From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Sekhar Nori <nsekhar@ti.com>, Kevin Hilman <khilman@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Boris Brezillon <boris.brezillon@bootlin.com>,
Marek Vasut <marek.vasut@gmail.com>,
Richard Weinberger <richard@nod.at>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
"David S . Miller" <davem@davemloft.net>,
Grygorii Strashko <grygorii.strashko@ti.com>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
Andrew Lunn <andrew@lunn.ch>,
Florian Fainelli <f.fainelli@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Wolfram Sang <wsa@the-dreams.de>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
linux-mtd@lists.infradead.org, netdev@vger.kernel.org,
linux-omap@vger.kernel.org, devicetree@vger.kernel.org,
Alban Bedel <albeu@free.fr>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH v2 02/25] mtd: add support for reading MTD devices via the nvmem API
Date: Tue, 13 Nov 2018 15:01:10 +0100 [thread overview]
Message-ID: <20181113140133.17385-3-brgl@bgdev.pl> (raw)
In-Reply-To: <20181113140133.17385-1-brgl@bgdev.pl>
From: Alban Bedel <albeu@free.fr>
Allow drivers that use the nvmem API to read data stored on MTD devices.
For this the mtd devices are registered as read-only NVMEM providers.
We don't support device tree systems for now.
Signed-off-by: Alban Bedel <albeu@free.fr>
[Bartosz:
- include linux/nvmem-provider.h
- set the name of the nvmem provider
- set no_of_node to true in nvmem_config
- don't check the return value of nvmem_unregister() - it cannot fail
- tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/mtd/Kconfig | 1 +
drivers/mtd/mtdcore.c | 56 +++++++++++++++++++++++++++++++++++++++++
include/linux/mtd/mtd.h | 2 ++
3 files changed, 59 insertions(+)
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index c77f537323ec..efbe7a6f1d8f 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -1,5 +1,6 @@
menuconfig MTD
tristate "Memory Technology Device (MTD) support"
+ imply NVMEM
help
Memory Technology Devices are flash, RAM and similar chips, often
used for solid state file systems on embedded devices. This option
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 97ac219c082e..5f1053d995b0 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -41,6 +41,7 @@
#include <linux/reboot.h>
#include <linux/leds.h>
#include <linux/debugfs.h>
+#include <linux/nvmem-provider.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
@@ -488,6 +489,50 @@ int mtd_pairing_groups(struct mtd_info *mtd)
}
EXPORT_SYMBOL_GPL(mtd_pairing_groups);
+static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct mtd_info *mtd = priv;
+ size_t retlen;
+ int err;
+
+ err = mtd_read(mtd, offset, bytes, &retlen, val);
+ if (err && err != -EUCLEAN)
+ return err;
+
+ return retlen == bytes ? 0 : -EIO;
+}
+
+static int mtd_nvmem_add(struct mtd_info *mtd)
+{
+ struct nvmem_config config = {};
+
+ config.dev = &mtd->dev;
+ config.name = mtd->name;
+ config.owner = THIS_MODULE;
+ config.reg_read = mtd_nvmem_reg_read;
+ config.size = mtd->size;
+ config.word_size = 1;
+ config.stride = 1;
+ config.read_only = true;
+ config.root_only = true;
+ config.no_of_node = true;
+ config.priv = mtd;
+
+ mtd->nvmem = nvmem_register(&config);
+ if (IS_ERR(mtd->nvmem)) {
+ /* Just ignore if there is no NVMEM support in the kernel */
+ if (PTR_ERR(mtd->nvmem) == -ENOSYS) {
+ mtd->nvmem = NULL;
+ } else {
+ dev_err(&mtd->dev, "Failed to register NVMEM device\n");
+ return PTR_ERR(mtd->nvmem);
+ }
+ }
+
+ return 0;
+}
+
static struct dentry *dfs_dir_mtd;
/**
@@ -570,6 +615,11 @@ int add_mtd_device(struct mtd_info *mtd)
if (error)
goto fail_added;
+ /* Add the nvmem provider */
+ error = mtd_nvmem_add(mtd);
+ if (error)
+ goto fail_nvmem_add;
+
if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
@@ -595,6 +645,8 @@ int add_mtd_device(struct mtd_info *mtd)
__module_get(THIS_MODULE);
return 0;
+fail_nvmem_add:
+ device_unregister(&mtd->dev);
fail_added:
of_node_put(mtd_get_of_node(mtd));
idr_remove(&mtd_idr, i);
@@ -637,6 +689,10 @@ int del_mtd_device(struct mtd_info *mtd)
mtd->index, mtd->name, mtd->usecount);
ret = -EBUSY;
} else {
+ /* Try to remove the NVMEM provider */
+ if (mtd->nvmem)
+ nvmem_unregister(mtd->nvmem);
+
device_unregister(&mtd->dev);
idr_remove(&mtd_idr, mtd->index);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index cd0be91bdefa..545070c2ee64 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -25,6 +25,7 @@
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/of.h>
+#include <linux/nvmem-provider.h>
#include <mtd/mtd-abi.h>
@@ -341,6 +342,7 @@ struct mtd_info {
struct device dev;
int usecount;
struct mtd_debug_info dbg;
+ struct nvmem_device *nvmem;
};
int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
--
2.19.1
next prev parent reply other threads:[~2018-11-13 14:05 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 14:01 [PATCH v2 00/25] at24: remove Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 01/25] nvmem: add new config option Bartosz Golaszewski
2018-11-29 14:30 ` Bartosz Golaszewski
2018-11-29 14:32 ` Srinivas Kandagatla
2018-11-29 14:35 ` Bartosz Golaszewski
2018-11-29 14:43 ` Boris Brezillon
2018-11-13 14:01 ` Bartosz Golaszewski [this message]
2018-11-18 16:06 ` [PATCH v2 02/25] mtd: add support for reading MTD devices via the nvmem API Boris Brezillon
2018-11-13 14:01 ` [PATCH v2 03/25] ARM: davinci: dm365-evm: use cell nvmem lookup for mac address Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 04/25] ARM: davinci: dm644x-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 05/25] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 06/25] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 07/25] ARM: davinci: mityomapl138: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 08/25] ARM: davinci: dm850-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 09/25] ARM: davinci: da850-evm: remove unnecessary include Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 10/25] net: ethernet: provide nvmem_get_mac_address() Bartosz Golaszewski
2018-11-29 16:45 ` Bartosz Golaszewski
2018-11-29 19:16 ` David Miller
2018-11-13 14:01 ` [PATCH v2 11/25] net: cadence: switch to using nvmem_get_mac_address() Bartosz Golaszewski
2018-11-18 15:42 ` Nicolas.Ferre
2018-11-13 14:01 ` [PATCH v2 12/25] of: net: kill of_get_nvmem_mac_address() Bartosz Golaszewski
2018-11-17 15:45 ` Rob Herring
2018-11-13 14:01 ` [PATCH v2 13/25] net: davinci_emac: use nvmem_get_mac_address() Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 14/25] ARM: davinci: da850-evm: remove dead MTD code Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 15/25] ARM: davinci: mityomapl138: don't read the MAC address from machine code Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 16/25] ARM: davinci: dm365-evm: use device properties for at24 eeprom Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 17/25] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 18/25] ARM: davinci: dm644x-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 19/25] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 20/25] ARM: davinci: sffsdr: fix the at24 eeprom device name Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 21/25] ARM: davinci: sffsdr: use device properties for at24 eeprom Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 22/25] ARM: davinci: remove dead code related to MAC address reading Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 23/25] ARM: davinci: mityomapl138: use nvmem notifiers Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 24/25] ARM: davinci: mityomapl138: use device properties for at24 eeprom Bartosz Golaszewski
2018-11-13 14:01 ` [PATCH v2 25/25] eeprom: at24: remove at24_platform_data Bartosz Golaszewski
2018-11-13 14:04 ` [PATCH v2 00/25] at24: remove Bartosz Golaszewski
2018-11-13 14:07 ` Wolfram Sang
2018-11-18 16:03 ` Boris Brezillon
2018-11-19 8:58 ` Bartosz Golaszewski
2018-11-19 9:08 ` Boris Brezillon
2018-12-06 12:33 ` Sekhar Nori
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