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 <Aaron.Wu@analog.com>
Acked-by: Bryan Wu <cooloney@gmail.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mike Frysinger <vapier@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 0 insertions, 93 deletions

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.