diff options
Diffstat (limited to 'drivers/mmc/core/core.c')
| -rw-r--r-- | drivers/mmc/core/core.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 1dbc1857621..5005a632316 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -942,6 +942,38 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr) return ocr; } +int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage) +{ + struct mmc_command cmd = {0}; + int err = 0; + + BUG_ON(!host); + + /* + * Send CMD11 only if the request is to switch the card to + * 1.8V signalling. + */ + if (signal_voltage == MMC_SIGNAL_VOLTAGE_180) { + cmd.opcode = SD_SWITCH_VOLTAGE; + cmd.arg = 0; + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + + err = mmc_wait_for_cmd(host, &cmd, 0); + if (err) + return err; + + if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR)) + return -EIO; + } + + host->ios.signal_voltage = signal_voltage; + + if (host->ops->start_signal_voltage_switch) + err = host->ops->start_signal_voltage_switch(host, &host->ios); + + return err; +} + /* * Select timing parameters for host. */ |