linux/drivers/mtd/lpddr/qinfo_probe.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Probing flash chips with QINFO records.
   4 * (C) 2008 Korolev Alexey <akorolev@infradead.org>
   5 * (C) 2008 Vasiliy Leonenko <vasiliy.leonenko@gmail.com>
   6 */
   7#include <linux/module.h>
   8#include <linux/types.h>
   9#include <linux/kernel.h>
  10#include <linux/init.h>
  11#include <linux/errno.h>
  12#include <linux/slab.h>
  13#include <linux/interrupt.h>
  14
  15#include <linux/mtd/xip.h>
  16#include <linux/mtd/map.h>
  17#include <linux/mtd/pfow.h>
  18#include <linux/mtd/qinfo.h>
  19
  20static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr);
  21struct mtd_info *lpddr_probe(struct map_info *map);
  22static struct lpddr_private *lpddr_probe_chip(struct map_info *map);
  23static int lpddr_pfow_present(struct map_info *map,
  24                        struct lpddr_private *lpddr);
  25
  26static struct qinfo_query_info qinfo_array[] = {
  27        /* General device info */
  28        {0, 0, "DevSizeShift", "Device size 2^n bytes"},
  29        {0, 3, "BufSizeShift", "Program buffer size 2^n bytes"},
  30        /* Erase block information */
  31        {1, 1, "TotalBlocksNum", "Total number of blocks"},
  32        {1, 2, "UniformBlockSizeShift", "Uniform block size 2^n bytes"},
  33        /* Partition information */
  34        {2, 1, "HWPartsNum", "Number of hardware partitions"},
  35        /* Optional features */
  36        {5, 1, "SuspEraseSupp", "Suspend erase supported"},
  37        /* Operation typical time */
  38        {10, 0, "SingleWordProgTime", "Single word program 2^n u-sec"},
  39        {10, 1, "ProgBufferTime", "Program buffer write 2^n u-sec"},
  40        {10, 2, "BlockEraseTime", "Block erase 2^n m-sec"},
  41        {10, 3, "FullChipEraseTime", "Full chip erase 2^n m-sec"},
  42};
  43
  44static long lpddr_get_qinforec_pos(struct map_info *map, char *id_str)
  45{
  46        int qinfo_lines = ARRAY_SIZE(qinfo_array);
  47        int i;
  48        int bankwidth = map_bankwidth(map) * 8;
  49        int major, minor;
  50
  51        for (i = 0; i < qinfo_lines; i++) {
  52                if (strcmp(id_str, qinfo_array[i].id_str) == 0) {
  53                        major = qinfo_array[i].major & ((1 << bankwidth) - 1);
  54                        minor = qinfo_array[i].minor & ((1 << bankwidth) - 1);
  55                        return minor | (major << bankwidth);
  56                }
  57        }
  58        printk(KERN_ERR"%s qinfo id string is wrong! \n", map->name);
  59        BUG();
  60        return -1;
  61}
  62
  63static uint16_t lpddr_info_query(struct map_info *map, char *id_str)
  64{
  65        unsigned int dsr, val;
  66        int bits_per_chip = map_bankwidth(map) * 8;
  67        unsigned long adr = lpddr_get_qinforec_pos(map, id_str);
  68        int attempts = 20;
  69
  70        /* Write a request for the PFOW record */
  71        map_write(map, CMD(LPDDR_INFO_QUERY),
  72                        map->pfow_base + PFOW_COMMAND_CODE);
  73        map_write(map, CMD(adr & ((1 << bits_per_chip) - 1)),
  74                        map->pfow_base + PFOW_COMMAND_ADDRESS_L);
  75        map_write(map, CMD(adr >> bits_per_chip),
  76                        map->pfow_base + PFOW_COMMAND_ADDRESS_H);
  77        map_write(map, CMD(LPDDR_START_EXECUTION),
  78                        map->pfow_base + PFOW_COMMAND_EXECUTE);
  79
  80        while ((attempts--) > 0) {
  81                dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
  82                if (dsr & DSR_READY_STATUS)
  83                        break;
  84                udelay(10);
  85        }
  86
  87        val = CMDVAL(map_read(map, map->pfow_base + PFOW_COMMAND_DATA));
  88        return val;
  89}
  90
  91static int lpddr_pfow_present(struct map_info *map, struct lpddr_private *lpddr)
  92{
  93        map_word pfow_val[4];
  94
  95        /* Check identification string */
  96        pfow_val[0] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_P);
  97        pfow_val[1] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_F);
  98        pfow_val[2] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_O);
  99        pfow_val[3] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_W);
 100
 101        if (!map_word_equal(map, CMD('P'), pfow_val[0]))
 102                goto out;
 103
 104        if (!map_word_equal(map, CMD('F'), pfow_val[1]))
 105                goto out;
 106
 107        if (!map_word_equal(map, CMD('O'), pfow_val[2]))
 108                goto out;
 109
 110        if (!map_word_equal(map, CMD('W'), pfow_val[3]))
 111                goto out;
 112
 113        return 1;       /* "PFOW" is found */
 114out:
 115        printk(KERN_WARNING"%s: PFOW string at 0x%lx is not found \n",
 116                                        map->name, map->pfow_base);
 117        return 0;
 118}
 119
 120static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr)
 121{
 122
 123        lpddr->qinfo = kzalloc(sizeof(struct qinfo_chip), GFP_KERNEL);
 124        if (!lpddr->qinfo)
 125                return 0;
 126
 127        /* Get the ManuID */
 128        lpddr->ManufactId = CMDVAL(map_read(map, map->pfow_base + PFOW_MANUFACTURER_ID));
 129        /* Get the DeviceID */
 130        lpddr->DevId = CMDVAL(map_read(map, map->pfow_base + PFOW_DEVICE_ID));
 131        /* read parameters from chip qinfo table */
 132        lpddr->qinfo->DevSizeShift = lpddr_info_query(map, "DevSizeShift");
 133        lpddr->qinfo->TotalBlocksNum = lpddr_info_query(map, "TotalBlocksNum");
 134        lpddr->qinfo->BufSizeShift = lpddr_info_query(map, "BufSizeShift");
 135        lpddr->qinfo->HWPartsNum = lpddr_info_query(map, "HWPartsNum");
 136        lpddr->qinfo->UniformBlockSizeShift =
 137                                lpddr_info_query(map, "UniformBlockSizeShift");
 138        lpddr->qinfo->SuspEraseSupp = lpddr_info_query(map, "SuspEraseSupp");
 139        lpddr->qinfo->SingleWordProgTime =
 140                                lpddr_info_query(map, "SingleWordProgTime");
 141        lpddr->qinfo->ProgBufferTime = lpddr_info_query(map, "ProgBufferTime");
 142        lpddr->qinfo->BlockEraseTime = lpddr_info_query(map, "BlockEraseTime");
 143        return 1;
 144}
 145static struct lpddr_private *lpddr_probe_chip(struct map_info *map)
 146{
 147        struct lpddr_private lpddr;
 148        struct lpddr_private *retlpddr;
 149        int numvirtchips;
 150
 151
 152        if ((map->pfow_base + 0x1000) >= map->size) {
 153                printk(KERN_NOTICE"%s Probe at base (0x%08lx) past the end of"
 154                                "the map(0x%08lx)\n", map->name,
 155                                (unsigned long)map->pfow_base, map->size - 1);
 156                return NULL;
 157        }
 158        memset(&lpddr, 0, sizeof(struct lpddr_private));
 159        if (!lpddr_pfow_present(map, &lpddr))
 160                return NULL;
 161
 162        if (!lpddr_chip_setup(map, &lpddr))
 163                return NULL;
 164
 165        /* Ok so we found a chip */
 166        lpddr.chipshift = lpddr.qinfo->DevSizeShift;
 167        lpddr.numchips = 1;
 168
 169        numvirtchips = lpddr.numchips * lpddr.qinfo->HWPartsNum;
 170        retlpddr = kzalloc(struct_size(retlpddr, chips, numvirtchips),
 171                           GFP_KERNEL);
 172        if (!retlpddr)
 173                return NULL;
 174
 175        memcpy(retlpddr, &lpddr, sizeof(struct lpddr_private));
 176
 177        retlpddr->numchips = numvirtchips;
 178        retlpddr->chipshift = retlpddr->qinfo->DevSizeShift -
 179                                __ffs(retlpddr->qinfo->HWPartsNum);
 180
 181        return retlpddr;
 182}
 183
 184struct mtd_info *lpddr_probe(struct map_info *map)
 185{
 186        struct mtd_info *mtd = NULL;
 187        struct lpddr_private *lpddr;
 188
 189        /* First probe the map to see if we havecan open PFOW here */
 190        lpddr = lpddr_probe_chip(map);
 191        if (!lpddr)
 192                return NULL;
 193
 194        map->fldrv_priv = lpddr;
 195        mtd = lpddr_cmdset(map);
 196        if (mtd) {
 197                if (mtd->size > map->size) {
 198                        printk(KERN_WARNING "Reducing visibility of %ldKiB chip"
 199                                "to %ldKiB\n", (unsigned long)mtd->size >> 10,
 200                                (unsigned long)map->size >> 10);
 201                        mtd->size = map->size;
 202                }
 203                return mtd;
 204        }
 205
 206        kfree(lpddr->qinfo);
 207        kfree(lpddr);
 208        map->fldrv_priv = NULL;
 209        return NULL;
 210}
 211
 212static struct mtd_chip_driver lpddr_chipdrv = {
 213        .probe          = lpddr_probe,
 214        .name           = "qinfo_probe",
 215        .module         = THIS_MODULE
 216};
 217
 218static int __init lpddr_probe_init(void)
 219{
 220        register_mtd_chip_driver(&lpddr_chipdrv);
 221        return 0;
 222}
 223
 224static void __exit lpddr_probe_exit(void)
 225{
 226        unregister_mtd_chip_driver(&lpddr_chipdrv);
 227}
 228
 229module_init(lpddr_probe_init);
 230module_exit(lpddr_probe_exit);
 231
 232MODULE_LICENSE("GPL");
 233MODULE_AUTHOR("Vasiliy Leonenko <vasiliy.leonenko@gmail.com>");
 234MODULE_DESCRIPTION("Driver to probe qinfo flash chips");
 235
 236