[PATCH 5.4 46/67] mmc: core: add helpers mmc_regulator_enable/disable_vqmmc

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Heiner Kallweit <hkallweit1@gmail.com>

[ Upstream commit 8d91f3f8ae57e6292142ca89f322e90fa0d6ac02 ]

There's a number of drivers (e.g. dw_mmc, meson-gx, mmci, sunxi) using
the same mechanism and a private flag vqmmc_enabled to deal with
enabling/disabling the vqmmc regulator.

Move this to the core and create new helpers mmc_regulator_enable_vqmmc
and mmc_regulator_disable_vqmmc.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/71586432-360f-9b92-17f6-b05a8a971bc2@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Stable-dep-of: 477865af60b2 ("mmc: sdhci-sprd: Fix vqmmc not shutting down after the card was pulled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mmc/core/regulator.c | 41 ++++++++++++++++++++++++++++++++++++
 include/linux/mmc/host.h     |  3 +++
 2 files changed, 44 insertions(+)

diff --git a/drivers/mmc/core/regulator.c b/drivers/mmc/core/regulator.c
index b6febbcf8978d..327032cbbb1f8 100644
--- a/drivers/mmc/core/regulator.c
+++ b/drivers/mmc/core/regulator.c
@@ -258,3 +258,44 @@ int mmc_regulator_get_supply(struct mmc_host *mmc)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);
+
+/**
+ * mmc_regulator_enable_vqmmc - enable VQMMC regulator for a host
+ * @mmc: the host to regulate
+ *
+ * Returns 0 or errno. Enables the regulator for vqmmc.
+ * Keeps track of the enable status for ensuring that calls to
+ * regulator_enable/disable are balanced.
+ */
+int mmc_regulator_enable_vqmmc(struct mmc_host *mmc)
+{
+	int ret = 0;
+
+	if (!IS_ERR(mmc->supply.vqmmc) && !mmc->vqmmc_enabled) {
+		ret = regulator_enable(mmc->supply.vqmmc);
+		if (ret < 0)
+			dev_err(mmc_dev(mmc), "enabling vqmmc regulator failed\n");
+		else
+			mmc->vqmmc_enabled = true;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mmc_regulator_enable_vqmmc);
+
+/**
+ * mmc_regulator_disable_vqmmc - disable VQMMC regulator for a host
+ * @mmc: the host to regulate
+ *
+ * Returns 0 or errno. Disables the regulator for vqmmc.
+ * Keeps track of the enable status for ensuring that calls to
+ * regulator_enable/disable are balanced.
+ */
+void mmc_regulator_disable_vqmmc(struct mmc_host *mmc)
+{
+	if (!IS_ERR(mmc->supply.vqmmc) && mmc->vqmmc_enabled) {
+		regulator_disable(mmc->supply.vqmmc);
+		mmc->vqmmc_enabled = false;
+	}
+}
+EXPORT_SYMBOL_GPL(mmc_regulator_disable_vqmmc);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index a0e1cf1bef4e5..68880c2b4fe07 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -397,6 +397,7 @@ struct mmc_host {
 	unsigned int		use_blk_mq:1;	/* use blk-mq */
 	unsigned int		retune_crc_disable:1; /* don't trigger retune upon crc */
 	unsigned int		can_dma_map_merge:1; /* merging can be used */
+	unsigned int		vqmmc_enabled:1; /* vqmmc regulator is enabled */
 
 	int			rescan_disable;	/* disable card detection */
 	int			rescan_entered;	/* used with nonremovable devices */
@@ -534,6 +535,8 @@ static inline int mmc_regulator_set_vqmmc(struct mmc_host *mmc,
 #endif
 
 int mmc_regulator_get_supply(struct mmc_host *mmc);
+int mmc_regulator_enable_vqmmc(struct mmc_host *mmc);
+void mmc_regulator_disable_vqmmc(struct mmc_host *mmc);
 
 static inline int mmc_card_is_removable(struct mmc_host *host)
 {
-- 
2.42.0