Re: [PATCH 08/14] qcom: mtd: nand: Add support for additional CSRs

From: Abhishek Sahu
Date: Mon Jul 17 2017 - 03:10:20 EST

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@xxxxxxxxxxxxxx>
---
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