Re: [PATCH v2 1/5] mtd: rawnand: qcom: Implement exec_op()

Miquel Raynal
2023-05-22T13:35:51Z

Hello,

quic_mdalam@quicinc.com wrote on Thu, 11 May 2023 19:00:13 +0530:

> Implement exec_op() so we can later get rid of the legacy interface
> implementation.
>
> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> ---
> Change in [v2]
>
> * Missed to post Cover-letter, so posting v2 patch with cover-letter
>
> drivers/mtd/nand/raw/qcom_nandc.c | 214 +++++++++++++++++++++++++++++-
> 1 file changed, 213 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 72d6168d8a1b..dae460e2aa0b 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -157,6 +157,7 @@
> #define OP_PAGE_PROGRAM_WITH_ECC 0x7
> #define OP_PROGRAM_PAGE_SPARE 0x9
> #define OP_BLOCK_ERASE 0xa
> +#define OP_CHECK_STATUS 0xc
> #define OP_FETCH_ID 0xb
> #define OP_RESET_DEVICE 0xd
>
> @@ -235,6 +236,7 @@ nandc_set_reg(chip, reg, \
> */
> #define NAND_ERASED_CW_SET BIT(4)
>
> +#define MAX_ADDRESS_CYCLE 5
> /*
> * This data type corresponds to the BAM transaction which will be used for all
> * NAND transfers.
> @@ -447,6 +449,29 @@ struct qcom_nand_boot_partition {
> u32 page_size;
> };
>
> +/*
> + * Qcom op for each exec_op transfer
> + *
> + * @data_instr: data instruction pointer
> + * @data_instr_idx: data instruction index
> + * @rdy_timeout_ms: wait ready timeout in ms
> + * @rdy_delay_ns: Additional delay in ns
> + * @addr1_reg: Address1 register value
> + * @addr2_reg: Address2 register value
> + * @cmd_reg: CMD register value
> + * @flag: flag for misc instruction
> + */
> +struct qcom_op {
> + const struct nand_op_instr *data_instr;
> + unsigned int data_instr_idx;
> + unsigned int rdy_timeout_ms;
> + unsigned int rdy_delay_ns;
> + u32 addr1_reg;
> + u32 addr2_reg;
> + u32 cmd_reg;
> + u8 flag;
> +};
> +
> /*
> * NAND chip structure
> *
> @@ -1517,7 +1542,8 @@ static void pre_command(struct qcom_nand_host *host, int command)
> clear_read_regs(nandc);
>
> if (command == NAND_CMD_RESET || command == NAND_CMD_READID ||
> - command == NAND_CMD_PARAM || command == NAND_CMD_ERASE1)
> + command == NAND_CMD_PARAM || command == NAND_CMD_ERASE1 ||
> + command == NAND_CMD_STATUS)

I don't like this much, is there another way to derive whether
clear_bam_transaction() is needed? What is the rationale behind it?

> clear_bam_transaction(nandc);
> }
>
> @@ -2867,8 +2893,194 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
> return 0;
> }
>
> +static int qcom_op_cmd_mapping(struct qcom_nand_controller *nandc, u8 cmd,
> + struct qcom_op *q_op)
> +{
> + int ret = 0;
> +
> + switch (cmd) {
> + case NAND_CMD_RESET:
> + ret = OP_RESET_DEVICE;
> + break;
> + case NAND_CMD_READID:
> + ret = OP_FETCH_ID;
> + break;
> + case NAND_CMD_PARAM:
> + if (nandc->props->qpic_v2)
> + ret = OP_PAGE_READ_ONFI_READ;
> + else
> + ret = OP_PAGE_READ;
> + break;
> + case NAND_CMD_ERASE1:
> + case NAND_CMD_ERASE2:
> + ret = OP_BLOCK_ERASE;
> + break;
> + case NAND_CMD_STATUS:
> + ret = OP_CHECK_STATUS;
> + break;
> + case NAND_CMD_PAGEPROG:
> + ret = OP_PROGRAM_PAGE;
> + break;
> + default:

This should error out and the error be catch in the check_only path.

> + break;
> + }
> +
> + return ret;
> +}
> +
> +/* NAND framework ->exec_op() hooks and related helpers */
> +static void qcom_parse_instructions(struct nand_chip *chip,
> + const struct nand_subop *subop,
> + struct qcom_op *q_op)
> +{
> + struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> + const struct nand_op_instr *instr = NULL;
> + unsigned int op_id;
> + int i;
> +
> + memset(q_op, 0, sizeof(*q_op));
> +
> + for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> + unsigned int offset, naddrs;
> + const u8 *addrs;
> +
> + instr = &subop->instrs[op_id];
> +
> + switch (instr->type) {
> + case NAND_OP_CMD_INSTR:
> + q_op->cmd_reg = qcom_op_cmd_mapping(nandc, instr->ctx.cmd.opcode, q_op);
> + q_op->rdy_delay_ns = instr->delay_ns;
> + break;
> +
> + case NAND_OP_ADDR_INSTR:
> + offset = nand_subop_get_addr_start_off(subop, op_id);
> + naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> + addrs = &instr->ctx.addr.addrs[offset];
> + for (i = 0; i < min(5U, naddrs); i++) {

Is this min() useful? You already limit the number of cycles to 5,
otherwise the pattern won't match, right?

> + if (i < 4)
> + q_op->addr1_reg |= (u32)addrs[i] << i * 8;
> + else
> + q_op->addr2_reg |= addrs[i];
> + }
> + q_op->rdy_delay_ns = instr->delay_ns;
> + break;
> +
> + case NAND_OP_DATA_IN_INSTR:
> + q_op->data_instr = instr;
> + q_op->data_instr_idx = op_id;
> + q_op->rdy_delay_ns = instr->delay_ns;
> + fallthrough;
> + case NAND_OP_DATA_OUT_INSTR:
> + q_op->rdy_delay_ns = instr->delay_ns;
> + break;
> +
> + case NAND_OP_WAITRDY_INSTR:
> + q_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> + q_op->rdy_delay_ns = instr->delay_ns;
> + break;
> + }
> + }
> +}
> +
> +static int qcom_read_status_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return 0;
> +}
> +
> +static int qcom_erase_cmd_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + return 0;
> +}
> +
> +static int qcom_param_page_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + return 0;
> +}
> +
> +static int qcom_read_id_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + return 0;
> +}
> +
> +static int qcom_misc_cmd_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + return 0;
> +}
> +
> +static int qcom_data_read_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + /* currently read_exec_op() return 0 , and all the read operation handle in
> + * actual API itself
> + */
> + return 0;

Please make all exec_op additions in the same patch, unless you're
truly adding a feature, in this case it can be split, but no pattern
should match what's unsupported by ->exec_op(). This way we avoid these
very strange (and wrong) empty functions).

> +}
> +
> +static int qcom_data_write_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> +{
> + /* currently write_exec_op() return 0, and all the write operation handle in
> + * actual API itself
> + */
> + struct qcom_op q_op;
> +
> + qcom_parse_instructions(chip, subop, &q_op);
> +
> + return 0;
> +}
> +
> +static const struct nand_op_parser qcom_op_parser = NAND_OP_PARSER(
> + NAND_OP_PARSER_PATTERN(
> + qcom_misc_cmd_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_read_id_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 8)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_param_page_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 512)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_read_status_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 1)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_erase_cmd_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_data_read_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> + NAND_OP_PARSER_PATTERN(
> + qcom_data_write_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(true),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(true, MAX_ADDRESS_CYCLE)),
> + );
> +
> +static int qcom_nand_exec_op(struct nand_chip *chip,
> + const struct nand_operation *op,
> + bool check_only)
> +{
> + if (check_only)
> + return 0;

This is wrong, you cannot blindly return 0 if check_only is true.

> + return nand_op_parser_exec_op(chip, &qcom_op_parser,
> + op, check_only);
> +}
> +
> static const struct nand_controller_ops qcom_nandc_ops = {
> .attach_chip = qcom_nand_attach_chip,
> + .exec_op = qcom_nand_exec_op,
> };
>
> static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)

Thanks,
Miquèl