linux/drivers/memory/of_memory.c

// 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 <[email protected]>
 */

#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)
{ … }
EXPORT_SYMBOL(…);

static int of_do_get_timings(struct device_node *np,
			     struct lpddr2_timings *tim)
{ … }

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

static int of_lpddr3_do_get_timings(struct device_node *np,
				    struct lpddr3_timings *tim)
{ … }

/**
 * 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)
{ … }
EXPORT_SYMBOL(…);

/**
 * of_lpddr2_get_info() - extracts information about the lpddr2 chip.
 * @np: Pointer to device tree node containing lpddr2 info
 * @dev: Device requesting info
 *
 * Populates lpddr2_info structure by extracting data from device
 * tree node. Returns pointer to populated structure. If error
 * happened while populating, returns NULL. If property is missing
 * in a device-tree, then the corresponding value is set to -ENOENT.
 */
const struct lpddr2_info
*of_lpddr2_get_info(struct device_node *np, struct device *dev)
{ … }
EXPORT_SYMBOL(…);