On Thu, May 5, 2011 at 2:49 AM, Arindam Nath <arindam.nath@xxxxxxx> wrote:
> eMMC chips do not use CMD11 when changing voltage. Add extra
> argument to call to indicate if CMD11 needs to be sent.
mmc_set_signal_voltage or start_signal_voltage_switch may not support
emmc, not only cmd11, but also start_signal_voltage_switch is wrote
according to sd phys spec.
JESD84-A441 A8.1 describes how to support dual voltage of emmc,
however it only support to 1.8v.
Still not find emmc card which could support 1.2v.
>
> Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
> Reviewed-by: Arindam Nath <arindam.nath@xxxxxxx>
> ---
> drivers/mmc/core/core.c | 4 ++--
> drivers/mmc/core/core.h | 3 ++-
> drivers/mmc/core/sd.c | 4 ++--
> 3 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 78a9b51..74b4409 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -942,7 +942,7 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
> return ocr;
> }
>
> -int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
> +int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, int cmd11)
> {
> struct mmc_command cmd;
> int err = 0;
> @@ -953,7 +953,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
> * Send CMD11 only if the request is to switch the card to
> * 1.8V signalling.
> */
> - if (signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
> + if ((signal_voltage != MMC_SIGNAL_VOLTAGE_330) && cmd11) {
> memset(&cmd, 0, sizeof(struct mmc_command));
>
> cmd.opcode = SD_SWITCH_VOLTAGE;
> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> index 93f3397..3c11e17 100644
> --- a/drivers/mmc/core/core.h
> +++ b/drivers/mmc/core/core.h
> @@ -41,7 +41,8 @@ void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
> void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
> unsigned int ddr);
> u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
> -int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
> +int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
> + int cmd11);
> void mmc_set_timing(struct mmc_host *host, unsigned int timing);
> void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 851c8fc..d2a05ab 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -731,7 +731,7 @@ try_again:
> */
> if (!mmc_host_is_spi(host) && rocr &&
> ((*rocr & 0x41000000) == 0x41000000)) {
> - err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 1);
> if (err) {
> ocr &= ~SD_OCR_S18R;
> goto try_again;
> @@ -1104,7 +1104,7 @@ int mmc_attach_sd(struct mmc_host *host)
> WARN_ON(!host->claimed);
>
> /* Make sure we are at 3.3V signalling voltage */
> - err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330);
> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);
> if (err)
> return err;
>
> --
> 1.7.1
>
>
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