[PATCH V2 1/5] mmc: pwrseq: add mmc-pwrseq file to provide a generic interface

[Jaehoon Chung]

Add mmc-pwrseq file to provide a generic interface.

Signed-off-by: Jaehoon Chung <jh80.chung at samsung.com>
---
Changelog on V2:
- Remove "default y" in Kconfig
---
 drivers/mmc/Kconfig      |  7 ++++++
 drivers/mmc/Makefile     |  1 +
 drivers/mmc/mmc-pwrseq.c | 51 ++++++++++++++++++++++++++++++++++++++++
 include/mmc.h            | 14 +++++++++++
 4 files changed, 73 insertions(+)
 create mode 100644 drivers/mmc/mmc-pwrseq.c

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index f8ea92172e44..f8ca52efb6b7 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -18,6 +18,13 @@ config MMC_WRITE
 	help
 	  Enable write access to MMC and SD Cards
 
+config MMC_PWRSEQ
+	bool "HW reset support for eMMC"
+	depends on PWRSEQ
+	help
+	  Ths select Hardware reset support aka pwrseq-emmc for eMMC
+	  devices.
+
 config MMC_BROKEN_CD
 	bool "Poll for broken card detection case"
 	help
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 1c849cbab2f1..89d6af3db30b 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -6,6 +6,7 @@
 obj-y += mmc.o
 obj-$(CONFIG_$(SPL_)DM_MMC) += mmc-uclass.o
 obj-$(CONFIG_$(SPL_)MMC_WRITE) += mmc_write.o
+obj-$(CONFIG_MMC_PWRSEQ) += mmc-pwrseq.o
 obj-$(CONFIG_MMC_SDHCI_ADMA_HELPERS) += sdhci-adma.o
 
 ifndef CONFIG_$(SPL_)BLK
diff --git a/drivers/mmc/mmc-pwrseq.c b/drivers/mmc/mmc-pwrseq.c
new file mode 100644
index 000000000000..2539f61323d1
--- /dev/null
+++ b/drivers/mmc/mmc-pwrseq.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021 SAMSUNG Electronics
+ * Jaehoon Chung <jh80.chung at samsung.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <mmc.h>
+#include <pwrseq.h>
+#include <asm/gpio.h>
+#include <linux/delay.h>
+
+int mmc_pwrseq_get_power(struct udevice *dev, struct mmc_config *cfg)
+{
+	/* Enable power if needed */
+	return uclass_get_device_by_phandle(UCLASS_PWRSEQ, dev, "mmc-pwrseq",
+					   &cfg->pwr_dev);
+}
+
+static int mmc_pwrseq_set_power(struct udevice *dev, bool enable)
+{
+	struct gpio_desc reset;
+	int ret;
+
+	ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
+	if (ret)
+		return ret;
+	dm_gpio_set_value(&reset, 1);
+	udelay(1);
+	dm_gpio_set_value(&reset, 0);
+	udelay(200);
+
+	return 0;
+}
+
+static const struct pwrseq_ops mmc_pwrseq_ops = {
+	.set_power	= mmc_pwrseq_set_power,
+};
+
+static const struct udevice_id mmc_pwrseq_ids[] = {
+	{ .compatible = "mmc-pwrseq-emmc" },
+	{ }
+};
+
+U_BOOT_DRIVER(mmc_pwrseq_drv) = {
+	.name		= "mmc_pwrseq_emmc",
+	.id		= UCLASS_PWRSEQ,
+	.of_match	= mmc_pwrseq_ids,
+	.ops		= &mmc_pwrseq_ops,
+};
diff --git a/include/mmc.h b/include/mmc.h
index 1d377e0281f1..637081415430 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -591,6 +591,9 @@ struct mmc_config {
 	uint f_max;
 	uint b_max;
 	unsigned char part_type;
+#ifdef CONFIG_MMC_PWRSEQ
+	struct udevice *pwr_dev;
+#endif
 };
 
 struct sd_ssr {
@@ -801,6 +804,17 @@ int mmc_deinit(struct mmc *mmc);
  */
 int mmc_of_parse(struct udevice *dev, struct mmc_config *cfg);
 
+#ifdef CONFIG_MMC_PWRSEQ
+/**
+ * mmc_pwrseq_get_power() - get a power device from device tree
+ *
+ * @dev:	MMC device
+ * @cfg:	MMC configuration
+ * @return 0 if OK, -ve on error
+ */
+int mmc_pwrseq_get_power(struct udevice *dev, struct mmc_config *cfg);
+#endif
+
 int mmc_read(struct mmc *mmc, u64 src, uchar *dst, int size);
 
 /**
-- 
2.29.0