[PATCH 11/14] qcom: mtd: nand: BAM raw read and write support

From: Abhishek Sahu
Date: Thu Jun 29 2017 - 03:18:53 EST


1. BAM uses READ_LOCATION registers to copy data from offset
into data buffer.

2. BAM requires EOT flag should be set only for the last data
write in a codeword.

Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
drivers/mtd/nand/qcom_nandc.c | 46 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index 4c6e594..6d749b6 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -1033,7 +1033,7 @@ static void config_bam_page_read(struct qcom_nand_controller *nandc)
*/
static void config_bam_cw_read(struct qcom_nand_controller *nandc)
{
- write_reg_dma(nandc, NAND_READ_LOCATION_0, 2, 0);
+ write_reg_dma(nandc, NAND_READ_LOCATION_0, 4, 0);
write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);

@@ -1734,6 +1734,7 @@ static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
u8 *data_buf, *oob_buf;
struct nand_ecc_ctrl *ecc = &chip->ecc;
int i, ret;
+ int read_location;

data_buf = buf;
oob_buf = chip->oob_poi;
@@ -1743,6 +1744,9 @@ static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
clear_bam_transaction(nandc);
update_rw_regs(host, ecc->steps, true);

+ if (nandc->dma_bam_enabled)
+ config_bam_page_read(nandc);
+
for (i = 0; i < ecc->steps; i++) {
int data_size1, data_size2, oob_size1, oob_size2;
int reg_off = FLASH_BUF_ACC;
@@ -1760,7 +1764,35 @@ static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
}

- config_cw_read(nandc);
+ if (nandc->dma_bam_enabled) {
+ read_location = 0;
+ nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+ (read_location << READ_LOCATION_OFFSET) |
+ (data_size1 << READ_LOCATION_SIZE) |
+ (0 << READ_LOCATION_LAST));
+ read_location += data_size1;
+
+ nandc_set_reg(nandc, NAND_READ_LOCATION_1,
+ (read_location << READ_LOCATION_OFFSET) |
+ (oob_size1 << READ_LOCATION_SIZE) |
+ (0 << READ_LOCATION_LAST));
+ read_location += oob_size1;
+
+ nandc_set_reg(nandc, NAND_READ_LOCATION_2,
+ (read_location << READ_LOCATION_OFFSET) |
+ (data_size2 << READ_LOCATION_SIZE) |
+ (0 << READ_LOCATION_LAST));
+ read_location += data_size2;
+
+ nandc_set_reg(nandc, NAND_READ_LOCATION_3,
+ (read_location << READ_LOCATION_OFFSET) |
+ (oob_size2 << READ_LOCATION_SIZE) |
+ (1 << READ_LOCATION_LAST));
+
+ config_bam_cw_read(nandc);
+ } else {
+ config_cw_read(nandc);
+ }

read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
reg_off += data_size1;
@@ -1914,15 +1946,18 @@ static int qcom_nandc_write_page_raw(struct mtd_info *mtd,

config_cw_write_pre(nandc);

- write_data_dma(nandc, reg_off, data_buf, data_size1, 0);
+ write_data_dma(nandc, reg_off, data_buf, data_size1,
+ NAND_BAM_NO_EOT);
reg_off += data_size1;
data_buf += data_size1;

- write_data_dma(nandc, reg_off, oob_buf, oob_size1, 0);
+ write_data_dma(nandc, reg_off, oob_buf, oob_size1,
+ NAND_BAM_NO_EOT);
reg_off += oob_size1;
oob_buf += oob_size1;

- write_data_dma(nandc, reg_off, data_buf, data_size2, 0);
+ write_data_dma(nandc, reg_off, data_buf, data_size2,
+ NAND_BAM_NO_EOT);
reg_off += data_size2;
data_buf += data_size2;

@@ -1968,6 +2003,7 @@ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
return ret;

clear_read_regs(nandc);
+ clear_bam_transaction(nandc);

/* calculate the data and oob size for the last codeword/step */
data_size = ecc->size - ((ecc->steps - 1) << 2);
--
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