+++ /dev/null
-From e53f712d8eac71f54399b61038ccf87d2cee99d7 Mon Sep 17 00:00:00 2001
-From: Bernhard Frauendienst <kernel@nospam.obeliks.de>
-Date: Sat, 25 Aug 2018 12:35:22 +0200
-Subject: [PATCH 497/497] mtd: mtdconcat: add dt driver for concat devices
-
-Some mtd drivers like physmap variants have support for concatenating
-multiple mtd devices, but there is no generic way to define such a
-concat device from within the device tree.
-
-This is useful for some SoC boards that use multiple flash chips as
-memory banks of a single mtd device, with partitions spanning chip
-borders.
-
-This commit adds a driver for creating virtual mtd-concat devices. They
-must have a compatible = "mtd-concat" line, and define a list of devices
-to concat in the 'devices' property, for example:
-
-flash {
- compatible = "mtd-concat";
-
- devices = <&flash0 &flash1>;
-
- partitions {
- ...
- };
-};
-
-The driver is added to the very end of the mtd Makefile to increase the
-likelyhood of all child devices already being loaded at the time of
-probing, preventing unnecessary deferred probes.
-
-Signed-off-by: Bernhard Frauendienst <kernel@nospam.obeliks.de>
----
- drivers/mtd/Kconfig | 2 +
- drivers/mtd/Makefile | 3 +
- drivers/mtd/composite/Kconfig | 12 +++
- drivers/mtd/composite/Makefile | 6 ++
- drivers/mtd/composite/virt_concat.c | 128 ++++++++++++++++++++++++++++
- 5 files changed, 151 insertions(+)
- create mode 100644 drivers/mtd/composite/Kconfig
- create mode 100644 drivers/mtd/composite/Makefile
- create mode 100644 drivers/mtd/composite/virt_concat.c
-
---- a/drivers/mtd/Kconfig
-+++ b/drivers/mtd/Kconfig
-@@ -374,4 +374,6 @@ source "drivers/mtd/spi-nor/Kconfig"
-
- source "drivers/mtd/ubi/Kconfig"
-
-+source "drivers/mtd/composite/Kconfig"
-+
- endif # MTD
---- a/drivers/mtd/Makefile
-+++ b/drivers/mtd/Makefile
-@@ -39,3 +39,6 @@ obj-y += chips/ lpddr/ maps/ devices/ n
-
- obj-$(CONFIG_MTD_SPI_NOR) += spi-nor/
- obj-$(CONFIG_MTD_UBI) += ubi/
-+
-+# Composite drivers must be loaded last
-+obj-y += composite/
---- /dev/null
-+++ b/drivers/mtd/composite/Kconfig
-@@ -0,0 +1,12 @@
-+menu "Composite MTD device drivers"
-+ depends on MTD!=n
-+
-+config MTD_VIRT_CONCAT
-+ tristate "Virtual concat MTD device"
-+ help
-+ This driver allows creation of a virtual MTD concat device, which
-+ concatenates multiple underlying MTD devices to a single device.
-+ This is required by some SoC boards where multiple memory banks are
-+ used as one device with partitions spanning across device boundaries.
-+
-+endmenu
---- /dev/null
-+++ b/drivers/mtd/composite/Makefile
-@@ -0,0 +1,6 @@
-+# SPDX-License-Identifier: GPL-2.0
-+#
-+# linux/drivers/mtd/composite/Makefile
-+#
-+
-+obj-$(CONFIG_MTD_VIRT_CONCAT) += virt_concat.o
---- /dev/null
-+++ b/drivers/mtd/composite/virt_concat.c
-@@ -0,0 +1,128 @@
-+// SPDX-License-Identifier: GPL-2.0+
-+/*
-+ * Virtual concat MTD device driver
-+ *
-+ * Copyright (C) 2018 Bernhard Frauendienst
-+ * Author: Bernhard Frauendienst, kernel@nospam.obeliks.de
-+ */
-+
-+#include <linux/module.h>
-+#include <linux/device.h>
-+#include <linux/mtd/concat.h>
-+#include <linux/mtd/mtd.h>
-+#include <linux/mtd/partitions.h>
-+#include <linux/of.h>
-+#include <linux/of_platform.h>
-+#include <linux/slab.h>
-+
-+/*
-+ * struct of_virt_concat - platform device driver data.
-+ * @cmtd the final mtd_concat device
-+ * @num_devices the number of devices in @devices
-+ * @devices points to an array of devices already loaded
-+ */
-+struct of_virt_concat {
-+ struct mtd_info *cmtd;
-+ int num_devices;
-+ struct mtd_info **devices;
-+};
-+
-+static int virt_concat_remove(struct platform_device *pdev)
-+{
-+ struct of_virt_concat *info;
-+ int i;
-+
-+ info = platform_get_drvdata(pdev);
-+ if (!info)
-+ return 0;
-+
-+ // unset data for when this is called after a probe error
-+ platform_set_drvdata(pdev, NULL);
-+
-+ if (info->cmtd) {
-+ mtd_device_unregister(info->cmtd);
-+ mtd_concat_destroy(info->cmtd);
-+ }
-+
-+ if (info->devices) {
-+ for (i = 0; i < info->num_devices; i++)
-+ put_mtd_device(info->devices[i]);
-+ }
-+
-+ return 0;
-+}
-+
-+static int virt_concat_probe(struct platform_device *pdev)
-+{
-+ struct device_node *node = pdev->dev.of_node;
-+ struct of_phandle_iterator it;
-+ struct of_virt_concat *info;
-+ struct mtd_info *mtd;
-+ int err = 0, count;
-+
-+ count = of_count_phandle_with_args(node, "devices", NULL);
-+ if (count <= 0)
-+ return -EINVAL;
-+
-+ info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
-+ if (!info)
-+ return -ENOMEM;
-+ info->devices = devm_kcalloc(&pdev->dev, count,
-+ sizeof(*(info->devices)), GFP_KERNEL);
-+ if (!info->devices) {
-+ err = -ENOMEM;
-+ goto err_remove;
-+ }
-+
-+ platform_set_drvdata(pdev, info);
-+
-+ of_for_each_phandle(&it, err, node, "devices", NULL, 0) {
-+ mtd = get_mtd_device_by_node(it.node);
-+ if (IS_ERR(mtd)) {
-+ of_node_put(it.node);
-+ err = -EPROBE_DEFER;
-+ goto err_remove;
-+ }
-+
-+ info->devices[info->num_devices++] = mtd;
-+ }
-+
-+ info->cmtd = mtd_concat_create(info->devices, info->num_devices,
-+ dev_name(&pdev->dev));
-+ if (!info->cmtd) {
-+ err = -ENXIO;
-+ goto err_remove;
-+ }
-+
-+ info->cmtd->dev.parent = &pdev->dev;
-+ mtd_set_of_node(info->cmtd, node);
-+ mtd_device_register(info->cmtd, NULL, 0);
-+
-+ return 0;
-+
-+err_remove:
-+ virt_concat_remove(pdev);
-+
-+ return err;
-+}
-+
-+static const struct of_device_id virt_concat_of_match[] = {
-+ { .compatible = "mtd-concat", },
-+ { /* sentinel */ }
-+};
-+MODULE_DEVICE_TABLE(of, virt_concat_of_match);
-+
-+static struct platform_driver virt_concat_driver = {
-+ .probe = virt_concat_probe,
-+ .remove = virt_concat_remove,
-+ .driver = {
-+ .name = "virt-mtdconcat",
-+ .of_match_table = virt_concat_of_match,
-+ },
-+};
-+
-+module_platform_driver(virt_concat_driver);
-+
-+MODULE_LICENSE("GPL v2");
-+MODULE_AUTHOR("Bernhard Frauendienst <kernel@nospam.obeliks.de>");
-+MODULE_DESCRIPTION("Virtual concat MTD device driver");
projects / openwrt / staging / chunkeey.git / blobdiff