drivers/memory/of_memory.c

Source file repositories/reference/linux-study-clean/drivers/memory/of_memory.c

File Facts

System
Linux kernel
Corpus path
drivers/memory/of_memory.c
Extension
.c
Size
12701 bytes
Lines
399
Domain
Driver Families
Bucket
drivers/memory
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

if (of_device_is_compatible(np_tim, tim_compat)) {
			if (of_do_get_timings(np_tim, &timings[i])) {
				of_node_put(np_tim);
				devm_kfree(dev, timings);
				goto default_timings;
			}
			i++;
		}
	}

	*nr_frequencies = arr_sz;

	return timings;

default_timings:
	dev_warn(dev, "Using default memory timings\n");
	*nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings);
	return lpddr2_jedec_timings;
}
EXPORT_SYMBOL(of_get_ddr_timings);

/**
 * of_lpddr3_get_min_tck() - extract min timing values for lpddr3
 * @np: pointer to ddr device tree node
 * @dev: device requesting for min timing values
 *
 * Populates the lpddr3_min_tck structure by extracting data
 * from device tree node. Returns a pointer to the populated
 * structure. If any error in populating the structure, returns NULL.
 */
const struct lpddr3_min_tck *of_lpddr3_get_min_tck(struct device_node *np,
						   struct device *dev)
{
	int			ret = 0;
	struct lpddr3_min_tck	*min;

	min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
	if (!min)
		goto default_min_tck;

	ret |= of_property_read_u32(np, "tRFC-min-tck", &min->tRFC);
	ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
	ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
	ret |= of_property_read_u32(np, "tRPpb-min-tck", &min->tRPpb);
	ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
	ret |= of_property_read_u32(np, "tRC-min-tck", &min->tRC);
	ret |= of_property_read_u32(np, "tRAS-min-tck", &min->tRAS);
	ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
	ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
	ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
	ret |= of_property_read_u32(np, "tW2W-C2C-min-tck", &min->tW2W_C2C);
	ret |= of_property_read_u32(np, "tR2R-C2C-min-tck", &min->tR2R_C2C);
	ret |= of_property_read_u32(np, "tWL-min-tck", &min->tWL);
	ret |= of_property_read_u32(np, "tDQSCK-min-tck", &min->tDQSCK);
	ret |= of_property_read_u32(np, "tRL-min-tck", &min->tRL);
	ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
	ret |= of_property_read_u32(np, "tXSR-min-tck", &min->tXSR);
	ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
	ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE);
	ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR);
	ret |= of_property_read_u32(np, "tMRD-min-tck", &min->tMRD);

	if (ret) {
		dev_warn(dev, "Errors while parsing min-tck values\n");
		devm_kfree(dev, min);
		goto default_min_tck;
	}

	return min;

default_min_tck:
	dev_warn(dev, "Using default min-tck values\n");
	return NULL;
}
EXPORT_SYMBOL(of_lpddr3_get_min_tck);

static int of_lpddr3_do_get_timings(struct device_node *np,
				    struct lpddr3_timings *tim)
{
	int ret;

	ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
	if (ret)
		/* Deprecated way of passing max-freq as 'reg' */
		ret = of_property_read_u32(np, "reg", &tim->max_freq);
	ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
	ret |= of_property_read_u32(np, "tRFC", &tim->tRFC);
	ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
	ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
	ret |= of_property_read_u32(np, "tRPpb", &tim->tRPpb);

Annotation

Implementation Notes