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-rw-r--r--nixos/modules/kernel-patches/0056-mtd-mtdconcat-add-dt-driver-for-concat-devices.patch232
1 files changed, 232 insertions, 0 deletions
diff --git a/nixos/modules/kernel-patches/0056-mtd-mtdconcat-add-dt-driver-for-concat-devices.patch b/nixos/modules/kernel-patches/0056-mtd-mtdconcat-add-dt-driver-for-concat-devices.patch
new file mode 100644
index 0000000..92f5603
--- /dev/null
+++ b/nixos/modules/kernel-patches/0056-mtd-mtdconcat-add-dt-driver-for-concat-devices.patch
@@ -0,0 +1,232 @@
+From 0a58b4681f061bf6a49c7102b08359c3ea19d84f 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 56/96] 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 f9ed93c4cf0f..7e4a3fa1dfd0 100644
+--- a/drivers/mtd/Kconfig
++++ b/drivers/mtd/Kconfig
+@@ -241,4 +241,6 @@ source "drivers/mtd/ubi/Kconfig"
+
+ source "drivers/mtd/hyperbus/Kconfig"
+
++source "drivers/mtd/composite/Kconfig"
++
+ endif # MTD
+diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
+index b14b7fe0f597..fbea3736b488 100644
+--- a/drivers/mtd/Makefile
++++ b/drivers/mtd/Makefile
+@@ -33,3 +33,6 @@ obj-y += chips/ lpddr/ maps/ devices/ nand/ tests/
+ obj-$(CONFIG_MTD_SPI_NOR) += spi-nor/
+ obj-$(CONFIG_MTD_UBI) += ubi/
+ obj-$(CONFIG_MTD_HYPERBUS) += hyperbus/
++
++# Composite drivers must be loaded last
++obj-y += composite/
+diff --git a/drivers/mtd/composite/Kconfig b/drivers/mtd/composite/Kconfig
+new file mode 100644
+index 000000000000..0490fc0284bb
+--- /dev/null
++++ b/drivers/mtd/composite/Kconfig
+@@ -0,0 +1,12 @@
++menu "Composite MTD device drivers"
++ depends on MTD!=n
++
++config MTD_VIRT_CONCAT
++ tristate "Virtual concat MTD device"
++ help
++ This driver allows creation of a virtual MTD concat device, which
++ concatenates multiple underlying MTD devices to a single device.
++ This is required by some SoC boards where multiple memory banks are
++ used as one device with partitions spanning across device boundaries.
++
++endmenu
+diff --git a/drivers/mtd/composite/Makefile b/drivers/mtd/composite/Makefile
+new file mode 100644
+index 000000000000..8421a0a30606
+--- /dev/null
++++ b/drivers/mtd/composite/Makefile
+@@ -0,0 +1,6 @@
++# SPDX-License-Identifier: GPL-2.0
++#
++# linux/drivers/mtd/composite/Makefile
++#
++
++obj-$(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");
+--
+2.37.2
+