Re: [PATCH v6 2/8] mtd: rawnand: rockchip: NFC drivers for RK3308, RK2928 and others

Johan Jonker
2020-06-09T20:18:23Z

On 6/9/20 6:10 PM, Johan Jonker wrote:

> On 6/9/20 9:40 AM, Yifeng Zhao wrote:

[..]

>> +static int rk_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
>> + const u8 *buf, int page, int raw)
>> +{
>> + struct rk_nfc *nfc = nand_get_controller_data(chip);
>> + struct rk_nfc_nand_chip *rk_nand = to_rk_nand(chip);
>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>> + int oob_step = (ecc->bytes > 60) ? NFC_MAX_OOB_PER_STEP :
>> + NFC_MIN_OOB_PER_STEP;
>> + int pages_per_blk = mtd->erasesize / mtd->writesize;
>> + int ret = 0, i, boot_rom_mode = 0;
>> + dma_addr_t dma_data, dma_oob;
>> + u32 reg;
>> + u8 *oob;
>> +
>> + nand_prog_page_begin_op(chip, page, 0, NULL, 0);
>> +
>> + if (!raw) {
>> + memcpy(nfc->page_buf, buf, mtd->writesize);
>> + memset(nfc->oob_buf, 0xff, oob_step * ecc->steps);
>> +
>
>> + /*
>> + * The first 8(some devices are 4 or 16) blocks in use by
>
> are in use by
>
>> + * the boot ROM and the first 32 bits of oob need to link
>> + * to the next page address in the same block.
>> + * Config the ECC algorithm supported by the boot ROM.
>> + */
>> + if (page < pages_per_blk * rk_nand->boot_blks &&
>> + chip->options & NAND_IS_BOOT_MEDIUM) {
>> + boot_rom_mode = 1;
>> + if (rk_nand->boot_ecc != ecc->strength)
>> + rk_nfc_hw_ecc_setup(chip, ecc,
>> + rk_nand->boot_ecc);
>> + }
>
> Helper?
>
>> +
>> + /*
>

>> + * Swap the first oob with the seventh oob and bad block
>
>
> Swap the first oob byte with the seventh oob byte.
>
>> + * mask is saved at the seventh oob.
>
> The bad block mask is stored at the seventh oob byte.

Just wondering bit or byte?
seventh or eight?

>
>> + */
>> + swap(chip->oob_poi[0], chip->oob_poi[7]);

uint8_t *oob_poi;

1: oob_poi points to a byte I think?

What was the swap puspose? A bit or a byte?
There's 4 bytes oob per step.
Could you explain?

2: oob_poi[7] counting starts at [0] #1, [7] is then #8 ?
Is that correct?

>> +
>> + for (i = 0; i < ecc->steps; i++) {
>> + oob = chip->oob_poi + i * NFC_SYS_DATA_SIZE;
>> + reg = oob[0] | oob[1] << 8 | oob[2] << 16 |
>> + oob[3] << 24;
>> + if (!i && boot_rom_mode)
>> + reg = (page & (pages_per_blk - 1)) * 4;
>> +
>> + if (nfc->cfg->type == NFC_V6 ||
>> + nfc->cfg->type == NFC_V8)
>> + nfc->oob_buf[i * oob_step / 4] = reg;
>> + else
>> + nfc->oob_buf[i] = reg;
>> + }
>> +
>> + dma_data = dma_map_single(nfc->dev, (void *)nfc->page_buf,
>> + mtd->writesize, DMA_TO_DEVICE);
>> + dma_oob = dma_map_single(nfc->dev, nfc->oob_buf,
>> + ecc->steps * oob_step,
>> + DMA_TO_DEVICE);
>> +
>> + reinit_completion(&nfc->done);
>> + writel(INT_DMA, nfc->regs + nfc->cfg->int_en_off);
>> +
>> + rk_nfc_xfer_start(nfc, NFC_WRITE, ecc->steps, dma_data,
>> + dma_oob);
>> + ret = wait_for_completion_timeout(&nfc->done,
>> + msecs_to_jiffies(100));
>> + if (!ret)
>> + dev_warn(nfc->dev, "write: wait dma done timeout.\n");
>> + /*
>> + * Whether the DMA transfer is completed or not. The driver
>> + * needs to check the NFC`s status register to see if the data
>> + * transfer was completed.
>> + */
>> + ret = rk_nfc_wait_for_xfer_done(nfc);
>> +
>> + dma_unmap_single(nfc->dev, dma_data, mtd->writesize,
>> + DMA_TO_DEVICE);
>> + dma_unmap_single(nfc->dev, dma_oob, ecc->steps * oob_step,
>> + DMA_TO_DEVICE);
>> +
>
>> + if (boot_rom_mode && rk_nand->boot_ecc != ecc->strength)
>> + rk_nfc_hw_ecc_setup(chip, ecc, ecc->strength);
>
> Helper?
>
>> +
>> + if (ret) {
>> + ret = -EIO;
>
>> + dev_err(nfc->dev,
>> + "write: wait transfer done timeout.\n");
>
> align
>
>> + }
>> + } else {

>> + rk_nfc_write_buf(chip, buf, mtd->writesize + + mtd->oobsize);

Too many +++ here? ^ ^

>> + }
>> +
>> + if (ret)
>> + return ret;
>> +
>> + ret = nand_prog_page_end_op(chip);
>> +
>> + /* Deselect the currently selected target. */
>> + rk_nfc_select_chip(chip, -1);
>> +
>> + return ret;
>> +}