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| author | Gregory CLEMENT <gregory.clement@free-electrons.com> | 2015-11-05 20:58:30 +0100 |
|---|---|---|
| committer | Andreas Bießmann <andreas.devel@googlemail.com> | 2016-01-27 13:58:58 +0100 |
| commit | b4670a0c2bb9fd0a141436626d1853f995c8ed54 (patch) | |
| tree | d632a7bd72baa8675396eb989eaa63ea57f1f229 /drivers | |
| parent | 9e4de7fd4acc8f99b6d383c711d21c0159849629 (diff) | |
| download | blackbird-obmc-uboot-b4670a0c2bb9fd0a141436626d1853f995c8ed54.tar.gz blackbird-obmc-uboot-b4670a0c2bb9fd0a141436626d1853f995c8ed54.zip | |
mmc: atmel: Properly fix clock configuration
Timing issue occurs on eMMC not only when modifying the frequency but
also for all the switch command(CMD6). According to the MMC spec waiting
8 clocks after a switch command would be the thing to do.
This patch allows fixing CPU hang observed when trying to changing the
bus width on a eMMC on SAMA5D4.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Marek Vasut <marex@denx.de> # on DENX MA5D4EV
Acked-by: Marek Vasut <marex@denx.de>
Tested-by: Andreas Bießmann <andreas.devel@googlemail.com> # on atngw100
Acked-by: Andreas Bießmann <andreas.devel@googlemail.com>
[fixed minor checkpatch warning]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/gen_atmel_mci.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/mmc/gen_atmel_mci.c b/drivers/mmc/gen_atmel_mci.c index da870c646e..0474a15484 100644 --- a/drivers/mmc/gen_atmel_mci.c +++ b/drivers/mmc/gen_atmel_mci.c @@ -36,6 +36,7 @@ struct atmel_mci_priv { struct mmc_config cfg; struct atmel_mci *mci; unsigned int initialized:1; + unsigned int curr_clk; }; /* Read Atmel MCI IP version */ @@ -91,7 +92,10 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen) } } - + if (version >= 0x500) + priv->curr_clk = bus_hz / (clkdiv * 2 + clkodd + 2); + else + priv->curr_clk = (bus_hz / (clkdiv + 1)) / 2; blklen &= 0xfffc; mr = MMCI_BF(CLKDIV, clkdiv); @@ -118,8 +122,6 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen) if (mmc->card_caps & mmc->cfg->host_caps & MMC_MODE_HS) writel(MMCI_BIT(HSMODE), &mci->cfg); - udelay(50); - priv->initialized = 1; } @@ -323,6 +325,13 @@ mci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data) } } + /* + * After the switch command, wait for 8 clocks before the next + * command + */ + if (cmd->cmdidx == MMC_CMD_SWITCH) + udelay(8*1000000 / priv->curr_clk); /* 8 clk in us */ + return 0; } |
