Add a quirk similar to eeprom_93xx46 to add an extra clock cycle before
reading data from the EEPROM.
The 93Cx6 family of EEPROMs output a "dummy 0 bit" between the writing
of the op-code/address from the host to the EEPROM and the reading of
the actual data from the EEPROM.
More info can be found on page 6 of the AT93C46 datasheet (linked below).
Similar notes are found in other 93xx6 datasheets.
In summary the read operation for a 93Cx6 EEPROM is:
Write to EEPROM: 110[A5-A0] (9 bits)
Read from EEPROM: 0[D15-D0] (17 bits)
Where:
110 is the start bit and READ OpCode
[A5-A0] is the address to read from
0 is a "dummy bit" preceding the actual data
[D15-D0] is the actual data.
Looking at the READ timing diagrams in the 93Cx6 datasheets the dummy
bit should be clocked out on the last address bit clock cycle meaning it
should be discarded naturally.
However, depending on the hardware configuration sometimes this dummy
bit is not discarded. This is the case with Exar PCI UARTs which require
an extra clock cycle between sending the address and reading the data.
Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-5193-SEEPROM-AT93C46D-Datasheet.pdf
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/0f23973efefccd2544705a0480b4ad4c2353e407.1727880931.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Copy-paste issue. Looks like the kerneldoc style descriptions for
these functions were taken from existing functions with slightly
different argument names.
Fixes the following W=1 warnings:
drivers/misc/eeprom/eeprom_93cx6.c:239: warning: Function parameter or member 'byte' not described in 'eeprom_93cx6_readb'
drivers/misc/eeprom/eeprom_93cx6.c:239: warning: Excess function parameter 'word' description in 'eeprom_93cx6_readb'
drivers/misc/eeprom/eeprom_93cx6.c:280: warning: Function parameter or member 'bytes' not described in 'eeprom_93cx6_multireadb'
drivers/misc/eeprom/eeprom_93cx6.c:280: warning: Excess function parameter 'words' description in 'eeprom_93cx6_multireadb'
Cc: Wolfram Sang <wsa@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200626130525.389469-7-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 3 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 this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
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 [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details
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 [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1105 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add read-only support for EEPROMs configured in 8-bit mode (ORG pin connected
to GND).
This will be used by wd719x driver.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add support for writing data to EEPROM.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some devices need to know if the data is to be output or read, so add a
data direction into the eeprom structure to tell the driver whether the
data line should be driven.
The user in this case is the Micrel KS8851 which has a direction
control for the EEPROM data line and thus needs to know whether
to drive it (writing) or to tristate it for receiving.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change eeprom_93cx6.c header file to format as in conventions
Signed-off-by: Abraham Arce <x0066660@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
