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/*
* generic mmc spi driver
*
* Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <malloc.h>
#include <part.h>
#include <mmc.h>
#include <spi.h>
#include <crc.h>
#include <linux/crc7.h>
#include <linux/byteorder/swab.h>
/* MMC/SD in SPI mode reports R1 status always */
#define R1_SPI_IDLE (1 << 0)
#define R1_SPI_ERASE_RESET (1 << 1)
#define R1_SPI_ILLEGAL_COMMAND (1 << 2)
#define R1_SPI_COM_CRC (1 << 3)
#define R1_SPI_ERASE_SEQ (1 << 4)
#define R1_SPI_ADDRESS (1 << 5)
#define R1_SPI_PARAMETER (1 << 6)
/* R1 bit 7 is always zero, reuse this bit for error */
#define R1_SPI_ERROR (1 << 7)
/* Response tokens used to ack each block written: */
#define SPI_MMC_RESPONSE_CODE(x) ((x) & 0x1f)
#define SPI_RESPONSE_ACCEPTED ((2 << 1)|1)
#define SPI_RESPONSE_CRC_ERR ((5 << 1)|1)
#define SPI_RESPONSE_WRITE_ERR ((6 << 1)|1)
/* Read and write blocks start with these tokens and end with crc;
* on error, read tokens act like a subset of R2_SPI_* values.
*/
#define SPI_TOKEN_SINGLE 0xfe /* single block r/w, multiblock read */
#define SPI_TOKEN_MULTI_WRITE 0xfc /* multiblock write */
#define SPI_TOKEN_STOP_TRAN 0xfd /* terminate multiblock write */
/* MMC SPI commands start with a start bit "0" and a transmit bit "1" */
#define MMC_SPI_CMD(x) (0x40 | (x & 0x3f))
/* bus capability */
#define MMC_SPI_VOLTAGE (MMC_VDD_32_33 | MMC_VDD_33_34)
#define MMC_SPI_MIN_CLOCK 400000 /* 400KHz to meet MMC spec */
/* timeout value */
#define CTOUT 8
#define RTOUT 3000000 /* 1 sec */
#define WTOUT 3000000 /* 1 sec */
static uint mmc_spi_sendcmd(struct mmc *mmc, ushort cmdidx, u32 cmdarg)
{
struct spi_slave *spi = mmc->priv;
u8 cmdo[7];
u8 r1;
int i;
cmdo[0] = 0xff;
cmdo[1] = MMC_SPI_CMD(cmdidx);
cmdo[2] = cmdarg >> 24;
cmdo[3] = cmdarg >> 16;
cmdo[4] = cmdarg >> 8;
cmdo[5] = cmdarg;
cmdo[6] = (crc7(0, &cmdo[1], 5) << 1) | 0x01;
spi_xfer(spi, sizeof(cmdo) * 8, cmdo, NULL, 0);
for (i = 0; i < CTOUT; i++) {
spi_xfer(spi, 1 * 8, NULL, &r1, 0);
if (i && (r1 & 0x80) == 0) /* r1 response */
break;
}
debug("%s:cmd%d resp%d %x\n", __func__, cmdidx, i, r1);
return r1;
}
static uint mmc_spi_readdata(struct mmc *mmc, void *xbuf,
u32 bcnt, u32 bsize)
{
struct spi_slave *spi = mmc->priv;
u8 *buf = xbuf;
u8 r1;
u16 crc;
int i;
while (bcnt--) {
for (i = 0; i < RTOUT; i++) {
spi_xfer(spi, 1 * 8, NULL, &r1, 0);
if (r1 != 0xff) /* data token */
break;
}
debug("%s:tok%d %x\n", __func__, i, r1);
if (r1 == SPI_TOKEN_SINGLE) {
spi_xfer(spi, bsize * 8, NULL, buf, 0);
spi_xfer(spi, 2 * 8, NULL, &crc, 0);
#ifdef CONFIG_MMC_SPI_CRC_ON
if (swab16(cyg_crc16(buf, bsize)) != crc) {
debug("%s: CRC error\n", mmc->name);
r1 = R1_SPI_COM_CRC;
break;
}
#endif
r1 = 0;
} else {
r1 = R1_SPI_ERROR;
break;
}
buf += bsize;
}
return r1;
}
static uint mmc_spi_writedata(struct mmc *mmc, const void *xbuf,
u32 bcnt, u32 bsize, int multi)
{
struct spi_slave *spi = mmc->priv;
const u8 *buf = xbuf;
u8 r1;
u16 crc;
u8 tok[2];
int i;
tok[0] = 0xff;
tok[1] = multi ? SPI_TOKEN_MULTI_WRITE : SPI_TOKEN_SINGLE;
while (bcnt--) {
#ifdef CONFIG_MMC_SPI_CRC_ON
crc = swab16(cyg_crc16((u8 *)buf, bsize));
#endif
spi_xfer(spi, 2 * 8, tok, NULL, 0);
spi_xfer(spi, bsize * 8, buf, NULL, 0);
spi_xfer(spi, 2 * 8, &crc, NULL, 0);
for (i = 0; i < CTOUT; i++) {
spi_xfer(spi, 1 * 8, NULL, &r1, 0);
if ((r1 & 0x10) == 0) /* response token */
break;
}
debug("%s:tok%d %x\n", __func__, i, r1);
if (SPI_MMC_RESPONSE_CODE(r1) == SPI_RESPONSE_ACCEPTED) {
for (i = 0; i < WTOUT; i++) { /* wait busy */
spi_xfer(spi, 1 * 8, NULL, &r1, 0);
if (i && r1 == 0xff) {
r1 = 0;
break;
}
}
if (i == WTOUT) {
debug("%s:wtout %x\n", __func__, r1);
r1 = R1_SPI_ERROR;
break;
}
} else {
debug("%s: err %x\n", __func__, r1);
r1 = R1_SPI_COM_CRC;
break;
}
buf += bsize;
}
if (multi && bcnt == -1) { /* stop multi write */
tok[1] = SPI_TOKEN_STOP_TRAN;
spi_xfer(spi, 2 * 8, tok, NULL, 0);
for (i = 0; i < WTOUT; i++) { /* wait busy */
spi_xfer(spi, 1 * 8, NULL, &r1, 0);
if (i && r1 == 0xff) {
r1 = 0;
break;
}
}
if (i == WTOUT) {
debug("%s:wstop %x\n", __func__, r1);
r1 = R1_SPI_ERROR;
}
}
return r1;
}
static int mmc_spi_request(struct mmc *mmc, struct mmc_cmd *cmd,
struct mmc_data *data)
{
struct spi_slave *spi = mmc->priv;
u8 r1;
int i;
int ret = 0;
debug("%s:cmd%d %x %x\n", __func__,
cmd->cmdidx, cmd->resp_type, cmd->cmdarg);
spi_claim_bus(spi);
spi_cs_activate(spi);
r1 = mmc_spi_sendcmd(mmc, cmd->cmdidx, cmd->cmdarg);
if (r1 == 0xff) { /* no response */
ret = NO_CARD_ERR;
goto done;
} else if (r1 & R1_SPI_COM_CRC) {
ret = COMM_ERR;
goto done;
} else if (r1 & ~R1_SPI_IDLE) { /* other errors */
ret = TIMEOUT;
goto done;
} else if (cmd->resp_type == MMC_RSP_R2) {
r1 = mmc_spi_readdata(mmc, cmd->response, 1, 16);
for (i = 0; i < 4; i++)
cmd->response[i] = swab32(cmd->response[i]);
debug("r128 %x %x %x %x\n", cmd->response[0], cmd->response[1],
cmd->response[2], cmd->response[3]);
} else if (!data) {
switch (cmd->cmdidx) {
case SD_CMD_APP_SEND_OP_COND:
case MMC_CMD_SEND_OP_COND:
cmd->response[0] = (r1 & R1_SPI_IDLE) ? 0 : OCR_BUSY;
break;
case SD_CMD_SEND_IF_COND:
case MMC_CMD_SPI_READ_OCR:
spi_xfer(spi, 4 * 8, NULL, cmd->response, 0);
cmd->response[0] = swab32(cmd->response[0]);
debug("r32 %x\n", cmd->response[0]);
break;
case MMC_CMD_SEND_STATUS:
spi_xfer(spi, 1 * 8, NULL, cmd->response, 0);
cmd->response[0] = (cmd->response[0] & 0xff) ?
MMC_STATUS_ERROR : MMC_STATUS_RDY_FOR_DATA;
break;
}
} else {
debug("%s:data %x %x %x\n", __func__,
data->flags, data->blocks, data->blocksize);
if (data->flags == MMC_DATA_READ)
r1 = mmc_spi_readdata(mmc, data->dest,
data->blocks, data->blocksize);
else if (data->flags == MMC_DATA_WRITE)
r1 = mmc_spi_writedata(mmc, data->src,
data->blocks, data->blocksize,
(cmd->cmdidx == MMC_CMD_WRITE_MULTIPLE_BLOCK));
if (r1 & R1_SPI_COM_CRC)
ret = COMM_ERR;
else if (r1) /* other errors */
ret = TIMEOUT;
}
done:
spi_cs_deactivate(spi);
spi_release_bus(spi);
return ret;
}
static void mmc_spi_set_ios(struct mmc *mmc)
{
struct spi_slave *spi = mmc->priv;
debug("%s: clock %u\n", __func__, mmc->clock);
if (mmc->clock)
spi_set_speed(spi, mmc->clock);
}
static int mmc_spi_init_p(struct mmc *mmc)
{
struct spi_slave *spi = mmc->priv;
mmc->clock = 0;
spi_set_speed(spi, MMC_SPI_MIN_CLOCK);
spi_claim_bus(spi);
/* cs deactivated for 100+ clock */
spi_xfer(spi, 18 * 8, NULL, NULL, 0);
spi_release_bus(spi);
return 0;
}
struct mmc *mmc_spi_init(uint bus, uint cs, uint speed, uint mode)
{
struct mmc *mmc;
mmc = malloc(sizeof(*mmc));
if (!mmc)
return NULL;
memset(mmc, 0, sizeof(*mmc));
mmc->priv = spi_setup_slave(bus, cs, speed, mode);
if (!mmc->priv) {
free(mmc);
return NULL;
}
sprintf(mmc->name, "MMC_SPI");
mmc->send_cmd = mmc_spi_request;
mmc->set_ios = mmc_spi_set_ios;
mmc->init = mmc_spi_init_p;
mmc->getcd = NULL;
mmc->host_caps = MMC_MODE_SPI;
mmc->voltages = MMC_SPI_VOLTAGE;
mmc->f_max = speed;
mmc->f_min = MMC_SPI_MIN_CLOCK;
mmc->block_dev.part_type = PART_TYPE_DOS;
mmc_register(mmc);
return mmc;
}
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