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hw/sd: ssi-sd: Suffix a data block with CRC16

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Per the SD spec, a valid data block is suffixed with a 16-bit CRC
generated by the standard CCITT polynomial x16+x12+x5+1. This part
is currently missing in the ssi-sd state machine. Without it, all
data block transfer fails in guest software because the expected
CRC16 is missing on the data out line.

Fixes: 775616c3ae ("Partial SD card SPI mode support")
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210123104016.17485-8-bmeng.cn@gmail.com>
[PMD: Change VMState version id 3 -> 4,
      check s->mode validity in post_load()]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This commit is contained in:
Bin Meng 2021-01-23 18:39:58 +08:00 committed by Philippe Mathieu-Daudé
parent 0b73ce3060
commit 2d174cc38b
1 changed files with 20 additions and 3 deletions
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23
hw/sd/ssi-sd.c
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@ -17,6 +17,7 @@
#include "hw/qdev-properties.h"
#include "hw/sd/sd.h"
#include "qapi/error.h"
#include "qemu/crc-ccitt.h"
#include "qemu/module.h"
#include "qom/object.h"
@ -40,6 +41,7 @@ typedef enum {
SSI_SD_RESPONSE,
SSI_SD_DATA_START,
SSI_SD_DATA_READ,
SSI_SD_DATA_CRC16,
} ssi_sd_mode;
struct ssi_sd_state {
@ -48,6 +50,7 @@ struct ssi_sd_state {
int cmd;
uint8_t cmdarg[4];
uint8_t response[5];
uint16_t crc16;
int32_t arglen;
int32_t response_pos;
int32_t stopping;
@ -194,12 +197,24 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
case SSI_SD_DATA_START:
DPRINTF("Start read block\n");
s->mode = SSI_SD_DATA_READ;
s->response_pos = 0;
return 0xfe;
case SSI_SD_DATA_READ:
val = sdbus_read_byte(&s->sdbus);
s->crc16 = crc_ccitt_false(s->crc16, (uint8_t *)&val, 1);
if (!sdbus_data_ready(&s->sdbus)) {
DPRINTF("Data read end\n");
s->mode = SSI_SD_DATA_CRC16;
}
return val;
case SSI_SD_DATA_CRC16:
val = (s->crc16 & 0xff00) >> 8;
s->crc16 <<= 8;
s->response_pos++;
if (s->response_pos == 2) {
DPRINTF("CRC16 read end\n");
s->mode = SSI_SD_CMD;
s->response_pos = 0;
}
return val;
}
@ -211,7 +226,7 @@ static int ssi_sd_post_load(void *opaque, int version_id)
{
ssi_sd_state *s = (ssi_sd_state *)opaque;
if (s->mode > SSI_SD_DATA_READ) {
if (s->mode > SSI_SD_DATA_CRC16) {
return -EINVAL;
}
if (s->mode == SSI_SD_CMDARG &&
@ -229,14 +244,15 @@ static int ssi_sd_post_load(void *opaque, int version_id)
static const VMStateDescription vmstate_ssi_sd = {
.name = "ssi_sd",
.version_id = 3,
.minimum_version_id = 3,
.version_id = 4,
.minimum_version_id = 4,
.post_load = ssi_sd_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT32(mode, ssi_sd_state),
VMSTATE_INT32(cmd, ssi_sd_state),
VMSTATE_UINT8_ARRAY(cmdarg, ssi_sd_state, 4),
VMSTATE_UINT8_ARRAY(response, ssi_sd_state, 5),
VMSTATE_UINT16(crc16, ssi_sd_state),
VMSTATE_INT32(arglen, ssi_sd_state),
VMSTATE_INT32(response_pos, ssi_sd_state),
VMSTATE_INT32(stopping, ssi_sd_state),
@ -288,6 +304,7 @@ static void ssi_sd_reset(DeviceState *dev)
s->cmd = 0;
memset(s->cmdarg, 0, sizeof(s->cmdarg));
memset(s->response, 0, sizeof(s->response));
s->crc16 = 0;
s->arglen = 0;
s->response_pos = 0;
s->stopping = 0;