[Qemu-devel] [PATCH v2 0/7] sdcard: cleanup the SD_SPEC version

[Qemu-devel] [PATCH v2 0/7] sdcard: cleanup the SD_SPEC version

[Philippe Mathieu-Daudé]

Since v2:
- heavy documentation improvements
- squashed previous 3+4 "add spec_version property default to v2" for atomicity
- SSI/SD patch downgraded to RFC
- added Alistair R-b tags

v1: http://lists.nongnu.org/archive/html/qemu-devel/2018-06/msg00388.html

Hi,

This series adds a 'spec_version' property to the SD Card device,
to allow to limit some commands to specific spec version range
(some firmwares use this feature to detect which spec version the
card implements).

This [v2: does NOT] restore the SSI/SD support of the Stellaris LM3S6965EVB
board, which allow to stress the SD Card code with a nice integration test
(waiting for another series to get merged to add the Avocado test):

    $ qemu-system-arm -M lm3s6965evb -serial stdio \
      -kernel sd_card.bin -sd sdcard.img

    SD Card Example Program
    Type 'help' for help.

    /> ls
    Open
    listing

    ----A 2012/04/25 17:44        12  README.TXT

       1 File(s),        12 bytes total
       0 Dir(s),      61182K bytes free

    /> cat README.TXT
    Hello World

See:
http://lists.nongnu.org/archive/html/qemu-devel/2012-04/msg03790.html
http://lists.nongnu.org/archive/html/qemu-devel/2018-06/msg00353.html

Regards,

Phil.

[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/8:[----] [--] 'sdcard: Update the Configuration Register (SCR) to Spec Version 1.10'
002/8:[----] [--] 'sdcard: Allow commands valid in SPI mode'
003/8:[0017] [FC] 'sdcard: Add a 'spec_version' property'
004/8:[down] 'sdcard: Set Spec v2.00 as default'
005/8:[----] [--] 'hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10'
006/8:[----] [--] 'sdcard: Disable SEND_IF_COND (CMD8) for Spec v1'
007/8:[----] [--] 'sdcard: Reflect when the Spec v3 is supported in the Config Register (SCR)'
008/8:[----] [--] 'sdcard: Disable CMD19/CMD23 for Spec v2'

Philippe Mathieu-Daudé (7):
  sdcard: Update the Configuration Register (SCR) to Spec Version 1.10
  sdcard: Allow commands valid in SPI mode
  sdcard: Add a 'spec_version' property, default to Spec v2.00
  sdcard: Disable SEND_IF_COND (CMD8) for Spec v1
  sdcard: Reflect when the Spec v3 is supported in the Config Register (SCR)
  sdcard: Disable CMD19/CMD23 for Spec v2
  hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10

 include/hw/sd/sd.h |  6 ++++++
 hw/sd/sd.c         | 50 +++++++++++++++++++++++++++++-----------------
 hw/sd/ssi-sd.c     |  2 ++
 3 files changed, 40 insertions(+), 18 deletions(-)

-- 
2.17.1

[Qemu-devel] [PATCH v2 1/7] sdcard: Update the Configuration Register (SCR) to Spec Version 1.10

[Philippe Mathieu-Daudé]

The initial implementation is based on the Specs v1.10 (see a1bb27b1e98).

However the SCR is anouncing the card being v1.01.

The new chapters added in version 1.10 are:

    4.3.10 Switch function command

    Switch function command (CMD6) 1 is used to switch or expand
    memory card functions. [...]
    This is a new feature, introduced in SD physical Layer
    Specification Version 1.10. Therefore, cards that are
    compatible with earlier versions of the spec do not support
    it. The host shall check the "SD_SPEC" field in the SCR
    register to recognize what version of the spec the card
    complies with before using CMD6. It is mandatory for SD
    memory card of Ver1.10 to support CMD6.

    4.3.11 High-Speed mode (25MB/sec interface speed)

    Though the Rev 1.01 SD memory card supports up to 12.5MB/sec
    interface speed, the speed of 25MB/sec is necessary to support
    increasing performance needs of the host and because of memory
    size which continues to grow.
    To achieve 25MB/sec interface speed, clock rate is increased to
    50MHz and CLK/CMD/DAT signal timing and circuit conditions are
    reconsidered and changed from Physical Layer Specification
    Version 1.01.

    4.3.12 Command system (This chapter is newly added in version 1.10)

    SD commands CMD34-37, CMD50, CMD57 are reserved for SD command
    system expansion via the switch command.
    [These commands] will be considered as illegal commands (as
    defined in revision 1.01 of the SD physical layer specification).

The SWITCH_FUNCTION is implemented since the first commit, a1bb27b1e98.

The 25MB/sec High-Speed mode was already updated in d7ecb867529.

The current implementation does not implements CMD34-37, CMD50 and
CMD57, thus these commands already return ILLEGAL.

With this patch, the SCR register now matches the description of the header:

 * SD Memory Card emulation as defined in the "SD Memory Card Physical
 * layer specification, Version 1.10."

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 7af19fa06c..e1218d1fb6 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -310,8 +310,8 @@ static void sd_ocr_powerup(void *opaque)
 
 static void sd_set_scr(SDState *sd)
 {
-    sd->scr[0] = (0 << 4)       /* SCR version 1.0 */
-                 | 0;           /* Spec Versions 1.0 and 1.01 */
+    sd->scr[0] = (0 << 4)       /* SCR structure version 1.0 */
+                 | 1;           /* Spec Version 1.10 */
     sd->scr[1] = (2 << 4)       /* SDSC Card (Security Version 1.01) */
                  | 0b0101;      /* 1-bit or 4-bit width bus modes */
     sd->scr[2] = 0x00;          /* Extended Security is not supported. */
-- 
2.17.1

[Qemu-devel] [PATCH v2 2/7] sdcard: Allow commands valid in SPI mode

[Philippe Mathieu-Daudé]

>From the "Physical Layer Simplified Specification Version 1.10"
  Chapter 7.3 "SPI Mode Transaction Packets"
    Table 57: "Commands and arguments"

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 hw/sd/sd.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index e1218d1fb6..80e70dd93e 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -960,8 +960,6 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         return sd_illegal;
 
     case 6:	/* CMD6:   SWITCH_FUNCTION */
-        if (sd->spi)
-            goto bad_cmd;
         switch (sd->mode) {
         case sd_data_transfer_mode:
             sd_function_switch(sd, req.arg);
@@ -1190,9 +1188,6 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
 
     /* Block write commands (Class 4) */
     case 24:	/* CMD24:  WRITE_SINGLE_BLOCK */
-        if (sd->spi) {
-            goto unimplemented_spi_cmd;
-        }
         switch (sd->state) {
         case sd_transfer_state:
             /* Writing in SPI mode not implemented.  */
@@ -1217,9 +1212,6 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 25:	/* CMD25:  WRITE_MULTIPLE_BLOCK */
-        if (sd->spi) {
-            goto unimplemented_spi_cmd;
-        }
         switch (sd->state) {
         case sd_transfer_state:
             /* Writing in SPI mode not implemented.  */
@@ -1259,9 +1251,6 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 27:	/* CMD27:  PROGRAM_CSD */
-        if (sd->spi) {
-            goto unimplemented_spi_cmd;
-        }
         switch (sd->state) {
         case sd_transfer_state:
             sd->state = sd_receivingdata_state;
@@ -1371,9 +1360,6 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
 
     /* Lock card commands (Class 7) */
     case 42:	/* CMD42:  LOCK_UNLOCK */
-        if (sd->spi) {
-            goto unimplemented_spi_cmd;
-        }
         switch (sd->state) {
         case sd_transfer_state:
             sd->state = sd_receivingdata_state;
-- 
2.17.1

[Qemu-devel] [PATCH v2 3/7] sdcard: Add a 'spec_version' property, default to Spec v2.00

[Philippe Mathieu-Daudé]

As of this commit, the Spec v1 is not working, and all controllers
expect the cards to be conformant to Spec v2.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/sd/sd.h |  5 +++++
 hw/sd/sd.c         | 23 ++++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index 9bdb3c9285..7c6ad3c8f1 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -54,6 +54,11 @@
 #define APP_CMD			(1 << 5)
 #define AKE_SEQ_ERROR		(1 << 3)
 
+enum SDPhySpecificationVersion {
+    SD_PHY_SPECv1_10_VERS     = 1,
+    SD_PHY_SPECv2_00_VERS     = 2,
+};
+
 typedef enum {
     SD_VOLTAGE_0_4V     = 400,  /* currently not supported */
     SD_VOLTAGE_1_8V     = 1800,
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 80e70dd93e..1ae085de69 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1,9 +1,10 @@
 /*
  * SD Memory Card emulation as defined in the "SD Memory Card Physical
- * layer specification, Version 1.10."
+ * layer specification, Version 2.00."
  *
  * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
  * Copyright (c) 2007 CodeSourcery
+ * Copyright (c) 2018 Philippe Mathieu-Daudé <f4bug@amsat.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -91,6 +92,7 @@ struct SDState {
     uint8_t sd_status[64];
 
     /* Configurable properties */
+    uint8_t spec_version;
     BlockBackend *blk;
     bool spi;
 
@@ -310,8 +312,12 @@ static void sd_ocr_powerup(void *opaque)
 
 static void sd_set_scr(SDState *sd)
 {
-    sd->scr[0] = (0 << 4)       /* SCR structure version 1.0 */
-                 | 1;           /* Spec Version 1.10 */
+    sd->scr[0] = 0 << 4;        /* SCR structure version 1.0 */
+    if (sd->spec_version == SD_PHY_SPECv1_10_VERS) {
+        sd->scr[0] |= 1;        /* Spec Version 1.10 */
+    } else {
+        sd->scr[0] |= 2;        /* Spec Version 2.00 */
+    }
     sd->scr[1] = (2 << 4)       /* SDSC Card (Security Version 1.01) */
                  | 0b0101;      /* 1-bit or 4-bit width bus modes */
     sd->scr[2] = 0x00;          /* Extended Security is not supported. */
@@ -2058,6 +2064,15 @@ static void sd_realize(DeviceState *dev, Error **errp)
 
     sd->proto_name = sd->spi ? "SPI" : "SD";
 
+    switch (sd->spec_version) {
+    case SD_PHY_SPECv1_10_VERS
+     ... SD_PHY_SPECv2_00_VERS:
+        break;
+    default:
+        error_setg(errp, "Invalid SD card Spec version: %u", sd->spec_version);
+        return;
+    }
+
     if (sd->blk && blk_is_read_only(sd->blk)) {
         error_setg(errp, "Cannot use read-only drive as SD card");
         return;
@@ -2074,6 +2089,8 @@ static void sd_realize(DeviceState *dev, Error **errp)
 }
 
 static Property sd_properties[] = {
+    DEFINE_PROP_UINT8("spec_version", SDState,
+                      spec_version, SD_PHY_SPECv2_00_VERS),
     DEFINE_PROP_DRIVE("drive", SDState, blk),
     /* We do not model the chip select pin, so allow the board to select
      * whether card should be in SSI or MMC/SD mode.  It is also up to the
-- 
2.17.1

[Qemu-devel] [PATCH v2 4/7] sdcard: Disable SEND_IF_COND (CMD8) for Spec v1

[Philippe Mathieu-Daudé]

CMD8 is "Reserved" in Spec v1.10.

Spec v2.00 introduces the SEND_IF_COND command:

  6.4.1 Power Up

    CMD8 is newly added in the Physical Layer Specification Version
    2.00 to support multiple voltage ranges and used to check whether
    the card supports supplied voltage. The version 2.00 or later host
    shall issue CMD8 and verify voltage before card initialization.
    The host that does not support CMD8 shall supply high voltage range.

Message-Id: 201204252110.20873.paul@codesourcery.com
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 1ae085de69..3ec0f71f24 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1018,7 +1018,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 8:	/* CMD8:   SEND_IF_COND */
-        /* Physical Layer Specification Version 2.00 command */
+        if (sd->spec_version < SD_PHY_SPECv2_00_VERS) {
+            break;
+        }
         if (sd->state != sd_idle_state) {
             break;
         }
-- 
2.17.1

[Qemu-devel] [PATCH v2 5/7] sdcard: Reflect when the Spec v3 is supported in the Config Register (SCR)

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/sd/sd.h | 1 +
 hw/sd/sd.c         | 7 +++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index 7c6ad3c8f1..b865aafc33 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -57,6 +57,7 @@
 enum SDPhySpecificationVersion {
     SD_PHY_SPECv1_10_VERS     = 1,
     SD_PHY_SPECv2_00_VERS     = 2,
+    SD_PHY_SPECv3_01_VERS     = 3,
 };
 
 typedef enum {
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 3ec0f71f24..4e49a3827a 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -316,11 +316,14 @@ static void sd_set_scr(SDState *sd)
     if (sd->spec_version == SD_PHY_SPECv1_10_VERS) {
         sd->scr[0] |= 1;        /* Spec Version 1.10 */
     } else {
-        sd->scr[0] |= 2;        /* Spec Version 2.00 */
+        sd->scr[0] |= 2;        /* Spec Version 2.00 or Version 3.0X */
     }
     sd->scr[1] = (2 << 4)       /* SDSC Card (Security Version 1.01) */
                  | 0b0101;      /* 1-bit or 4-bit width bus modes */
     sd->scr[2] = 0x00;          /* Extended Security is not supported. */
+    if (sd->spec_version >= SD_PHY_SPECv3_01_VERS) {
+        sd->scr[2] |= 1 << 7;   /* Spec Version 3.0X */
+    }
     sd->scr[3] = 0x00;
     /* reserved for manufacturer usage */
     sd->scr[4] = 0x00;
@@ -2068,7 +2071,7 @@ static void sd_realize(DeviceState *dev, Error **errp)
 
     switch (sd->spec_version) {
     case SD_PHY_SPECv1_10_VERS
-     ... SD_PHY_SPECv2_00_VERS:
+     ... SD_PHY_SPECv3_01_VERS:
         break;
     default:
         error_setg(errp, "Invalid SD card Spec version: %u", sd->spec_version);
-- 
2.17.1

[Qemu-devel] [PATCH v2 6/7] sdcard: Disable CMD19/CMD23 for Spec v2

[Philippe Mathieu-Daudé]

These commands got introduced by Spec v3
(see 0c3fb03f7ec and 4481bbc79d2).

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sd.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 4e49a3827a..540bccb8d1 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1179,6 +1179,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 19:    /* CMD19: SEND_TUNING_BLOCK (SD) */
+        if (sd->spec_version < SD_PHY_SPECv3_01_VERS) {
+            break;
+        }
         if (sd->state == sd_transfer_state) {
             sd->state = sd_sendingdata_state;
             sd->data_offset = 0;
@@ -1187,6 +1190,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 23:    /* CMD23: SET_BLOCK_COUNT */
+        if (sd->spec_version < SD_PHY_SPECv3_01_VERS) {
+            break;
+        }
         switch (sd->state) {
         case sd_transfer_state:
             sd->multi_blk_cnt = req.arg;
-- 
2.17.1

[Qemu-devel] [RFC PATCH v2 7/7] hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10

[Philippe Mathieu-Daudé]

Due to physical restriction in SPI mode the maximum transfer
speed is limited. All the extensions added after Spec v3 are
simply not supported in SPI mode:

  7.1 Introduction

    The SPI mode consists of a secondary communication protocol
    that is offered by Flash-based SD Memory Cards. This mode is
    a subset of the SD Memory Card protocol, designed to communicate
    with a SPI channel, commonly found in Motorola's (and lately a
    few other vendors') microcontrollers. The interface is selected
    during the first reset command after power up (CMD0) and cannot
    be changed once the part is powered on.
    The SPI standard defines the physical link only, and not the
    complete data transfer protocol. The SD Memory Card SPI
    implementation uses a subset of the SD Memory Card protocol and
    command set. The advantage of the SPI mode is the capability of
    using an off-the-shelf host, hence reducing the design-in effort
    to minimum. The disadvantage is the loss of performance of the
    SPI mode versus SD mode (e.g. Single data line and hardware CS
    signal per card).
    The commands and functions in SD mode defined after the Version
    2.00 are not supported in SPI mode. The card may respond to the
    commands and functions even if the card is in SPI mode but host
    should not use them in SPI mode.

Some firmwares use the CMD8 in SPI mode to poll which Spec version
the SD card supports.

  7.2.1 Mode Selection and Initialization (SPI mode)

    The SD Card is powered up in the SD mode. It will enter SPI mode
    if the CS signal is asserted (negative) during the reception of
    the reset command (CMD0). If the card recognizes that the SD mode
    is required it will not respond to the command and remain in the
    SD mode. If SPI mode is required, the card will switch to SPI and
    respond with the SPI mode R1 response.
    The only way to return to the SD mode is by entering the power
    cycle. In SPI mode, the SD Card protocol state machine in SD mode
    is not observed. All the SD Card commands supported in SPI mode
    are always available. [...]
    If the card indicates an illegal command, the card is legacy and
    does not support CMD8. If the card supports CMD8 and can operate
    on the supplied voltage, the response echoes back the supply
    voltage and the check pattern that were set in the command
    argument.

The NuttX RTOS use it too:

    /* Check for SDHC Version 2.x.  CMD 8 is reserved on SD version 1.0 and
     * MMC.
     */
    finfo("Send CMD8\n");
    result = mmcsd_sendcmd(slot, &g_cmd8, 0x1aa);
    if (result == MMCSD_SPIR1_IDLESTATE)
      ...
    /* Check for SDC version 1.x or MMC */
    else
      ...

See https://bitbucket.org/nuttx/nuttx/src/nuttx-7.25/drivers/mmcsd/mmcsd_spi.c?mmcsd_spi.c-1645#mmcsd_spi.c-1645

The Stellaris LM3S6965EVB board is the only model using SD cards in
SPI mode. The firmware found to work with the board expect the card
to be following Spec v1 to work, and is the only one stressing the
v1 code path of the SD card model.
Thus it seems clever to restrict SPI connected cards to use Spec v1.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
This change would be better in the lm3s6965evb_init() rathar than here in
ssi-sd.

As suggested by Peter and Thomas here:
http://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg06616.html

We can use -device sd-card,spec_version=1 to avoid this change.

$ arm-softmmu/qemu-system-arm \
      -M lm3s6965evb -nodefaults \
      -serial stdio \
      -kernel sd_card.bin \
      -drive file=sdcard.img,id=mycard,if=none \
      -device sd-card,spi=true,spec_version=1,drive=mycard 
qemu-system-arm: warning: nic stellaris_enet.0 has no peer
SD Card Example Program
Type 'help' for help.

/> ls
Open
listing

----A 2012/04/25 17:44        12  README.TXT

   1 File(s),        12 bytes total
   0 Dir(s),      61182K bytes free

/> cat README.TXT
Hello World

/> 

Even if there are still 2 cards...

(qemu) info qtree
bus: main-system-bus
  type System
  dev: pl022, id ""
    gpio-out "sysbus-irq" 1
    mmio 0000000040008000/0000000000001000
    bus: ssi
      type SSI
      dev: ssd0323, id ""
        gpio-in "" 1
        gpio-in "ssi-gpio-cs" 1
      dev: ssi-sd, id ""
        gpio-in "ssi-gpio-cs" 1
        bus: sd-bus
          type sd-bus
          dev: sd-card, id ""
            spec_version = 1 (0x1)
            drive = "mycard"
            spi = true
          dev: sd-card, id ""
            spec_version = 2 (0x2)
            drive = ""
            spi = true

 hw/sd/ssi-sd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index 96542ecd62..82470a12e2 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -252,6 +252,8 @@ static void ssi_sd_realize(SSISlave *d, Error **errp)
     /* FIXME use a qdev drive property instead of drive_get_next() */
     dinfo = drive_get_next(IF_SD);
     carddev = qdev_create(&s->sdbus.qbus, TYPE_SD_CARD);
+    object_property_set_uint(OBJECT(carddev),
+                             SD_PHY_SPECv1_10_VERS, "spec_version", &err);
     if (dinfo) {
         qdev_prop_set_drive(carddev, "drive", blk_by_legacy_dinfo(dinfo), &err);
     }
-- 
2.17.1

Re: [Qemu-devel] [PATCH v2 0/7] sdcard: cleanup the SD_SPEC version

[Philippe Mathieu-Daudé]

On 06/07/2018 03:06 PM, Philippe Mathieu-Daudé wrote:
> Since v2:
> - heavy documentation improvements
> - squashed previous 3+4 "add spec_version property default to v2" for atomicity
> - SSI/SD patch downgraded to RFC
> - added Alistair R-b tags

Patches missing review: #1 and #4 (#6 being RFC waits for comments).

Re: [Qemu-devel] [RFC PATCH v2 7/7] hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10

[Peter Maydell]

On 7 June 2018 at 19:06, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> Due to physical restriction in SPI mode the maximum transfer
> speed is limited. All the extensions added after Spec v3 are
> simply not supported in SPI mode:

You say here that SPI mode doesn't support extensions added
"after spec v3"...

>   7.1 Introduction
>
>     The SPI mode consists of a secondary communication protocol
>     that is offered by Flash-based SD Memory Cards. This mode is
>     a subset of the SD Memory Card protocol, designed to communicate
>     with a SPI channel, commonly found in Motorola's (and lately a
>     few other vendors') microcontrollers. The interface is selected
>     during the first reset command after power up (CMD0) and cannot
>     be changed once the part is powered on.
>     The SPI standard defines the physical link only, and not the
>     complete data transfer protocol. The SD Memory Card SPI
>     implementation uses a subset of the SD Memory Card protocol and
>     command set. The advantage of the SPI mode is the capability of
>     using an off-the-shelf host, hence reducing the design-in effort
>     to minimum. The disadvantage is the loss of performance of the
>     SPI mode versus SD mode (e.g. Single data line and hardware CS
>     signal per card).
>     The commands and functions in SD mode defined after the Version
>     2.00 are not supported in SPI mode.

...but here quote the spec which says that commands defined after
version 2.00 are not supported in SPI mode...

and then the patch itself enforces spec 1.10, rather than 2.
So I'm confused.

> The card may respond to the
>     commands and functions even if the card is in SPI mode but host
>     should not use them in SPI mode.
>
> Some firmwares use the CMD8 in SPI mode to poll which Spec version
> the SD card supports.
>
>   7.2.1 Mode Selection and Initialization (SPI mode)
>
>     The SD Card is powered up in the SD mode. It will enter SPI mode
>     if the CS signal is asserted (negative) during the reception of
>     the reset command (CMD0). If the card recognizes that the SD mode
>     is required it will not respond to the command and remain in the
>     SD mode. If SPI mode is required, the card will switch to SPI and
>     respond with the SPI mode R1 response.
>     The only way to return to the SD mode is by entering the power
>     cycle. In SPI mode, the SD Card protocol state machine in SD mode
>     is not observed. All the SD Card commands supported in SPI mode
>     are always available. [...]
>     If the card indicates an illegal command, the card is legacy and
>     does not support CMD8. If the card supports CMD8 and can operate
>     on the supplied voltage, the response echoes back the supply
>     voltage and the check pattern that were set in the command
>     argument.
>
> The NuttX RTOS use it too:
>
>     /* Check for SDHC Version 2.x.  CMD 8 is reserved on SD version 1.0 and
>      * MMC.
>      */
>     finfo("Send CMD8\n");
>     result = mmcsd_sendcmd(slot, &g_cmd8, 0x1aa);
>     if (result == MMCSD_SPIR1_IDLESTATE)
>       ...
>     /* Check for SDC version 1.x or MMC */
>     else
>       ...
>
> See https://bitbucket.org/nuttx/nuttx/src/nuttx-7.25/drivers/mmcsd/mmcsd_spi.c?mmcsd_spi.c-1645#mmcsd_spi.c-1645

This seems reasonable guest behaviour, and it's what the spec says
to do. Why do we need to enforce 1.10 to get things to work?

thanks
-- PMM

Re: [Qemu-devel] [PATCH v2 0/7] sdcard: cleanup the SD_SPEC version

[Peter Maydell]

On 7 June 2018 at 19:06, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> Since v2:
> - heavy documentation improvements
> - squashed previous 3+4 "add spec_version property default to v2" for atomicity
> - SSI/SD patch downgraded to RFC
> - added Alistair R-b tags

> Philippe Mathieu-Daudé (7):
>   sdcard: Update the Configuration Register (SCR) to Spec Version 1.10
>   sdcard: Allow commands valid in SPI mode
>   sdcard: Add a 'spec_version' property, default to Spec v2.00
>   sdcard: Disable SEND_IF_COND (CMD8) for Spec v1
>   sdcard: Reflect when the Spec v3 is supported in the Config Register (SCR)
>   sdcard: Disable CMD19/CMD23 for Spec v2
>   hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10

Hi; I've applied patches 1-6 to target-arm.next. 7 I had a
question about.

thanks
-- PMM

Re: [Qemu-devel] [Qemu-arm] [PATCH v2 0/7] sdcard: cleanup the SD_SPEC version

[Philippe Mathieu-Daudé]

On 06/08/2018 09:14 AM, Peter Maydell wrote:
> On 7 June 2018 at 19:06, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>> Since v2:
>> - heavy documentation improvements
>> - squashed previous 3+4 "add spec_version property default to v2" for atomicity
>> - SSI/SD patch downgraded to RFC
>> - added Alistair R-b tags
> 
>> Philippe Mathieu-Daudé (7):
>>   sdcard: Update the Configuration Register (SCR) to Spec Version 1.10
>>   sdcard: Allow commands valid in SPI mode
>>   sdcard: Add a 'spec_version' property, default to Spec v2.00
>>   sdcard: Disable SEND_IF_COND (CMD8) for Spec v1
>>   sdcard: Reflect when the Spec v3 is supported in the Config Register (SCR)
>>   sdcard: Disable CMD19/CMD23 for Spec v2
>>   hw/sd/ssi-sd: Force cards connected in SPI mode to use Spec v1.10
> 
> Hi; I've applied patches 1-6 to target-arm.next. 7 I had a
> question about.

Thanks!