From 4ba66a9760722ccbb691b8f7116cad2f791cca7b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 7 Mar 2018 22:23:24 +0100 Subject: arch: remove blackfin port The Analog Devices Blackfin port was added in 2007 and was rather active for a while, but all work on it has come to a standstill over time, as Analog have changed their product line-up. Aaron Wu confirmed that the architecture port is no longer relevant, and multiple people suggested removing blackfin independently because of some of its oddities like a non-working SMP port, and the amount of duplication between the chip variants, which cause extra work when doing cross-architecture changes. Link: https://docs.blackfin.uclinux.org/ Acked-by: Aaron Wu Acked-by: Bryan Wu Cc: Steven Miao Cc: Mike Frysinger Signed-off-by: Arnd Bergmann --- Documentation/blackfin/00-INDEX | 6 --- Documentation/blackfin/bfin-gpio-notes.txt | 71 ------------------------------ Documentation/blackfin/bfin-spi-notes.txt | 16 ------- 3 files changed, 93 deletions(-) delete mode 100644 Documentation/blackfin/00-INDEX delete mode 100644 Documentation/blackfin/bfin-gpio-notes.txt delete mode 100644 Documentation/blackfin/bfin-spi-notes.txt (limited to 'Documentation/blackfin') diff --git a/Documentation/blackfin/00-INDEX b/Documentation/blackfin/00-INDEX deleted file mode 100644 index 265a1ef..0000000 --- a/Documentation/blackfin/00-INDEX +++ /dev/null @@ -1,6 +0,0 @@ -00-INDEX - - This file -bfin-gpio-notes.txt - - Notes in developing/using bfin-gpio driver. -bfin-spi-notes.txt - - Notes for using bfin spi bus driver. diff --git a/Documentation/blackfin/bfin-gpio-notes.txt b/Documentation/blackfin/bfin-gpio-notes.txt deleted file mode 100644 index d245f39..0000000 --- a/Documentation/blackfin/bfin-gpio-notes.txt +++ /dev/null @@ -1,71 +0,0 @@ -/* - * File: Documentation/blackfin/bfin-gpio-notes.txt - * Based on: - * Author: - * - * Created: $Id: bfin-gpio-note.txt 2008-11-24 16:42 grafyang $ - * Description: This file contains the notes in developing/using bfin-gpio. - * - * - * Rev: - * - * Modified: - * Copyright 2004-2008 Analog Devices Inc. - * - * Bugs: Enter bugs at http://blackfin.uclinux.org/ - * - */ - - -1. Blackfin GPIO introduction - - There are many GPIO pins on Blackfin. Most of these pins are muxed to - multi-functions. They can be configured as peripheral, or just as GPIO, - configured to input with interrupt enabled, or output. - - For detailed information, please see "arch/blackfin/kernel/bfin_gpio.c", - or the relevant HRM. - - -2. Avoiding resource conflict - - Followed function groups are used to avoiding resource conflict, - - Use the pin as peripheral, - int peripheral_request(unsigned short per, const char *label); - int peripheral_request_list(const unsigned short per[], const char *label); - void peripheral_free(unsigned short per); - void peripheral_free_list(const unsigned short per[]); - - Use the pin as GPIO, - int bfin_gpio_request(unsigned gpio, const char *label); - void bfin_gpio_free(unsigned gpio); - - Use the pin as GPIO interrupt, - int bfin_gpio_irq_request(unsigned gpio, const char *label); - void bfin_gpio_irq_free(unsigned gpio); - - The request functions will record the function state for a certain pin, - the free functions will clear its function state. - Once a pin is requested, it can't be requested again before it is freed by - previous caller, otherwise kernel will dump stacks, and the request - function fail. - These functions are wrapped by other functions, most of the users need not - care. - - -3. But there are some exceptions - - Kernel permit the identical GPIO be requested both as GPIO and GPIO - interrupt. - Some drivers, like gpio-keys, need this behavior. Kernel only print out - warning messages like, - bfin-gpio: GPIO 24 is already reserved by gpio-keys: BTN0, and you are -configuring it as IRQ! - - Note: Consider the case that, if there are two drivers need the - identical GPIO, one of them use it as GPIO, the other use it as - GPIO interrupt. This will really cause resource conflict. So if - there is any abnormal driver behavior, please check the bfin-gpio - warning messages. - - - Kernel permit the identical GPIO be requested from the same driver twice. - - - diff --git a/Documentation/blackfin/bfin-spi-notes.txt b/Documentation/blackfin/bfin-spi-notes.txt deleted file mode 100644 index eae6eaf..0000000 --- a/Documentation/blackfin/bfin-spi-notes.txt +++ /dev/null @@ -1,16 +0,0 @@ -SPI Chip Select behavior: - -With the Blackfin on-chip SPI peripheral, there is some logic tied to the CPHA -bit whether the Slave Select Line is controlled by hardware (CPHA=0) or -controlled by software (CPHA=1). However, the Linux SPI bus driver assumes that -the Slave Select is always under software control and being asserted during -the entire SPI transfer. - And not just bits_per_word duration. - -In most cases you can utilize SPI MODE_3 instead of MODE_0 to work-around this -behavior. If your SPI slave device in question requires SPI MODE_0 or MODE_2 -timing, you can utilize the GPIO controlled SPI Slave Select option instead. -In this case, you should use GPIO based CS for all of your slaves and not just -the ones using mode 0 or 2 in order to guarantee correct CS toggling behavior. - -You can even use the same pin whose peripheral role is a SSEL, -but use it as a GPIO instead. -- cgit v1.1