diff options
| -rw-r--r-- | cpu/at32ap/atmel_mci.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/cpu/at32ap/atmel_mci.c b/cpu/at32ap/atmel_mci.c index bdca1c1..cf48be1 100644 --- a/cpu/at32ap/atmel_mci.c +++ b/cpu/at32ap/atmel_mci.c @@ -56,6 +56,7 @@ #define MMC_DEFAULT_RCA 1 static unsigned int mmc_rca; +static int mmc_card_is_sd; static block_dev_desc_t mmc_blkdev; block_dev_desc_t *mmc_get_dev(int dev) @@ -373,6 +374,7 @@ static int sd_init_card(struct mmc_cid *cid, int verbose) mmc_rca = resp[0] >> 16; if (verbose) printf("SD Card detected (RCA %u)\n", mmc_rca); + mmc_card_is_sd = 1; return 0; } @@ -407,6 +409,59 @@ static int mmc_init_card(struct mmc_cid *cid, int verbose) return ret; } +static void mci_set_data_timeout(struct mmc_csd *csd) +{ + static const unsigned int dtomul_to_shift[] = { + 0, 4, 7, 8, 10, 12, 16, 20, + }; + static const unsigned int taac_exp[] = { + 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, + }; + static const unsigned int taac_mant[] = { + 0, 10, 12, 13, 15, 60, 25, 30, + 35, 40, 45, 50, 55, 60, 70, 80, + }; + unsigned int timeout_ns, timeout_clks; + unsigned int e, m; + unsigned int dtocyc, dtomul; + unsigned int shift; + u32 dtor; + + e = csd->taac & 0x07; + m = (csd->taac >> 3) & 0x0f; + + timeout_ns = (taac_exp[e] * taac_mant[m] + 9) / 10; + timeout_clks = csd->nsac * 100; + + timeout_clks += (((timeout_ns + 9) / 10) + * ((CFG_MMC_CLK_PP + 99999) / 100000) + 9999) / 10000; + if (!mmc_card_is_sd) + timeout_clks *= 10; + else + timeout_clks *= 100; + + dtocyc = timeout_clks; + dtomul = 0; + while (dtocyc > 15 && dtomul < 8) { + dtomul++; + shift = dtomul_to_shift[dtomul]; + dtocyc = (timeout_clks + (1 << shift) - 1) >> shift; + } + + if (dtomul >= 8) { + dtomul = 7; + dtocyc = 15; + puts("Warning: Using maximum data timeout\n"); + } + + dtor = (MMCI_BF(DTOMUL, dtomul) + | MMCI_BF(DTOCYC, dtocyc)); + mmci_writel(DTOR, dtor); + + printf("mmc: Using %u cycles data timeout (DTOR=0x%x)\n", + dtocyc << shift, dtor); +} + int mmc_init(int verbose) { struct mmc_cid cid; @@ -421,6 +476,8 @@ int mmc_init(int verbose) mmci_writel(IDR, ~0UL); mci_set_mode(CFG_MMC_CLK_OD, MMC_DEFAULT_BLKLEN); + mmc_card_is_sd = 0; + ret = sd_init_card(&cid, verbose); if (ret) { mmc_rca = MMC_DEFAULT_RCA; @@ -436,6 +493,8 @@ int mmc_init(int verbose) if (verbose) mmc_dump_csd(&csd); + mci_set_data_timeout(&csd); + /* Initialize the blockdev structure */ mmc_blkdev.if_type = IF_TYPE_MMC; mmc_blkdev.part_type = PART_TYPE_DOS; |