kernel/linux.git/include/linux/eeprom_93cx6.h, branch v6.6.131

misc: eeprom: eeprom_93cx6: Add quirk for extra read clock cycle

2024-12-14T19:00:16+00:00

[ Upstream commit 7738a7ab9d12c5371ed97114ee2132d4512e9fd5 ] 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 Signed-off-by: Parker Newman Link: https://lore.kernel.org/r/0f23973efefccd2544705a0480b4ad4c2353e407.1727880931.git.pnewman@connecttech.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

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 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 you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

eeprom-93cx6: Add (read-only) support for 8-bit mode

2014-11-25T14:42:53+00:00

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 Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig

eeprom_93cx6: Add write support

2011-11-26T19:59:39+00:00

Add support for writing data to EEPROM. Signed-off-by: Ben Dooks Cc: Wolfram Sang Cc: Jean Delvare Cc: Linux Kernel Signed-off-by: Stephen Boyd Signed-off-by: David S. Miller

eeprom_93cx6: Add data direction control.

2011-11-26T19:59:38+00:00

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 Cc: Wolfram Sang Cc: Jean Delvare Signed-off-by: Stephen Boyd Signed-off-by: David S. Miller

eeprom_93cx6: Add support for 93c86 EEPROMs.

2010-06-30T19:00:50+00:00

Signed-off-by: Gertjan van Wingerde Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville

ax88796: add 93cx6 eeprom support

2007-10-10T23:53:56+00:00

Hook up the 93cx6 eeprom code to the ax88796 driver and modify the ax88796 driver to read out the mac address from the eeprom. We need this for the ax88796 on certain SuperH boards. The pin configuration used to connect the eeprom to the ax88796 on these boards is the same as pointed out by the ax88796 datasheet, so we can probably reuse this code for multiple platforms in the future. Signed-off-by: Magnus Damm Cc: Ben Dooks Cc: Paul Mundt Signed-off-by: Andrew Morton Signed-off-by: Jeff Garzik

[PATCH] Add 93cx6 eeprom library

2007-07-09T02:16:36+00:00

This patch adds a library for reading from 93cx6 eeproms. Signed-off-by: Michael Wu Signed-off-by: John W. Linville