dm: disk: add UCLASS_PARTITION

NOTE: probably we have to update config dependencies,
in particular, SPL/TPL_PRINTF?

With this new function, UCLASS_PARTITION devices will be created as
child nodes of UCLASS_BLK device.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

disk/Makefile

@@ -6,6 +6,9 @@
 #ccflags-y += -DET_DEBUG -DDEBUG
 
 obj-$(CONFIG_$(SPL_TPL_)PARTITIONS)  += part.o
+ifdef CONFIG_$(SPL_TPL_)BLK
+obj-$(CONFIG_$(SPL_TPL_)PARTITIONS)  += disk-uclass.o
+endif
 obj-$(CONFIG_$(SPL_TPL_)MAC_PARTITION)   += part_mac.o
 obj-$(CONFIG_$(SPL_TPL_)DOS_PARTITION)   += part_dos.o
 obj-$(CONFIG_$(SPL_TPL_)ISO_PARTITION)   += part_iso.o

disk/disk-uclass.c

@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Software partition device (UCLASS_PARTITION)
+ *
+ *  Copyright (c) 2021 Linaro Limited
+ *			Author: AKASHI Takahiro
+ */
+
+#define LOG_CATEGORY UCLASS_PARTITION
+
+#include <blk.h>
+#include <dm.h>
+#include <log.h>
+#include <part.h>
+#include <vsprintf.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+
+int part_create_block_devices(struct udevice *blk_dev)
+{
+	int part, count;
+	struct blk_desc *desc = dev_get_uclass_plat(blk_dev);
+	struct disk_partition info;
+	struct disk_part *part_data;
+	char devname[32];
+	struct udevice *dev;
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(PARTITIONS) ||
+	    !CONFIG_IS_ENABLED(HAVE_BLOCK_DEVICE))
+		return 0;
+
+	if (device_get_uclass_id(blk_dev) != UCLASS_BLK)
+		return 0;
+
+	/* Add devices for each partition */
+	for (count = 0, part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
+		if (part_get_info(desc, part, &info))
+			continue;
+		snprintf(devname, sizeof(devname), "%s:%d", blk_dev->name,
+			 part);
+
+		ret = device_bind_driver(blk_dev, "blk_partition",
+					 strdup(devname), &dev);
+		if (ret)
+			return ret;
+
+		part_data = dev_get_uclass_plat(dev);
+		part_data->partnum = part;
+		part_data->gpt_part_info = info;
+		count++;
+
+		ret = device_probe(dev);
+		if (ret) {
+			debug("Can't probe\n");
+			count--;
+			device_unbind(dev);
+
+			continue;
+		}
+	}
+	debug("%s: %d partitions found in %s\n", __func__, count,
+	      blk_dev->name);
+
+	return 0;
+}
+
+static ulong blk_part_read(struct udevice *dev, lbaint_t start,
+			   lbaint_t blkcnt, void *buffer)
+{
+	struct udevice *parent;
+	struct disk_part *part;
+	const struct blk_ops *ops;
+
+	parent = dev_get_parent(dev);
+	ops = blk_get_ops(parent);
+	if (!ops->read)
+		return -ENOSYS;
+
+	part = dev_get_uclass_plat(dev);
+	if (start >= part->gpt_part_info.size)
+		return 0;
+
+	if ((start + blkcnt) > part->gpt_part_info.size)
+		blkcnt = part->gpt_part_info.size - start;
+	start += part->gpt_part_info.start;
+
+	return ops->read(parent, start, blkcnt, buffer);
+}
+
+static ulong blk_part_write(struct udevice *dev, lbaint_t start,
+			    lbaint_t blkcnt, const void *buffer)
+{
+	struct udevice *parent;
+	struct disk_part *part;
+	const struct blk_ops *ops;
+
+	parent = dev_get_parent(dev);
+	ops = blk_get_ops(parent);
+	if (!ops->write)
+		return -ENOSYS;
+
+	part = dev_get_uclass_plat(dev);
+	if (start >= part->gpt_part_info.size)
+		return 0;
+
+	if ((start + blkcnt) > part->gpt_part_info.size)
+		blkcnt = part->gpt_part_info.size - start;
+	start += part->gpt_part_info.start;
+
+	return ops->write(parent, start, blkcnt, buffer);
+}
+
+static ulong blk_part_erase(struct udevice *dev, lbaint_t start,
+			    lbaint_t blkcnt)
+{
+	struct udevice *parent;
+	struct disk_part *part;
+	const struct blk_ops *ops;
+
+	parent = dev_get_parent(dev);
+	ops = blk_get_ops(parent);
+	if (!ops->erase)
+		return -ENOSYS;
+
+	part = dev_get_uclass_plat(dev);
+	if (start >= part->gpt_part_info.size)
+		return 0;
+
+	if ((start + blkcnt) > part->gpt_part_info.size)
+		blkcnt = part->gpt_part_info.size - start;
+	start += part->gpt_part_info.start;
+
+	return ops->erase(parent, start, blkcnt);
+}
+
+static const struct blk_ops blk_part_ops = {
+	.read	= blk_part_read,
+	.write	= blk_part_write,
+	.erase	= blk_part_erase,
+};
+
+U_BOOT_DRIVER(blk_partition) = {
+	.name		= "blk_partition",
+	.id		= UCLASS_PARTITION,
+	.ops		= &blk_part_ops,
+};
+
+UCLASS_DRIVER(partition) = {
+	.id		= UCLASS_PARTITION,
+	.per_device_plat_auto	= sizeof(struct disk_part),
+	.name		= "partition",
+};

include/dm/uclass-id.h

@@ -83,6 +83,7 @@ enum uclass_id {
 	UCLASS_P2SB,		/* (x86) Primary-to-Sideband Bus */
 	UCLASS_PANEL,		/* Display panel, such as an LCD */
 	UCLASS_PANEL_BACKLIGHT,	/* Backlight controller for panel */
+	UCLASS_PARTITION,	/* Logical disk partition device */
 	UCLASS_PCH,		/* x86 platform controller hub */
 	UCLASS_PCI,		/* PCI bus */
 	UCLASS_PCI_EP,		/* PCI endpoint device */

include/part.h

@@ -303,6 +303,16 @@ part_get_info_by_dev_and_name_or_num(const char *dev_iface,
 }
 #endif
 
+struct udevice;
+/**
+ * part_create_block_devices - Create block devices for disk partitions
+ *
+ * Create UCLASS_PARTITION udevices for each of disk partitions in @parent
+ *
+ * @blk_dev:	Whole disk device
+ */
+int part_create_block_devices(struct udevice *blk_dev);
+
 /*
  * We don't support printing partition information in SPL and only support
  * getting partition information in a few cases.