_state(struct scmi_iterator_state *st,
+                                        const void *response, void *priv)
+{
+       int ret = 0;
+       u32 flags;
+       const struct scmi_msg_resp_describe_levels *r = response;
+       struct scmi_volt_ipriv *p = priv;
+
+       flags = le32_to_cpu(r->flags);
+       st->num_returned = NUM_RETURNED_LEVELS(flags);
+       st->num_remaining = NUM_REMAINING_LEVELS(flags);
+
+       /* Allocate space for num_levels if not already done */
+       if (!p->v->num_levels) {
+               ret = scmi_init_voltage_levels(p->dev, p->v, st->num_returned,
+                                              st->num_remaining,
+                                             SUPPORTS_SEGMENTED_LEVELS(flags));
+               if (!ret)
+                       st->max_resources = p->v->num_levels;
+       }
+
+       return ret;
+}
+
+static int
+iter_volt_levels_process_response(const struct scmi_protocol_handle *ph,
+                                 const void *response,
+                                 struct scmi_iterator_state *st, void *priv)
+{
+       s32 val;
+       const struct scmi_msg_resp_describe_levels *r = response;
+       struct scmi_volt_ipriv *p = priv;
+
+       val = (s32)le32_to_cpu(r->voltage[st->loop_idx]);
+       p->v->levels_uv[st->desc_index + st->loop_idx] = val;
+       if (val < 0)
+               p->v->negative_volts_allowed = true;
+
+       return 0;
+}
+
+static int scmi_voltage_levels_get(const struct scmi_protocol_handle *ph,
+                                  struct scmi_voltage_info *v)
+{
+       int ret;
+       void *iter;
+       struct scmi_msg_cmd_describe_levels *msg;
+       struct scmi_iterator_ops ops = {
+               .prepare_message = iter_volt_levels_prepare_message,
+               .update_state = iter_volt_levels_update_state,
+               .process_response = iter_volt_levels_process_response,
+       };
+       struct scmi_volt_ipriv vpriv = {
+               .dev = ph->dev,
+               .v = v,
+       };
+
+       iter = ph->hops->iter_response_init(ph, &ops, v->num_levels,
+                                           VOLTAGE_DESCRIBE_LEVELS,
+                                           sizeof(*msg), &vpriv);
+       if (IS_ERR(iter))
+               return PTR_ERR(iter);
+
+       ret = ph->hops->iter_response_run(iter);
+       if (ret) {
+               v->num_levels = 0;
+               devm_kfree(ph->dev, v->levels_uv);
+       }
+
+       return ret;
+}
+
 static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
                                        struct voltage_info *vinfo)
 {
        int ret, dom;
-       struct scmi_xfer *td, *tl;
-       struct device *dev = ph->dev;
+       struct scmi_xfer *td;
        struct scmi_msg_resp_domain_attributes *resp_dom;
-       struct scmi_msg_resp_describe_levels *resp_levels;
 
        ret = ph->xops->xfer_get_init(ph, VOLTAGE_DOMAIN_ATTRIBUTES,
                                      sizeof(__le32), sizeof(*resp_dom), &td);
@@ -127,16 +213,7 @@ static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
                return ret;
        resp_dom = td->rx.buf;
 
-       ret = ph->xops->xfer_get_init(ph, VOLTAGE_DESCRIBE_LEVELS,
-                                     sizeof(__le64), 0, &tl);
-       if (ret)
-               goto outd;
-       resp_levels = tl->rx.buf;
-
        for (dom = 0; dom < vinfo->num_domains; dom++) {
-               u32 desc_index = 0;
-               u16 num_returned = 0, num_remaining = 0;
-               struct scmi_msg_cmd_describe_levels *cmd;
                struct scmi_voltage_info *v;
 
                /* Retrieve domain attributes at first ... */
@@ -161,66 +238,14 @@ static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
                                                    v->id, v->name,
                                                    SCMI_MAX_STR_SIZE);
 
-               cmd = tl->tx.buf;
-               /* ...then retrieve domain levels descriptions */
-               do {
-                       u32 flags;
-                       int cnt;
-
-                       cmd->domain_id = cpu_to_le32(v->id);
-                       cmd->level_index = cpu_to_le32(desc_index);
-                       ret = ph->xops->do_xfer(ph, tl);
-                       if (ret)
-                               break;
-
-                       flags = le32_to_cpu(resp_levels->flags);
-                       num_returned = NUM_RETURNED_LEVELS(flags);
-                       num_remaining = NUM_REMAINING_LEVELS(flags);
-
-                       /* Allocate space for num_levels if not already done */
-                       if (!v->num_levels) {
-                               ret = scmi_init_voltage_levels(dev, v,
-                                                              num_returned,
-                                                              num_remaining,
-                                             SUPPORTS_SEGMENTED_LEVELS(flags));
-                               if (ret)
-                                       break;
-                       }
-
-                       if (desc_index + num_returned > v->num_levels) {
-                               dev_err(ph->dev,
-                                       "No. of voltage levels can't exceed %d\n",
-                                       v->num_levels);
-                               ret = -EINVAL;
-                               break;
-                       }
-
-                       for (cnt = 0; cnt < num_returned; cnt++) {
-                               s32 val;
-
-                               val =
-                                   (s32)le32_to_cpu(resp_levels->voltage[cnt]);
-                               v->levels_uv[desc_index + cnt] = val;
-                               if (val < 0)
-                                       v->negative_volts_allowed = true;
-                       }
-
-                       desc_index += num_returned;
-
-                       ph->xops->reset_rx_to_maxsz(ph, tl);
-                       /* check both to avoid infinite loop due to buggy fw */
-               } while (num_returned && num_remaining);
-
-               if (ret) {
-                       v->num_levels = 0;
-                       devm_kfree(dev, v->levels_uv);
-               }
+               ret = scmi_voltage_levels_get(ph, v);
+               /* Skip invalid voltage descriptors */
+               if (ret)
+                       continue;
 
                ph->xops->reset_rx_to_maxsz(ph, td);
        }
 
-       ph->xops->xfer_put(ph, tl);
-outd:
        ph->xops->xfer_put(ph, td);
 
        return ret;