[PATCH v13 3/8] thermal/drivers/qcom/lmh: Switch to match data for SoC CPU-to-node mappings

[Sreeshankar K <sreeshankar0910@gmail.com>]

lmh_probe() hardcodes the mapping of logical CPU IDs to LMh
hardware cluster node IDs: CPU 0 maps to LMH_CLUSTER0_NODE_ID, and CPU 4
maps to LMH_CLUSTER1_NODE_ID.

This assumption only holds true for 4+4 big.LITTLE architectures like
SDM845 and SM8150. On platforms with asymmetric cluster layouts, such as
the 6+2 topology on SM7250 where the big cluster starts at logical CPU 6,
lmh_probe() fails with -EINVAL. Consequently, the second LMh node does
not register its interrupt domain, which in turn causes dependent drivers
like qcom-cpufreq-hw to fail or indefinitely defer probing via fw_devlink.

Address this by introducing a SoC descriptor structure (struct qcom_lmh_soc_data)
and an explicit mapping table (struct qcom_lmh_node_map) associated with of_device_id
match data. This encapsulates both the algorithm enable flags and the CPU-to-node
mappings per compatible string.

Signed-off-by: Sreeshankar K <sreeshankar0910@gmail.com>
---
 drivers/thermal/qcom/lmh.c | 73 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 53 insertions(+), 20 deletions(-)

diff --git a/drivers/thermal/qcom/lmh.c b/drivers/thermal/qcom/lmh.c
index 99396b93e..ef49ed1c6 100644
--- a/drivers/thermal/qcom/lmh.c
+++ b/drivers/thermal/qcom/lmh.c
@@ -94,19 +94,61 @@ static const struct irq_domain_ops lmh_irq_ops = {
 	.xlate = irq_domain_xlate_onecell,
 };
 
+struct qcom_lmh_node_map {
+	int cpu_id;
+	u32 node_id;
+};
+
+struct qcom_lmh_soc_data {
+	uintptr_t flags;
+	const struct qcom_lmh_node_map *map;
+	size_t num_nodes;
+};
+
+static const struct qcom_lmh_node_map sdm845_lmh_map[] = {
+	{ .cpu_id = 0, .node_id = LMH_CLUSTER0_NODE_ID },
+	{ .cpu_id = 4, .node_id = LMH_CLUSTER1_NODE_ID },
+};
+
+static const struct qcom_lmh_soc_data sdm845_lmh_data = {
+	.map = sdm845_lmh_map,
+	.num_nodes = ARRAY_SIZE(sdm845_lmh_map),
+	.flags = LMH_ENABLE_ALGOS,
+};
+
+static const struct qcom_lmh_soc_data sm8150_lmh_data = {
+	.map = sdm845_lmh_map,
+	.num_nodes = ARRAY_SIZE(sdm845_lmh_map),
+};
+
+static const struct of_device_id lmh_table[] = {
+	{ .compatible = "qcom,sc8180x-lmh", .data = &sm8150_lmh_data },
+	{ .compatible = "qcom,sdm845-lmh", .data = &sdm845_lmh_data },
+	{ .compatible = "qcom,sm8150-lmh",  .data = &sm8150_lmh_data },
+	{}
+};
+MODULE_DEVICE_TABLE(of, lmh_table);
+
 static int lmh_probe(struct platform_device *pdev)
 {
+	const struct qcom_lmh_soc_data *soc_data;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct device_node *cpu_node;
 	struct lmh_hw_data *lmh_data;
 	int temp_low, temp_high, temp_arm, cpu_id, ret;
 	unsigned int enable_alg;
+	bool found = false;
 	u32 node_id;
+	int i;
 
 	if (!qcom_scm_is_available())
 		return -EPROBE_DEFER;
 
+	soc_data = of_device_get_match_data(dev);
+	if (!soc_data)
+		return -EINVAL;
+
 	lmh_data = devm_kzalloc(dev, sizeof(*lmh_data), GFP_KERNEL);
 	if (!lmh_data)
 		return -ENOMEM;
@@ -139,24 +181,23 @@ static int lmh_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/*
-	 * Only sdm845 has lmh hardware currently enabled from hlos. If this is needed
-	 * for other platforms, revisit this to check if the <cpu-id, node-id> should be part
-	 * of a dt match table.
-	 */
-	if (cpu_id == 0) {
-		node_id = LMH_CLUSTER0_NODE_ID;
-	} else if (cpu_id == 4) {
-		node_id = LMH_CLUSTER1_NODE_ID;
-	} else {
-		dev_err(dev, "Wrong CPU id associated with LMh node\n");
+	for (i = 0; i < soc_data->num_nodes; i++) {
+		if (cpu_id == soc_data->map[i].cpu_id) {
+			node_id = soc_data->map[i].node_id;
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		dev_err(dev, "Wrong CPU id %d associated with LMh node\n", cpu_id);
 		return -EINVAL;
 	}
 
 	if (!qcom_scm_lmh_dcvsh_available())
 		return -EINVAL;
 
-	enable_alg = (uintptr_t)of_device_get_match_data(dev);
+	enable_alg = soc_data->flags;
 
 	if (enable_alg) {
 		ret = qcom_scm_lmh_dcvsh(LMH_SUB_FN_CRNT, LMH_ALGO_MODE_ENABLE, 1,
@@ -230,14 +271,6 @@ static int lmh_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id lmh_table[] = {
-	{ .compatible = "qcom,sc8180x-lmh", },
-	{ .compatible = "qcom,sdm845-lmh", .data = (void *)LMH_ENABLE_ALGOS},
-	{ .compatible = "qcom,sm8150-lmh", },
-	{}
-};
-MODULE_DEVICE_TABLE(of, lmh_table);
-
 static struct platform_driver lmh_driver = {
 	.probe = lmh_probe,
 	.driver = {

-- 
2.43.0