firmware: arm_scmi: Use common iterators in the clock protocol

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

Link: https://lore.kernel.org/r/20220330150551.2573938-17-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/clock.c b/drivers/firmware/arm_scmi/clock.c
index cf26f18..5af14b0 100644 (file)
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -164,81 +164,111 @@ static int rate_cmp_func(const void *_r1, const void *_r2)
                return 1;
 }
 
-static int
-scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
-                             struct scmi_clock_info *clk)
-{
-       u64 *rate = NULL;
-       int ret, cnt;
-       bool rate_discrete = false;
-       u32 tot_rate_cnt = 0, rates_flag;
-       u16 num_returned, num_remaining;
-       struct scmi_xfer *t;
-       struct scmi_msg_clock_describe_rates *clk_desc;
-       struct scmi_msg_resp_clock_describe_rates *rlist;
+struct scmi_clk_ipriv {
+       u32 clk_id;
+       struct scmi_clock_info *clk;
+};
 
-       ret = ph->xops->xfer_get_init(ph, CLOCK_DESCRIBE_RATES,
-                                     sizeof(*clk_desc), 0, &t);
-       if (ret)
-               return ret;
+static void iter_clk_describe_prepare_message(void *message,
+                                             const unsigned int desc_index,
+                                             const void *priv)
+{
+       struct scmi_msg_clock_describe_rates *msg = message;
+       const struct scmi_clk_ipriv *p = priv;
 
-       clk_desc = t->tx.buf;
-       rlist = t->rx.buf;
+       msg->id = cpu_to_le32(p->clk_id);
+       /* Set the number of rates to be skipped/already read */
+       msg->rate_index = cpu_to_le32(desc_index);
+}
 
-       do {
-               clk_desc->id = cpu_to_le32(clk_id);
-               /* Set the number of rates to be skipped/already read */
-               clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
+static int
+iter_clk_describe_update_state(struct scmi_iterator_state *st,
+                              const void *response, void *priv)
+{
+       u32 flags;
+       struct scmi_clk_ipriv *p = priv;
+       const struct scmi_msg_resp_clock_describe_rates *r = response;
 
-               ret = ph->xops->do_xfer(ph, t);
-               if (ret)
-                       goto err;
+       flags = le32_to_cpu(r->num_rates_flags);
+       st->num_remaining = NUM_REMAINING(flags);
+       st->num_returned = NUM_RETURNED(flags);
+       p->clk->rate_discrete = RATE_DISCRETE(flags);
 
-               rates_flag = le32_to_cpu(rlist->num_rates_flags);
-               num_remaining = NUM_REMAINING(rates_flag);
-               rate_discrete = RATE_DISCRETE(rates_flag);
-               num_returned = NUM_RETURNED(rates_flag);
+       return 0;
+}
 
-               if (tot_rate_cnt + num_returned > SCMI_MAX_NUM_RATES) {
-                       dev_err(ph->dev, "No. of rates > MAX_NUM_RATES");
+static int
+iter_clk_describe_process_response(const struct scmi_protocol_handle *ph,
+                                  const void *response,
+                                  struct scmi_iterator_state *st, void *priv)
+{
+       int ret = 0;
+       struct scmi_clk_ipriv *p = priv;
+       const struct scmi_msg_resp_clock_describe_rates *r = response;
+
+       if (!p->clk->rate_discrete) {
+               switch (st->desc_index + st->loop_idx) {
+               case 0:
+                       p->clk->range.min_rate = RATE_TO_U64(r->rate[0]);
                        break;
-               }
-
-               if (!rate_discrete) {
-                       clk->range.min_rate = RATE_TO_U64(rlist->rate[0]);
-                       clk->range.max_rate = RATE_TO_U64(rlist->rate[1]);
-                       clk->range.step_size = RATE_TO_U64(rlist->rate[2]);
-                       dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
-                               clk->range.min_rate, clk->range.max_rate,
-                               clk->range.step_size);
+               case 1:
+                       p->clk->range.max_rate = RATE_TO_U64(r->rate[1]);
+                       break;
+               case 2:
+                       p->clk->range.step_size = RATE_TO_U64(r->rate[2]);
+                       break;
+               default:
+                       ret = -EINVAL;
                        break;
                }
+       } else {
+               u64 *rate = &p->clk->list.rates[st->desc_index + st->loop_idx];
 
-               rate = &clk->list.rates[tot_rate_cnt];
-               for (cnt = 0; cnt < num_returned; cnt++, rate++) {
-                       *rate = RATE_TO_U64(rlist->rate[cnt]);
-                       dev_dbg(ph->dev, "Rate %llu Hz\n", *rate);
-               }
+               *rate = RATE_TO_U64(r->rate[st->loop_idx]);
+               p->clk->list.num_rates++;
+               //XXX dev_dbg(ph->dev, "Rate %llu Hz\n", *rate);
+       }
+
+       return ret;
+}
 
-               tot_rate_cnt += num_returned;
+static int
+scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
+                             struct scmi_clock_info *clk)
+{
+       int ret;
 
-               ph->xops->reset_rx_to_maxsz(ph, t);
-               /*
-                * check for both returned and remaining to avoid infinite
-                * loop due to buggy firmware
-                */
-       } while (num_returned && num_remaining);
+       void *iter;
+       struct scmi_msg_clock_describe_rates *msg;
+       struct scmi_iterator_ops ops = {
+               .prepare_message = iter_clk_describe_prepare_message,
+               .update_state = iter_clk_describe_update_state,
+               .process_response = iter_clk_describe_process_response,
+       };
+       struct scmi_clk_ipriv cpriv = {
+               .clk_id = clk_id,
+               .clk = clk,
+       };
+
+       iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES,
+                                           CLOCK_DESCRIBE_RATES,
+                                           sizeof(*msg), &cpriv);
+       if (IS_ERR(iter))
+               return PTR_ERR(iter);
+
+       ret = ph->hops->iter_response_run(iter);
+       if (ret)
+               return ret;
 
-       if (rate_discrete && rate) {
-               clk->list.num_rates = tot_rate_cnt;
-               sort(clk->list.rates, tot_rate_cnt, sizeof(*rate),
-                    rate_cmp_func, NULL);
+       if (!clk->rate_discrete) {
+               dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
+                       clk->range.min_rate, clk->range.max_rate,
+                       clk->range.step_size);
+       } else if (clk->list.num_rates) {
+               sort(clk->list.rates, clk->list.num_rates,
+                    sizeof(clk->list.rates[0]), rate_cmp_func, NULL);
        }
 
-       clk->rate_discrete = rate_discrete;
-
-err:
-       ph->xops->xfer_put(ph, t);
        return ret;
 }