From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Jonathan Corbet <corbet@lwn.net>, 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>,
Grygorii Strashko <grygorii.strashko@ti.com>,
"David S . Miller" <davem@davemloft.net>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
Naren <naren.kernel@gmail.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Lukas Wunner <lukas@wunner.de>,
Dan Carpenter <dan.carpenter@oracle.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>,
Sven Van Asbroeck <svendev@arcx.com>,
Paolo Abeni <pabeni@redhat.com>, Alban Bedel <albeu@free.fr>,
Rob Herring <robh@kernel.org>,
David Lechner <david@lechnology.com>,
Andrew Lunn <andrew@lunn.ch>
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org,
netdev@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH 06/28] mtd: Add support for reading MTD devices via the nvmem API
Date: Wed, 8 Aug 2018 17:31:28 +0200 [thread overview]
Message-ID: <20180808153150.23444-7-brgl@bgdev.pl> (raw)
In-Reply-To: <20180808153150.23444-1-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.
On OF systems only devices that have the 'nvmem-provider' property
are registered, on non-OF system all MTD devices are registered.
Signed-off-by: Alban Bedel <albeu@free.fr>
[Bartosz:
- use the managed variant of nvmem_register(),
- set the nvmem name]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/mtd/Kconfig | 1 +
drivers/mtd/mtdcore.c | 50 +++++++++++++++++++++++++++++++++++++++++
include/linux/mtd/mtd.h | 2 ++
3 files changed, 53 insertions(+)
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 46ab7feec6b6..f5549482d0df 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 42395df06be9..a57302eaceb5 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -488,6 +488,49 @@ 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.owner = THIS_MODULE;
+ config.name = mtd->name;
+ 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.priv = mtd;
+
+ mtd->nvmem = devm_nvmem_register(&mtd->dev, &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 +613,11 @@ 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 +643,8 @@ 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);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index a86c4fa93115..8121c6582285 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>
@@ -339,6 +340,7 @@ 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,
--
2.18.0
next prev parent reply other threads:[~2018-08-08 15:33 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-08 15:31 [PATCH 00/28] at24: remove at24_platform_data Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 01/28] nvmem: add support for cell lookups Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 02/28] Documentation: nvmem: document lookup entries Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 03/28] nvmem: add a notifier chain Bartosz Golaszewski
2018-08-08 16:13 ` Andrew Lunn
2018-08-08 16:30 ` Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 04/28] nvmem: provide nvmem_device_name() Bartosz Golaszewski
2018-08-08 17:42 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 05/28] nvmem: remove the name field from struct nvmem_device Bartosz Golaszewski
2018-08-08 15:31 ` Bartosz Golaszewski [this message]
2018-08-08 16:20 ` [PATCH 06/28] mtd: Add support for reading MTD devices via the nvmem API Andrew Lunn
2018-08-08 16:26 ` Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 07/28] ARM: davinci: dm365-evm: use nvmem lookup for mac address Bartosz Golaszewski
2018-08-08 17:43 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 08/28] ARM: davinci: dm644-evm: " Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 09/28] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 10/28] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 11/28] ARM: davinci: mityomapl138: add nvmem cells lookup entries Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 12/28] ARM: davinci: da850-evm: use nvmem lookup for mac address Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 13/28] ARM: davinci: da850-evm: remove unnecessary include Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 14/28] net: split eth_platform_get_mac_address() into subroutines Bartosz Golaszewski
2018-08-08 17:50 ` Andy Shevchenko
2018-08-09 11:12 ` Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 15/28] net: add support for nvmem to eth_platform_get_mac_address() Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 16/28] net: davinci_emac: use eth_platform_get_mac_address() Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 17/28] ARM: davinci: da850-evm: remove dead MTD code Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 18/28] ARM: davinci: mityomapl138: don't read the MAC address from machine code Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 19/28] ARM: davinci: dm365-evm: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-08 17:54 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 20/28] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-08-08 17:55 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 21/28] ARM: davinci: dm644x-evm: " Bartosz Golaszewski
2018-08-08 17:55 ` Andy Shevchenko
2018-08-08 17:59 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 22/28] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-08-08 17:56 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 23/28] ARM: davinci: sffsdr: fix the at24 eeprom device name Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 24/28] ARM: davinci: sffsdr: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-08 17:57 ` Andy Shevchenko
2018-08-08 18:00 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 25/28] ARM: davinci: remove dead code related to MAC address reading Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 26/28] ARM: davinci: mityomapl138: use nvmem notifiers Bartosz Golaszewski
2018-08-08 15:31 ` [PATCH 27/28] ARM: davinci: mityomapl138: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-08 17:58 ` Andy Shevchenko
2018-08-08 18:00 ` Andy Shevchenko
2018-08-08 15:31 ` [PATCH 28/28] eeprom: at24: kill at24_platform_data Bartosz Golaszewski
2018-08-08 18:03 ` Andy Shevchenko
2018-08-09 11:33 ` Bartosz Golaszewski
2018-08-09 11:35 ` Bartosz Golaszewski
2018-08-08 15:55 ` [PATCH 00/28] at24: remove at24_platform_data Wolfram Sang
2018-08-08 16:27 ` Bartosz Golaszewski
2018-08-08 16:44 ` Andrew Lunn
2018-08-08 16:52 ` Bartosz Golaszewski
2018-08-10 8:12 ` Sekhar Nori
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