u-boot/drivers/mmc/davinci_mmc.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Davinci MMC Controller Driver
*
* Copyright (C) 2010 Texas Instruments Incorporated
*/
#include <config.h>
#include <common.h>
#include <command.h>
#include <errno.h>
#include <mmc.h>
#include <part.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/sdmmc_defs.h>
#define DAVINCI_MAX_BLOCKS (32)
#define WATCHDOG_COUNT (100000)
#define get_val(addr) REG(addr)
#define set_val(addr, val) REG(addr) = (val)
#define set_bit(addr, val) set_val((addr), (get_val(addr) | (val)))
#define clear_bit(addr, val) set_val((addr), (get_val(addr) & ~(val)))
/* Set davinci clock prescalar value based on the required clock in HZ */
static void dmmc_set_clock(struct mmc *mmc, uint clock)
{
struct davinci_mmc *host = mmc->priv;
struct davinci_mmc_regs *regs = host->reg_base;
uint clkrt, sysclk2, act_clock;
if (clock < mmc->cfg->f_min)
clock = mmc->cfg->f_min;
if (clock > mmc->cfg->f_max)
clock = mmc->cfg->f_max;
set_val(&regs->mmcclk, 0);
sysclk2 = host->input_clk;
clkrt = (sysclk2 / (2 * clock)) - 1;
/* Calculate the actual clock for the divider used */
act_clock = (sysclk2 / (2 * (clkrt + 1)));
/* Adjust divider if actual clock exceeds the required clock */
if (act_clock > clock)
clkrt++;
/* check clock divider boundary and correct it */
if (clkrt > 0xFF)
clkrt = 0xFF;
set_val(&regs->mmcclk, (clkrt | MMCCLK_CLKEN));
}
/* Status bit wait loop for MMCST1 */
static int
dmmc_wait_fifo_status(volatile struct davinci_mmc_regs *regs, uint status)
{
uint wdog = WATCHDOG_COUNT;
while (--wdog && ((get_val(&regs->mmcst1) & status) != status))
udelay(10);
if (!(get_val(&regs->mmcctl) & MMCCTL_WIDTH_4_BIT))
udelay(100);
if (wdog == 0)
return -ECOMM;
return 0;
}
/* Busy bit wait loop for MMCST1 */
static int dmmc_busy_wait(volatile struct davinci_mmc_regs *regs)
{
uint wdog = WATCHDOG_COUNT;
while (--wdog && (get_val(&regs->mmcst1) & MMCST1_BUSY))
udelay(10);
if (wdog == 0)
return -ECOMM;
return 0;
}
/* Status bit wait loop for MMCST0 - Checks for error bits as well */
static int dmmc_check_status(volatile struct davinci_mmc_regs *regs,
uint *cur_st, uint st_ready, uint st_error)
{
uint wdog = WATCHDOG_COUNT;
uint mmcstatus = *cur_st;
while (wdog--) {
if (mmcstatus & st_ready) {
*cur_st = mmcstatus;
mmcstatus = get_val(&regs->mmcst1);
return 0;
} else if (mmcstatus & st_error) {
if (mmcstatus & MMCST0_TOUTRS)
return -ETIMEDOUT;
printf("[ ST0 ERROR %x]\n", mmcstatus);
/*
* Ignore CRC errors as some MMC cards fail to
* initialize on DM365-EVM on the SD1 slot
*/
if (mmcstatus & MMCST0_CRCRS)
return 0;
return -ECOMM;
}
udelay(10);
mmcstatus = get_val(&regs->mmcst0);
}
printf("Status %x Timeout ST0:%x ST1:%x\n", st_ready, mmcstatus,
get_val(&regs->mmcst1));
return -ECOMM;
}
/*
* Sends a command out on the bus. Takes the mmc pointer,
* a command pointer, and an optional data pointer.
*/
static int
dmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
{
struct davinci_mmc *host = mmc->priv;
volatile struct davinci_mmc_regs *regs = host->reg_base;
uint mmcstatus, status_rdy, status_err;
uint i, cmddata, bytes_left = 0;
int fifo_words, fifo_bytes, err;
char *data_buf = NULL;
/* Clear status registers */
mmcstatus = get_val(&regs->mmcst0);
fifo_words = (host->version == MMC_CTLR_VERSION_2) ? 16 : 8;
fifo_bytes = fifo_words << 2;
/* Wait for any previous busy signal to be cleared */
dmmc_busy_wait(regs);
cmddata = cmd->cmdidx;
cmddata |= MMCCMD_PPLEN;
/* Send init clock for CMD0 */
if (cmd->cmdidx == MMC_CMD_GO_IDLE_STATE)
cmddata |= MMCCMD_INITCK;
switch (cmd->resp_type) {
case MMC_RSP_R1b:
cmddata |= MMCCMD_BSYEXP;
/* Fall-through */
case MMC_RSP_R1: /* R1, R1b, R5, R6, R7 */
cmddata |= MMCCMD_RSPFMT_R1567;
break;
case MMC_RSP_R2:
cmddata |= MMCCMD_RSPFMT_R2;
break;
case MMC_RSP_R3: /* R3, R4 */
cmddata |= MMCCMD_RSPFMT_R3;
break;
}
set_val(&regs->mmcim, 0);
if (data) {
/* clear previous data transfer if any and set new one */
bytes_left = (data->blocksize * data->blocks);
/* Reset FIFO - Always use 32 byte fifo threshold */
set_val(&regs->mmcfifoctl,
(MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));
if (host->version == MMC_CTLR_VERSION_2)
cmddata |= MMCCMD_DMATRIG;
cmddata |= MMCCMD_WDATX;
if (data->flags == MMC_DATA_READ) {
set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
} else if (data->flags == MMC_DATA_WRITE) {
set_val(&regs->mmcfifoctl,
(MMCFIFOCTL_FIFOLEV |
MMCFIFOCTL_FIFODIR));
cmddata |= MMCCMD_DTRW;
}
set_val(&regs->mmctod, 0xFFFF);
set_val(&regs->mmcnblk, (data->blocks & MMCNBLK_NBLK_MASK));
set_val(&regs->mmcblen, (data->blocksize & MMCBLEN_BLEN_MASK));
if (data->flags == MMC_DATA_WRITE) {
uint val;
data_buf = (char *)data->src;
/* For write, fill FIFO with data before issue of CMD */
for (i = 0; (i < fifo_words) && bytes_left; i++) {
memcpy((char *)&val, data_buf, 4);
set_val(&regs->mmcdxr, val);
data_buf += 4;
bytes_left -= 4;
}
}
} else {
set_val(&regs->mmcblen, 0);
set_val(&regs->mmcnblk, 0);
}
set_val(&regs->mmctor, 0x1FFF);
/* Send the command */
set_val(&regs->mmcarghl, cmd->cmdarg);
set_val(&regs->mmccmd, cmddata);
status_rdy = MMCST0_RSPDNE;
status_err = (MMCST0_TOUTRS | MMCST0_TOUTRD |
MMCST0_CRCWR | MMCST0_CRCRD);
if (cmd->resp_type & MMC_RSP_CRC)
status_err |= MMCST0_CRCRS;
mmcstatus = get_val(&regs->mmcst0);
err = dmmc_check_status(regs, &mmcstatus, status_rdy, status_err);
if (err)
return err;
/* For R1b wait for busy done */
if (cmd->resp_type == MMC_RSP_R1b)
dmmc_busy_wait(regs);
/* Collect response from controller for specific commands */
if (mmcstatus & MMCST0_RSPDNE) {
/* Copy the response to the response buffer */
if (cmd->resp_type & MMC_RSP_136) {
cmd->response[0] = get_val(&regs->mmcrsp67);
cmd->response[1] = get_val(&regs->mmcrsp45);
cmd->response[2] = get_val(&regs->mmcrsp23);
cmd->response[3] = get_val(&regs->mmcrsp01);
} else if (cmd->resp_type & MMC_RSP_PRESENT) {
cmd->response[0] = get_val(&regs->mmcrsp67);
}
}
if (data == NULL)
return 0;
if (data->flags == MMC_DATA_READ) {
/* check for DATDNE along with DRRDY as the controller might
* set the DATDNE without DRRDY for smaller transfers with
* less than FIFO threshold bytes
*/
status_rdy = MMCST0_DRRDY | MMCST0_DATDNE;
status_err = MMCST0_TOUTRD | MMCST0_CRCRD;
data_buf = data->dest;
} else {
status_rdy = MMCST0_DXRDY | MMCST0_DATDNE;
status_err = MMCST0_CRCWR;
}
/* Wait until all of the blocks are transferred */
while (bytes_left) {
err = dmmc_check_status(regs, &mmcstatus, status_rdy,
status_err);
if (err)
return err;
if (data->flags == MMC_DATA_READ) {
/*
* MMC controller sets the Data receive ready bit
* (DRRDY) in MMCST0 even before the entire FIFO is
* full. This results in erratic behavior if we start
* reading the FIFO soon after DRRDY. Wait for the
* FIFO full bit in MMCST1 for proper FIFO clearing.
*/
if (bytes_left > fifo_bytes)
dmmc_wait_fifo_status(regs, 0x4a);
else if (bytes_left == fifo_bytes) {
dmmc_wait_fifo_status(regs, 0x40);
if (cmd->cmdidx == MMC_CMD_SEND_EXT_CSD)
udelay(600);
}
for (i = 0; bytes_left && (i < fifo_words); i++) {
cmddata = get_val(&regs->mmcdrr);
memcpy(data_buf, (char *)&cmddata, 4);
data_buf += 4;
bytes_left -= 4;
}
} else {
/*
* MMC controller sets the Data transmit ready bit
* (DXRDY) in MMCST0 even before the entire FIFO is
* empty. This results in erratic behavior if we start
* writing the FIFO soon after DXRDY. Wait for the
* FIFO empty bit in MMCST1 for proper FIFO clearing.
*/
dmmc_wait_fifo_status(regs, MMCST1_FIFOEMP);
for (i = 0; bytes_left && (i < fifo_words); i++) {
memcpy((char *)&cmddata, data_buf, 4);
set_val(&regs->mmcdxr, cmddata);
data_buf += 4;
bytes_left -= 4;
}
dmmc_busy_wait(regs);
}
}
err = dmmc_check_status(regs, &mmcstatus, MMCST0_DATDNE, status_err);
if (err)
return err;
return 0;
}
/* Initialize Davinci MMC controller */
static int dmmc_init(struct mmc *mmc)
{
struct davinci_mmc *host = mmc->priv;
struct davinci_mmc_regs *regs = host->reg_base;
/* Clear status registers explicitly - soft reset doesn't clear it
* If Uboot is invoked from UBL with SDMMC Support, the status
* registers can have uncleared bits
*/
get_val(&regs->mmcst0);
get_val(&regs->mmcst1);
/* Hold software reset */
set_bit(&regs->mmcctl, MMCCTL_DATRST);
set_bit(&regs->mmcctl, MMCCTL_CMDRST);
udelay(10);
set_val(&regs->mmcclk, 0x0);
set_val(&regs->mmctor, 0x1FFF);
set_val(&regs->mmctod, 0xFFFF);
/* Clear software reset */
clear_bit(&regs->mmcctl, MMCCTL_DATRST);
clear_bit(&regs->mmcctl, MMCCTL_CMDRST);
udelay(10);
/* Reset FIFO - Always use the maximum fifo threshold */
set_val(&regs->mmcfifoctl, (MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));
set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
return 0;
}
/* Set buswidth or clock as indicated by the MMC framework */
static int dmmc_set_ios(struct mmc *mmc)
{
struct davinci_mmc *host = mmc->priv;
struct davinci_mmc_regs *regs = host->reg_base;
/* Set the bus width */
if (mmc->bus_width == 4)
set_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
else
clear_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
/* Set clock speed */
if (mmc->clock)
dmmc_set_clock(mmc, mmc->clock);
return 0;
}
static const struct mmc_ops dmmc_ops = {
.send_cmd = dmmc_send_cmd,
.set_ios = dmmc_set_ios,
.init = dmmc_init,
};
/* Called from board_mmc_init during startup. Can be called multiple times
* depending on the number of slots available on board and controller
*/
int davinci_mmc_init(bd_t *bis, struct davinci_mmc *host)
{
host->cfg.name = "davinci";
host->cfg.ops = &dmmc_ops;
host->cfg.f_min = 200000;
host->cfg.f_max = 25000000;
host->cfg.voltages = host->voltages;
host->cfg.host_caps = host->host_caps;
host->cfg.b_max = DAVINCI_MAX_BLOCKS;
mmc_create(&host->cfg, host);
return 0;
}