diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-xenon.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-xenon.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c index a0b5089b3274..ca34fa424634 100644 --- a/drivers/mmc/host/sdhci-xenon.c +++ b/drivers/mmc/host/sdhci-xenon.c @@ -170,7 +170,12 @@ static void xenon_reset_exit(struct sdhci_host *host, /* Disable tuning request and auto-retuning again */ xenon_retune_setup(host); - xenon_set_acg(host, true); + /* + * The ACG should be turned off at the early init time, in order + * to solve a possible issues with the 1.8V regulator stabilization. + * The feature is enabled in later stage. + */ + xenon_set_acg(host, false); xenon_set_sdclk_off_idle(host, sdhc_id, false); @@ -238,6 +243,16 @@ static void xenon_voltage_switch(struct sdhci_host *host) { /* Wait for 5ms after set 1.8V signal enable bit */ usleep_range(5000, 5500); + + /* + * For some reason the controller's Host Control2 register reports + * the bit representing 1.8V signaling as 0 when read after it was + * written as 1. Subsequent read reports 1. + * + * Since this may cause some issues, do an empty read of the Host + * Control2 register here to circumvent this. + */ + sdhci_readw(host, SDHCI_HOST_CONTROL2); } static const struct sdhci_ops sdhci_xenon_ops = { |