dm: blk: Add a block-device uclass

Add a uclass for block devices. These provide block-oriented data access,
supporting reading, writing and erasing of whole blocks.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

3 files changed, 188 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 990f768..f35c4d4 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -1,3 +1,14 @@
+config BLK
+	bool "Support block devices"
+	depends on DM
+	help
+	  Enable support for block devices, such as SCSI, MMC and USB
+	  flash sticks. These provide a block-level interface which permits
+	  reading, writing and (in some cases) erasing blocks. Block
+	  devices often have a partition table which allows the device to
+	  be partitioned into several areas, called 'partitions' in U-Boot.
+	  A filesystem can be placed in each partition.
+
 config DISK
 	bool "Support disk controllers with driver model"
 	depends on DM
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 5eb87e0..b5c7ae1 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -5,6 +5,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-$(CONFIG_BLK) += blk-uclass.o
+
 obj-$(CONFIG_DISK) += disk-uclass.o
 obj-$(CONFIG_SCSI_AHCI) += ahci.o
 obj-$(CONFIG_DWC_AHSATA) += dwc_ahsata.o
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
new file mode 100644
index 0000000..49df2a6
--- /dev/null
+++ b/drivers/block/blk-uclass.c
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <blk.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+
+int blk_first_device(int if_type, struct udevice **devp)
+{
+	struct blk_desc *desc;
+	int ret;
+
+	ret = uclass_first_device(UCLASS_BLK, devp);
+	if (ret)
+		return ret;
+	if (!*devp)
+		return -ENODEV;
+	do {
+		desc = dev_get_uclass_platdata(*devp);
+		if (desc->if_type == if_type)
+			return 0;
+		ret = uclass_next_device(devp);
+		if (ret)
+			return ret;
+	} while (*devp);
+
+	return -ENODEV;
+}
+
+int blk_next_device(struct udevice **devp)
+{
+	struct blk_desc *desc;
+	int ret, if_type;
+
+	desc = dev_get_uclass_platdata(*devp);
+	if_type = desc->if_type;
+	do {
+		ret = uclass_next_device(devp);
+		if (ret)
+			return ret;
+		if (!*devp)
+			return -ENODEV;
+		desc = dev_get_uclass_platdata(*devp);
+		if (desc->if_type == if_type)
+			return 0;
+	} while (1);
+}
+
+int blk_get_device(int if_type, int devnum, struct udevice **devp)
+{
+	struct uclass *uc;
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_get(UCLASS_BLK, &uc);
+	if (ret)
+		return ret;
+	uclass_foreach_dev(dev, uc) {
+		struct blk_desc *desc = dev_get_uclass_platdata(dev);
+
+		debug("%s: if_type=%d, devnum=%d: %s, %d, %d\n", __func__,
+		      if_type, devnum, dev->name, desc->if_type, desc->devnum);
+		if (desc->if_type == if_type && desc->devnum == devnum) {
+			*devp = dev;
+			return device_probe(dev);
+		}
+	}
+
+	return -ENODEV;
+}
+
+unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
+			lbaint_t blkcnt, void *buffer)
+{
+	struct udevice *dev = block_dev->bdev;
+	const struct blk_ops *ops = blk_get_ops(dev);
+
+	if (!ops->read)
+		return -ENOSYS;
+
+	return ops->read(dev, start, blkcnt, buffer);
+}
+
+unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
+			 lbaint_t blkcnt, const void *buffer)
+{
+	struct udevice *dev = block_dev->bdev;
+	const struct blk_ops *ops = blk_get_ops(dev);
+
+	if (!ops->write)
+		return -ENOSYS;
+
+	return ops->write(dev, start, blkcnt, buffer);
+}
+
+unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
+			 lbaint_t blkcnt)
+{
+	struct udevice *dev = block_dev->bdev;
+	const struct blk_ops *ops = blk_get_ops(dev);
+
+	if (!ops->erase)
+		return -ENOSYS;
+
+	return ops->erase(dev, start, blkcnt);
+}
+
+int blk_prepare_device(struct udevice *dev)
+{
+	struct blk_desc *desc = dev_get_uclass_platdata(dev);
+
+	part_init(desc);
+
+	return 0;
+}
+
+int blk_create_device(struct udevice *parent, const char *drv_name,
+		      const char *name, int if_type, int devnum, int blksz,
+		      lbaint_t size, struct udevice **devp)
+{
+	struct blk_desc *desc;
+	struct udevice *dev;
+	int ret;
+
+	ret = device_bind_driver(parent, drv_name, name, &dev);
+	if (ret)
+		return ret;
+	desc = dev_get_uclass_platdata(dev);
+	desc->if_type = if_type;
+	desc->blksz = blksz;
+	desc->lba = size / blksz;
+	desc->part_type = PART_TYPE_UNKNOWN;
+	desc->bdev = dev;
+	desc->devnum = devnum;
+	*devp = dev;
+
+	return 0;
+}
+
+int blk_unbind_all(int if_type)
+{
+	struct uclass *uc;
+	struct udevice *dev, *next;
+	int ret;
+
+	ret = uclass_get(UCLASS_BLK, &uc);
+	if (ret)
+		return ret;
+	uclass_foreach_dev_safe(dev, next, uc) {
+		struct blk_desc *desc = dev_get_uclass_platdata(dev);
+
+		if (desc->if_type == if_type) {
+			ret = device_remove(dev);
+			if (ret)
+				return ret;
+			ret = device_unbind(dev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+UCLASS_DRIVER(blk) = {
+	.id		= UCLASS_BLK,
+	.name		= "blk",
+	.per_device_platdata_auto_alloc_size = sizeof(struct blk_desc),
+};