Message-ID: <96e8b3b923090357484d59a8dbd80630@codeaurora.org>
Date:   Mon, 17 Jul 2017 12:40:11 +0530
From:   Abhishek Sahu <absahu@...eaurora.org>
To:     Archit Taneja <architt@...eaurora.org>
Cc:     dwmw2@...radead.org, computersforpeace@...il.com,
        boris.brezillon@...e-electrons.com, marek.vasut@...il.com,
        richard@....at, cyrille.pitchen@...ev4u.fr, robh+dt@...nel.org,
        mark.rutland@....com, linux-mtd@...ts.infradead.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, andy.gross@...aro.org,
        sricharan@...eaurora.org
Subject: Re: [PATCH 08/14] qcom: mtd: nand: Add support for additional CSRs

On 2017-07-04 12:24, Archit Taneja wrote:
> On 06/29/2017 12:46 PM, Abhishek Sahu wrote:
>> 1. NAND_READ_LOCATION: provides the offset in page for
>>     reading in BAM DMA mode
>> 
>> 2. NAND_ERASED_CW_DETECT_CFG: contains the status for erased
>>     code words
>> 
>> 3. NAND_BUFFER_STATUS: contains the status for ECC
>> 
>> Signed-off-by: Abhishek Sahu <absahu@...eaurora.org>
>> ---
>>   drivers/mtd/nand/qcom_nandc.c | 67 
>> ++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 66 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/mtd/nand/qcom_nandc.c 
>> b/drivers/mtd/nand/qcom_nandc.c
>> index 65c9059..8e7dc9e 100644
>> --- a/drivers/mtd/nand/qcom_nandc.c
>> +++ b/drivers/mtd/nand/qcom_nandc.c
>> @@ -54,6 +54,8 @@
>>   #define	NAND_VERSION			0xf08
>>   #define	NAND_READ_LOCATION_0		0xf20
>>   #define	NAND_READ_LOCATION_1		0xf24
>> +#define	NAND_READ_LOCATION_2		0xf28
>> +#define	NAND_READ_LOCATION_3		0xf2c
>> 
>>   /* dummy register offsets, used by write_reg_dma */
>>   #define	NAND_DEV_CMD1_RESTORE		0xdead
>> @@ -132,6 +134,11 @@
>>   #define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
>>   #define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
>> 
>> +/* NAND_READ_LOCATION_n bits */
>> +#define READ_LOCATION_OFFSET		0
>> +#define READ_LOCATION_SIZE		16
>> +#define READ_LOCATION_LAST		31
>> +
>>   /* Version Mask */
>>   #define	NAND_VERSION_MAJOR_MASK		0xf0000000
>>   #define	NAND_VERSION_MAJOR_SHIFT	28
>> @@ -177,6 +184,11 @@
>>   #define NAND_BAM_NWD			(0x0002)
>>   /* Finish writing in the current sgl and start writing in another 
>> sgl */
>>   #define NAND_BAM_NEXT_SGL		(0x0004)
>> +/*
>> + * Erased codeword status is being used two times in single transfer 
>> so this
>> + * flag will determine the current value of erased codeword status 
>> register
>> + */
>> +#define NAND_ERASED_CW_SET		(0x0008)
>> 
>>   #define QPIC_PER_CW_MAX_CMD_ELEMENTS	(32)
>>   #define QPIC_PER_CW_MAX_CMD_SGL		(32)
>> @@ -258,6 +270,13 @@ struct nandc_regs {
>>   	__le32 orig_vld;
>> 
>>   	__le32 ecc_buf_cfg;
>> +	__le32 read_location0;
>> +	__le32 read_location1;
>> +	__le32 read_location2;
>> +	__le32 read_location3;
>> +
>> +	__le32 erased_cw_detect_cfg_clr;
>> +	__le32 erased_cw_detect_cfg_set;
>>   };
>> 
>>   /*
>> @@ -504,6 +523,16 @@ static __le32 *offset_to_nandc_reg(struct 
>> nandc_regs *regs, int offset)
>>   		return &regs->orig_vld;
>>   	case NAND_EBI2_ECC_BUF_CFG:
>>   		return &regs->ecc_buf_cfg;
>> +	case NAND_BUFFER_STATUS:
>> +		return &regs->clrreadstatus;
>> +	case NAND_READ_LOCATION_0:
>> +		return &regs->read_location0;
>> +	case NAND_READ_LOCATION_1:
>> +		return &regs->read_location1;
>> +	case NAND_READ_LOCATION_2:
>> +		return &regs->read_location2;
>> +	case NAND_READ_LOCATION_3:
>> +		return &regs->read_location3;
>>   	default:
>>   		return NULL;
>>   	}
>> @@ -545,7 +574,7 @@ static void update_rw_regs(struct qcom_nand_host 
>> *host, int num_cw, bool read)
>>   {
>>   	struct nand_chip *chip = &host->chip;
>>   	struct qcom_nand_controller *nandc = 
>> get_qcom_nand_controller(chip);
>> -	u32 cmd, cfg0, cfg1, ecc_bch_cfg;
>> +	u32 cmd, cfg0, cfg1, ecc_bch_cfg, read_location0;
>> 
>>   	if (read) {
>>   		if (host->use_ecc)
>> @@ -562,12 +591,20 @@ static void update_rw_regs(struct qcom_nand_host 
>> *host, int num_cw, bool read)
>> 
>>   		cfg1 = host->cfg1;
>>   		ecc_bch_cfg = host->ecc_bch_cfg;
>> +		if (read)
>> +			read_location0 = (0 << READ_LOCATION_OFFSET) |
>> +				(host->cw_data << READ_LOCATION_SIZE) |
>> +				(1 << READ_LOCATION_LAST);
>>   	} else {
>>   		cfg0 = (host->cfg0_raw & ~(7U << CW_PER_PAGE)) |
>>   				(num_cw - 1) << CW_PER_PAGE;
>> 
>>   		cfg1 = host->cfg1_raw;
>>   		ecc_bch_cfg = 1 << ECC_CFG_ECC_DISABLE;
>> +		if (read)
>> +			read_location0 = (0 << READ_LOCATION_OFFSET) |
>> +				(host->cw_size << READ_LOCATION_SIZE) |
>> +				(1 << READ_LOCATION_LAST);
>>   	}
>> 
>>   	nandc_set_reg(nandc, NAND_FLASH_CMD, cmd);
>> @@ -578,6 +615,9 @@ static void update_rw_regs(struct qcom_nand_host 
>> *host, int num_cw, bool read)
>>   	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
>>   	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
>>   	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>> +
>> +	if (read)
>> +		nandc_set_reg(nandc, NAND_READ_LOCATION_0, read_location0);
>>   }
>> 
>>   /*
>> @@ -756,6 +796,13 @@ static int write_reg_dma(struct 
>> qcom_nand_controller *nandc, int first,
>>   	if (first == NAND_FLASH_CMD)
>>   		flow_control = true;
>> 
>> +	if (first == NAND_ERASED_CW_DETECT_CFG) {
>> +		if (flags & NAND_ERASED_CW_SET)
>> +			vaddr = &regs->erased_cw_detect_cfg_set;
>> +		else
>> +			vaddr = &regs->erased_cw_detect_cfg_clr;
>> +	}
>> +
>>   	if (first == NAND_EXEC_CMD)
>>   		flags |= NAND_BAM_NWD;
>> 
>> @@ -808,6 +855,12 @@ static void config_cw_read(struct 
>> qcom_nand_controller *nandc)
>>   	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>>   	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
>> 
>> +	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
>> +	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 
>> NAND_ERASED_CW_SET);
>> +	if (nandc->dma_bam_enabled)
>> +		write_reg_dma(nandc, NAND_READ_LOCATION_0, 1,
>> +			      NAND_BAM_NEXT_SGL);
>> +
>>   	write_reg_dma(nandc, NAND_EXEC_CMD, 1,
>>   		      NAND_BAM_NWD | NAND_BAM_NEXT_SGL);
>> 
>> @@ -882,6 +935,10 @@ static int nandc_param(struct qcom_nand_host 
>> *host)
>> 
>>   	nandc_set_reg(nandc, NAND_DEV_CMD1_RESTORE, nandc->cmd1);
>>   	nandc_set_reg(nandc, NAND_DEV_CMD_VLD_RESTORE, nandc->vld);
>> +	nandc_set_reg(nandc, NAND_READ_LOCATION_0,
>> +		      (0 << READ_LOCATION_OFFSET) |
>> +		      (512 << READ_LOCATION_SIZE) |
>> +		      (1 << READ_LOCATION_LAST));
>> 
>>   	write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
>>   	write_reg_dma(nandc, NAND_DEV_CMD1, 1, NAND_BAM_NEXT_SGL);
>> @@ -1413,6 +1470,10 @@ static int copy_last_cw(struct qcom_nand_host 
>> *host, int page)
>> 
>>   	set_address(host, host->cw_size * (ecc->steps - 1), page);
>>   	update_rw_regs(host, 1, true);
>> +	nandc_set_reg(nandc, NAND_READ_LOCATION_0,
>> +		      (0 << READ_LOCATION_OFFSET) |
>> +		      (size << READ_LOCATION_SIZE) |
>> +		      (1 << READ_LOCATION_LAST));
>> 
>>   	config_cw_read(nandc);
>> 
>> @@ -2147,6 +2208,10 @@ static int qcom_nand_host_setup(struct 
>> qcom_nand_host *host)
>> 
>>   	host->clrflashstatus = FS_READY_BSY_N;
>>   	host->clrreadstatus = 0xc0;
>> +	nandc->regs->erased_cw_detect_cfg_clr =
>> +		cpu_to_le32(CLR_ERASED_PAGE_DET);
>> +	nandc->regs->erased_cw_detect_cfg_set =
>> +		cpu_to_le32(SET_ERASED_PAGE_DET);
>> 
> 
> Can these 2 be put in qcom_nand_host like done for other registers?
> 

  For, All the other registers, the register is being used only once
  in per codeword read/write and its values changes for different
  operations but the erased codeword register is being used twice in
  the same codeword which we can't differentiate in nandc_set_reg.

  Also, the values for this will be fixed and it will never change
  so its better to assign directly in nandc->regs.

> Thanks,
> Archit
> 
>>   	dev_dbg(nandc->dev,
>>   		"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data 
>> %d strength %d parity_bytes %d steps %d\n",
>> 

-- 
Abhishek Sahu

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