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path: root/drivers/misc/eeprom/at24.c
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2016-08-22eeprom: at24: check if the chip is functional in probe()Bartosz Golaszewski1-2/+13
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>
2016-07-18eeprom: at24: tweak the loop_until_timeout() macroBartosz Golaszewski1-4/+4
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>
2016-07-17eeprom: at24: add support for at24mac seriesBartosz Golaszewski1-0/+42
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>
2016-07-17eeprom: at24: support reading the serial number for 24csxxBartosz Golaszewski1-2/+78
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>
2016-07-17eeprom: at24: split at24_eeprom_write() into specialized functionsBartosz Golaszewski1-43/+91
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>
2016-07-17eeprom: at24: split at24_eeprom_read() into specialized functionsBartosz Golaszewski1-54/+71
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>
2016-07-17eeprom: at24: hide the read/write loop behind a macroBartosz Golaszewski1-22/+20
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>
2016-07-17eeprom: at24: call read/write functions via function pointersBartosz Golaszewski1-2/+9
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>
2016-07-17eeprom: at24: coding style fixesBartosz Golaszewski1-5/+5
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>
2016-07-17eeprom: at24: move at24_read() below at24_eeprom_write()Bartosz Golaszewski1-32/+32
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>
2016-07-17eeprom: at24: improve the device_id table readabilityBartosz Golaszewski1-14/+14
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>
2016-05-20Merge tag 'char-misc-4.7-rc1' of ↵Linus Torvalds1-81/+22
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 ...
2016-05-01eeprom: at24: remove nvmem regmap dependencySrinivas Kandagatla1-81/+22
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>
2016-04-16eeprom: at24: replace msleep() with usleep_range()Bartosz Golaszewski1-4/+2
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>
2016-04-16eeprom: at24: remove a reduntant ifBartosz Golaszewski1-3/+0
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>
2016-03-01misc: at24: replace memory_accessor with nvmem_device_readAndrew Lunn1-30/+1
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>
2016-03-01eeprom: at24: extend driver to plug into the NVMEM frameworkAndrew Lunn1-41/+80
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>
2016-02-07misc: eeprom: use kobj_to_dev()Geliang Tang1-2/+2
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>
2015-10-26at24: enable ACPI device found on Galileo Gen2Andy Shevchenko1-3/+19
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>
2015-08-24eeprom: at24: use i2c_smbus_read_i2c_block_data_or_emulatedIrina Tirdea1-31/+6
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>
2015-08-10misc: Drop owner assignment from i2c_driverKrzysztof Kozlowski1-1/+0
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>
2015-07-31misc: eeprom: at24: clean up at24_bin_write()Vladimir Zapolskiy1-3/+0
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>
2014-11-17eeprom: at24: extend driver to allow writing via i2c_smbus_write_byte_dataChristian Gmeiner1-6/+29
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>
2013-11-18Merge branch 'i2c/for-next' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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 ...
2013-10-29misc/at24: avoid infinite loop on write()Vladimir Zapolskiy1-0/+3
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>
2013-09-30misc: (at24) move header to linux/platform_data/Vivien Didelot1-1/+1
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>
2013-05-30drivers/misc: at24: convert to use devm_kzallocNikolay Balandin1-29/+15
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>
2012-11-21misc: remove use of __devexitBill Pemberton1-1/+1
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>
2012-11-21drivers/misc: remove use of __devexit_pBill Pemberton1-1/+1
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>
2010-12-24misc/at24: add more sanity checks for parametersWolfram Sang1-0/+10
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>
2010-12-24misc/at24: parse device tree dataWolfram Sang1-6/+27
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>
2010-06-03i2c: Remove all i2c_set_clientdata(client, NULL) in driversWolfram Sang1-1/+0
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 e4a7b9b04de15f6b63da5ccdd373ffa3057a3681 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>
2010-05-21Merge branch 'i2c-for-linus' of ↵Linus Torvalds1-11/+48
git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging * '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
2010-05-21at24: Fall back to byte or word reads if neededJean Delvare1-11/+48
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>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright1-2/+4
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>
2010-03-13at24: Init dynamic bin_attribute structuresWolfram Sang1-0/+1
Commit 6992f5334995af474c2b58d010d08bc597f0f2fe 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>
2009-11-26at24: Use timeout also for readWolfram Sang1-31/+45
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>
2009-04-13at24: make input buffers of at24_*write() constGeert Uytterhoeven1-4/+4
| drivers/misc/eeprom/at24.c:508: warning: assignment from incompatible pointer type Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: 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>
2009-04-02memory_accessor: implement the new memory_accessor interface for I2C EEPROMKevin Hilman1-13/+54
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>
2009-01-26i2c: Move at24 to drivers/misc/eepromWolfram Sang1-0/+582
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>
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