1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
new file mode 100644
index 000000000000..60074351f17e
--- /dev/null
+++ b/drivers/memory/of_memory.c
@@ -0,0 +1,153 @@
+/*
+ * OpenFirmware helpers for memory drivers
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/gfp.h>
+#include <memory/jedec_ddr.h>
+#include <linux/export.h>
+
+/**
+ * of_get_min_tck() - extract min timing values for ddr
+ * @np: pointer to ddr device tree node
+ * @device: device requesting for min timing values
+ *
+ * Populates the lpddr2_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
+ * default min timings provided by JEDEC.
+ */
+const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
+		struct device *dev)
+{
+	int			ret = 0;
+	struct lpddr2_min_tck	*min;
+
+	min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
+	if (!min)
+		goto default_min_tck;
+
+	ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
+	ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
+	ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
+	ret |= of_property_read_u32(np, "tRASmin-min-tck", &min->tRASmin);
+	ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
+	ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
+	ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
+	ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
+	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, "tFAW-min-tck", &min->tFAW);
+
+	if (ret) {
+		devm_kfree(dev, min);
+		goto default_min_tck;
+	}
+
+	return min;
+
+default_min_tck:
+	dev_warn(dev, "%s: using default min-tck values\n", __func__);
+	return &lpddr2_jedec_min_tck;
+}
+EXPORT_SYMBOL(of_get_min_tck);
+
+static int of_do_get_timings(struct device_node *np,
+		struct lpddr2_timings *tim)
+{
+	int ret;
+
+	ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
+	ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
+	ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
+	ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
+	ret |= of_property_read_u32(np, "tWR", &tim->tWR);
+	ret |= of_property_read_u32(np, "tRAS-min", &tim->tRAS_min);
+	ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
+	ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
+	ret |= of_property_read_u32(np, "tXP", &tim->tXP);
+	ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
+	ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
+	ret |= of_property_read_u32(np, "tDQSCK-max", &tim->tDQSCK_max);
+	ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
+	ret |= of_property_read_u32(np, "tZQCS", &tim->tZQCS);
+	ret |= of_property_read_u32(np, "tZQCL", &tim->tZQCL);
+	ret |= of_property_read_u32(np, "tZQinit", &tim->tZQinit);
+	ret |= of_property_read_u32(np, "tRAS-max-ns", &tim->tRAS_max_ns);
+	ret |= of_property_read_u32(np, "tDQSCK-max-derated",
+		&tim->tDQSCK_max_derated);
+
+	return ret;
+}
+
+/**
+ * of_get_ddr_timings() - extracts the ddr timings and updates no of
+ * frequencies available.
+ * @np_ddr: Pointer to ddr device tree node
+ * @dev: Device requesting for ddr timings
+ * @device_type: Type of ddr(LPDDR2 S2/S4)
+ * @nr_frequencies: No of frequencies available for ddr
+ * (updated by this function)
+ *
+ * Populates lpddr2_timings structure by extracting data from device
+ * tree node. Returns pointer to populated structure. If any error
+ * while populating, returns default timings provided by JEDEC.
+ */
+const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
+		struct device *dev, u32 device_type, u32 *nr_frequencies)
+{
+	struct lpddr2_timings	*timings = NULL;
+	u32			arr_sz = 0, i = 0;
+	struct device_node	*np_tim;
+	char			*tim_compat;
+
+	switch (device_type) {
+	case DDR_TYPE_LPDDR2_S2:
+	case DDR_TYPE_LPDDR2_S4:
+		tim_compat = "jedec,lpddr2-timings";
+		break;
+	default:
+		dev_warn(dev, "%s: un-supported memory type\n", __func__);
+	}
+
+	for_each_child_of_node(np_ddr, np_tim)
+		if (of_device_is_compatible(np_tim, tim_compat))
+			arr_sz++;
+
+	if (arr_sz)
+		timings = devm_kzalloc(dev, sizeof(*timings) * arr_sz,
+			GFP_KERNEL);
+
+	if (!timings)
+		goto default_timings;
+
+	for_each_child_of_node(np_ddr, np_tim) {
+		if (of_device_is_compatible(np_tim, tim_compat)) {
+			if (of_do_get_timings(np_tim, &timings[i])) {
+				devm_kfree(dev, timings);
+				goto default_timings;
+			}
+			i++;
+		}
+	}
+
+	*nr_frequencies = arr_sz;
+
+	return timings;
+
+default_timings:
+	dev_warn(dev, "%s: using default timings\n", __func__);
+	*nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings);
+	return lpddr2_jedec_timings;
+}
+EXPORT_SYMBOL(of_get_ddr_timings);