diff mbox series

[v2,1/1] hw/block/m25p80: Fix Numonyx fast read dummy cycle count

Message ID 1603842220-215321-2-git-send-email-komlodi@xilinx.com
State New
Headers show
Series hw/block/m25p80: Fix Numonyx flash dummy cycle register behavior | expand

Commit Message

Joe Komlodi Oct. 27, 2020, 11:43 p.m. UTC
Numonyx chips determine the number of cycles to wait based on bits 7:4 in the
volatile configuration register.

However, if these bits are 0x0 or 0xF, the number of dummy cycles to wait is
10 on a QIOR or QIOR4 command, or 8 on any other currently supported
fast read command. [1]

[1] https://www.micron.com/-/media/client/global/documents/products/data-sheet/
nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_02g_cbb_0.pdf
?rev=9b167fbf2b3645efba6385949a72e453
Page 34, page 39 note 5

Signed-off-by: Joe Komlodi <komlodi@xilinx.com>
---
 hw/block/m25p80.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

Comments

Philippe Mathieu-Daudé Oct. 28, 2020, 9:26 a.m. UTC | #1
Hi Joe,

On 10/28/20 12:43 AM, Joe Komlodi wrote:
> Numonyx chips determine the number of cycles to wait based on bits 7:4 in the

> volatile configuration register.

> 

> However, if these bits are 0x0 or 0xF, the number of dummy cycles to wait is

> 10 on a QIOR or QIOR4 command, or 8 on any other currently supported

> fast read command. [1]

> 

> [1] https://www.micron.com/-/media/client/global/documents/products/data-sheet/

> nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_02g_cbb_0.pdf

> ?rev=9b167fbf2b3645efba6385949a72e453


Please use single line for URL (even longer than 80 characters):
https://www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_02g_cbb_0.pdf

Or use

Datasheet: "MT25QU02GCBB Rev. H 05/19 EN"

> Page 34, page 39 note 5


The note 5 is not restricted to QIOR/QIOR4 commands,
so your patch seems incomplete.

> 

> Signed-off-by: Joe Komlodi <komlodi@xilinx.com>

> ---

>  hw/block/m25p80.c | 26 +++++++++++++++++++++++---

>  1 file changed, 23 insertions(+), 3 deletions(-)

> 

> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c

> index 483925f..302ed9d 100644

> --- a/hw/block/m25p80.c

> +++ b/hw/block/m25p80.c

> @@ -820,6 +820,26 @@ static void reset_memory(Flash *s)

>      trace_m25p80_reset_done(s);

>  }

>  

> +static uint8_t numonyx_extract_cfg_num_dummies(Flash *s)

> +{

> +    uint8_t cycle_count;

> +    uint8_t num_dummies;

> +    assert(get_man(s) == MAN_NUMONYX);

> +

> +    cycle_count = extract32(s->volatile_cfg, 4, 4);


Could be easier to review as:

       num_dummies = extract32(s->volatile_cfg, 4, 4);

       switch (s->cmd_in_progress) {
       /* note 5 comment ... */
       case FAST_READ:
       case ...
           /* field erased or reset in NVRAM */
           if (cycle_count == 0x0 || cycle_count == 0xf) {
               switch (s->cmd_in_progress) {
               case FAST_READ:
               case ...:
                   num_dummies = 10;
                   break;
               case ...:
               case ...:
                   /* assert(s->quad_enable); */
                   num_dummies = 8;
                   break;
               default:
                   qemu_log_mask(GUEST_ERROR, ...);
                   break;
               }
           }
           break;
       default:
           break;
       }

       return num_dummies;

> +    if (cycle_count == 0x0 || cycle_count == 0x0F) {

> +        if (s->cmd_in_progress == QIOR || s->cmd_in_progress == QIOR4) {

> +            num_dummies = 10;

> +        } else {

> +            num_dummies = 8;


Note, this is only true if s->quad_enable.

Maybe clever to use the dumbest approach and copy the table...

static uint8_t numonyx_extract_cfg_num_dummies(Flash *s)
{
    static const unsigned dummy_clock_cycles[0x100][3] = {
      [FAST_READ] = {8, 8, 10},
      ...
    };
    uint8_t num_dummies = extract32(s->volatile_cfg, 4, 4);

    if (cycle_count == 0x0 || cycle_count == 0xf) {
        num_dummies = dummy_clock_cycles[s->cmd_in_progress][mode];
    }

    return num_dummies;
}

> +        }

> +    } else {

> +        num_dummies = cycle_count;

> +    }

> +

> +    return num_dummies;

> +}

> +

>  static void decode_fast_read_cmd(Flash *s)

>  {

>      s->needed_bytes = get_addr_length(s);

> @@ -829,7 +849,7 @@ static void decode_fast_read_cmd(Flash *s)

>          s->needed_bytes += 8;

>          break;

>      case MAN_NUMONYX:

> -        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);

> +        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);

>          break;

>      case MAN_MACRONIX:

>          if (extract32(s->volatile_cfg, 6, 2) == 1) {

> @@ -868,7 +888,7 @@ static void decode_dio_read_cmd(Flash *s)

>                                      );

>          break;

>      case MAN_NUMONYX:

> -        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);

> +        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);

>          break;

>      case MAN_MACRONIX:

>          switch (extract32(s->volatile_cfg, 6, 2)) {

> @@ -908,7 +928,7 @@ static void decode_qio_read_cmd(Flash *s)

>                                      );

>          break;

>      case MAN_NUMONYX:

> -        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);

> +        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);

>          break;

>      case MAN_MACRONIX:

>          switch (extract32(s->volatile_cfg, 6, 2)) {

>
diff mbox series

Patch

diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
index 483925f..302ed9d 100644
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -820,6 +820,26 @@  static void reset_memory(Flash *s)
     trace_m25p80_reset_done(s);
 }
 
+static uint8_t numonyx_extract_cfg_num_dummies(Flash *s)
+{
+    uint8_t cycle_count;
+    uint8_t num_dummies;
+    assert(get_man(s) == MAN_NUMONYX);
+
+    cycle_count = extract32(s->volatile_cfg, 4, 4);
+    if (cycle_count == 0x0 || cycle_count == 0x0F) {
+        if (s->cmd_in_progress == QIOR || s->cmd_in_progress == QIOR4) {
+            num_dummies = 10;
+        } else {
+            num_dummies = 8;
+        }
+    } else {
+        num_dummies = cycle_count;
+    }
+
+    return num_dummies;
+}
+
 static void decode_fast_read_cmd(Flash *s)
 {
     s->needed_bytes = get_addr_length(s);
@@ -829,7 +849,7 @@  static void decode_fast_read_cmd(Flash *s)
         s->needed_bytes += 8;
         break;
     case MAN_NUMONYX:
-        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);
+        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);
         break;
     case MAN_MACRONIX:
         if (extract32(s->volatile_cfg, 6, 2) == 1) {
@@ -868,7 +888,7 @@  static void decode_dio_read_cmd(Flash *s)
                                     );
         break;
     case MAN_NUMONYX:
-        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);
+        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);
         break;
     case MAN_MACRONIX:
         switch (extract32(s->volatile_cfg, 6, 2)) {
@@ -908,7 +928,7 @@  static void decode_qio_read_cmd(Flash *s)
                                     );
         break;
     case MAN_NUMONYX:
-        s->needed_bytes += extract32(s->volatile_cfg, 4, 4);
+        s->needed_bytes += numonyx_extract_cfg_num_dummies(s);
         break;
     case MAN_MACRONIX:
         switch (extract32(s->volatile_cfg, 6, 2)) {