mmc: atmel-mci: add vmmc-supply support

Other MMC hosts handle a regulator named vmmc-supply that allows to power
the MMC card or SDIO device before communicating on the bus.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Chris Ball <chris@printf.net>

drivers/mmc/host/atmel-mci.c

@@ -1402,8 +1402,14 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		clk_unprepare(host->mck);
 
 	switch (ios->power_mode) {
+	case MMC_POWER_OFF:
+		if (!IS_ERR(mmc->supply.vmmc))
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+		break;
 	case MMC_POWER_UP:
 		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
+		if (!IS_ERR(mmc->supply.vmmc))
+			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
 		break;
 	default:
 		/*
@@ -2215,6 +2221,7 @@ static int __init atmci_init_slot(struct atmel_mci *host,
 	}
 
 	host->slot[id] = slot;
+	mmc_regulator_get_supply(mmc);
 	mmc_add_host(mmc);
 
 	if (gpio_is_valid(slot->detect_pin)) {