of_memory.c

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/*
 * 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>

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;
}

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);