Re: [PATCH] mtd: rawnand: qcom: Implement exec_op()

From: Md Sadre Alam
Date: Mon Jun 06 2022 - 01:07:49 EST



On 6/3/2022 10:27 PM, Miquel Raynal wrote:
Hello,

quic_mdalam@xxxxxxxxxxx wrote on Fri, 3 Jun 2022 21:54:58 +0530:

Implement exec_op() so we can later get rid of the legacy interface
implementation.
Thanks for doing this conversion!

Co-developed-by: Sricharan R <quic_srichara@xxxxxxxxxxx>
Signed-off-by: Sricharan R <quic_srichara@xxxxxxxxxxx>
Signed-off-by: Md Sadre Alam <quic_mdalam@xxxxxxxxxxx>
---
drivers/mtd/nand/raw/qcom_nandc.c | 368 +++++++++++++++++++++-----------------
1 file changed, 204 insertions(+), 164 deletions(-)

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 048b255..507921b 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -14,6 +14,7 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/delay.h>
+#include <linux/iopoll.h>
#include <linux/dma/qcom_bam_dma.h>
/* NANDc reg offsets */
@@ -1305,15 +1306,13 @@ static int nandc_param(struct qcom_nand_host *host)
}
/* sets up descriptors for NAND_CMD_ERASE1 */
-static int erase_block(struct qcom_nand_host *host, int page_addr)
+static int erase_block(struct qcom_nand_host *host)
{
struct nand_chip *chip = &host->chip;
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
nandc_set_reg(chip, NAND_FLASH_CMD,
OP_BLOCK_ERASE | PAGE_ACC | LAST_PAGE);
- nandc_set_reg(chip, NAND_ADDR0, page_addr);
- nandc_set_reg(chip, NAND_ADDR1, 0);
nandc_set_reg(chip, NAND_DEV0_CFG0,
host->cfg0_raw & ~(7 << CW_PER_PAGE));
nandc_set_reg(chip, NAND_DEV0_CFG1, host->cfg1_raw);
@@ -1321,14 +1320,8 @@ static int erase_block(struct qcom_nand_host *host, int page_addr)
nandc_set_reg(chip, NAND_FLASH_STATUS, host->clrflashstatus);
nandc_set_reg(chip, NAND_READ_STATUS, host->clrreadstatus);
- write_reg_dma(nandc, NAND_FLASH_CMD, 3, NAND_BAM_NEXT_SGL);
+ write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
write_reg_dma(nandc, NAND_DEV0_CFG0, 2, NAND_BAM_NEXT_SGL);
- write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
-
- read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
-
- write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
- write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
return 0;
}
@@ -1343,16 +1336,12 @@ static int read_id(struct qcom_nand_host *host, int column)
return 0;
nandc_set_reg(chip, NAND_FLASH_CMD, OP_FETCH_ID);
- nandc_set_reg(chip, NAND_ADDR0, column);
- nandc_set_reg(chip, NAND_ADDR1, 0);
nandc_set_reg(chip, NAND_FLASH_CHIP_SELECT,
nandc->props->is_bam ? 0 : DM_EN);
nandc_set_reg(chip, NAND_EXEC_CMD, 1);
- write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
- write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
-
- read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
+ write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
+ write_reg_dma(nandc, NAND_FLASH_CHIP_SELECT, 1, NAND_BAM_NEXT_SGL);
return 0;
}
@@ -1491,7 +1480,6 @@ static void parse_erase_write_errors(struct qcom_nand_host *host, int command)
for (i = 0; i < num_cw; i++) {
u32 flash_status = le32_to_cpu(nandc->reg_read_buf[i]);
-
if (flash_status & FS_MPU_ERR)
host->status &= ~NAND_STATUS_WP;
@@ -1523,86 +1511,6 @@ static void post_command(struct qcom_nand_host *host, int command)
}
/*
- * Implements chip->legacy.cmdfunc. It's only used for a limited set of
- * commands. The rest of the commands wouldn't be called by upper layers.
- * For example, NAND_CMD_READOOB would never be called because we have our own
- * versions of read_oob ops for nand_ecc_ctrl.
- */
-static void qcom_nandc_command(struct nand_chip *chip, unsigned int command,
- int column, int page_addr)
-{
- struct qcom_nand_host *host = to_qcom_nand_host(chip);
- struct nand_ecc_ctrl *ecc = &chip->ecc;
- struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
- bool wait = false;
- int ret = 0;
-
- pre_command(host, command);
-
- switch (command) {
- case NAND_CMD_RESET:
- ret = reset(host);
- wait = true;
- break;
-
- case NAND_CMD_READID:
- nandc->buf_count = 4;
- ret = read_id(host, column);
- wait = true;
- break;
-
- case NAND_CMD_PARAM:
- ret = nandc_param(host);
- wait = true;
- break;
-
- case NAND_CMD_ERASE1:
- ret = erase_block(host, page_addr);
- wait = true;
- break;
-
- case NAND_CMD_READ0:
- /* we read the entire page for now */
- WARN_ON(column != 0);
-
- host->use_ecc = true;
- set_address(host, 0, page_addr);
- update_rw_regs(host, ecc->steps, true, 0);
- break;
-
- case NAND_CMD_SEQIN:
- WARN_ON(column != 0);
- set_address(host, 0, page_addr);
- break;
-
- case NAND_CMD_PAGEPROG:
- case NAND_CMD_STATUS:
- case NAND_CMD_NONE:
- default:
- break;
- }
-
- if (ret) {
- dev_err(nandc->dev, "failure executing command %d\n",
- command);
- free_descs(nandc);
- return;
- }
-
- if (wait) {
- ret = submit_descs(nandc);
- if (ret)
- dev_err(nandc->dev,
- "failure submitting descs for command %d\n",
- command);
- }
-
- free_descs(nandc);
-
- post_command(host, command);
-}
-
-/*
* when using BCH ECC, the HW flags an error in NAND_FLASH_STATUS if it read
* an erased CW, and reports an erased CW in NAND_ERASED_CW_DETECT_STATUS.
*
@@ -2044,7 +1952,6 @@ static int qcom_nandc_read_page(struct nand_chip *chip, uint8_t *buf,
struct qcom_nand_host *host = to_qcom_nand_host(chip);
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
u8 *data_buf, *oob_buf = NULL;
-
nand_read_page_op(chip, page, 0, NULL, 0);
data_buf = buf;
oob_buf = oob_required ? chip->oob_poi : NULL;
@@ -2366,64 +2273,6 @@ static int qcom_nandc_block_markbad(struct nand_chip *chip, loff_t ofs)
}
/*
- * the three functions below implement chip->legacy.read_byte(),
- * chip->legacy.read_buf() and chip->legacy.write_buf() respectively. these
- * aren't used for reading/writing page data, they are used for smaller data
- * like reading id, status etc
- */
-static uint8_t qcom_nandc_read_byte(struct nand_chip *chip)
-{
- struct qcom_nand_host *host = to_qcom_nand_host(chip);
- struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
- u8 *buf = nandc->data_buffer;
- u8 ret = 0x0;
-
- if (host->last_command == NAND_CMD_STATUS) {
- ret = host->status;
-
- host->status = NAND_STATUS_READY | NAND_STATUS_WP;
-
- return ret;
- }
-
- if (nandc->buf_start < nandc->buf_count)
- ret = buf[nandc->buf_start++];
-
- return ret;
-}
-
-static void qcom_nandc_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
-{
- struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
- int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
-
- memcpy(buf, nandc->data_buffer + nandc->buf_start, real_len);
- nandc->buf_start += real_len;
-}
-
-static void qcom_nandc_write_buf(struct nand_chip *chip, const uint8_t *buf,
- int len)
-{
- struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
- int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
-
- memcpy(nandc->data_buffer + nandc->buf_start, buf, real_len);
-
- nandc->buf_start += real_len;
-}
-
-/* we support only one external chip for now */
-static void qcom_nandc_select_chip(struct nand_chip *chip, int chipnr)
-{
- struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
-
- if (chipnr <= 0)
- return;
-
- dev_warn(nandc->dev, "invalid chip select\n");
-}
-
-/*
* NAND controller page layout info
*
* Layout with ECC enabled:
@@ -2738,8 +2587,207 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
return 0;
}
+static int nandc_status(struct nand_chip *chip)
+{
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ struct qcom_nand_host *host = to_qcom_nand_host(chip);
+
+ memcpy(nandc->data_buffer, &host->status, 1);
+
+ return 0;
+}
+
+static int qcom_nand_send_command(struct nand_chip *chip, u8 command)
+{
+ struct qcom_nand_host *host = to_qcom_nand_host(chip);
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+ int ret = 0;
+
+ pre_command(host, command);
+
+ switch (command) {
+ case NAND_CMD_RESET:
+ ret = reset(host);
+ break;
+ case NAND_CMD_READID:
+ nandc->buf_count = 4;
+ ret = read_id(host, 0);
+ break;
+ case NAND_CMD_PARAM:
+ ret = nandc_param(host);
+ break;
+ case NAND_CMD_ERASE1:
+ ret = erase_block(host);
+ break;
+ case NAND_CMD_STATUS:
+ ret = nandc_status(chip);
+ break;
+ case NAND_CMD_READ0:
+ host->use_ecc = true;
->exec_op() and ECC are orthogonal

+ update_rw_regs(host, ecc->steps, true, 0);
+ break;
+ case NAND_CMD_ERASE2:
+ break;
+ case NAND_CMD_SEQIN:
+ break;
+ case NAND_CMD_PAGEPROG:
+ break;
I am sorry but this is not following ->exec_op() main idea. The
controller is just here to forward requests to the device it must
respect a number of cycles but that's pretty much all. Here you are
actually re-writing ->cmdfunc() which is not what we expect.


 Thanks for reviewing this. I will address this all comments in next patch.



+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static int qcom_nand_send_address(struct nand_chip *chip,
+ const struct nand_op_instr *instr, int cmd)
+{
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ u32 page_addr = 0x0, page_mask = 0x0;
+
+ page_addr = instr->ctx.addr.addrs[0];
+
+ /*
+ *Form page address for erase, read, write to using existing api
+ */
+
+ switch (cmd) {
+ case NAND_CMD_ERASE1:
+ page_addr = instr->ctx.addr.addrs[0];
+ page_mask = instr->ctx.addr.addrs[1];
+ page_mask <<= 8;
+ page_addr = (page_addr | page_mask);
+ page_mask = instr->ctx.addr.addrs[2];
+ page_mask <<= 16;
+ page_addr = (page_addr | page_mask);
+ page_mask = instr->ctx.addr.addrs[3];
+ page_mask <<= 24;
+ page_addr = (page_addr | page_mask);
+ break;
+ case NAND_CMD_READ0:
+ case NAND_CMD_SEQIN:
+ page_addr = instr->ctx.addr.addrs[3];
+ page_addr <<= 24;
+ page_mask = instr->ctx.addr.addrs[2];
+ page_mask <<= 16;
+ page_addr |= page_mask;
+ page_mask = instr->ctx.addr.addrs[1];
+ page_mask <<= 8;
+ page_addr |= page_mask;
+ page_mask = instr->ctx.addr.addrs[0];
+ page_addr |= page_mask;
Same here, just write the number of address cycles that were requested
by the core.


 Sure, I will modify this in next patch.


+ break;
+ default:
+ break;
+ }
+
+ if (cmd == NAND_CMD_PARAM)
+ return 0;
+
+ nandc_set_reg(chip, NAND_ADDR0, page_addr);
+ nandc_set_reg(chip, NAND_ADDR1, 0);
+
+ if (cmd != NAND_CMD_SEQIN)
+ write_reg_dma(nandc, NAND_ADDR0, 2, 0);
+
+ return 0;
+}
+
+static void qcom_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
+{
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+
+ memcpy(buf, nandc->data_buffer, len);
Is this bounce buffer needed?
 Yes , for read id data we need this bounce buffer.

+}
+
+static int qcom_nand_exec_instr(struct nand_chip *chip,
+ const struct nand_op_instr *instr)
+{
+ struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
+ struct qcom_nand_host *host = to_qcom_nand_host(chip);
+ u32 status;
+ int ret = 0;
+ bool wait = false;
+ static int opcode;
+
+ switch (instr->type) {
+ case NAND_OP_CMD_INSTR:
+ ret = qcom_nand_send_command(chip, instr->ctx.cmd.opcode);
+ if (instr->ctx.cmd.opcode == NAND_CMD_RESET)
+ wait = true;
+ opcode = instr->ctx.cmd.opcode;
+ break;
+ case NAND_OP_ADDR_INSTR:
+ qcom_nand_send_address(chip, instr, opcode);
+ if (opcode != NAND_CMD_READ0 && opcode != NAND_CMD_READSTART &&
+ opcode != NAND_CMD_PARAM && opcode != NAND_CMD_SEQIN)
+ wait = true;
+ break;
+ case NAND_OP_DATA_IN_INSTR:
+ qcom_nand_read_buf(chip, instr->ctx.data.buf.in, instr->ctx.data.len);
+ break;
+ case NAND_OP_DATA_OUT_INSTR:
+ wait = false;
+ break;
+ case NAND_OP_WAITRDY_INSTR:
+ ret = readl_poll_timeout(nandc->base + NAND_FLASH_STATUS, status,
+ (status & FS_READY_BSY_N), 20,
+ instr->ctx.waitrdy.timeout_ms * 1000);
+ if (opcode == NAND_CMD_PARAM)
+ wait = true;
+ default:
+ break;
+ }
+
+ if (wait) {
+ if (opcode != NAND_CMD_PARAM)
+ write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
+
+ if (opcode == NAND_CMD_READID)
+ read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
+
+ if (opcode == NAND_CMD_ERASE1) {
+ read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
+ write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
+ write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
+ }
+
+ ret = submit_descs(nandc);
+ if (ret)
+ dev_err(nandc->dev, "failure submitting descs for command 0x%02x\n",
+ opcode);
+
+ free_descs(nandc);
+ post_command(host, opcode);
+ }
+
+ return ret;
+}
+
+static int qcom_nand_exec_op(struct nand_chip *chip,
+ const struct nand_operation *op,
+ bool check_only)
+{
+ unsigned int i;
+ int ret = 0;
+
+ if (check_only)
+ return 0;
+
+ for (i = 0; i < op->ninstrs; i++) {
+ ret = qcom_nand_exec_instr(chip, &op->instrs[i]);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
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)
@@ -2938,14 +2986,6 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
mtd->owner = THIS_MODULE;
mtd->dev.parent = dev;
- chip->legacy.cmdfunc = qcom_nandc_command;
- chip->legacy.select_chip = qcom_nandc_select_chip;
- chip->legacy.read_byte = qcom_nandc_read_byte;
- chip->legacy.read_buf = qcom_nandc_read_buf;
- chip->legacy.write_buf = qcom_nandc_write_buf;
- chip->legacy.set_features = nand_get_set_features_notsupp;
- chip->legacy.get_features = nand_get_set_features_notsupp;
-
/*
* the bad block marker is readable only when we read the last codeword
* of a page with ECC disabled. currently, the nand_base and nand_bbt

Thanks,
Miquèl