Before the DTOR register is set to a fixed value and resulted in some cards not working. Setting the fixed value to a hihger value is not appropriate cause we could wait way to long for slow clock rates.
This patch moves the mci_set_data_timeout() from old atmel_mci driver to gen_atmel_mci driver and adopts to the parameters. In contrast to the origin this version of mci_set_data_timeout() relies on some fixed input values for timeout_ns and timeout_clks. Before these values where taken from the card's CSD.
Signed-off-by: Andreas Bießmann biessmann@corscience.de CC: Sven Schnelle svens@stackframe.org CC: Reinhard Meyer u-boot@emk-elektronik.de CC: Andy Fleming afleming@gmail.com --- RESENT TO LIST ...
This is an RFC. The most questionary thing is whether we use fixed values for timeout_ns/timeout_clks or take the values from CSD as before.
I wonder if we should add the taac and nsac values to the mmc struct or if we should handle the mmc->csd[] inside the driver if we requiore the card data as input for the timeout equtation.
Please read also http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/112056/focus=112057
total: 0 errors, 0 warnings, 74 lines checked
0001-gen_atmel_mci-add-mci_set_data_timeout.patch has no obvious style problems and is ready for submission.
drivers/mmc/gen_atmel_mci.c | 56 +++++++++++++++++++++++++++++++++++++++++- 1 files changed, 54 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/gen_atmel_mci.c b/drivers/mmc/gen_atmel_mci.c index f346b24..9f9ea38 100644 --- a/drivers/mmc/gen_atmel_mci.c +++ b/drivers/mmc/gen_atmel_mci.c @@ -62,6 +62,58 @@ static void dump_cmd(u32 cmdr, u32 arg, u32 status, const char* msg) cmdr, cmdr&0x3F, arg, status, msg); }
+static void mci_set_data_timeout(struct mmc *mmc) +{ + atmel_mci_t *mci = (atmel_mci_t *)mmc->priv; + + static const unsigned int dtomul_to_shift[] = { + 0, 4, 7, 8, 10, 12, 16, 20, + }; + + unsigned int timeout_ns, timeout_clks; + unsigned int dtocyc, dtomul; + unsigned int shift; + u32 dtor; + + /* we assume 1.5 ms data-read-access-time-1 (taac -> see CSD spec) + * and 0 clock data-read-access-time-2 (nsac -> see CSD spec) + */ + timeout_ns = 1500000; + timeout_clks = 0; + + printf("gen_atmel_mci: timeout_ns = %u\n", timeout_ns); + + timeout_clks += (((timeout_ns + 9) / 10) + * ((mmc->clock + 99999) / 100000) + 9999) / 10000; + if (!IS_SD(mmc)) + timeout_clks *= 10; + else + timeout_clks *= 100; + printf("gen_atmel_mci: timeout_clks = %u\n", timeout_clks); + + dtocyc = timeout_clks; + dtomul = 0; + shift = 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)); + writel(dtor, &mci->dtor); + + printf("mci: Using %u cycles data timeout (DTOR=0x%x)\n", + dtocyc << shift, dtor); +} + /* Setup for MCI Clock and Block Size */ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen) { @@ -81,6 +133,8 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen) printf("mci: setting clock %u Hz, block size %u\n", (bus_hz / (clkdiv+1)) / 2, blklen);
+ mci_set_data_timeout(mmc); + blklen &= 0xfffc; /* On some platforms RDPROOF and WRPROOF are ignored */ writel((MMCI_BF(CLKDIV, clkdiv) @@ -310,8 +364,6 @@ static int mci_init(struct mmc *mmc) writel(MMCI_BIT(MCIEN), &mci->cr); /* enable mci */ writel(MMCI_BF(SCDSEL, MCI_BUS), &mci->sdcr); /* select port */
- /* Initial Time-outs */ - writel(0x5f, &mci->dtor); /* Disable Interrupts */ writel(~0UL, &mci->idr);