diff options
Diffstat (limited to 'drivers/mmc/davinci_mmc.c')
| -rw-r--r-- | drivers/mmc/davinci_mmc.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/mmc/davinci_mmc.c b/drivers/mmc/davinci_mmc.c new file mode 100644 index 0000000..4e572dc --- /dev/null +++ b/drivers/mmc/davinci_mmc.c @@ -0,0 +1,404 @@ +/* + * Davinci MMC Controller Driver + * + * Copyright (C) 2010 Texas Instruments Incorporated + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <config.h> +#include <common.h> +#include <command.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->f_min) + clock = mmc->f_min; + if (clock > mmc->f_max) + clock = mmc->f_max; + + set_val(®s->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(®s->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 mmcstatus1, wdog = WATCHDOG_COUNT; + mmcstatus1 = get_val(®s->mmcst1); + while (--wdog && ((get_val(®s->mmcst1) & status) != status)) + udelay(10); + + if (!(get_val(®s->mmcctl) & MMCCTL_WIDTH_4_BIT)) + udelay(100); + + if (wdog == 0) + return COMM_ERR; + + return 0; +} + +/* Busy bit wait loop for MMCST1 */ +static int dmmc_busy_wait(volatile struct davinci_mmc_regs *regs) +{ + uint mmcstatus1, wdog = WATCHDOG_COUNT; + + mmcstatus1 = get_val(®s->mmcst1); + while (--wdog && (get_val(®s->mmcst1) & MMCST1_BUSY)) + udelay(10); + + if (wdog == 0) + return COMM_ERR; + + 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(®s->mmcst1); + return 0; + } else if (mmcstatus & st_error) { + if (mmcstatus & MMCST0_TOUTRS) + return TIMEOUT; + 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 COMM_ERR; + } + udelay(10); + + mmcstatus = get_val(®s->mmcst0); + } + + printf("Status %x Timeout ST0:%x ST1:%x\n", st_ready, mmcstatus, + get_val(®s->mmcst1)); + return COMM_ERR; +} + +/* + * 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(®s->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(®s->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(®s->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(®s->mmcfifoctl, MMCFIFOCTL_FIFOLEV); + } else if (data->flags == MMC_DATA_WRITE) { + set_val(®s->mmcfifoctl, + (MMCFIFOCTL_FIFOLEV | + MMCFIFOCTL_FIFODIR)); + cmddata |= MMCCMD_DTRW; + } + + set_val(®s->mmctod, 0xFFFF); + set_val(®s->mmcnblk, (data->blocks & MMCNBLK_NBLK_MASK)); + set_val(®s->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(®s->mmcdxr, val); + data_buf += 4; + bytes_left -= 4; + } + } + } else { + set_val(®s->mmcblen, 0); + set_val(®s->mmcnblk, 0); + } + + set_val(®s->mmctor, 0x1FFF); + + /* Send the command */ + set_val(®s->mmcarghl, cmd->cmdarg); + set_val(®s->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(®s->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(®s->mmcrsp67); + cmd->response[1] = get_val(®s->mmcrsp45); + cmd->response[2] = get_val(®s->mmcrsp23); + cmd->response[3] = get_val(®s->mmcrsp01); + } else if (cmd->resp_type & MMC_RSP_PRESENT) { + cmd->response[0] = get_val(®s->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); + + for (i = 0; bytes_left && (i < fifo_words); i++) { + cmddata = get_val(®s->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(®s->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(®s->mmcst0); + get_val(®s->mmcst1); + + /* Hold software reset */ + set_bit(®s->mmcctl, MMCCTL_DATRST); + set_bit(®s->mmcctl, MMCCTL_CMDRST); + udelay(10); + + set_val(®s->mmcclk, 0x0); + set_val(®s->mmctor, 0x1FFF); + set_val(®s->mmctod, 0xFFFF); + + /* Clear software reset */ + clear_bit(®s->mmcctl, MMCCTL_DATRST); + clear_bit(®s->mmcctl, MMCCTL_CMDRST); + + udelay(10); + + /* Reset FIFO - Always use the maximum fifo threshold */ + set_val(®s->mmcfifoctl, (MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST)); + set_val(®s->mmcfifoctl, MMCFIFOCTL_FIFOLEV); + + return 0; +} + +/* Set buswidth or clock as indicated by the GENERIC_MMC framework */ +static void 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(®s->mmcctl, MMCCTL_WIDTH_4_BIT); + else + clear_bit(®s->mmcctl, MMCCTL_WIDTH_4_BIT); + + /* Set clock speed */ + if (mmc->clock) + dmmc_set_clock(mmc, mmc->clock); +} + +/* 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) +{ + struct mmc *mmc; + + mmc = malloc(sizeof(struct mmc)); + memset(mmc, 0, sizeof(struct mmc)); + + sprintf(mmc->name, "davinci"); + mmc->priv = host; + mmc->send_cmd = dmmc_send_cmd; + mmc->set_ios = dmmc_set_ios; + mmc->init = dmmc_init; + + mmc->f_min = 200000; + mmc->f_max = 25000000; + mmc->voltages = host->voltages; + mmc->host_caps = host->host_caps; + +#ifdef CONFIG_MMC_MBLOCK + mmc->b_max = DAVINCI_MAX_BLOCKS; +#endif + mmc_register(mmc); + + return 0; +} + |