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authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-08 09:27:33 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-08 09:27:33 -0800
commit6c3f98faddc7f07981c5365ba2f45905ad75fcaa (patch)
treea999723d659850bd26dd95f05c5c9b12289ca91c /Documentation
parent1cabd3e0bd88d7ba9854cbb9213ef40eccad603b (diff)
parent93b6604c5a669d84e45fe5129294875bf82eb1ff (diff)
downloadlinux-6c3f98faddc7f07981c5365ba2f45905ad75fcaa.tar.bz2
Merge branch 'i2c/for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang: - the I2C core gained helpers to assist drivers in handling their suspended state, and drivers were converted to use it - two new fault-injectors for stress-testing - bigger refactoring and feature improvements for the ocores, sh_mobile, and tegra drivers - platform_data removal for the at24 EEPROM driver - ... and various improvements and bugfixes all over the subsystem * 'i2c/for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (69 commits) i2c: Allow recovery of the initial IRQ by an I2C client device. i2c: ocores: turn incomplete kdoc into a comment i2c: designware: Do not allow i2c_dw_xfer() calls while suspended i2c: tegra: Only display error messages if DMA setup fails i2c: gpio: fault-injector: add 'inject_panic' injector i2c: gpio: fault-injector: add 'lose_arbitration' injector i2c: tegra: remove multi-master support i2c: tegra: remove master fifo support on tegra186 i2c: tegra: change phrasing, "fallbacking" to "falling back" i2c: expand minor range when registering chrdev region i2c: aspeed: Add multi-master use case support i2c: core-smbus: don't trace smbus_reply data on errors i2c: ocores: Add support for bus clock via platform data i2c: ocores: Add support for IO mapper registers. i2c: ocores: checkpatch fixes i2c: ocores: add SPDX tag i2c: ocores: add polling interface i2c: ocores: do not handle IRQ if IF is not set i2c: ocores: stop transfer on timeout i2c: tegra: add i2c interface timing support ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/eeprom/at24.txt3
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-mtk.txt1
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-xscale.txt20
-rw-r--r--Documentation/i2c/fault-codes4
-rw-r--r--Documentation/i2c/gpio-fault-injection61
5 files changed, 86 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
index f9a7c984274c..0e456bbc1213 100644
--- a/Documentation/devicetree/bindings/eeprom/at24.txt
+++ b/Documentation/devicetree/bindings/eeprom/at24.txt
@@ -75,6 +75,8 @@ Optional properties:
- address-width: number of address bits (one of 8, 16).
+ - num-addresses: total number of i2c slave addresses this device takes
+
Example:
eeprom@52 {
@@ -82,4 +84,5 @@ eeprom@52 {
reg = <0x52>;
pagesize = <32>;
wp-gpios = <&gpio1 3 0>;
+ num-addresses = <8>;
};
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mtk.txt b/Documentation/devicetree/bindings/i2c/i2c-mtk.txt
index e199695b1c96..ee4c32454198 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mtk.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mtk.txt
@@ -10,6 +10,7 @@ Required properties:
"mediatek,mt6589-i2c": for MediaTek MT6589
"mediatek,mt7622-i2c": for MediaTek MT7622
"mediatek,mt7623-i2c", "mediatek,mt6577-i2c": for MediaTek MT7623
+ "mediatek,mt7629-i2c", "mediatek,mt2712-i2c": for MediaTek MT7629
"mediatek,mt8173-i2c": for MediaTek MT8173
- reg: physical base address of the controller and dma base, length of memory
mapped region.
diff --git a/Documentation/devicetree/bindings/i2c/i2c-xscale.txt b/Documentation/devicetree/bindings/i2c/i2c-xscale.txt
new file mode 100644
index 000000000000..dcc8390e0d24
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-xscale.txt
@@ -0,0 +1,20 @@
+i2c Controller on XScale platforms such as IOP3xx and IXP4xx
+
+Required properties:
+- compatible : Must be one of
+ "intel,iop3xx-i2c"
+ "intel,ixp4xx-i2c";
+- reg
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties:
+- Child nodes conforming to i2c bus binding
+
+Example:
+
+i2c@c8011000 {
+ compatible = "intel,ixp4xx-i2c";
+ reg = <0xc8011000 0x18>;
+ interrupts = <33 IRQ_TYPE_LEVEL_LOW>;
+};
diff --git a/Documentation/i2c/fault-codes b/Documentation/i2c/fault-codes
index 47c25abb7d52..0cee0fc545b4 100644
--- a/Documentation/i2c/fault-codes
+++ b/Documentation/i2c/fault-codes
@@ -112,6 +112,10 @@ EPROTO
case is when the length of an SMBus block data response
(from the SMBus slave) is outside the range 1-32 bytes.
+ESHUTDOWN
+ Returned when a transfer was requested using an adapter
+ which is already suspended.
+
ETIMEDOUT
This is returned by drivers when an operation took too much
time, and was aborted before it completed.
diff --git a/Documentation/i2c/gpio-fault-injection b/Documentation/i2c/gpio-fault-injection
index a4ce62090fd5..c87f416d53dd 100644
--- a/Documentation/i2c/gpio-fault-injection
+++ b/Documentation/i2c/gpio-fault-injection
@@ -1,3 +1,4 @@
+=========================
Linux I2C fault injection
=========================
@@ -13,6 +14,9 @@ mounted at /sys/kernel/debug. There will be a separate subdirectory per GPIO
driven I2C bus. Each subdirectory will contain files to trigger the fault
injection. They will be described now along with their intended use-cases.
+Wire states
+===========
+
"scl"
-----
@@ -34,10 +38,10 @@ I2C specification version 4, section 3.1.16) using the helpers of the Linux I2C
core (see 'struct bus_recovery_info'). However, the bus recovery will not
succeed because SDA is still pinned low until you manually release it again
with "echo 1 > sda". A test with an automatic release can be done with the
-following class of fault injectors.
+"incomplete transfers" class of fault injectors.
-Introduction to incomplete transfers
-------------------------------------
+Incomplete transfers
+====================
The following fault injectors create situations where SDA will be held low by a
device. Bus recovery should be able to fix these situations. But please note:
@@ -79,3 +83,54 @@ This is why bus recovery (up to 9 clock pulses) must either check SDA or send
additional STOP conditions to ensure the bus has been released. Otherwise
random data will be written to a device!
+Lost arbitration
+================
+
+Here, we want to simulate the condition where the master under test loses the
+bus arbitration against another master in a multi-master setup.
+
+"lose_arbitration"
+------------------
+
+This file is write only and you need to write the duration of the arbitration
+intereference (in µs, maximum is 100ms). The calling process will then sleep
+and wait for the next bus clock. The process is interruptible, though.
+
+Arbitration lost is achieved by waiting for SCL going down by the master under
+test and then pulling SDA low for some time. So, the I2C address sent out
+should be corrupted and that should be detected properly. That means that the
+address sent out should have a lot of '1' bits to be able to detect corruption.
+There doesn't need to be a device at this address because arbitration lost
+should be detected beforehand. Also note, that SCL going down is monitored
+using interrupts, so the interrupt latency might cause the first bits to be not
+corrupted. A good starting point for using this fault injector on an otherwise
+idle bus is:
+
+# echo 200 > lose_arbitration &
+# i2cget -y <bus_to_test> 0x3f
+
+Panic during transfer
+=====================
+
+This fault injector will create a Kernel panic once the master under test
+started a transfer. This usually means that the state machine of the bus master
+driver will be ungracefully interrupted and the bus may end up in an unusual
+state. Use this to check if your shutdown/reboot/boot code can handle this
+scenario.
+
+"inject_panic"
+--------------
+
+This file is write only and you need to write the delay between the detected
+start of a transmission and the induced Kernel panic (in µs, maximum is 100ms).
+The calling process will then sleep and wait for the next bus clock. The
+process is interruptible, though.
+
+Start of a transfer is detected by waiting for SCL going down by the master
+under test. A good starting point for using this fault injector is:
+
+# echo 0 > inject_panic &
+# i2cget -y <bus_to_test> <some_address>
+
+Note that there doesn't need to be a device listening to the address you are
+using. Results may vary depending on that, though.