drivers/interconnect/qcom/bcm-voter.c

Source file repositories/reference/linux-study-clean/drivers/interconnect/qcom/bcm-voter.c

File Facts

System
Linux kernel
Corpus path
drivers/interconnect/qcom/bcm-voter.c
Extension
.c
Size
11222 bytes
Lines
414
Domain
Driver Families
Bucket
drivers/interconnect
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct bcm_voter {
	struct device *dev;
	struct device_node *np;
	struct mutex lock;
	struct list_head commit_list;
	struct list_head ws_list;
	struct list_head voter_node;
	u32 tcs_wait;
};

static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b)
{
	const struct qcom_icc_bcm *bcm_a = list_entry(a, struct qcom_icc_bcm, list);
	const struct qcom_icc_bcm *bcm_b = list_entry(b, struct qcom_icc_bcm, list);

	return bcm_a->aux_data.vcd - bcm_b->aux_data.vcd;
}

static u64 bcm_div(u64 num, u32 base)
{
	/* Ensure that small votes aren't lost. */
	if (num && num < base)
		return 1;

	do_div(num, base);

	return num;
}

/* BCMs with enable_mask use one-hot-encoding for on/off signaling */
static void bcm_aggregate_mask(struct qcom_icc_bcm *bcm)
{
	struct qcom_icc_node *node;
	int bucket, i;

	for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
		bcm->vote_x[bucket] = 0;
		bcm->vote_y[bucket] = 0;

		for (i = 0; i < bcm->num_nodes; i++) {
			node = bcm->nodes[i];

			/* If any vote in this bucket exists, keep the BCM enabled */
			if (node->sum_avg[bucket] || node->max_peak[bucket]) {
				bcm->vote_x[bucket] = 0;
				bcm->vote_y[bucket] = bcm->enable_mask;
				break;
			}
		}
	}

	if (bcm->keepalive) {
		bcm->vote_x[QCOM_ICC_BUCKET_AMC] = bcm->enable_mask;
		bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = bcm->enable_mask;
		bcm->vote_y[QCOM_ICC_BUCKET_AMC] = bcm->enable_mask;
		bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = bcm->enable_mask;
	}
}

static void bcm_aggregate(struct qcom_icc_bcm *bcm)
{
	struct qcom_icc_node *node;
	size_t i, bucket;
	u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
	u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
	u64 temp;

	for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
		for (i = 0; i < bcm->num_nodes; i++) {
			node = bcm->nodes[i];
			temp = bcm_div(node->sum_avg[bucket] * bcm->aux_data.width,
				       node->buswidth * node->channels);
			agg_avg[bucket] = max(agg_avg[bucket], temp);

			temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
				       node->buswidth);
			agg_peak[bucket] = max(agg_peak[bucket], temp);
		}

		temp = agg_avg[bucket] * bcm->vote_scale;
		bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);

		temp = agg_peak[bucket] * bcm->vote_scale;
		bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
	}

	if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
	    bcm->vote_y[QCOM_ICC_BUCKET_AMC] == 0) {
		bcm->vote_x[QCOM_ICC_BUCKET_AMC] = 1;
		bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = 1;

Annotation

Implementation Notes