Re: [PATCH v1 1/5] mtd: rawnand: meson: fix NAND access for read/write

From: Liang Yang
Date: Wed Apr 12 2023 - 09:32:14 EST


Hi,

On 2023/4/12 20:03, Arseniy Krasnov wrote:
[ EXTERNAL EMAIL ]



On 12.04.2023 13:24, Arseniy Krasnov wrote:


On 12.04.2023 12:37, Liang Yang wrote:
Hi Arseniy,

Thanks for pointing out this problem. also comment inline.

On 2023/4/12 14:16, Arseniy Krasnov wrote:
[ EXTERNAL EMAIL ]

This fixes read/write functionality. New command sequences were ported
from old vendor's driver. Without this patch driver works unstable. This
change is tested with 'nanddump'/'nandwrite' utilities and mounting
JFFS2 filesystem on AXG family (A113X SoC).

Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
  drivers/mtd/nand/raw/meson_nand.c | 116 ++++++++++++++++++++++++++----
  1 file changed, 101 insertions(+), 15 deletions(-)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 074e14225c06..256c37c76526 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -26,6 +26,7 @@
  #define NFC_CMD_IDLE        (0xc << 14)
  #define NFC_CMD_CLE        (0x5 << 14)
  #define NFC_CMD_ALE        (0x6 << 14)
+#define NFC_CMD_DRD        (0x8 << 14)
  #define NFC_CMD_ADL        ((0 << 16) | (3 << 20))
  #define NFC_CMD_ADH        ((1 << 16) | (3 << 20))
  #define NFC_CMD_AIL        ((2 << 16) | (3 << 20))
@@ -84,6 +85,7 @@
    #define DMA_BUSY_TIMEOUT    0x100000
  #define CMD_FIFO_EMPTY_TIMEOUT    1000
+#define DEVICE_READY_TIMEOUT    1000
    #define MAX_CE_NUM        2
  @@ -255,8 +257,26 @@ static void meson_nfc_select_chip(struct nand_chip *nand, int chip)
      }
  }
  +static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
+                     unsigned int timeout_ms)
+{
+    u32 cmd_size = 0;
+    int ret;
+
+    /* wait cmd fifo is empty */
+    ret = readl_relaxed_poll_timeout(nfc->reg_base + NFC_REG_CMD, cmd_size,
+                     !NFC_CMD_GET_SIZE(cmd_size),
+                     10, timeout_ms * 1000);
+    if (ret)
+        dev_err(nfc->dev, "wait for empty CMD FIFO timed out\n");
+
+    return ret;
+}
+
  static void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
  {
+    meson_nfc_wait_cmd_finish(nfc, 0);
+
      writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
             nfc->reg_base + NFC_REG_CMD);
  }
@@ -308,23 +328,9 @@ static void meson_nfc_drain_cmd(struct meson_nfc *nfc)
       */
      meson_nfc_cmd_idle(nfc, 0);
      meson_nfc_cmd_idle(nfc, 0);
+    meson_nfc_wait_cmd_finish(nfc, 1000);
  }
  -static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
-                     unsigned int timeout_ms)
-{
-    u32 cmd_size = 0;
-    int ret;
-
-    /* wait cmd fifo is empty */
-    ret = readl_relaxed_poll_timeout(nfc->reg_base + NFC_REG_CMD, cmd_size,
-                     !NFC_CMD_GET_SIZE(cmd_size),
-                     10, timeout_ms * 1000);
-    if (ret)
-        dev_err(nfc->dev, "wait for empty CMD FIFO time out\n");
-
-    return ret;
-}
    static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
  {
@@ -631,6 +637,48 @@ static int meson_nfc_rw_cmd_prepare_and_execute(struct nand_chip *nand,
      return 0;
  }
  +static uint8_t meson_nfc_read_byte(struct nand_chip *nand)
+{
+    struct meson_nfc *nfc = nand_get_controller_data(nand);
+
+    writel(NFC_CMD_DRD, nfc->reg_base + NFC_REG_CMD);
+    meson_nfc_cmd_idle(nfc, nfc->timing.twb);
+    meson_nfc_drain_cmd(nfc);
+
+    return readl(nfc->reg_base + NFC_REG_BUF);
+}
+
+static int meson_nfc_wait_dev_ready(struct nand_chip *nand)
+{
+    struct meson_nfc *nfc = nand_get_controller_data(nand);
+    u32 cs = nfc->param.chip_select;
+    unsigned long cnt = 0;
+
+    meson_nfc_drain_cmd(nfc);
+
+    writel(cs | NFC_CMD_CLE | NAND_CMD_STATUS, nfc->reg_base + NFC_REG_CMD);
+
+    /* 10 ms. */
+    while (cnt < DEVICE_READY_TIMEOUT) {
+        uint8_t status;
+
+        status = meson_nfc_read_byte(nand);
+
+        if (status & NAND_STATUS_READY)
+            break;
+
+        usleep_range(10, 11);
+        cnt++;
+    }
+
+    if (cnt == DEVICE_READY_TIMEOUT) {
+        dev_err(nfc->dev, "device ready timeout\n");
+        return -ETIMEDOUT;
+    }
+
+    return 0;
+}
+
  static int meson_nfc_write_page_sub(struct nand_chip *nand,
                      int page, int raw)
  {
@@ -643,6 +691,10 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand,
      u32 cmd;
      int ret;
  +    ret = meson_nfc_wait_dev_ready(nand);
+    if (ret)
+        return ret;
+
      meson_nfc_select_chip(nand, nand->cur_cs);
        data_len =  mtd->writesize + mtd->oobsize;
@@ -667,12 +719,20 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand,
                       NFC_CMD_SCRAMBLER_DISABLE);
      }
  +    ret = meson_nfc_wait_dma_finish(nfc);
+    if (ret)
+        return ret;
+
      cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG;
      writel(cmd, nfc->reg_base + NFC_REG_CMD);
      meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max));
        meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_TO_DEVICE);
  +    ret = meson_nfc_wait_dev_ready(nand);
+    if (ret)
+        return ret;
+
      return ret;
  }
  @@ -720,6 +780,21 @@ static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc,
      } while (!ret);
  }
  +static inline int meson_nfc_send_read(struct nand_chip *nand)
+{
+    struct meson_nfc *nfc = nand_get_controller_data(nand);
+    u32 cs = nfc->param.chip_select;
+    int ret;
+
+    ret = meson_nfc_wait_dev_ready(nand);
+    if (ret)
+        return ret;
+
+    writel(cs | NFC_CMD_CLE | NAND_CMD_READ0, nfc->reg_base + NFC_REG_CMD);
+
+    return 0;
+}
+

it already calls meson_nfc_queue_rb() in meson_nfc_rw_cmd_prepare_and_execute(). Could you implements this in meson_nfc_queue_rb()? and we can use the irq method.
also without Ready/Busy pin, the meson_nfc_queue_rb() should change like below:
    ......
    #define NFC_CMD_RB_INT    ((0xb << 10) | BIT(18))

Sorry, I can see this define as (and it is used in the driver):
#define NFC_CMD_RB_INT BIT(14)

in drivers/mtd/nand/raw/meson_nand.c

Which one is correct ?

we need to modify the define 'NFC_CMD_RB_INT' as ((0xb << 10) | BIT(18)).


Thanks, Arseniy


    meson_nfc_cmd_idle(nfc, 0);
    cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_STATUS;
    writel(cmd, nfc->reg_base + NFC_REG_CMD);
    meson_nfc_cmd_idle(nfc, 5);
    cmd = NFC_CMD_RB | NFC_CMD_RB_INT | nfc->timing.tbers_max;
    writel(cmd, nfc->reg_base + NFC_REG_CMD);

    ret = wait_for_completion_timeout(&nfc->completion,
                      msecs_to_jiffies(timeout_ms));
    if (ret == 0)
        ret = -1;

    writel(cs | NFC_CMD_CLE | NAND_CMD_READ0, nfc->reg_base + NFC_REG_CMD);
    ......


Thanks for reply! I'll try this code! One more question about OOB processing in this
driver (as You are author of it):

OOB size is 64 bytes, but for example if I have 1K ECC, 2 bytes user bytes and 14
bytes for ECC code for each 1K. In this case I have access to only 32 bytes of OOB:
2 x (2 user bytes + 14 ECC bytes). Correct me if i'm wrong, but rest of OOB (next
32 bytes) become unavailable (in both raw and ECC modes) ?

Thanks, Arseniy

  static int meson_nfc_read_page_sub(struct nand_chip *nand,
                     int page, int raw)
  {
@@ -734,10 +809,18 @@ static int meson_nfc_read_page_sub(struct nand_chip *nand,
      data_len =  mtd->writesize + mtd->oobsize;
      info_len = nand->ecc.steps * PER_INFO_BYTE;
  +    ret = meson_nfc_wait_dev_ready(nand);
+    if (ret)
+        return ret;
+
      ret = meson_nfc_rw_cmd_prepare_and_execute(nand, page, DIRREAD);
      if (ret)
          return ret;
  +    ret = meson_nfc_send_read(nand);
+    if (ret)
+        return ret;
+
      ret = meson_nfc_dma_buffer_setup(nand, meson_chip->data_buf,
                       data_len, meson_chip->info_buf,
                       info_len, DMA_FROM_DEVICE);
@@ -754,6 +837,9 @@ static int meson_nfc_read_page_sub(struct nand_chip *nand,
      }
        ret = meson_nfc_wait_dma_finish(nfc);
+    if (ret)
+        return ret;
+
      meson_nfc_check_ecc_pages_valid(nfc, nand, raw);
        meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_FROM_DEVICE);



--
Thanks,
Liang