mmc: pwrseq: add mmc-pwrseq file to provide a generic interface

Add mmc-pwrseq file to provide a generic interface.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index f8ea92172e44226dc902ebda009f4cd4557bdcb2..f8ca52efb6b7d405b18abb1577d166855179a628 100644 (file)
--- 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 1c849cbab2f10a1b8ad83f830fa35a7d071493ec..89d6af3db30b9a729bb55af8132f29fb11ef6fed 100644 (file)
--- 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 (file)
index 0000000..2539f61
--- /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@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 effccaaca086fb35bcd0e680c68112a345ba59d1..8600881705f44b0f4ff04ff060f1420cd1bf079d 100644 (file)
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -592,6 +592,9 @@ 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 {
@@ -808,6 +811,17 @@ 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);
 
 /**