2021-02-22 22:33:50

by Md Sadre Alam

[permalink] [raw]
Subject: [PATCH] mtd: rawnand: qcom: update last code word register

From QPIC version 2.0 onwards new register got added to read last
codeword. This change will add the READ_LOCATION_LAST_CW_n register.

For first three code word READ_LOCATION_n register will be
use.For last code word READ_LOCATION_LAST_CW_n register will be
use.

Signed-off-by: Md Sadre Alam <[email protected]>
---
drivers/mtd/nand/raw/qcom_nandc.c | 90 +++++++++++++++++++++++++++++----------
1 file changed, 67 insertions(+), 23 deletions(-)

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 82d083ad..50fdf55 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -48,6 +48,10 @@
#define NAND_READ_LOCATION_1 0xf24
#define NAND_READ_LOCATION_2 0xf28
#define NAND_READ_LOCATION_3 0xf2c
+#define NAND_READ_LOCATION_LAST_CW_0 0xf40
+#define NAND_READ_LOCATION_LAST_CW_1 0xf44
+#define NAND_READ_LOCATION_LAST_CW_2 0xf48
+#define NAND_READ_LOCATION_LAST_CW_3 0xf4c

/* dummy register offsets, used by write_reg_dma */
#define NAND_DEV_CMD1_RESTORE 0xdead
@@ -187,6 +191,11 @@ nandc_set_reg(nandc, reg, \
((read_size) << READ_LOCATION_SIZE) | \
((is_last_read_loc) << READ_LOCATION_LAST))

+#define nandc_set_read_loc_last(nandc, reg, cw_offset, read_size, is_last_read_loc) \
+nandc_set_reg(nandc, reg, \
+ ((cw_offset) << READ_LOCATION_OFFSET) | \
+ ((read_size) << READ_LOCATION_SIZE) | \
+ ((is_last_read_loc) << READ_LOCATION_LAST))
/*
* Returns the actual register address for all NAND_DEV_ registers
* (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
@@ -316,6 +325,10 @@ struct nandc_regs {
__le32 read_location1;
__le32 read_location2;
__le32 read_location3;
+ __le32 read_location_last0;
+ __le32 read_location_last1;
+ __le32 read_location_last2;
+ __le32 read_location_last3;

__le32 erased_cw_detect_cfg_clr;
__le32 erased_cw_detect_cfg_set;
@@ -644,6 +657,14 @@ static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
return &regs->read_location2;
case NAND_READ_LOCATION_3:
return &regs->read_location3;
+ case NAND_READ_LOCATION_LAST_CW_0:
+ return &regs->read_location_last0;
+ case NAND_READ_LOCATION_LAST_CW_1:
+ return &regs->read_location_last1;
+ case NAND_READ_LOCATION_LAST_CW_2:
+ return &regs->read_location_last2;
+ case NAND_READ_LOCATION_LAST_CW_3:
+ return &regs->read_location_last3;
default:
return NULL;
}
@@ -672,13 +693,19 @@ static void nandc_set_read_loc(struct nand_chip *chip, int cw, int reg,
int cw_offset, int read_size, int is_last_read_loc)
{
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
-
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
int reg_base = NAND_READ_LOCATION_0;

- reg_base += reg * 4;
+ if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
+ reg_base = NAND_READ_LOCATION_LAST_CW_0;

- return nandc_set_read_loc_first(nandc, reg_base, cw_offset,
- read_size, is_last_read_loc);
+ reg_base += reg * 4;
+ if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
+ return nandc_set_read_loc_last(nandc, reg_base, cw_offset,
+ read_size, is_last_read_loc);
+ else
+ return nandc_set_read_loc_first(nandc, reg_base, cw_offset,
+ read_size, is_last_read_loc);
}

/* helper to configure address register values */
@@ -700,8 +727,9 @@ static void set_address(struct qcom_nand_host *host, u16 column, int page)
*
* @num_cw: number of steps for the read/write operation
* @read: read or write operation
+ * @cw : which code word
*/
-static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
+static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read, int cw)
{
struct nand_chip *chip = &host->chip;
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
@@ -740,7 +768,7 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
nandc_set_reg(nandc, NAND_EXEC_CMD, 1);

if (read)
- nandc_set_read_loc(chip, 0, 0, 0, host->use_ecc ?
+ nandc_set_read_loc(chip, cw, 0, 0, host->use_ecc ?
host->cw_data : host->cw_size, 1);
}

@@ -1111,18 +1139,34 @@ static void config_nand_page_read(struct nand_chip *chip)
NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
}

+/* helper to check which location register should be use for this
+ * code word. NAND_READ_LOCATION or NAND_READ_LOCATION_LAST_CW
+ */
+static bool config_loc_last_reg(struct nand_chip *chip, int cw)
+{
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+ if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
+ return true;
+
+ return false;
+}
/*
* Helper to prepare DMA descriptors for configuring registers
* before reading each codeword in NAND page.
*/
static void
-config_nand_cw_read(struct nand_chip *chip, bool use_ecc)
+config_nand_cw_read(struct nand_chip *chip, bool use_ecc, int cw)
{
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ int reg = NAND_READ_LOCATION_0;
+
+ if (config_loc_last_reg(chip, cw))
+ reg = NAND_READ_LOCATION_LAST_CW_0;

if (nandc->props->is_bam)
- write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
- NAND_BAM_NEXT_SGL);
+ write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);

write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
@@ -1142,12 +1186,12 @@ config_nand_cw_read(struct nand_chip *chip, bool use_ecc)
*/
static void
config_nand_single_cw_page_read(struct nand_chip *chip,
- bool use_ecc)
+ bool use_ecc, int cw)
{
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);

config_nand_page_read(chip);
- config_nand_cw_read(chip, use_ecc);
+ config_nand_cw_read(chip, use_ecc, cw);
}

/*
@@ -1245,7 +1289,7 @@ static int nandc_param(struct qcom_nand_host *host)
nandc->buf_count = 512;
memset(nandc->data_buffer, 0xff, nandc->buf_count);

- config_nand_single_cw_page_read(chip, false);
+ config_nand_single_cw_page_read(chip, false, 0);

read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
nandc->buf_count, 0);
@@ -1522,7 +1566,7 @@ static void qcom_nandc_command(struct nand_chip *chip, unsigned int command,

host->use_ecc = true;
set_address(host, 0, page_addr);
- update_rw_regs(host, ecc->steps, true);
+ update_rw_regs(host, ecc->steps, true, 0);
break;

case NAND_CMD_SEQIN:
@@ -1646,7 +1690,7 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,

clear_bam_transaction(nandc);
set_address(host, host->cw_size * cw, page);
- update_rw_regs(host, 1, true);
+ update_rw_regs(host, 1, true, cw);
config_nand_page_read(chip);

data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
@@ -1675,7 +1719,7 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
nandc_set_read_loc(chip, cw, 3, read_loc, oob_size2, 1);
}

- config_nand_cw_read(chip, false);
+ config_nand_cw_read(chip, false, cw);

read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
reg_off += data_size1;
@@ -1914,7 +1958,7 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
}
}

- config_nand_cw_read(chip, true);
+ config_nand_cw_read(chip, true, i);

if (data_buf)
read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
@@ -1974,9 +2018,9 @@ static int copy_last_cw(struct qcom_nand_host *host, int page)
memset(nandc->data_buffer, 0xff, size);

set_address(host, host->cw_size * (ecc->steps - 1), page);
- update_rw_regs(host, 1, true);
+ update_rw_regs(host, 1, true, ecc->steps - 1);

- config_nand_single_cw_page_read(chip, host->use_ecc);
+ config_nand_single_cw_page_read(chip, host->use_ecc, ecc->steps - 1);

read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);

@@ -2041,7 +2085,7 @@ static int qcom_nandc_read_oob(struct nand_chip *chip, int page)

host->use_ecc = true;
set_address(host, 0, page);
- update_rw_regs(host, ecc->steps, true);
+ update_rw_regs(host, ecc->steps, true, 0);

return read_page_ecc(host, NULL, chip->oob_poi, page);
}
@@ -2065,7 +2109,7 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const uint8_t *buf,
oob_buf = chip->oob_poi;

host->use_ecc = true;
- update_rw_regs(host, ecc->steps, false);
+ update_rw_regs(host, ecc->steps, false, 0);
config_nand_page_write(chip);

for (i = 0; i < ecc->steps; i++) {
@@ -2136,7 +2180,7 @@ static int qcom_nandc_write_page_raw(struct nand_chip *chip,
oob_buf = chip->oob_poi;

host->use_ecc = false;
- update_rw_regs(host, ecc->steps, false);
+ update_rw_regs(host, ecc->steps, false, 0);
config_nand_page_write(chip);

for (i = 0; i < ecc->steps; i++) {
@@ -2219,7 +2263,7 @@ static int qcom_nandc_write_oob(struct nand_chip *chip, int page)
0, mtd->oobavail);

set_address(host, host->cw_size * (ecc->steps - 1), page);
- update_rw_regs(host, 1, false);
+ update_rw_regs(host, 1, false, 0);

config_nand_page_write(chip);
write_data_dma(nandc, FLASH_BUF_ACC,
@@ -2298,7 +2342,7 @@ static int qcom_nandc_block_markbad(struct nand_chip *chip, loff_t ofs)
/* prepare write */
host->use_ecc = false;
set_address(host, host->cw_size * (ecc->steps - 1), page);
- update_rw_regs(host, 1, false);
+ update_rw_regs(host, 1, false, ecc->steps - 1);

config_nand_page_write(chip);
write_data_dma(nandc, FLASH_BUF_ACC,
--
2.7.4


2021-02-23 16:37:44

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

Hello,

Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
01:34:27 +0530:

> From QPIC version 2.0 onwards new register got added to read last

a new

> codeword. This change will add the READ_LOCATION_LAST_CW_n register.

Add support for this READ_LOCATION_LAST_CW_n register.

>
> For first three code word READ_LOCATION_n register will be
> use.For last code word READ_LOCATION_LAST_CW_n register will be
> use.

"
In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
READ_LOCATION_n, while codeword 3 will be accessed through
READ_LOCATION_LAST_CW_n.
"

When I read my own sentence, I feel that there is something wrong.
If there are only 4 codewords, I guess a QPIC v2 is able to use
READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?

I guess the point of having these "last_cw_n" registers is to support
up to 8 codewords, am I wrong? If this the case, the current patch
completely fails doing that I don't get the point of such change.

> Signed-off-by: Md Sadre Alam <[email protected]>
> ---

[...]

> /* helper to configure address register values */
> @@ -700,8 +727,9 @@ static void set_address(struct qcom_nand_host *host, u16 column, int page)
> *
> * @num_cw: number of steps for the read/write operation
> * @read: read or write operation
> + * @cw : which code word
> */
> -static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
> +static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read, int cw)
> {
> struct nand_chip *chip = &host->chip;
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> @@ -740,7 +768,7 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>
> if (read)
> - nandc_set_read_loc(chip, 0, 0, 0, host->use_ecc ?
> + nandc_set_read_loc(chip, cw, 0, 0, host->use_ecc ?
> host->cw_data : host->cw_size, 1);
> }
>
> @@ -1111,18 +1139,34 @@ static void config_nand_page_read(struct nand_chip *chip)
> NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
> }
>
> +/* helper to check which location register should be use for this

/*
* Check which location...

> + * code word. NAND_READ_LOCATION or NAND_READ_LOCATION_LAST_CW
> + */
> +static bool config_loc_last_reg(struct nand_chip *chip, int cw)
> +{
> + struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> + struct nand_ecc_ctrl *ecc = &chip->ecc;
> +
> + if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
> + return true;

Not sure this is really useful, it's probably better to drop this
helper and just use...

> +
> + return false;
> +}
> /*
> * Helper to prepare DMA descriptors for configuring registers
> * before reading each codeword in NAND page.
> */
> static void
> -config_nand_cw_read(struct nand_chip *chip, bool use_ecc)
> +config_nand_cw_read(struct nand_chip *chip, bool use_ecc, int cw)
> {
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> + int reg = NAND_READ_LOCATION_0;
> +
> + if (config_loc_last_reg(chip, cw))

... if (nandc->props->qpic_v2 && qcom_nandc_is_lastcw()) here.

> + reg = NAND_READ_LOCATION_LAST_CW_0;
>
> if (nandc->props->is_bam)
> - write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
> - NAND_BAM_NEXT_SGL);
> + write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
>
> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> @@ -1142,12 +1186,12 @@ config_nand_cw_read(struct nand_chip *chip, bool use_ecc)

Thanks,
Miquèl

2021-02-23 20:56:05

by Md Sadre Alam

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

On 2021-02-23 22:04, Miquel Raynal wrote:
> Hello,
>
> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
> 01:34:27 +0530:
>
>> From QPIC version 2.0 onwards new register got added to read last
>
> a new
>
>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
>
> Add support for this READ_LOCATION_LAST_CW_n register.
>
>>
>> For first three code word READ_LOCATION_n register will be
>> use.For last code word READ_LOCATION_LAST_CW_n register will be
>> use.
>
> "
> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
> READ_LOCATION_n, while codeword 3 will be accessed through
> READ_LOCATION_LAST_CW_n.
> "
>
> When I read my own sentence, I feel that there is something wrong.
> If there are only 4 codewords, I guess a QPIC v2 is able to use
> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
>
> I guess the point of having these "last_cw_n" registers is to support
> up to 8 codewords, am I wrong? If this the case, the current patch
> completely fails doing that I don't get the point of such change.

This register is only use to read last code word.

I have address all the comments from all the previous sub sequent
patches and pushed
all patches in only one series.

Please check.

>
>> Signed-off-by: Md Sadre Alam <[email protected]>
>> ---
>
> [...]
>
>> /* helper to configure address register values */
>> @@ -700,8 +727,9 @@ static void set_address(struct qcom_nand_host
>> *host, u16 column, int page)
>> *
>> * @num_cw: number of steps for the read/write operation
>> * @read: read or write operation
>> + * @cw : which code word
>> */
>> -static void update_rw_regs(struct qcom_nand_host *host, int num_cw,
>> bool read)
>> +static void update_rw_regs(struct qcom_nand_host *host, int num_cw,
>> bool read, int cw)
>> {
>> struct nand_chip *chip = &host->chip;
>> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> @@ -740,7 +768,7 @@ static void update_rw_regs(struct qcom_nand_host
>> *host, int num_cw, bool read)
>> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>>
>> if (read)
>> - nandc_set_read_loc(chip, 0, 0, 0, host->use_ecc ?
>> + nandc_set_read_loc(chip, cw, 0, 0, host->use_ecc ?
>> host->cw_data : host->cw_size, 1);
>> }
>>
>> @@ -1111,18 +1139,34 @@ static void config_nand_page_read(struct
>> nand_chip *chip)
>> NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
>> }
>>
>> +/* helper to check which location register should be use for this
>
> /*
> * Check which location...
>
>> + * code word. NAND_READ_LOCATION or NAND_READ_LOCATION_LAST_CW
>> + */
>> +static bool config_loc_last_reg(struct nand_chip *chip, int cw)
>> +{
>> + struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>> +
>> + if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
>> + return true;
>
> Not sure this is really useful, it's probably better to drop this
> helper and just use...
>
>> +
>> + return false;
>> +}
>> /*
>> * Helper to prepare DMA descriptors for configuring registers
>> * before reading each codeword in NAND page.
>> */
>> static void
>> -config_nand_cw_read(struct nand_chip *chip, bool use_ecc)
>> +config_nand_cw_read(struct nand_chip *chip, bool use_ecc, int cw)
>> {
>> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> + int reg = NAND_READ_LOCATION_0;
>> +
>> + if (config_loc_last_reg(chip, cw))
>
> ... if (nandc->props->qpic_v2 && qcom_nandc_is_lastcw()) here.
>
>> + reg = NAND_READ_LOCATION_LAST_CW_0;
>>
>> if (nandc->props->is_bam)
>> - write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
>> - NAND_BAM_NEXT_SGL);
>> + write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
>>
>> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
>> write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>> @@ -1142,12 +1186,12 @@ config_nand_cw_read(struct nand_chip *chip,
>> bool use_ecc)
>
> Thanks,
> Miquèl

2021-02-24 08:08:59

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

Hello,

[email protected] wrote on Wed, 24 Feb 2021 10:09:48 +0530:

> On 2021-02-24 01:13, [email protected] wrote:
> > On 2021-02-23 22:04, Miquel Raynal wrote:
> >> Hello,
> >> >> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
> >> 01:34:27 +0530:
> >> >>> From QPIC version 2.0 onwards new register got added to read last
> >> >> a new
> >> >>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
> >> >> Add support for this READ_LOCATION_LAST_CW_n register.
> >> >>> >>> For first three code word READ_LOCATION_n register will be
> >>> use.For last code word READ_LOCATION_LAST_CW_n register will be
> >>> use.
> >> >> "
> >> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
> >> READ_LOCATION_n, while codeword 3 will be accessed through
> >> READ_LOCATION_LAST_CW_n.
> >> "
> >> >> When I read my own sentence, I feel that there is something wrong.
> >> If there are only 4 codewords, I guess a QPIC v2 is able to use
> >> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
> >> >> I guess the point of having these "last_cw_n" registers is to support
> >> up to 8 codewords, am I wrong? If this the case, the current patch
> >> completely fails doing that I don't get the point of such change.
> >
> > This register is only use to read last code word.
> >
> > I have address all the comments from all the previous sub sequent
> > patches and pushed
> > all patches in only one series.
> >
> > Please check.
>
> The registers READ_LOCATION & READ_LOCATION_LAST are not associated with number of code words.
> These two registers are used to access the location inside a code word.

Ok. Can you please explain what is a location then? Or point me to a
datasheet that explains it.

Bottom line question: why having READ_LOCATION_0, _1,... an
READ_LOCATION_LAST_0, _1, etc?

> So whether we are having 4 code words
> or 8 code words it doesn't matter. If we wanted access the location within normal code word we have to
> use READ_LOCATION register and if we wanted to access location in last code word then we have to use
> READ_LOCATION_LAST.
> >
> >> >>> Signed-off-by: Md Sadre Alam <[email protected]>

Thanks,
Miquèl

2021-02-24 12:45:06

by Md Sadre Alam

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

On 2021-02-24 01:13, [email protected] wrote:
> On 2021-02-23 22:04, Miquel Raynal wrote:
>> Hello,
>>
>> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
>> 01:34:27 +0530:
>>
>>> From QPIC version 2.0 onwards new register got added to read last
>>
>> a new
>>
>>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
>>
>> Add support for this READ_LOCATION_LAST_CW_n register.
>>
>>>
>>> For first three code word READ_LOCATION_n register will be
>>> use.For last code word READ_LOCATION_LAST_CW_n register will be
>>> use.
>>
>> "
>> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
>> READ_LOCATION_n, while codeword 3 will be accessed through
>> READ_LOCATION_LAST_CW_n.
>> "
>>
>> When I read my own sentence, I feel that there is something wrong.
>> If there are only 4 codewords, I guess a QPIC v2 is able to use
>> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
>>
>> I guess the point of having these "last_cw_n" registers is to support
>> up to 8 codewords, am I wrong? If this the case, the current patch
>> completely fails doing that I don't get the point of such change.
>
> This register is only use to read last code word.
>
> I have address all the comments from all the previous sub sequent
> patches and pushed
> all patches in only one series.
>
> Please check.

The registers READ_LOCATION & READ_LOCATION_LAST are not associated
with number of code words.
These two registers are used to access the location inside a code word.
So whether we are having 4 code words
or 8 code words it doesn't matter. If we wanted access the location
within normal code word we have to
use READ_LOCATION register and if we wanted to access location in last
code word then we have to use
READ_LOCATION_LAST.
>
>>
>>> Signed-off-by: Md Sadre Alam <[email protected]>
>>> ---
>>
>> [...]
>>
>>> /* helper to configure address register values */
>>> @@ -700,8 +727,9 @@ static void set_address(struct qcom_nand_host
>>> *host, u16 column, int page)
>>> *
>>> * @num_cw: number of steps for the read/write operation
>>> * @read: read or write operation
>>> + * @cw : which code word
>>> */
>>> -static void update_rw_regs(struct qcom_nand_host *host, int num_cw,
>>> bool read)
>>> +static void update_rw_regs(struct qcom_nand_host *host, int num_cw,
>>> bool read, int cw)
>>> {
>>> struct nand_chip *chip = &host->chip;
>>> struct qcom_nand_controller *nandc =
>>> get_qcom_nand_controller(chip);
>>> @@ -740,7 +768,7 @@ static void update_rw_regs(struct qcom_nand_host
>>> *host, int num_cw, bool read)
>>> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>>>
>>> if (read)
>>> - nandc_set_read_loc(chip, 0, 0, 0, host->use_ecc ?
>>> + nandc_set_read_loc(chip, cw, 0, 0, host->use_ecc ?
>>> host->cw_data : host->cw_size, 1);
>>> }
>>>
>>> @@ -1111,18 +1139,34 @@ static void config_nand_page_read(struct
>>> nand_chip *chip)
>>> NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
>>> }
>>>
>>> +/* helper to check which location register should be use for this
>>
>> /*
>> * Check which location...
>>
>>> + * code word. NAND_READ_LOCATION or NAND_READ_LOCATION_LAST_CW
>>> + */
>>> +static bool config_loc_last_reg(struct nand_chip *chip, int cw)
>>> +{
>>> + struct qcom_nand_controller *nandc =
>>> get_qcom_nand_controller(chip);
>>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>>> +
>>> + if (nandc->props->qpic_v2 && qcom_nandc_is_last_cw(ecc, cw))
>>> + return true;
>>
>> Not sure this is really useful, it's probably better to drop this
>> helper and just use...
>>
>>> +
>>> + return false;
>>> +}
>>> /*
>>> * Helper to prepare DMA descriptors for configuring registers
>>> * before reading each codeword in NAND page.
>>> */
>>> static void
>>> -config_nand_cw_read(struct nand_chip *chip, bool use_ecc)
>>> +config_nand_cw_read(struct nand_chip *chip, bool use_ecc, int cw)
>>> {
>>> struct qcom_nand_controller *nandc =
>>> get_qcom_nand_controller(chip);
>>> + int reg = NAND_READ_LOCATION_0;
>>> +
>>> + if (config_loc_last_reg(chip, cw))
>>
>> ... if (nandc->props->qpic_v2 && qcom_nandc_is_lastcw()) here.
>>
>>> + reg = NAND_READ_LOCATION_LAST_CW_0;
>>>
>>> if (nandc->props->is_bam)
>>> - write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
>>> - NAND_BAM_NEXT_SGL);
>>> + write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
>>>
>>> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
>>> write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>>> @@ -1142,12 +1186,12 @@ config_nand_cw_read(struct nand_chip *chip,
>>> bool use_ecc)
>>
>> Thanks,
>> Miquèl

2021-02-24 16:39:44

by Md Sadre Alam

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

On 2021-02-24 12:18, Miquel Raynal wrote:
> Hello,
>
> [email protected] wrote on Wed, 24 Feb 2021 10:09:48 +0530:
>
>> On 2021-02-24 01:13, [email protected] wrote:
>> > On 2021-02-23 22:04, Miquel Raynal wrote:
>> >> Hello,
>> >> >> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
>> >> 01:34:27 +0530:
>> >> >>> From QPIC version 2.0 onwards new register got added to read last
>> >> >> a new
>> >> >>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
>> >> >> Add support for this READ_LOCATION_LAST_CW_n register.
>> >> >>> >>> For first three code word READ_LOCATION_n register will be
>> >>> use.For last code word READ_LOCATION_LAST_CW_n register will be
>> >>> use.
>> >> >> "
>> >> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
>> >> READ_LOCATION_n, while codeword 3 will be accessed through
>> >> READ_LOCATION_LAST_CW_n.
>> >> "
>> >> >> When I read my own sentence, I feel that there is something wrong.
>> >> If there are only 4 codewords, I guess a QPIC v2 is able to use
>> >> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
>> >> >> I guess the point of having these "last_cw_n" registers is to support
>> >> up to 8 codewords, am I wrong? If this the case, the current patch
>> >> completely fails doing that I don't get the point of such change.
>> >
>> > This register is only use to read last code word.
>> >
>> > I have address all the comments from all the previous sub sequent
>> > patches and pushed
>> > all patches in only one series.
>> >
>> > Please check.
>>
>> The registers READ_LOCATION & READ_LOCATION_LAST are not associated
>> with number of code words.
>> These two registers are used to access the location inside a code
>> word.
>
> Ok. Can you please explain what is a location then? Or point me to a
> datasheet that explains it.

The location is the position inside a code word.

>
> Bottom line question: why having READ_LOCATION_0, _1,... an
> READ_LOCATION_LAST_0, _1, etc?

READ_LOCATION_0, _1,... are used to extract multiple chunks from a code
word.

e.g If we wanted to extract first 100 bytes from a code word then
(0...99) READ_LOCATION_0 will be configured.
if we wanted to extract next 100 bytes (100...199) then
READ_LOCATION_1 will be configured.

same way for last code word READ_LOCATION_LAST_0, _1, will be used.


Below is the mapping example for a 2K page size.


<---------------------2048------------------------------------------------><------64---------->2111

_______________________________________________________________________________________________
|
| | |
|
| | |
|
| | |
|
| | |
|__________________________________________________________________________|___|_______________|

2048-bytes

factory BBM


One code word:

1-byte BBM 7-bytes ECC
______________________________________
| | | | | |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
|____________|__|____________|___|____|
<-----------512 bytes-------> 4-bytes spare
data



<-------------------------------------2048-------------------------------------------------->2047<------64---------->2111

____________________________________________________________________________________________________________________
|
| | | |
|
| | | |
|
| | | |
|
| | | |
|_____________________________________________________________________________________________|___|_____________|____|

| |

| |

| |<-----mapping

| |

| |

____________________________________________________________________________________________________|___|______
| | |
| |
| | |
| |
| | |
| |
| | |
| |
| | |
| |
|______________________|___________________________|_______________________________|____________________________|
<-------CW1-----------><----------CW2-------------><-----------CW3----------------><----------CW4--------------->
/ \
/ \
/ \
/ \
/ \
/ \
/ \
/ \

_________________________________________________________________ \___
|
|
|
|
|
|
|
|
|
|
|
|
|<--read_location_0--> <---read_location_1-->
<--read_location_n-->|
|

|_____________________________________________________________________|



So in QPIC V2 onwards to access last code word same way we have to use
read_location_last_0,1,2..3 etc.


>
>> So whether we are having 4 code words
>> or 8 code words it doesn't matter. If we wanted access the location
>> within normal code word we have to
>> use READ_LOCATION register and if we wanted to access location in
>> last code word then we have to use
>> READ_LOCATION_LAST.
>> >
>> >> >>> Signed-off-by: Md Sadre Alam <[email protected]>
>
> Thanks,
> Miquèl

2021-02-24 16:46:07

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

Hello,

[email protected] wrote on Wed, 24 Feb 2021 22:00:05 +0530:

> On 2021-02-24 12:18, Miquel Raynal wrote:
> > Hello,
> >
> > [email protected] wrote on Wed, 24 Feb 2021 10:09:48 +0530:
> >
> >> On 2021-02-24 01:13, [email protected] wrote:
> >> > On 2021-02-23 22:04, Miquel Raynal wrote:
> >> >> Hello,
> >> >> >> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
> >> >> 01:34:27 +0530:
> >> >> >>> From QPIC version 2.0 onwards new register got added to read last
> >> >> >> a new
> >> >> >>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
> >> >> >> Add support for this READ_LOCATION_LAST_CW_n register.
> >> >> >>> >>> For first three code word READ_LOCATION_n register will be
> >> >>> use.For last code word READ_LOCATION_LAST_CW_n register will be
> >> >>> use.
> >> >> >> "
> >> >> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
> >> >> READ_LOCATION_n, while codeword 3 will be accessed through
> >> >> READ_LOCATION_LAST_CW_n.
> >> >> "
> >> >> >> When I read my own sentence, I feel that there is something wrong.
> >> >> If there are only 4 codewords, I guess a QPIC v2 is able to use
> >> >> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
> >> >> >> I guess the point of having these "last_cw_n" registers is to support
> >> >> up to 8 codewords, am I wrong? If this the case, the current patch
> >> >> completely fails doing that I don't get the point of such change.
> >> >
> >> > This register is only use to read last code word.
> >> >
> >> > I have address all the comments from all the previous sub sequent
> >> > patches and pushed
> >> > all patches in only one series.
> >> >
> >> > Please check.
> >> >> The registers READ_LOCATION & READ_LOCATION_LAST are not associated >> with number of code words.
> >> These two registers are used to access the location inside a code >> word.
> >
> > Ok. Can you please explain what is a location then? Or point me to a
> > datasheet that explains it.
>
> The location is the position inside a code word.
>
> >
> > Bottom line question: why having READ_LOCATION_0, _1,... an
> > READ_LOCATION_LAST_0, _1, etc?
>
> READ_LOCATION_0, _1,... are used to extract multiple chunks from a code word.
>
> e.g If we wanted to extract first 100 bytes from a code word then (0...99) READ_LOCATION_0 will be configured.
> if we wanted to extract next 100 bytes (100...199) then READ_LOCATION_1 will be configured.
>
> same way for last code word READ_LOCATION_LAST_0, _1, will be used.
>

Nice explanation, and thanks for the below figures. So I guess there is some kind of "small SRAM" that is
directly addressable perhaps?

I think I'm fine with your series now. Just a small nit: next time you send a series, please update the version number "[PATCH v6]" (automatically added with the -v6 parameter in git-format-patch). But no need to resend just for that.


Thanks,
Miquèl

2021-02-26 18:27:37

by Md Sadre Alam

[permalink] [raw]
Subject: Re: [PATCH] mtd: rawnand: qcom: update last code word register

On 2021-02-24 22:06, Miquel Raynal wrote:
> Hello,
>
> [email protected] wrote on Wed, 24 Feb 2021 22:00:05 +0530:
>
>> On 2021-02-24 12:18, Miquel Raynal wrote:
>> > Hello,
>> >
>> > [email protected] wrote on Wed, 24 Feb 2021 10:09:48 +0530:
>> >
>> >> On 2021-02-24 01:13, [email protected] wrote:
>> >> > On 2021-02-23 22:04, Miquel Raynal wrote:
>> >> >> Hello,
>> >> >> >> Md Sadre Alam <[email protected]> wrote on Tue, 23 Feb 2021
>> >> >> 01:34:27 +0530:
>> >> >> >>> From QPIC version 2.0 onwards new register got added to read last
>> >> >> >> a new
>> >> >> >>> codeword. This change will add the READ_LOCATION_LAST_CW_n register.
>> >> >> >> Add support for this READ_LOCATION_LAST_CW_n register.
>> >> >> >>> >>> For first three code word READ_LOCATION_n register will be
>> >> >>> use.For last code word READ_LOCATION_LAST_CW_n register will be
>> >> >>> use.
>> >> >> >> "
>> >> >> In the case of QPIC v2, codewords 0, 1 and 2 will be accessed through
>> >> >> READ_LOCATION_n, while codeword 3 will be accessed through
>> >> >> READ_LOCATION_LAST_CW_n.
>> >> >> "
>> >> >> >> When I read my own sentence, I feel that there is something wrong.
>> >> >> If there are only 4 codewords, I guess a QPIC v2 is able to use
>> >> >> READ_LOCATION_3 or READ_LOCATION_LAST_CW_0 interchangeably. Isn't it?
>> >> >> >> I guess the point of having these "last_cw_n" registers is to support
>> >> >> up to 8 codewords, am I wrong? If this the case, the current patch
>> >> >> completely fails doing that I don't get the point of such change.
>> >> >
>> >> > This register is only use to read last code word.
>> >> >
>> >> > I have address all the comments from all the previous sub sequent
>> >> > patches and pushed
>> >> > all patches in only one series.
>> >> >
>> >> > Please check.
>> >> >> The registers READ_LOCATION & READ_LOCATION_LAST are not associated >> with number of code words.
>> >> These two registers are used to access the location inside a code >> word.
>> >
>> > Ok. Can you please explain what is a location then? Or point me to a
>> > datasheet that explains it.
>>
>> The location is the position inside a code word.
>>
>> >
>> > Bottom line question: why having READ_LOCATION_0, _1,... an
>> > READ_LOCATION_LAST_0, _1, etc?
>>
>> READ_LOCATION_0, _1,... are used to extract multiple chunks from a
>> code word.
>>
>> e.g If we wanted to extract first 100 bytes from a code word then
>> (0...99) READ_LOCATION_0 will be configured.
>> if we wanted to extract next 100 bytes (100...199) then
>> READ_LOCATION_1 will be configured.
>>
>> same way for last code word READ_LOCATION_LAST_0, _1, will be
>> used.
>>
>
> Nice explanation, and thanks for the below figures. So I guess there
> is some kind of "small SRAM" that is
> directly addressable perhaps?
>
> I think I'm fine with your series now. Just a small nit: next time you
> send a series, please update the version number "[PATCH v6]"
> (automatically added with the -v6 parameter in git-format-patch). But
> no need to resend just for that.
>

Thanks Miquel. So now no need to test these patches further. I have
already tested these patches on IPQ5018 SoC with mtd_test module &
nand-utils tool.

>
> Thanks,
> Miquèl