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Message-ID: <7f2f1322-2f1d-b846-1213-28a0fa327e1e@quicinc.com>
Date:   Wed, 24 May 2023 14:43:36 +0530
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Subject: Re: [PATCH v2 1/5] mtd: rawnand: qcom: Implement exec_op()
To:     Miquel Raynal <miquel.raynal@bootlin.com>
CC:     <mani@kernel.org>, <richard@nod.at>, <vigneshr@ti.com>,
        <linux-mtd@lists.infradead.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <quic_srichara@quicinc.com>
References: <20230511133017.6307-1-quic_mdalam@quicinc.com>
 <20230511133017.6307-2-quic_mdalam@quicinc.com>
 <20230522153519.6b574789@xps-13>
Content-Language: en-US
From:   Md Sadre Alam <quic_mdalam@quicinc.com>
In-Reply-To: <20230522153519.6b574789@xps-13>
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On 5/22/2023 7:05 PM, Miquel Raynal wrote:
> 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_transcation() is resting all the bam realted counter to 0 before starting new transcation.
   I will move these all condition check to exec_ops() specific API , and remove pre_command itself.
   Will fix this in next patch V3.
> 
>>   		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.

   Will fix it in next patch V3.
> 
>> +		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?

   Yeah you are right. If address cycle is fixed to 5 , then this min not required.
   will fix this in next v3 patch.
> 
>> +				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).

   Sure, will take care this in patch V3.
> 
>> +}
>> +
>> +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.

   Will fix this in next patch V3.
> 
>> +	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