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SubjectRe: [LINUX PATCH v17 2/2] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface
On Mon, 24 Jun 2019 22:46:30 -0600
Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> wrote:


> +
> +/**
> + * pl353_nand_exec_op_cmd - Send command to NAND device
> + * @chip: Pointer to the NAND chip info structure
> + * @subop: Pointer to array of instructions
> + * Return: Always return zero
> + */
> +static int pl353_nand_exec_op_cmd(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + const struct nand_op_instr *instr;
> + struct pl353_nfc_op nfc_op = {};
> + struct pl353_nand_controller *xnfc = to_pl353_nand(chip);
> + unsigned long cmd_phase_data = 0, end_cmd_valid = 0;
> + unsigned long end_cmd;
> + unsigned int op_id, len;
> + bool reading;
> + u32 cmdphase_addrflags;
> +
> + pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> + instr = nfc_op.data_instr;
> + op_id = nfc_op.data_instr_idx;
> + pl353_smc_clr_nand_int();
> +
> + /* Get the command phase address */
> + if (nfc_op.cmnds[1] != 0) {
> + if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> + end_cmd_valid = 0;
> + else
> + end_cmd_valid = 1;

You're testing the opcode, again. As I said several times, the
->exec_op() implementation should be opcode agnostic, it should just try
to match sequences of <CMD>-<ADDR>-<DATA> cycles.

> + }
> +
> + end_cmd = nfc_op.cmnds[1];
> +
> + /*
> + * The SMC defines two phases of commands when transferring data to or
> + * from NAND flash.
> + * Command phase: Commands and optional address information are written
> + * to the NAND flash.The command and address can be associated with
> + * either a data phase operation to write to or read from the array,
> + * or a status/ID register transfer.
> + * Data phase: Data is either written to or read from the NAND flash.
> + * This data can be either data transferred to or from the array,
> + * or status/ID register information.
> + */
> + cmdphase_addrflags = ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> + (end_cmd_valid << END_CMD_VALID_SHIFT) |
> + (COMMAND_PHASE) |
> + (end_cmd << END_CMD_SHIFT) |
> + (nfc_op.cmnds[0] << START_CMD_SHIFT));
> +
> + /* Get the data phase address */
> + end_cmd_valid = 0;
> +
> + xnfc->dataphase_addrflags = ((0x0 << CLEAR_CS_SHIFT) |
> + (end_cmd_valid << END_CMD_VALID_SHIFT) |
> + (DATA_PHASE) |
> + (end_cmd << END_CMD_SHIFT) |
> + (0x0 << ECC_LAST_SHIFT));
> +
> + /* Command phase AXI Read & Write */
> + if (nfc_op.naddrs >= 5) {
> + if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> + cmd_phase_data = nfc_op.addrs;
> +
> + /* Another address cycle for devices > 128MiB */
> + if (chip->options & NAND_ROW_ADDR_3) {

Clearly, none of this belongs in the ->exec_op() implementation. Looks
like something related to page read...

> + writel_relaxed(cmd_phase_data,
> + xnfc->regs + cmdphase_addrflags);
> + cmd_phase_data = nfc_op.addrs_56;
> + }
> + }
> + } else {
> + if (nfc_op.addrs != -1) {
> + int column = nfc_op.addrs;
> +
> + /*
> + * Change read/write column, read id etc
> + * Adjust columns for 16 bit bus width
> + */
> + if ((chip->options & NAND_BUSWIDTH_16) &&
> + (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> + nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> + nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> + nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> + column >>= 1;

And you keep testing opcodes here. Note that the address cycles should
have been adjusted by core already when we have 16-bit accesses.


> + }
> + cmd_phase_data = column;
> + }
> + }
> +
> + writel_relaxed(cmd_phase_data, xnfc->regs + cmdphase_addrflags);
> + if (!nfc_op.data_instr) {
> + if (nfc_op.rdy_timeout_ms) {
> + if (pl353_wait_for_dev_ready(chip))
> + return -ETIMEDOUT;
> + }
> +
> + return 0;
> + }
> +
> + reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> + if (!reading) {
> + len = nand_subop_get_data_len(subop, op_id);
> + pl353_nand_write_data_op(chip, instr->ctx.data.buf.out,
> + len, instr->ctx.data.force_8bit);
> + if (nfc_op.rdy_timeout_ms) {
> + if (pl353_wait_for_dev_ready(chip))
> + return -ETIMEDOUT;
> + }
> +
> + ndelay(nfc_op.rdy_delay_ns);
> + } else {
> + len = nand_subop_get_data_len(subop, op_id);
> + ndelay(nfc_op.rdy_delay_ns);
> + if (nfc_op.rdy_timeout_ms) {
> + if (pl353_wait_for_dev_ready(chip))
> + return -ETIMEDOUT;
> + }
> +
> + pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len,
> + instr->ctx.data.force_8bit);
> + }
> +
> + return 0;
> +}

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