mmc: sdhci-iproc: Fix vmmc regulators on iProc

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

The Linux support for controlling card power via regulators appears to
be contentious. I would argue that the default behaviour is contrary to
the SDHCI spec - turning off the power writes a reserved value to the
SD Bus Voltage Select field of the Power Control Register, which
seems to kill the Arasan/iProc controller - but fortunately there is a
hook in sdhci_ops to override the behaviour. Borrow the implementation
from sdhci_arasan_set_power.
Signed-off-by: NPhil Elwell <phil@raspberrypi.org>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/mmc/host/sdhci-iproc.c

@@ -173,6 +173,17 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host)
 		return pltfm_host->clock;
 }
 
+static void sdhci_iproc_set_power(struct sdhci_host *host, unsigned char mode,
+				  unsigned short vdd)
+{
+	if (!IS_ERR(host->mmc->supply.vmmc)) {
+		struct mmc_host *mmc = host->mmc;
+
+		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
+	}
+	sdhci_set_power_noreg(host, mode, vdd);
+}
+
 static const struct sdhci_ops sdhci_iproc_ops = {
 	.set_clock = sdhci_set_clock,
 	.get_max_clock = sdhci_iproc_get_max_clock,
@@ -190,6 +201,7 @@ static const struct sdhci_ops sdhci_iproc_32only_ops = {
 	.write_b = sdhci_iproc_writeb,
 	.set_clock = sdhci_set_clock,
 	.get_max_clock = sdhci_iproc_get_max_clock,
+	.set_power = sdhci_iproc_set_power,
 	.set_bus_width = sdhci_set_bus_width,
 	.reset = sdhci_reset,
 	.set_uhs_signaling = sdhci_set_uhs_signaling,