eeprom: at25: Convert to use fwnode_device_is_compatible()

Replace open coded fwnode_device_is_compatible() in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230119175742.77723-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Rework buggy read splitting

The recent change to split reads into chunks has several problems:
1. If an SPI controller has no transfer size limit, max_chunk is
SIZE_MAX, and num_msgs becomes zero, causing no data to be read
into the buffer, and exposing the original contents of the buffer
to userspace,
2. If the requested read size is not a multiple of the maximum
transfer size, the last transfer reads too much data, overflowing
the buffer,
3. The loop logic differs from the write case.

Fix the above by:
1. Keeping track of the number of bytes that are still to be
transferred, instead of precalculating the number of messages and
keeping track of the number of bytes tranfered,
2. Calculating the transfer size of each individual message, taking
into account the number of bytes left,
3. Switching from a "while"-loop to a "do-while"-loop, and renaming
"msg_count" to "segment".

While at it, drop the superfluous cast from "unsigned int" to "unsigned
int", also from at25_ee_write(), where it was probably copied from.

Fixes: 0a35780c755ccec0 ("eeprom: at25: Split reads into chunks and cap write size")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/7ae260778d2c08986348ea48ce02ef148100e088.1655817534.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Split reads into chunks and cap write size

Make use of spi_max_transfer_size to avoid requesting transfers that are
too large for some spi controllers.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220524215142.60047-1-eajames@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Use DMA safe buffers

Reading EEPROM fails with following warning:

[ 16.357496] ------------[ cut here ]------------
[ 16.357529] fsl_spi b01004c0.spi: rejecting DMA map of vmalloc memory
[ 16.357698] WARNING: CPU: 0 PID: 371 at include/linux/dma-mapping.h:326 fsl_spi_cpm_bufs+0x2a0/0x2d8
[ 16.357775] CPU: 0 PID: 371 Comm: od Not tainted 5.16.11-s3k-dev-01743-g19beecbfe9d6-dirty #109
[ 16.357806] NIP: c03fbc9c LR: c03fbc9c CTR: 00000000
[ 16.357825] REGS: e68d9b20 TRAP: 0700 Not tainted (5.16.11-s3k-dev-01743-g19beecbfe9d6-dirty)
[ 16.357849] MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24002282 XER: 00000000
[ 16.357931]
[ 16.357931] GPR00: c03fbc9c e68d9be0 c26d06a0 00000039 00000001 c0d36364 c0e96428 00000027
[ 16.357931] GPR08: 00000001 00000000 00000023 3fffc000 24002282 100d3dd6 100a2ffc 00000000
[ 16.357931] GPR16: 100cd280 100b0000 00000000 aff54f7e 100d0000 100d0000 00000001 100cf328
[ 16.357931] GPR24: 100cf328 00000000 00000003 e68d9e30 c156b410 e67ab4c0 e68d9d38 c24ab278
[ 16.358253] NIP [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8
[ 16.358292] LR [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8
[ 16.358325] Call Trace:
[ 16.358336] [e68d9be0] [c03fbc9c] fsl_spi_cpm_bufs+0x2a0/0x2d8 (unreliable)
[ 16.358388] [e68d9c00] [c03fcb44] fsl_spi_bufs.isra.0+0x94/0x1a0
[ 16.358436] [e68d9c20] [c03fd970] fsl_spi_do_one_msg+0x254/0x3dc
[ 16.358483] [e68d9cb0] [c03f7e50] __spi_pump_messages+0x274/0x8a4
[ 16.358529] [e68d9ce0] [c03f9d30] __spi_sync+0x344/0x378
[ 16.358573] [e68d9d20] [c03fb52c] spi_sync+0x34/0x60
[ 16.358616] [e68d9d30] [c03b4dec] at25_ee_read+0x138/0x1a8
[ 16.358667] [e68d9e50] [c04a8fb8] bin_attr_nvmem_read+0x98/0x110
[ 16.358725] [e68d9e60] [c0204b14] kernfs_fop_read_iter+0xc0/0x1fc
[ 16.358774] [e68d9e80] [c0168660] vfs_read+0x284/0x410
[ 16.358821] [e68d9f00] [c016925c] ksys_read+0x6c/0x11c
[ 16.358863] [e68d9f30] [c00160e0] ret_from_syscall+0x0/0x28
...
[ 16.359608] ---[ end trace a4ce3e34afef0cb5 ]---
[ 16.359638] fsl_spi b01004c0.spi: unable to map tx dma

This is due to the AT25 driver using buffers on stack, which is not
possible with CONFIG_VMAP_STACK.

As mentionned in kernel Documentation (Documentation/spi/spi-summary.rst):

- Follow standard kernel rules, and provide DMA-safe buffers in
your messages. That way controller drivers using DMA aren't forced
to make extra copies unless the hardware requires it (e.g. working
around hardware errata that force the use of bounce buffering).

Modify the driver to use a buffer located in the at25 device structure
which is allocated via kmalloc during probe.

Protect writes in this new buffer with the driver's mutex.

Fixes: b587b13a4f67 ("[PATCH] SPI eeprom driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/230a9486fc68ea0182df46255e42a51099403642.1648032613.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Replace strncpy() with strscpy()

Use strscpy() instead of strncpy(), since its use has been deprecated[1].

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220118182047.3385295-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Restore missing allocation

The at25 driver regressed in v5.17-rc1 due to a broken conflict
resolution: the allocation of the object was accidentally removed. Restore
it.

This was found when building under CONFIG_FORTIFY_SOURCE=y and
-Warray-bounds, which complained about strncpy() being used against an
empty object:

In function 'strncpy',
inlined from 'at25_fw_to_chip.constprop' at drivers/misc/eeprom/at25.c:312:2:
./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
48 | #define __underlying_strncpy __builtin_strncpy
| ^
./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
59 | return __underlying_strncpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
inlined from 'at25_fram_to_chip' at drivers/misc/eeprom/at25.c:373:2,
inlined from 'at25_probe' at drivers/misc/eeprom/at25.c:453:10:
./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
48 | #define __underlying_strncpy __builtin_strncpy
| ^
./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
59 | return __underlying_strncpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~~

Link: https://lore.kernel.org/lkml/CAHp75VdqK7h63fz-cPaQ2MGaVdaR2f1Fb5kKCZidUG3RwLsAVA@mail.gmail.com/
Fixes: af40d16042d6 ("Merge v5.15-rc5 into char-misc-next")
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220118182003.3385019-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Align comment style

Make multi-line comment style aligned.
While at it, drop filename from the file.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Replace commas by spaces in the ID tables

For better readability replace commas by spaces in the ID tables.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Reorganize headers for better maintenance

Split headers to three groups and sort alphabetically in each of them.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-9-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Factor out at_fram_to_chip()

In the similar way as it's done for EEPROM, factor out
a new helper function for FRAM.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Switch to use BIT() instead of custom approaches

It's obvious that custom approach of getting power of 2 number with
int_pow() kinda interesting. Replace it and some others approaches
by using a simple BIT() operation.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Get rid of intermediate storage for AT25 chip data

There is no need to copy twice the same data. Drop needless local
variable.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Get platform data via dev_get_platdata()

Access to platform data via dev_get_platdata() getter to make code cleaner.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Check new property ("address-width") first

As it's done elsewhere in at25_fw_to_chip() check new property
("address-width") first.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Unshadow error codes in at25_fw_to_chip()

device_property_read_u32() may return different error codes.
Unshadow them in the at25_fw_to_chip() to give better error
report.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Use at25->chip instead of local chip everywhere in ->probe()

Currently some values are compared against the contents of the chip structure
and most are from its updated copy in at25->chip. Use the latter one everywhere
in ->probe().

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125213203.86693-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Check proper value of chip length in FRAM case

Obviously the byte_len value should be checked from the chip
and not from at25->chip.

Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125212729.86585-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Don't copy garbage to the at25->chip in FRAM case

Even if we know that we are going to fill everything later on
it's bad style and fragile to copy garbage from the stack to
the data structure that will be used in the driver.

Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125212729.86585-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Make driver OF independent again

The commit f60e7074902a ("misc: at25: Make use of device property API")
made a good job by enabling the driver for non-OF platforms, but the
recent commit 604288bc6196 ("nvmem: eeprom: at25: fix type compiler warnings")
brought that back.

Restore greatness of the driver once again.

Fixes: eab61fb1cc2e ("nvmem: eeprom: at25: fram discovery simplification")
Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211125212729.86585-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem: eeprom: at25: fix FRAM byte_len

Commit fd307a4ad332 ("nvmem: prepare basics for FRAM support") added
support for FRAM devices such as the Cypress FM25V. During testing, it
was found that the FRAM detects properly, however reads and writes fail.
Upon further investigation, two problem were found in at25_probe() routine.

1) In the case of an FRAM device without platform data, eg.
fram == true && spi->dev.platform_data == NULL
the stack local variable "struct spi_eeprom chip" is not initialized
fully, prior to being copied into at25->chip. The chip.flags field in
particular can cause problems.

2) The byte_len of FRAM is computed from its ID register, and is stored
into the stack local "struct spi_eeprom chip" structure. This happens
after the same structure has been copied into at25->chip. As a result,
at25->chip.byte_len does not contain the correct length of the device.
In turn this can cause checks at beginning of at25_ee_read() to fail
(or equally, it could allow reads beyond the end of the device length).

Fix both of these issues by eliminating the on-stack struct spi_eeprom.
Instead use the one inside at25_data structure, which starts of zeroed.

Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Link: https://lore.kernel.org/r/20211108181627.645638-1-ralph.siemsen@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Add SPI ID table

Currently autoloading for SPI devices does not use the DT ID table, it uses
SPI modalises. Supporting OF modalises is going to be difficult if not
impractical, an attempt was made but has been reverted, so ensure that
module autoloading works for this driver by adding an id_table listing the
SPI IDs for everything.

Fixes: 96c8395e2166 ("spi: Revert modalias changes")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210923172453.4921-1-broonie@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem: eeprom: at25: fram discovery simplification

Changed "is_fram" to bool and set it based on compatible string.

Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Link: https://lore.kernel.org/r/20210611152416.68386-1-jiri.prchal@aksignal.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem: eeprom: at25: fix type compiler warnings

Fixes:
drivers/misc/eeprom/at25.c:181:28: warning: field width should have type 'int', but argument has type 'unsigned long'
drivers/misc/eeprom/at25.c:386:13: warning: cast to smaller integer type 'int' from 'const void *'

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Link: https://lore.kernel.org/r/20210611142706.27336-1-jiri.prchal@aksignal.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem: prepare basics for FRAM support

Added enum and string for FRAM (ferroelectric RAM) to expose it as file
named "fram".
Added documentation of sysfs file.

Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Link: https://lore.kernel.org/r/20210611094601.95131-2-jiri.prchal@aksignal.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Add example part numbers

To save the interested reader some time, add examples of AT25 part
numbers that correspond to EEPROMs rather than flashes.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201107133337.1066271-1-j.neuschaefer@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: set type id as EEPROM

Set type as NVMEM_TYPE_EEPROM to expose this info via
sysfs:

$ cat /sys/bus/nvmem/devices/{DEVICE}/type
EEPROM

Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Link: https://lore.kernel.org/r/20200916170933.20302-3-vadym.kochan@plvision.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: set minimum read/write access stride to 1

SPI eeproms are addressed by byte.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200728092959.24600-1-ceggers@arri.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: allow page sizes greater than 16 bit

Storage technologies like FRAM have no "write pages", the whole chip can
be written within one SPI transfer. For these chips, the page size can
be set equal to the device size. Currently available devices are already
bigger than 64 kiB.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Link: https://lore.kernel.org/r/20200727111218.26926-1-ceggers@arri.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: remove unneeded 'at25_remove'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/misc/eeprom/at25.c: In function 'at25_remove':
drivers/misc/eeprom/at25.c:384:20: warning:
variable 'at25' set but not used [-Wunused-but-set-variable]

Since commit 96d08fb43e30 ("eeprom: at25: use devm_nvmem_register()"),
at25_remove is do nothing, so can be removed.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: use devm_nvmem_register()

Use the resource managed variant of nvmem_register().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: sizeof t should be sizeof(t)

Resolved checkpatch warning "sizeof t should be sizeof(t)"
issue found by checkpatch.

Signed-off-by: Devang Panchal <devang.panchal@softnautics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Add DT support for EEPROMs with odd address bits

Certain EEPROMS have a size that is larger than the number of address
bytes would allow, and store the MSB of the address in bit 3 of the
instruction byte.

This can be described in platform data using EE_INSTR_BIT3_IS_ADDR, or
in DT using the obsolete legacy "at25,addr-mode" property.
But currently there exists no non-deprecated way to describe this in DT.

Hence extend the existing "address-width" DT property to allow
specifying 9 address bits, and enable support for that in the driver.

This has been tested with a Microchip 25LC040A.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

at25: fix debug and error messaging

The patch does the following:
- fixes specifiers and removes explicit casting of the parameters
- joins literals to one line
- increases readability of the parameters

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Fix SPI device leak

The at25 driver is using spi_dev_get() apparently just to take a copy
of the SPI device used to instantiate it but never calls spi_dev_put()
to free it. Since the device is guaranteed to exist between probe() and
remove() there should be no need for the driver to take an extra
reference to it so fix the leak by just using a straight assignment.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: remove nvmem regmap dependency

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>

eeprom: at25: extend driver to plug into the NVMEM framework

Add a regmap for accessing the EEPROM, and then use that with the
NVMEM framework. Enable backwards compatibility in the NVMEM config,
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: at25: Remove in kernel API for accessing the EEPROM

The setup() callback is not used by any in kernel code. Remove it.
Any new code which requires access to the eeprom can use the NVMEM
API.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: eeprom: use kobj_to_dev()

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>

spi: Drop owner assignment from spi_drivers

An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

misc: at25: Make use of device property API

Make use of device property API in this driver so that both DT and ACPI
based systems can use this driver.

In addition we hard-code the name of the chip to be "at25" for the
reason that there is no common mechanism to fetch name of the firmware
node. The only existing user (arch/arm/boot/dts/phy3250.dts) uses the
same name so it should continue to work.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/misc: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc/at25, dt: support probing at25 SPI EEPROM from DT

The commit d6ae0d578d24303941c1424b049d2cae28277666 introduced devicetree
binding documentation for this driver, but the driver itself does not yet
support the documented compatible entry. Fix this by adding the documented
entry to the driver.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc: at25: convert to use devm_kzalloc

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>

misc: at25: use spi_get_drvdata() and spi_set_drvdata()

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: remove use of __devexit

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>

drivers/misc: remove use of __devexit_p

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>

misc/at25, dt: Improve at25 SPI eeprom device tree bindings.

Commit 002176db (misc: at25: Parse dt settings) added device tree
bindings the differ significantly in style from the I2C EEPROM
bindings and don't seem well vetted. Here I deprecate (but still
support) the "at25,*" properties, and add what I hope is a better
alternative. These new bindings also happen to be deployed in the
field and were previously submitted for consideration here:

https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-May/015556.html

The advantages of the new bindings are that they are similar to the
I2C EEPROMs and they don't conflate read-only and the address width
modes in a binary encoded blob.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: at25: Parse dt settings

This adds dt support to the at25 eeprom driver.

Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Tested-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Support M95040 SPI EEPROM

Updated the generic SPI EEPROM driver AT25 for support of an additional address
bit in the instruction byte. Certain EEPROMS have a size that is larger than the
number of address bytes would allow (e.g. like M95040 from ST that has 512 Byte
size but uses only one address byte (A0 to A7) for addressing.) For the extra
address bit (A8, A16 or A24) bit 3 of the instruction byte is used. This
instruction bit is normally defined as don't care for other AT25 like chips.

Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MISC: convert drivers/misc/* to use module_spi_driver()

This patch converts the drivers in drivers/misc/* to use the
module_spi_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Michael Hennerich <hennerich@blackfin.uclinux.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Daniel Mack <zonque@gmail.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

sysfs: add struct file* to bin_attr callbacks

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>

init dynamic bin_attribute structures

Commit 6992f5334995af474c2b58d010d08bc597f0f2fe ("sysfs: Use one lockdep
class per sysfs attribute.") introduced this requirement. First, at25
was fixed manually. Then, other occurences were found with coccinelle
and the following semantic patch. Results were reviewed and fixed up:

@ init @
identifier struct_name, bin;
@@

struct struct_name {
...
struct bin_attribute bin;
...
};

@ main extends init @
expression E;
statement S;
identifier name, err;
@@

(
struct struct_name *name;
|
- struct struct_name *name = NULL;
+ struct struct_name *name;
)
...
(
sysfs_bin_attr_init(&name->bin);
|
+ sysfs_bin_attr_init(&name->bin);
if (sysfs_create_bin_file(E, &name->bin))
S
|
+ sysfs_bin_attr_init(&name->bin);
err = sysfs_create_bin_file(E, &name->bin);
)

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

spi: prefix modalias with "spi:"

This makes it consistent with other buses (platform, i2c, vio, ...). I'm
not sure why we use the prefixes, but there must be a reason.

This was easy enough to do it, and I did it.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Acked-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

eeprom/at25: bugfix "not ready" timeout after write

Under certain circumstances msleep(1) within the loop, which waits for the
EEPROM to be finished, might take longer than the timeout. On the next
loop the status register might now return to be ready and therefore the
loop finishes. The following check now tests if a timeout occurred and if
so returns an error although the device reported it was ready.

This fix replaces testing the occurrence of the timeout by testing the
"not ready" bit in the status register.

Signed-off-by: Sebastian Heutling <heutling@who-ing.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

at25: make input buffers of at25_*write() const

| drivers/misc/eeprom/at25.c:358: 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>

memory_accessor: implement the new memory_accessor interfaces for SPI EEPROMs

- Define new setup() hook to export the accessor
- Implement accessor methods

Moves some error checking out of the sysfs interface code into the layer
below it, which is now shared by both sysfs and memory access code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
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>

spi: Move at25 (for SPI eeproms) to /drivers/misc/eeprom

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>