qinfo_probe.c

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/*
 * Probing flash chips with QINFO records.
 * (C) 2008 Korolev Alexey <[email protected]>
 * (C) 2008 Vasiliy Leonenko <[email protected]>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

#include <linux/mtd/xip.h>
#include <linux/mtd/map.h>
#include <linux/mtd/pfow.h>
#include <linux/mtd/qinfo.h>

static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr);
struct mtd_info *lpddr_probe(struct map_info *map);
static struct lpddr_private *lpddr_probe_chip(struct map_info *map);
static int lpddr_pfow_present(struct map_info *map,
            struct lpddr_private *lpddr);

static struct qinfo_query_info qinfo_array[] = {
    /* General device info */
    {0, 0, "DevSizeShift", "Device size 2^n bytes"},
    {0, 3, "BufSizeShift", "Program buffer size 2^n bytes"},
    /* Erase block information */
    {1, 1, "TotalBlocksNum", "Total number of blocks"},
    {1, 2, "UniformBlockSizeShift", "Uniform block size 2^n bytes"},
    /* Partition information */
    {2, 1, "HWPartsNum", "Number of hardware partitions"},
    /* Optional features */
    {5, 1, "SuspEraseSupp", "Suspend erase supported"},
    /* Operation typical time */
    {10, 0, "SingleWordProgTime", "Single word program 2^n u-sec"},
    {10, 1, "ProgBufferTime", "Program buffer write 2^n u-sec"},
    {10, 2, "BlockEraseTime", "Block erase 2^n m-sec"},
    {10, 3, "FullChipEraseTime", "Full chip erase 2^n m-sec"},
};

static long lpddr_get_qinforec_pos(struct map_info *map, char *id_str)
{
    int qinfo_lines = ARRAY_SIZE(qinfo_array);
    int i;
    int bankwidth = map_bankwidth(map) * 8;
    int major, minor;

    for (i = 0; i < qinfo_lines; i++) {
        if (strcmp(id_str, qinfo_array[i].id_str) == 0) {
            major = qinfo_array[i].major & ((1 << bankwidth) - 1);
            minor = qinfo_array[i].minor & ((1 << bankwidth) - 1);
            return minor | (major << bankwidth);
        }
    }
    printk(KERN_ERR"%s qinfo id string is wrong! \n", map->name);
    BUG();
    return -1;
}

static uint16_t lpddr_info_query(struct map_info *map, char *id_str)
{
    unsigned int dsr, val;
    int bits_per_chip = map_bankwidth(map) * 8;
    unsigned long adr = lpddr_get_qinforec_pos(map, id_str);
    int attempts = 20;

    /* Write a request for the PFOW record */
    map_write(map, CMD(LPDDR_INFO_QUERY),
            map->pfow_base + PFOW_COMMAND_CODE);
    map_write(map, CMD(adr & ((1 << bits_per_chip) - 1)),
            map->pfow_base + PFOW_COMMAND_ADDRESS_L);
    map_write(map, CMD(adr >> bits_per_chip),
            map->pfow_base + PFOW_COMMAND_ADDRESS_H);
    map_write(map, CMD(LPDDR_START_EXECUTION),
            map->pfow_base + PFOW_COMMAND_EXECUTE);

    while ((attempts--) > 0) {
        dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
        if (dsr & DSR_READY_STATUS)
            break;
        udelay(10);
    }

    val = CMDVAL(map_read(map, map->pfow_base + PFOW_COMMAND_DATA));
    return val;
}

static int lpddr_pfow_present(struct map_info *map, struct lpddr_private *lpddr)
{
    map_word pfow_val[4];

    /* Check identification string */
    pfow_val[0] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_P);
    pfow_val[1] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_F);
    pfow_val[2] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_O);
    pfow_val[3] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_W);

    if (!map_word_equal(map, CMD('P'), pfow_val[0]))
        goto out;

    if (!map_word_equal(map, CMD('F'), pfow_val[1]))
        goto out;

    if (!map_word_equal(map, CMD('O'), pfow_val[2]))
        goto out;

    if (!map_word_equal(map, CMD('W'), pfow_val[3]))
        goto out;

    return 1;   /* "PFOW" is found */
out:
    printk(KERN_WARNING"%s: PFOW string at 0x%lx is not found \n",
                    map->name, map->pfow_base);
    return 0;
}

static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr)
{

    lpddr->qinfo = kzalloc(sizeof(struct qinfo_chip), GFP_KERNEL);
    if (!lpddr->qinfo) {
        printk(KERN_WARNING "%s: no memory for LPDDR qinfo structure\n",
                map->name);
        return 0;
    }

    /* Get the ManuID */
    lpddr->ManufactId = CMDVAL(map_read(map, map->pfow_base + PFOW_MANUFACTURER_ID));
    /* Get the DeviceID */
    lpddr->DevId = CMDVAL(map_read(map, map->pfow_base + PFOW_DEVICE_ID));
    /* read parameters from chip qinfo table */
    lpddr->qinfo->DevSizeShift = lpddr_info_query(map, "DevSizeShift");
    lpddr->qinfo->TotalBlocksNum = lpddr_info_query(map, "TotalBlocksNum");
    lpddr->qinfo->BufSizeShift = lpddr_info_query(map, "BufSizeShift");
    lpddr->qinfo->HWPartsNum = lpddr_info_query(map, "HWPartsNum");
    lpddr->qinfo->UniformBlockSizeShift =
                lpddr_info_query(map, "UniformBlockSizeShift");
    lpddr->qinfo->SuspEraseSupp = lpddr_info_query(map, "SuspEraseSupp");
    lpddr->qinfo->SingleWordProgTime =
                lpddr_info_query(map, "SingleWordProgTime");
    lpddr->qinfo->ProgBufferTime = lpddr_info_query(map, "ProgBufferTime");
    lpddr->qinfo->BlockEraseTime = lpddr_info_query(map, "BlockEraseTime");
    return 1;
}
static struct lpddr_private *lpddr_probe_chip(struct map_info *map)
{
    struct lpddr_private lpddr;
    struct lpddr_private *retlpddr;
    int numvirtchips;


    if ((map->pfow_base + 0x1000) >= map->size) {
        printk(KERN_NOTICE"%s Probe at base (0x%08lx) past the end of"
                "the map(0x%08lx)\n", map->name,
                (unsigned long)map->pfow_base, map->size - 1);
        return NULL;
    }
    memset(&lpddr, 0, sizeof(struct lpddr_private));
    if (!lpddr_pfow_present(map, &lpddr))
        return NULL;

    if (!lpddr_chip_setup(map, &lpddr))
        return NULL;

    /* Ok so we found a chip */
    lpddr.chipshift = lpddr.qinfo->DevSizeShift;
    lpddr.numchips = 1;

    numvirtchips = lpddr.numchips * lpddr.qinfo->HWPartsNum;
    retlpddr = kzalloc(sizeof(struct lpddr_private) +
            numvirtchips * sizeof(struct flchip), GFP_KERNEL);
    if (!retlpddr)
        return NULL;

    memcpy(retlpddr, &lpddr, sizeof(struct lpddr_private));

    retlpddr->numchips = numvirtchips;
    retlpddr->chipshift = retlpddr->qinfo->DevSizeShift -
                __ffs(retlpddr->qinfo->HWPartsNum);

    return retlpddr;
}

struct mtd_info *lpddr_probe(struct map_info *map)
{
    struct mtd_info *mtd = NULL;
    struct lpddr_private *lpddr;

    /* First probe the map to see if we havecan open PFOW here */
    lpddr = lpddr_probe_chip(map);
    if (!lpddr)
        return NULL;

    map->fldrv_priv = lpddr;
    mtd = lpddr_cmdset(map);
    if (mtd) {
        if (mtd->size > map->size) {
            printk(KERN_WARNING "Reducing visibility of %ldKiB chip"
                "to %ldKiB\n", (unsigned long)mtd->size >> 10,
                (unsigned long)map->size >> 10);
            mtd->size = map->size;
        }
        return mtd;
    }

    kfree(lpddr->qinfo);
    kfree(lpddr);
    map->fldrv_priv = NULL;
    return NULL;
}

static struct mtd_chip_driver lpddr_chipdrv = {
    .probe      = lpddr_probe,
    .name       = "qinfo_probe",
    .module     = THIS_MODULE
};

static int __init lpddr_probe_init(void)
{
    register_mtd_chip_driver(&lpddr_chipdrv);
    return 0;
}

static void __exit lpddr_probe_exit(void)
{
    unregister_mtd_chip_driver(&lpddr_chipdrv);
}

module_init(lpddr_probe_init);
module_exit(lpddr_probe_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vasiliy Leonenko <[email protected]>");
MODULE_DESCRIPTION("Driver to probe qinfo flash chips");