--- /dev/null
+From 1bd1b740f208d1cf4071932cc51860d37266c402 Mon Sep 17 00:00:00 2001
+From: Bernhard Frauendienst <kernel@nospam.obeliks.de>
+Date: Sat, 1 Sep 2018 00:30:11 +0200
+Subject: [PATCH 495/497] mtd: core: add get_mtd_device_by_node
+
+Add function to retrieve a mtd device by its OF node. Since drivers can
+assign arbitrary names to mtd devices in the absence of a label
+property, there is no other reliable way to retrieve a mtd device for a
+given OF node.
+
+Signed-off-by: Bernhard Frauendienst <kernel@nospam.obeliks.de>
+Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
+---
+ drivers/mtd/mtdcore.c | 38 ++++++++++++++++++++++++++++++++++++++
+ include/linux/mtd/mtd.h | 2 ++
+ 2 files changed, 40 insertions(+)
+
+diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
+index e7ea842ba3db..1134bb81d2e5 100644
+--- a/drivers/mtd/mtdcore.c
++++ b/drivers/mtd/mtdcore.c
+@@ -936,6 +936,44 @@ struct mtd_info *get_mtd_device_nm(const char *name)
+ }
+ EXPORT_SYMBOL_GPL(get_mtd_device_nm);
+
++/**
++ * get_mtd_device_by_node - obtain a validated handle for an MTD device
++ * by of_node
++ * @of_node: OF node of MTD device to open
++ *
++ * This function returns MTD device description structure in case of
++ * success and an error code in case of failure.
++ */
++struct mtd_info *get_mtd_device_by_node(const struct device_node *of_node)
++{
++ int err = -ENODEV;
++ struct mtd_info *mtd = NULL, *other;
++
++ mutex_lock(&mtd_table_mutex);
++
++ mtd_for_each_device(other) {
++ if (of_node == other->dev.of_node) {
++ mtd = other;
++ break;
++ }
++ }
++
++ if (!mtd)
++ goto out_unlock;
++
++ err = __get_mtd_device(mtd);
++ if (err)
++ goto out_unlock;
++
++ mutex_unlock(&mtd_table_mutex);
++ return mtd;
++
++out_unlock:
++ mutex_unlock(&mtd_table_mutex);
++ return ERR_PTR(err);
++}
++EXPORT_SYMBOL_GPL(get_mtd_device_by_node);
++
+ void put_mtd_device(struct mtd_info *mtd)
+ {
+ mutex_lock(&mtd_table_mutex);
+diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
+index 6cd0f6b7658b..cf7c8030cd8e 100644
+--- a/include/linux/mtd/mtd.h
++++ b/include/linux/mtd/mtd.h
+@@ -557,6 +557,8 @@ extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
+ extern int __get_mtd_device(struct mtd_info *mtd);
+ extern void __put_mtd_device(struct mtd_info *mtd);
+ extern struct mtd_info *get_mtd_device_nm(const char *name);
++extern struct mtd_info *get_mtd_device_by_node(
++ const struct device_node *of_node);
+ extern void put_mtd_device(struct mtd_info *mtd);
+
+
+--
+2.18.0
+
--- /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
+
+diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
+index 5a2d71729b9a..de18bc568e3e 100644
+--- a/drivers/mtd/Kconfig
++++ b/drivers/mtd/Kconfig
+@@ -342,4 +342,6 @@ source "drivers/mtd/spi-nor/Kconfig"
+
+ source "drivers/mtd/ubi/Kconfig"
+
++source "drivers/mtd/composite/Kconfig"
++
+ endif # MTD
+diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
+index d6f8f625e1ff..a6c5f134c35d 100644
+--- a/drivers/mtd/Makefile
++++ b/drivers/mtd/Makefile
+@@ -36,3 +36,6 @@ obj-y += chips/ lpddr/ maps/ devices/ nand/ onenand/ tests/
+
+ obj-$(CONFIG_MTD_SPI_NOR) += spi-nor/
+ obj-$(CONFIG_MTD_UBI) += ubi/
++
++# Composite drivers must be loaded last
++obj-y += composite/
+diff --git a/drivers/mtd/composite/Kconfig b/drivers/mtd/composite/Kconfig
+new file mode 100644
+index 000000000000..0490fc0284bb
+--- /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
+diff --git a/drivers/mtd/composite/Makefile b/drivers/mtd/composite/Makefile
+new file mode 100644
+index 000000000000..8421a0a30606
+--- /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
+diff --git a/drivers/mtd/composite/virt_concat.c b/drivers/mtd/composite/virt_concat.c
+new file mode 100644
+index 000000000000..bfd432188c35
+--- /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");
+--
+2.18.0
+
projects / openwrt / openwrt.git / commitdiff