[PATCH 2/7] soc: qcom: geni-se: Populate clk_perf_tbl with SE source clock frequencies from perf OPP table

[Praveen Talari]

Currently, on the SA8255P platform, protocol drivers attached via
geni_se_domain_attach() treat each OPP on the perf domain as directly
corresponding to a protocol value such as a baudrate or requested
frequency, and simply request that OPP via
geni_se_set_perf_level()/geni_se_set_perf_opp(). This does not allow
computing a source clock and divider combination for a protocol
requested frequency, unlike the Linux clock managed path which derives
this from se->clk_perf_tbl via geni_se_clk_freq_match(), and then
applies the matched source clock frequency with dev_pm_opp_set_rate().

Change this by treating the OPP table exposed on the perf domain
device as representing the actual SE HW supported source clock
frequencies, the same role clk_perf_tbl plays for the Linux clock
managed path. Populate se->clk_perf_tbl and se->num_clk_levels by
iterating over this OPP table in geni_se_domain_attach(), so that
protocol drivers on the firmware managed (SA8255P) path can also use
geni_se_clk_freq_match() to pick the closest supported source clock
frequency and calculate the required divider, and apply it with
dev_pm_opp_set_rate() the same way as it is done for the Linux clock
managed path, instead of relying on a direct frequency/baudrate-to-
perf-level mapping.

Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
---
 drivers/soc/qcom/qcom-geni-se.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index 873bfbd6b2b7..a88bd092b87e 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -1155,7 +1155,8 @@ EXPORT_SYMBOL_GPL(geni_se_set_perf_opp);
  *
  * This function attaches the power domains ("power" and "perf") required
  * in the SCMI auto-VM environment to the GENI Serial Engine device. It
- * initializes se->pd_list with the attached domains.
+ * initializes se->pd_list with the attached domains, and populates
+ * se->clk_perf_tbl from the OPP table of the "perf" domain device.
  *
  * Return: 0 on success, or a negative error code on failure.
  */
@@ -1166,7 +1167,12 @@ int geni_se_domain_attach(struct geni_se *se)
 		.pd_names = (const char*[]) { "power", "perf" },
 		.num_pd_names = 2,
 	};
+	struct device *perf_dev;
+	struct dev_pm_opp *opp;
+	unsigned int level;
+	int num_opps;
 	int ret;
+	int i;
 
 	ret = devm_pm_domain_attach_list(se->dev,
 					 &pd_data, &se->pd_list);
@@ -1175,6 +1181,29 @@ int geni_se_domain_attach(struct geni_se *se)
 	else if (ret < 0)
 		return ret;
 
+	perf_dev = se->pd_list->pd_devs[DOMAIN_IDX_PERF];
+
+	num_opps = dev_pm_opp_get_opp_count(perf_dev);
+	if (num_opps <= 0)
+		return num_opps < 0 ? num_opps : -ENODEV;
+
+	se->clk_perf_tbl = devm_kcalloc(se->dev, num_opps,
+					sizeof(*se->clk_perf_tbl),
+					GFP_KERNEL);
+	if (!se->clk_perf_tbl)
+		return -ENOMEM;
+
+	for (i = 0, level = 0; i < num_opps; i++, level++) {
+		opp = dev_pm_opp_find_level_ceil(perf_dev, &level);
+		if (IS_ERR(opp))
+			return PTR_ERR(opp);
+
+		se->clk_perf_tbl[i] = level;
+		dev_pm_opp_put(opp);
+	}
+	se->num_clk_levels = num_opps;
+	se->has_opp = true;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(geni_se_domain_attach);

-- 
2.34.1