diff options
Diffstat (limited to 'drivers/mmc/imxmmc.c')
| -rw-r--r-- | drivers/mmc/imxmmc.c | 84 |
1 files changed, 58 insertions, 26 deletions
diff --git a/drivers/mmc/imxmmc.c b/drivers/mmc/imxmmc.c index ffb7f55..a4eb1d0 100644 --- a/drivers/mmc/imxmmc.c +++ b/drivers/mmc/imxmmc.c @@ -102,6 +102,7 @@ struct imxmci_host { #define IMXMCI_PEND_CPU_DATA_b 5 #define IMXMCI_PEND_CARD_XCHG_b 6 #define IMXMCI_PEND_SET_INIT_b 7 +#define IMXMCI_PEND_STARTED_b 8 #define IMXMCI_PEND_IRQ_m (1 << IMXMCI_PEND_IRQ_b) #define IMXMCI_PEND_DMA_END_m (1 << IMXMCI_PEND_DMA_END_b) @@ -111,6 +112,7 @@ struct imxmci_host { #define IMXMCI_PEND_CPU_DATA_m (1 << IMXMCI_PEND_CPU_DATA_b) #define IMXMCI_PEND_CARD_XCHG_m (1 << IMXMCI_PEND_CARD_XCHG_b) #define IMXMCI_PEND_SET_INIT_m (1 << IMXMCI_PEND_SET_INIT_b) +#define IMXMCI_PEND_STARTED_m (1 << IMXMCI_PEND_STARTED_b) static void imxmci_stop_clock(struct imxmci_host *host) { @@ -131,23 +133,52 @@ static void imxmci_stop_clock(struct imxmci_host *host) dev_dbg(mmc_dev(host->mmc), "imxmci_stop_clock blocked, no luck\n"); } -static void imxmci_start_clock(struct imxmci_host *host) +static int imxmci_start_clock(struct imxmci_host *host) { - int i = 0; + unsigned int trials = 0; + unsigned int delay_limit = 128; + unsigned long flags; + MMC_STR_STP_CLK &= ~STR_STP_CLK_STOP_CLK; - while(i < 0x1000) { - if(!(i & 0x7f)) - MMC_STR_STP_CLK |= STR_STP_CLK_START_CLK; - if(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN) { - /* Check twice before cut */ + clear_bit(IMXMCI_PEND_STARTED_b, &host->pending_events); + + /* + * Command start of the clock, this usually succeeds in less + * then 6 delay loops, but during card detection (low clockrate) + * it takes up to 5000 delay loops and sometimes fails for the first time + */ + MMC_STR_STP_CLK |= STR_STP_CLK_START_CLK; + + do { + unsigned int delay = delay_limit; + + while(delay--){ if(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN) - return; + /* Check twice before cut */ + if(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN) + return 0; + + if(test_bit(IMXMCI_PEND_STARTED_b, &host->pending_events)) + return 0; } - i++; - } - dev_dbg(mmc_dev(host->mmc), "imxmci_start_clock blocked, no luck\n"); + local_irq_save(flags); + /* + * Ensure, that request is not doubled under all possible circumstances. + * It is possible, that cock running state is missed, because some other + * IRQ or schedule delays this function execution and the clocks has + * been already stopped by other means (response processing, SDHC HW) + */ + if(!test_bit(IMXMCI_PEND_STARTED_b, &host->pending_events)) + MMC_STR_STP_CLK |= STR_STP_CLK_START_CLK; + local_irq_restore(flags); + + } while(++trials<256); + + dev_err(mmc_dev(host->mmc), "imxmci_start_clock blocked, no luck\n"); + + return -1; } static void imxmci_softreset(void) @@ -187,8 +218,10 @@ static int imxmci_busy_wait_for_status(struct imxmci_host *host, if(!loops) return 0; - dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n", - loops, where, *pstat, stat_mask); + /* The busy-wait is expected there for clock <8MHz due to SDHC hardware flaws */ + if(!(stat_mask & STATUS_END_CMD_RESP) || (host->mmc->ios.clock>=8000000)) + dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n", + loops, where, *pstat, stat_mask); return loops; } @@ -302,6 +335,9 @@ static void imxmci_start_cmd(struct imxmci_host *host, struct mmc_command *cmd, WARN_ON(host->cmd != NULL); host->cmd = cmd; + /* Ensure, that clock are stopped else command programming and start fails */ + imxmci_stop_clock(host); + if (cmd->flags & MMC_RSP_BUSY) cmdat |= CMD_DAT_CONT_BUSY; @@ -498,7 +534,7 @@ static int imxmci_data_done(struct imxmci_host *host, unsigned int stat) data_error = imxmci_finish_data(host, stat); - if (host->req->stop && (data_error == MMC_ERR_NONE)) { + if (host->req->stop) { imxmci_stop_clock(host); imxmci_start_cmd(host, host->req->stop, 0); } else { @@ -522,7 +558,7 @@ static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat) int trans_done = 0; unsigned int stat = *pstat; - if(host->actual_bus_width == MMC_BUS_WIDTH_4) + if(host->actual_bus_width != MMC_BUS_WIDTH_4) burst_len = 16; else burst_len = 64; @@ -560,8 +596,7 @@ static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat) stat = MMC_STATUS; /* Flush extra bytes from FIFO */ - while(flush_len >= 2){ - flush_len -= 2; + while(flush_len && !(stat & STATUS_DATA_TRANS_DONE)){ i = MMC_BUFFER_ACCESS; stat = MMC_STATUS; stat &= ~STATUS_CRC_READ_ERR; /* Stupid but required there */ @@ -622,6 +657,7 @@ static irqreturn_t imxmci_irq(int irq, void *devid, struct pt_regs *regs) atomic_set(&host->stuck_timeout, 0); host->status_reg = stat; set_bit(IMXMCI_PEND_IRQ_b, &host->pending_events); + set_bit(IMXMCI_PEND_STARTED_b, &host->pending_events); tasklet_schedule(&host->tasklet); return IRQ_RETVAL(handled);; @@ -714,10 +750,6 @@ static void imxmci_tasklet_fnc(unsigned long data) data_dir_mask = STATUS_DATA_TRANS_DONE; } - imxmci_busy_wait_for_status(host, &stat, - data_dir_mask, - 50, "imxmci_tasklet_fnc data"); - if(stat & data_dir_mask) { clear_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events); imxmci_data_done(host, stat); @@ -775,10 +807,6 @@ static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) struct imxmci_host *host = mmc_priv(mmc); int prescaler; - dev_dbg(mmc_dev(host->mmc), "clock %u power %u vdd %u width %u\n", - ios->clock, ios->power_mode, ios->vdd, - (ios->bus_width==MMC_BUS_WIDTH_4)?4:1); - if( ios->bus_width==MMC_BUS_WIDTH_4 ) { host->actual_bus_width = MMC_BUS_WIDTH_4; imx_gpio_mode(PB11_PF_SD_DAT3); @@ -837,7 +865,11 @@ static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) imxmci_stop_clock(host); MMC_CLK_RATE = (prescaler<<3) | clk; - imxmci_start_clock(host); + /* + * Under my understanding, clock should not be started there, because it would + * initiate SDHC sequencer and send last or random command into card + */ + /*imxmci_start_clock(host);*/ dev_dbg(mmc_dev(host->mmc), "MMC_CLK_RATE: 0x%08x\n", MMC_CLK_RATE); } else { |