Commit e93762bbf6 ("w1: masters: omap_hdq: add support for 1-wire
mode") added a statement to clear the hdq_irqstatus flags in
hdq_read_byte().
If the hdq reading process is scheduled slowly or interrupts are
disabled for a while the hardware read activity might already be
finished on entry of hdq_read_byte(). And hdq_isr() already has set the
hdq_irqstatus to 0x6 (can be seen in debug mode) denoting that both, the
TXCOMPLETE and RXCOMPLETE interrupts occurred in parallel.
This means there is no need to wait and the hdq_read_byte() can just
read the byte from the hdq controller.
By resetting hdq_irqstatus to 0 the read process is forced to be always
waiting again (because the if statement always succeeds) but the
hardware will not issue another RXCOMPLETE interrupt. This results in a
false timeout.
After such a situation the hdq bus hangs.
Link: http://lkml.kernel.org/r/b724765f87ad276a69625bc19806c8c8844c4590.1469513669.git.hns@goldelico.com
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit enables the active pullup (APU bit) by default for
the DS2482 1-Wire master.
>From the DS2482 datasheet:
"The APU bit controls whether an active pullup (controlled slew-rate
transistor) or a passive pullup (Rwpu resistor) will be used to drive
a 1-Wire line from low to high. When APU = 0, active pullup is disabled
(resistor mode). Active Pullup should always be selected unless there is
only a single slave on the 1-Wire line."
According to the module author, Ben Gardner:
"It doesn't look like active pullup would cause any hurt if there
is only a single slave."
And my tests with multiple and single slaves on 1-Wire bus
confirms that.
This active pullup can be manually disabled using the introduced
module parameter:
active_pullup = 0
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hdq_usecount was set to zero after a successful read, so
omap_hdq_put could not properly free resources which leads
e.g. to increasing usecounts in lsmod output
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Reviewed-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's stop using legacy platform driver hooks for power management and
switch to using the standard dev_pm_ops-based hooks.
Also, instead of guarding PM methods with #ifdef CONFIG_PM annotate them
as __maybe_unused as it provides better compile coverage.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use module_pci_driver for drivers whose init and exit functions
only register and unregister, respectively.
A simplified version of the Coccinelle semantic patch that performs
this transformation is as follows:
@a@
identifier f, x;
@@
-static f(...) { return pci_register_driver(&x); }
@b depends on a@
identifier e, a.x;
@@
-static e(...) { pci_unregister_driver(&x); }
@c depends on a && b@
identifier a.f;
declarer name module_init;
@@
-module_init(f);
@d depends on a && b && c@
identifier b.e, a.x;
declarer name module_exit;
declarer name module_pci_driver;
@@
-module_exit(e);
+module_pci_driver(x);
Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add i2c alias to enable autoloading of the module for device specified
in device-tree.
Signed-off-by: Ludek Hlavacek <ludek_h@seznam.cz>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char/misc driver updates from Greg KH:
"Here's the big char/misc driver update for 3.19-rc1
Lots of little things all over the place in different drivers, and a
new subsystem, "coresight" has been added. Full details are in the
shortlog"
* tag 'char-misc-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (73 commits)
parport: parport_pc, do not remove parent devices early
spmi: Remove shutdown/suspend/resume kernel-doc
carma-fpga-program: drop videobuf dependency
carma-fpga: drop videobuf dependency
carma-fpga-program.c: fix compile errors
i8k: Fix temperature bug handling in i8k_get_temp()
cxl: Name interrupts in /proc/interrupt
CXL: Return error to PSL if IRQ demultiplexing fails & print clearer warning
coresight-replicator: remove .owner field for driver
coresight: fixed comments in coresight.h
coresight: fix typo in comment in coresight-priv.h
coresight: bindings for coresight drivers
coresight: Adding ABI documentation
w1: support auto-load of w1_bq27000 module.
w1: avoid potential u16 overflow
cn: verify msg->len before making callback
mei: export fw status registers through sysfs
mei: read and print all six FW status registers
mei: txe: add cherrytrail device id
mei: kill cached host and me csr values
...
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
This driver has no 'compatible' string and so is not found when
using device-tree.
Add one with value to match
hdqw1w: 1w@480b2000 {
device in omap3.dtsi.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Adjust the bulk message timeout to the other ones (1000ms). Otherwise the
following dmesg errors can be seen on a Raspberry Pi:
[ 31.492386] Failed to read 1-wire data from 0x81: err=-110.
[ 31.504168] 0x81: count=-110, status:
[ 31.613404] Failed to read 1-wire data from 0x81: err=-110.
[ 31.621915] 0x81: count=-110, status:
[ 43.260968] Failed to read 1-wire data from 0x81: err=-110.
[ 43.270998] 0x81: count=-110, status:
[ 43.379959] Failed to read 1-wire data from 0x81: err=-110.
[ 43.388854] 0x81: count=-110, status:
Signed-off-by: Alexander Stein <alexanders83@web.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces all calls to the "printk" function within the "masters"
subdirectory by calls to the appropriate "pr_*" function thus addressing
the following warning generated by the checkpatch script:
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ...
then dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...
Signed-off-by: Fjodor Schelichow <fjodor.schelichow@hotmail.com>
Signed-off-by: Roman Sommer <romsom2@yahoo.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to the i.MX reference manual, the read/write bit operations
takes from 60 us to 120 us.
This patch optimizes mxc_w1_ds2_touch_bit() function to use proper
value for such delay. Nevertheless, a small margin for the timeout has
been added for the case if clock frequency is inaccurate.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a software reset for 1-Wire module at driver startup.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to the i.MX reference manual, the reset procedure and
"presence" pulse takes 511 and 512 us, respectively. Measurement for
i.MX27 is about 1100 us. There is no need to wait Reset+Presence
more than this time.
This patch optimizes mxc_w1_ds2_reset_bus() function to use proper
value for delay after w1 bus reset. Nevertheless, a small margin for
the timeout has been added for the case if clock frequency is inaccurate.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
W1 reset_bus() should return zero if slave device is present.
This patch fix this issue.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This helps increasing build testing coverage.
To do this, __raw_{read,write}b() functions was be replaced with
simple {read,write}b() variants.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Remove old and currently wrong address of the FSF from license
parts of the code.
- Remove unused #include and sort remaining headers alphabetically.
- Remove unised definitions.
- Add definitions for bit-fields.
- Add missing module owner field.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fix mxc_w1_ds2_reset_bus() return value.
According to i.MX reference manual, "presence status" reflected
in the bit 6 of control register.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Configuration for masters and slaves is included only if W1 symbol
enabled, so no reason to check it once more.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
H. Nikolaus Schaller
Mariusz Bialonczyk
Andreas Kemnade
Dmitry Torokhov
Vignesh R
Linus Torvalds
Masanari Iida
Vaishali Thakkar
Krzysztof Kozlowski
Ludek Hlavacek
Fabian Frederick
NeilBrown
Alexander Stein
Wolfram Sang
Fjodor Schelichow
Alexander Shiyan