From 1365d863a71803a8aac7922986c858ed4dedd826 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Thu, 28 Jan 2021 14:30:27 +0800 Subject: [PATCH] hw/sd: ssi-sd: Support multiple block read MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In the case of a multiple block read operation every transferred block has its suffix of CRC16. Update the state machine logic to handle multiple block read. Signed-off-by: Bin Meng [PMD: Change VMState version id 5 -> 6] Signed-off-by: Philippe Mathieu-Daudé Tested-by: Philippe Mathieu-Daudé Acked-by: Alistair Francis Message-Id: <20210128063035.15674-2-bmeng.cn@gmail.com> Signed-off-by: Philippe Mathieu-Daudé --- hw/sd/ssi-sd.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c index be1bb10164..6d20a240c6 100644 --- a/hw/sd/ssi-sd.c +++ b/hw/sd/ssi-sd.c @@ -52,6 +52,7 @@ struct ssi_sd_state { uint8_t cmdarg[4]; uint8_t response[5]; uint16_t crc16; + int32_t read_bytes; int32_t arglen; int32_t response_pos; int32_t stopping; @@ -88,11 +89,26 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val) { ssi_sd_state *s = SSI_SD(dev); - /* Special case: allow CMD12 (STOP TRANSMISSION) while reading data. */ - if (s->mode == SSI_SD_DATA_READ && val == 0x4c) { - s->mode = SSI_SD_CMD; - /* There must be at least one byte delay before the card responds. */ - s->stopping = 1; + /* + * Special case: allow CMD12 (STOP TRANSMISSION) while reading data. + * + * See "Physical Layer Specification Version 8.00" chapter 7.5.2.2, + * to avoid conflict between CMD12 response and next data block, + * timing of CMD12 should be controlled as follows: + * + * - CMD12 issued at the timing that end bit of CMD12 and end bit of + * data block is overlapped + * - CMD12 issued after one clock cycle after host receives a token + * (either Start Block token or Data Error token) + * + * We need to catch CMD12 in all of the data read states. + */ + if (s->mode >= SSI_SD_PREP_DATA && s->mode <= SSI_SD_DATA_CRC16) { + if (val == 0x4c) { + s->mode = SSI_SD_CMD; + /* There must be at least one byte delay before the card responds */ + s->stopping = 1; + } } switch (s->mode) { @@ -212,8 +228,9 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val) return SSI_TOKEN_SINGLE; case SSI_SD_DATA_READ: val = sdbus_read_byte(&s->sdbus); + s->read_bytes++; s->crc16 = crc_ccitt_false(s->crc16, (uint8_t *)&val, 1); - if (!sdbus_data_ready(&s->sdbus)) { + if (!sdbus_data_ready(&s->sdbus) || s->read_bytes == 512) { DPRINTF("Data read end\n"); s->mode = SSI_SD_DATA_CRC16; } @@ -224,7 +241,12 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val) s->response_pos++; if (s->response_pos == 2) { DPRINTF("CRC16 read end\n"); - s->mode = SSI_SD_CMD; + if (s->read_bytes == 512 && s->cmd != 17) { + s->mode = SSI_SD_PREP_DATA; + } else { + s->mode = SSI_SD_CMD; + } + s->read_bytes = 0; s->response_pos = 0; } return val; @@ -255,8 +277,8 @@ static int ssi_sd_post_load(void *opaque, int version_id) static const VMStateDescription vmstate_ssi_sd = { .name = "ssi_sd", - .version_id = 5, - .minimum_version_id = 5, + .version_id = 6, + .minimum_version_id = 6, .post_load = ssi_sd_post_load, .fields = (VMStateField []) { VMSTATE_UINT32(mode, ssi_sd_state), @@ -264,6 +286,7 @@ static const VMStateDescription vmstate_ssi_sd = { VMSTATE_UINT8_ARRAY(cmdarg, ssi_sd_state, 4), VMSTATE_UINT8_ARRAY(response, ssi_sd_state, 5), VMSTATE_UINT16(crc16, ssi_sd_state), + VMSTATE_INT32(read_bytes, ssi_sd_state), VMSTATE_INT32(arglen, ssi_sd_state), VMSTATE_INT32(response_pos, ssi_sd_state), VMSTATE_INT32(stopping, ssi_sd_state), @@ -316,6 +339,7 @@ static void ssi_sd_reset(DeviceState *dev) memset(s->cmdarg, 0, sizeof(s->cmdarg)); memset(s->response, 0, sizeof(s->response)); s->crc16 = 0; + s->read_bytes = 0; s->arglen = 0; s->response_pos = 0; s->stopping = 0; -- 2.11.4.GIT