LXR linux/drivers/memory/of

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * OpenFirmware helpers for memory drivers
   4 *
   5 * Copyright (C) 2012 Texas Instruments, Inc.
   6 */
   7
   8#include <linux/device.h>
   9#include <linux/platform_device.h>
  10#include <linux/list.h>
  11#include <linux/of.h>
  12#include <linux/gfp.h>
  13#include <linux/export.h>
  14
  15#include "jedec_ddr.h"
  16#include "of_memory.h"
  17
  18/**
  19 * of_get_min_tck() - extract min timing values for ddr
  20 * @np: pointer to ddr device tree node
  21 * @device: device requesting for min timing values
  22 *
  23 * Populates the lpddr2_min_tck structure by extracting data
  24 * from device tree node. Returns a pointer to the populated
  25 * structure. If any error in populating the structure, returns
  26 * default min timings provided by JEDEC.
  27 */
  28const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
  29                struct device *dev)
  30{
  31        int                     ret = 0;
  32        struct lpddr2_min_tck   *min;
  33
  34        min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
  35        if (!min)
  36                goto default_min_tck;
  37
  38        ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
  39        ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
  40        ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
  41        ret |= of_property_read_u32(np, "tRASmin-min-tck", &min->tRASmin);
  42        ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
  43        ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
  44        ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
  45        ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
  46        ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE);
  47        ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR);
  48        ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
  49
  50        if (ret) {
  51                devm_kfree(dev, min);
  52                goto default_min_tck;
  53        }
  54
  55        return min;
  56
  57default_min_tck:
  58        dev_warn(dev, "%s: using default min-tck values\n", __func__);
  59        return &lpddr2_jedec_min_tck;
  60}
  61EXPORT_SYMBOL(of_get_min_tck);
  62
  63static int of_do_get_timings(struct device_node *np,
  64                struct lpddr2_timings *tim)
  65{
  66        int ret;
  67
  68        ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
  69        ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
  70        ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
  71        ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
  72        ret |= of_property_read_u32(np, "tWR", &tim->tWR);
  73        ret |= of_property_read_u32(np, "tRAS-min", &tim->tRAS_min);
  74        ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
  75        ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
  76        ret |= of_property_read_u32(np, "tXP", &tim->tXP);
  77        ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
  78        ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
  79        ret |= of_property_read_u32(np, "tDQSCK-max", &tim->tDQSCK_max);
  80        ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
  81        ret |= of_property_read_u32(np, "tZQCS", &tim->tZQCS);
  82        ret |= of_property_read_u32(np, "tZQCL", &tim->tZQCL);
  83        ret |= of_property_read_u32(np, "tZQinit", &tim->tZQinit);
  84        ret |= of_property_read_u32(np, "tRAS-max-ns", &tim->tRAS_max_ns);
  85        ret |= of_property_read_u32(np, "tDQSCK-max-derated",
  86                &tim->tDQSCK_max_derated);
  87
  88        return ret;
  89}
  90
  91/**
  92 * of_get_ddr_timings() - extracts the ddr timings and updates no of
  93 * frequencies available.
  94 * @np_ddr: Pointer to ddr device tree node
  95 * @dev: Device requesting for ddr timings
  96 * @device_type: Type of ddr(LPDDR2 S2/S4)
  97 * @nr_frequencies: No of frequencies available for ddr
  98 * (updated by this function)
  99 *
 100 * Populates lpddr2_timings structure by extracting data from device
 101 * tree node. Returns pointer to populated structure. If any error
 102 * while populating, returns default timings provided by JEDEC.
 103 */
 104const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
 105                struct device *dev, u32 device_type, u32 *nr_frequencies)
 106{
 107        struct lpddr2_timings   *timings = NULL;
 108        u32                     arr_sz = 0, i = 0;
 109        struct device_node      *np_tim;
 110        char                    *tim_compat = NULL;
 111
 112        switch (device_type) {
 113        case DDR_TYPE_LPDDR2_S2:
 114        case DDR_TYPE_LPDDR2_S4:
 115                tim_compat = "jedec,lpddr2-timings";
 116                break;
 117        default:
 118                dev_warn(dev, "%s: un-supported memory type\n", __func__);
 119        }
 120
 121        for_each_child_of_node(np_ddr, np_tim)
 122                if (of_device_is_compatible(np_tim, tim_compat))
 123                        arr_sz++;
 124
 125        if (arr_sz)
 126                timings = devm_kcalloc(dev, arr_sz, sizeof(*timings),
 127                                       GFP_KERNEL);
 128
 129        if (!timings)
 130                goto default_timings;
 131
 132        for_each_child_of_node(np_ddr, np_tim) {
 133                if (of_device_is_compatible(np_tim, tim_compat)) {
 134                        if (of_do_get_timings(np_tim, &timings[i])) {
 135                                devm_kfree(dev, timings);
 136                                goto default_timings;
 137                        }
 138                        i++;
 139                }
 140        }
 141
 142        *nr_frequencies = arr_sz;
 143
 144        return timings;
 145
 146default_timings:
 147        dev_warn(dev, "%s: using default timings\n", __func__);
 148        *nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings);
 149        return lpddr2_jedec_timings;
 150}
 151EXPORT_SYMBOL(of_get_ddr_timings);
 152