drivers/memory/of_memory.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * OpenFirmware helpers for memory drivers
  *
  * Copyright (C) 2012 Texas Instruments, Inc.
  * Copyright (C) 2019 Samsung Electronics Co., Ltd.
  * Copyright (C) 2020 Krzysztof Kozlowski <krzk@kernel.org>
  */

 #include <linux/device.h>
 #include <linux/of.h>
 #include <linux/gfp.h>
 #include <linux/export.h>

 #include "jedec_ddr.h"
 #include "of_memory.h"

 /**
  * of_get_min_tck() - extract min timing values for ddr
  * @np: pointer to ddr device tree node
  * @dev: 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, "Using default min-tck values\n");
 	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 = NULL;

 	switch (device_type) {
 	case DDR_TYPE_LPDDR2_S2:
 	case DDR_TYPE_LPDDR2_S4:
 		tim_compat = "jedec,lpddr2-timings";
 		break;
 	default:
 		dev_warn(dev, "Unsupported memory type\n");
 	}

 	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_kcalloc(dev, arr_sz, sizeof(*timings),
 				       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, "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;

 	/* The 'reg' param required since DT has changed, used as 'max-freq' */
 	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);
 	ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
 	ret |= of_property_read_u32(np, "tRC", &tim->tRC);
 	ret |= of_property_read_u32(np, "tRAS", &tim->tRAS);
 	ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
 	ret |= of_property_read_u32(np, "tWR", &tim->tWR);
 	ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
 	ret |= of_property_read_u32(np, "tW2W-C2C", &tim->tW2W_C2C);
 	ret |= of_property_read_u32(np, "tR2R-C2C", &tim->tR2R_C2C);
 	ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
 	ret |= of_property_read_u32(np, "tXSR", &tim->tXSR);
 	ret |= of_property_read_u32(np, "tXP", &tim->tXP);
 	ret |= of_property_read_u32(np, "tCKE", &tim->tCKE);
 	ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
 	ret |= of_property_read_u32(np, "tMRD", &tim->tMRD);

 	return ret;
 }

 /**
  * of_lpddr3_get_ddr_timings() - extracts the lpddr3 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
  * @nr_frequencies: No of frequencies available for ddr
  * (updated by this function)
  *
  * Populates lpddr3_timings structure by extracting data from device
  * tree node. Returns pointer to populated structure. If any error
  * while populating, returns NULL.
  */
 const struct lpddr3_timings
 *of_lpddr3_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
 			   u32 device_type, u32 *nr_frequencies)
 {
 	struct lpddr3_timings	*timings = NULL;
 	u32			arr_sz = 0, i = 0;
 	struct device_node	*np_tim;
 	char			*tim_compat = NULL;

 	switch (device_type) {
 	case DDR_TYPE_LPDDR3:
 		tim_compat = "jedec,lpddr3-timings";
 		break;
 	default:
 		dev_warn(dev, "Unsupported memory type\n");
 	}

 	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_kcalloc(dev, arr_sz, sizeof(*timings),
 				       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_lpddr3_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, "Failed to get timings\n");
 	*nr_frequencies = 0;
 	return NULL;
 }
 EXPORT_SYMBOL(of_lpddr3_get_ddr_timings);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* OpenFirmware helpers for memory drivers
	*
	* Copyright (C) 2012 Texas Instruments, Inc.
	* Copyright (C) 2019 Samsung Electronics Co., Ltd.
	* Copyright (C) 2020 Krzysztof Kozlowski <krzk@kernel.org>
	*/

	#include <linux/device.h>
	#include <linux/of.h>
	#include <linux/gfp.h>
	#include <linux/export.h>

	#include "jedec_ddr.h"
	#include "of_memory.h"

	/**
	* of_get_min_tck() - extract min timing values for ddr
	* @np: pointer to ddr device tree node
	* @dev: 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, "Using default min-tck values\n");
	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 = NULL;

	switch (device_type) {
	case DDR_TYPE_LPDDR2_S2:
	case DDR_TYPE_LPDDR2_S4:
	tim_compat = "jedec,lpddr2-timings";
	break;
	default:
	dev_warn(dev, "Unsupported memory type\n");
	}

	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_kcalloc(dev, arr_sz, sizeof(*timings),
	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, "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;

	/* The 'reg' param required since DT has changed, used as 'max-freq' */
	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);
	ret \|= of_property_read_u32(np, "tRCD", &tim->tRCD);
	ret \|= of_property_read_u32(np, "tRC", &tim->tRC);
	ret \|= of_property_read_u32(np, "tRAS", &tim->tRAS);
	ret \|= of_property_read_u32(np, "tWTR", &tim->tWTR);
	ret \|= of_property_read_u32(np, "tWR", &tim->tWR);
	ret \|= of_property_read_u32(np, "tRTP", &tim->tRTP);
	ret \|= of_property_read_u32(np, "tW2W-C2C", &tim->tW2W_C2C);
	ret \|= of_property_read_u32(np, "tR2R-C2C", &tim->tR2R_C2C);
	ret \|= of_property_read_u32(np, "tFAW", &tim->tFAW);
	ret \|= of_property_read_u32(np, "tXSR", &tim->tXSR);
	ret \|= of_property_read_u32(np, "tXP", &tim->tXP);
	ret \|= of_property_read_u32(np, "tCKE", &tim->tCKE);
	ret \|= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
	ret \|= of_property_read_u32(np, "tMRD", &tim->tMRD);

	return ret;
	}

	/**
	* of_lpddr3_get_ddr_timings() - extracts the lpddr3 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
	* @nr_frequencies: No of frequencies available for ddr
	* (updated by this function)
	*
	* Populates lpddr3_timings structure by extracting data from device
	* tree node. Returns pointer to populated structure. If any error
	* while populating, returns NULL.
	*/
	const struct lpddr3_timings
	of_lpddr3_get_ddr_timings(struct device_node np_ddr, struct device *dev,
	u32 device_type, u32 *nr_frequencies)
	{
	struct lpddr3_timings *timings = NULL;
	u32 arr_sz = 0, i = 0;
	struct device_node *np_tim;
	char *tim_compat = NULL;

	switch (device_type) {
	case DDR_TYPE_LPDDR3:
	tim_compat = "jedec,lpddr3-timings";
	break;
	default:
	dev_warn(dev, "Unsupported memory type\n");
	}

	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_kcalloc(dev, arr_sz, sizeof(*timings),
	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_lpddr3_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, "Failed to get timings\n");
	*nr_frequencies = 0;
	return NULL;
	}
	EXPORT_SYMBOL(of_lpddr3_get_ddr_timings);