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>
Since many temperature sensors come "preconfigured" with a lower
precision, people are stuck at that precision when running on a kernel
based device (unlike the Dallas 1Wire library for e.g. Arduino, which
supports writing the configuration/scratchpad). This patch adds write
support for the scratchpad/precision registers via w1_slave sysfs.
Signed-off-by: Ben Sen <0.x29a.0@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
w1_process() calls try_to_freeze(), but the thread doesn't mark itself
freezable through set_freezable(), so the try_to_freeze() call is useless.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
Currently, memsetting and kfreeing the device is bad behaviour. The
device will have a reference count of 1 and hence can cause trouble
because it has kfree'd. Proper way to handle a failed device_register is
to call put_device right after it fails.
Signed-off-by: Levente Kurusa <levex@linux.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When initialized as a platform device the initializer must now specify
a device. An empty device name is no longer valid.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Rename functions that are used by multiple devices. New devices
have been added and the function names and driver name are no longer
general enough for the functionality they provide.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: GUAN Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Sebastian Reichel <sre@kernel.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>
I noticed there was a problem here because Smatch complained:
drivers/w1/slaves/w1_therm.c:416 w1_seq_show() warn:
inconsistent returns 'mutex:&sl->master->mutex'.
Locked on: line 416
Unlocked on: line 413
The problem is that we lock ->mutex but we unlock ->bus_mutex on error.
David Fries says that ->bus_mutex is correct and ->mutex is incorrect.
Fixes: d9411e57dc ('w1: Add support for DS28EA00 sequence to w1-therm')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The W1_42_FINISHED_BYTE is 0xFF so the cast means the condition is
never true.
Fixes: d9411e57dc ('w1: Add support for DS28EA00 sequence to w1-therm')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
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>
This patch provides support for the DS28EA00 digital thermometer.
The DS28EA00 provides an additional two pins for implementing a sequence
detection algorithm. This feature allows you to determine the physical
location of the chip in the 1-wire bus without needing pre-existing
knowledge of the bus ordering. Support is provided through the sysfs
w1_seq file. The file will contain a single line with an integer value
representing the device index in the bus starting at 0.
Signed-off-by: Matt Campbell <mattrcampbell@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A temperature conversion can take 750 ms and when possible the
w1_therm slave driver drops the bus_mutex to allow other bus
operations, but that includes operations such as a periodic slave
search, which can remove this slave when it is no longer detected.
If that happens the sl->family_data will be freed and set to NULL
causing w1_slave_show to crash when it wakes up.
Signed-off-by: David Fries <David@Fries.net>
Reported-By: Thorsten Bschorr <thorsten@bschorr.de>
Tested-by: Thorsten Bschorr <thorsten@bschorr.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of 1-Wire devices commonly associated with physical access control
systems are attached/generate presence for as short as 100 ms - hence
the tens-to-hundreds milliseconds scan intervals are required.
Signed-off-by: Dmitry Khromov <dk@icelogic.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
