The at24 driver doesn't check if the chip is functional in its probe
function. This leads to instantiating devices that are not physically
present. For example the cape EEPROMs for BeagleBone Black are defined
in the device tree at four addresses on i2c2, but normally only one of
them is present.
If the userspace doesn't know the location in advance, it will need to
check if reading the nvmem attributes fails to determine which EEPROM
is actually there.
Try to read a single byte in probe() and bail-out with -ENODEV if the
read fails.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
loop_until_timeout() replaced a do {} while loop in the at24 driver
with a for loop which, under certain circumstances (such as heavy load
or low value of the write_timeout argument), can lead to the code in
the loop never being executed.
Make sure that at least one iteration of the code enclosed within
loop_until_timeout() is always executed.
Suggested-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add a new read function to the at24 driver allowing to retrieve the
factory-programmed mac address embedded in chips from the at24mac
family.
These chips can be instantiated similarily to the at24cs family,
except that there's no way of having access to both the serial number
and the mac address at the same time - the user must instantiate
either an at24cs or at24mac device as both special memory areas are
accessible on the same slave address.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The chips from the at24cs family have two memory areas - a regular
read-write block and a read-only area containing the serial number.
The latter is visible on a different slave address (the address of the
rw memory block + 0x08). In order to access both blocks the user needs
to instantiate a regular at24c device for the rw block address and a
corresponding at24cs device on the serial number block address.
Add a function that allows to access the serial number and assign it
to at24->read_func if the chip allows serial number read operations
and the driver was passed the relevant flag for this device.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Split at24_eeprom_write() into three smaller functions - one for the
i2c operations and two for the smbus extensions (separate routines for
block and byte transfers). Assign them in at24_probe() depending on
the bus capabilities.
Also: in order to avoid duplications move code adjusting the count
argument into a separate function and use it for i2c and smbus block
writes (no need for a roll-over for byte writes as we're always
writing one byte).
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Split at24_eeprom_read() into two smaller functions - one for the
i2c operations and one for the smbus extensions. Assign them in
at24_probe() depending on the bus capabilities.
Also: in order to avoid duplications move the comments related to
offset calculations above the at24_translate_offset() routine.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Before splitting the read/write routines into smaller, more
specialized functions, unduplicate some code in advance.
Use a 'for' loop instead of 'do while' when waiting for the previous
write to complete and hide it behind a macro.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The first step in simplifying the read and write functions is to call
them via function pointers stored in at24_data. When we eventually
split the routines into smaller ones (depending on whether they use
smbus or i2c operations) we'll simply assign them to said pointers
instead of checking the flags at runtime every time we read/write.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Align the arguments in broken lines with the arguments list's opening
brackets and make checkpatch.pl happy by converting 'unsigned' into
'unsigned int'.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In preparation for splitting at24_eeprom_write() & at24_eeprom_read()
into smaller, specialized routines move at24_read() below, so that it
won't be intertwined with the low-level EEPROM accessors.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
As part of the preparation for introducing support for more chips,
improve the readability of the device table by separating columns
with tabs.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Here's the big char and misc driver update for 4.7-rc1.
Lots of different tiny driver subsystems have updates here with new
drivers and functionality. Details in the shortlog.
All have been in linux-next with no reported issues for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc driver updates from Greg KH:
"Here's the big char and misc driver update for 4.7-rc1.
Lots of different tiny driver subsystems have updates here with new
drivers and functionality. Details in the shortlog.
All have been in linux-next with no reported issues for a while"
* tag 'char-misc-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (125 commits)
mcb: Delete num_cells variable which is not required
mcb: Fixed bar number assignment for the gdd
mcb: Replace ioremap and request_region with the devm version
mcb: Implement bus->dev.release callback
mcb: export bus information via sysfs
mcb: Correctly initialize the bus's device
mei: bus: call mei_cl_read_start under device lock
coresight: etb10: adjust read pointer only when needed
coresight: configuring ETF in FIFO mode when acting as link
coresight: tmc: implementing TMC-ETF AUX space API
coresight: moving struct cs_buffers to header file
coresight: tmc: keep track of memory width
coresight: tmc: make sysFS and Perf mode mutually exclusive
coresight: tmc: dump system memory content only when needed
coresight: tmc: adding mode of operation for link/sinks
coresight: tmc: getting rid of multiple read access
coresight: tmc: allocating memory when needed
coresight: tmc: making prepare/unprepare functions generic
coresight: tmc: splitting driver in ETB/ETF and ETR components
coresight: tmc: cleaning up header file
...
This patch moves to nvmem support in the driver to use callback instead
of regmap.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We cannot expect msleep(1) to actually sleep for a period shorter than
20 ms. Replace all calls to msleep() with usleep_range().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The second check for I2C_FUNC_I2C is reduntant, so remove it.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
[wsa: reworded commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Now that the AT24 uses the NVMEM framework, replace the
memory_accessor in the setup() callback with nvmem API calls.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a regmap for accessing the EEPROM, and then use that with the
NVMEM framework. Set the NVMEM config structure to enable backward, so
that the 'eeprom' file in sys is provided by the framework.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use kobj_to_dev() instead of open-coding it.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a 24c08 chip connected to i2c bus on Intel Galileo Gen2 board. Enable
it via ACPI ID INT3499.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For i2c busses that support only SMBUS extensions, the eeprom at24
driver reads data from the device using the SMBus block, word or byte
read protocols depending on availability.
Replace the block read emulation from the driver with the
i2c_smbus_read_i2c_block_data_or_emulated call from i2c core.
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The change removes redundant sysfs binary file boundary check, since
this task is already done on caller side in fs/sysfs/file.c
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I have a at24 EEPROM connected via i2c bus provided by ISCH i2c
bus driver. This bus driver does not support
I2C_FUNC_SMBUS_WRITE_I2C_BLOCK and so I was looking for a way
to be able to write the eeprom. This patch adds support for
I2C_SMBUS_BYTE_DATA writing via i2c_smbus_write_byte_data.
It is quite slow, but it works.
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
[wsa: s/use_smbuse_write/use_smbus_write/]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c changes from Wolfram Sang:
- new drivers for exynos5, bcm kona, and st micro
- bigger overhauls for drivers mxs and rcar
- typical driver bugfixes, cleanups, improvements
- got rid of the superfluous 'driver' member in i2c_client struct This
touches a few drivers in other subsystems. All acked.
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (38 commits)
i2c: bcm-kona: fix error return code in bcm_kona_i2c_probe()
i2c: i2c-eg20t: do not print error message in syslog if no ACK received
i2c: bcm-kona: Introduce Broadcom I2C Driver
i2c: cbus-gpio: Fix device tree binding
i2c: wmt: add missing clk_disable_unprepare() on error
i2c: designware: add new ACPI IDs
i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCH
i2c: exynos5: Remove incorrect clk_disable_unprepare
i2c: i2c-st: Add ST I2C controller
i2c: exynos5: add High Speed I2C controller driver
i2c: rcar: fixup rcar type naming
i2c: scmi: remove some bogus NULL checks
i2c: sh_mobile & rcar: Enable the driver on all ARM platforms
i2c: sh_mobile: Convert to clk_prepare/unprepare
i2c: mux: gpio: use reg value for i2c_add_mux_adapter
i2c: mux: gpio: use gpio_set_value_cansleep()
i2c: Include linux/of.h header
i2c: mxs: Fix PIO mode on i.MX23
i2c: mxs: Rework the PIO mode operation
i2c: mxs: distinguish i.MX23 and i.MX28 based I2C controller
...
This change fixes a problem of infinite zero byte write() without
an error status, if there is an attempt to write a file bigger than
EEPROM size over sysfs interface.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch moves the at24.h header from include/linux/i2c to
include/linux/platform_data and updates existing support accordingly.
It also fixes the following checkpatch warning:
WARNING: please, no space before tabs
#436: FILE: include/linux/platform_data/at24.h:31:
+ * ^Iu8 *mac_addr = ethernet_pdata->mac_addr;$
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use devm_kzalloc to make cleanup paths simpler
Signed-off-by: Nikolay Balandin <nbalandin@dev.rtsoft.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Side-effects happen when passing 0 to either io_limit or page_size. Give
an error in case of this misconfiguration.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Information about the pagesize and read-only-status may also come from
the devicetree. Parse this data, too, and act accordingly. While we are
here, change the initialization printout a bit. write_max is useful to
know to detect performance bottlenecks, the rest is superfluous.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
I2C drivers can use the clientdata-pointer to point to private data. As I2C
devices are not really unregistered, but merely detached from their driver, it
used to be the drivers obligation to clear this pointer during remove() or a
failed probe(). As a couple of drivers forgot to do this, it was agreed that it
was cleaner if the i2c-core does this clearance when appropriate, as there is
no guarantee for the lifetime of the clientdata-pointer after remove() anyhow.
This feature was added to the core with commit
e4a7b9b04d to fix the faulty drivers.
As there is no need anymore to clear the clientdata-pointer, remove all current
occurrences in the drivers to simplify the code and prevent confusion.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c-nforce2: Remove redundant error messages on ACPI conflict
i2c: Use <linux/io.h> instead of <asm/io.h>
i2c-algo-pca: Fix coding style issues
i2c-dev: Fix all coding style issues
i2c-core: Fix some coding style issues
i2c-gpio: Move initialization code to subsys_initcall()
i2c-parport: Make template structure const
i2c-dev: Remove unnecessary casts
at24: Fall back to byte or word reads if needed
i2c-stub: Expose the default functionality flags
i2c/scx200_acb: Make PCI device ids constant
i2c-i801: Fix all checkpatch warnings
i2c-i801: All newer devices have all the optional features
i2c-i801: Let the user disable selected driver features
Increase the portability of the at24 driver by letting it read from
EEPROM chips connected to cheap SMBus controllers that support neither
raw I2C messages nor even I2C block reads. All SMBus controllers
should support either word reads or byte reads, so read support
becomes universal, much like with the legacy "eeprom" driver.
Obviously, this only works with EEPROM chips up to AT24C16, that use
8-bit offset addressing. 16-bit offset addressing is almost impossible
to support on SMBus controllers.
I did not add universal support for writes, as I had no immediate need
for this, but it could be added later if needed (with the same
performance issue as byte and word reads have, of course.)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Konstantin Lazarev <klazarev@sbcglobal.net>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 6992f53349 introduced this requirement.
Reported-by: Albrecht Dress <albrecht.dress@arcor.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Writes may take some time on EEPROMs, so for consecutive writes, we already
have a loop waiting for the EEPROM to become ready. Use such a loop for reads,
too, in case somebody wants to immediately read after a write. Detailed bug
report and test case can be found here:
http://article.gmane.org/gmane.linux.drivers.i2c/4660
Reported-by: Aleksandar Ivanov <ivanov.aleks@gmail.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: Aleksandar Ivanov <ivanov.aleks@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
In the case of at24, the platform code registers a 'setup' callback with
the at24_platform_data. When the at24 driver detects an EEPROM, it fills
out the read and write functions of the memory_accessor and calls the
setup callback passing the memory_accessor struct. The platform code can
then use the read/write functions in the memory_accessor struct for
reading and writing the EEPROM.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As drivers/i2c/chips is going to go away, move the driver to
drivers/misc/eeprom. Other eeprom drivers may be moved here later, too.
Update Kconfig text to specify this driver as I2C.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
