| Age | Commit message (Collapse) | Author | Files | Lines |
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Protect against suspect hardware causing the bus to read off more data
than defined in the SMBus specification.
Some investigation that suggests that the DEVICE_ID command (0xfd) to
a UCD9xxx power sequencer occasionally returns all 0xff, causing the bus
driver to overrun the 34-byte data buffer provided by the I2C core with
a 255-byte broken response. Usually the result was the following:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted
in: 802e5e38
CPU: 0 PID: 1559 Comm: zaius_vcs.sh Not tainted
4.7.10-f26558191540830589fe03932d05577957670b8d #2
Hardware name: ASpeed SoC
[<801072f8>] (unwind_backtrace) from [<80105558>] (show_stack+0x10/0x14)
[<80105558>] (show_stack) from [<8016d06c>] (panic+0xb8/0x248)
[<8016d06c>] (panic) from [<80110df4>] (__stack_chk_fail+0x10/0x14)
[<80110df4>] (__stack_chk_fail) from [<802e5e38>]
(i2c_smbus_xfer+0x508/0x54c)
[<802e5e38>] (i2c_smbus_xfer) from [<ffffffff>] (0xffffffff)
This patch prevents the broken response from trashing the surrounding
memory and returns an error code up the call-chain.
The I2C core doesn't help itself in this case as it does not provide any
means for the bus driver to sanity check the caller-provided
response-buffer length against the device-provided payload length. At
the point where we perform the I2C transfers for the SMBus protocol
we've lost the information about what type of transaction is being
performed (i.e. that we're performing an SMBus block transfer), so we
cannot in general make assumptions about the buffer size based on the
protocol (i2c, SMBus, PMBus). Further, struct i2c_msg is defined in the
uapi headers so no further members (e.g. a length field) can be added
without breaking userspace.
Instead, let's move the buffers off the stack and expand them such that
they will fit any payload length reported by the bus.
The patch has been tested on a Zaius system, consecutively unbinding and
binding the UCD9000 driver over 1000 times. Whilst errors were reported
during probe in some cases ("ucd9000: probe of 0-0064 failed with error
-74"), the system remained stable and did not reboot. Triggering the bug
without the patch typically at most requires in the order of 100
unbind/bind attempts, often significantly less.
Finally, the host was successfully powered up immediately after the 1000
unbind/bind attempts.
Suggested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
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This is the 4.7.7 stable release
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commit e35478eac030990e23a56bf11dc074c5a069124a upstream.
We can't use a static property for all the changesets, so we now create
dynamic ones for each changeset.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: 50a5ba87690814 ("i2c: mux: demux-pinctrl: add driver")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is the 4.7.6 stable release
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commit 331dcf421c34d227784d07943eb01e4023a42b0a upstream.
If the i2c device is already runtime suspended, if qup_i2c_suspend is
executed during suspend-to-idle or suspend-to-ram it will result in the
following splat:
WARNING: CPU: 3 PID: 1593 at drivers/clk/clk.c:476 clk_core_unprepare+0x80/0x90
Modules linked in:
CPU: 3 PID: 1593 Comm: bash Tainted: G W 4.8.0-rc3 #14
Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
PC is at clk_core_unprepare+0x80/0x90
LR is at clk_unprepare+0x28/0x40
pc : [<ffff0000086eecf0>] lr : [<ffff0000086f0c58>] pstate: 60000145
Call trace:
clk_core_unprepare+0x80/0x90
qup_i2c_disable_clocks+0x2c/0x68
qup_i2c_suspend+0x10/0x20
platform_pm_suspend+0x24/0x68
...
This patch fixes the issue by executing qup_i2c_pm_suspend_runtime
conditionally in qup_i2c_suspend.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 463e8f845cbf1c01e4cc8aeef1703212991d8e1e upstream.
The cached value of the last selected channel prevents retries on the
next call, even on failure to update the selected channel. Fix that.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 371a015344b6e270e7e3632107d9554ec6d27a6b upstream.
the eg20t driver call request_irq() function before the pch_base_address,
base address of i2c controller's register, is assigned an effective value.
there is one possible scenario that an interrupt which isn't inside eg20t
arrives immediately after request_irq() is executed when i2c controller
shares an interrupt number with others. since the interrupt handler
pch_i2c_handler() has already active as shared action, it will be called
and read its own register to determine if this interrupt is from itself.
At that moment, since base address of i2c registers is not remapped
in kernel space yet,so the INT handler will access an illegal address
and then a error occurs.
Signed-off-by: Yadi.hu <yadi.hu@windriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is the 4.7.3 stable release
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commit 4d01d88019261d05ec3bff5f1a6013393faa3b9e upstream.
cros_ec_cmd_xfer returns success status if the command transport
completes successfully, but the execution result is incorrectly ignored.
In many cases, the execution result is assumed to be successful, leading
to ignored errors and operating on uninitialized data.
We've recently introduced the cros_ec_cmd_xfer_status() helper to avoid these
problems. Let's use it.
[Regarding the 'Fixes' tag; there is significant refactoring since the driver's
introduction, but the underlying logical error exists throughout I believe]
Fixes: 9d230c9e4f4e ("i2c: ChromeOS EC tunnel driver")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ce8cb803d8b90458495f23606c706f0c0c857cdc upstream.
We also need to revert the dynamic OF change, so we get a consistent
state again. Otherwise, we might have two devices enabled e.g. after
pinctrl setup fails.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is the 4.7.2 stable release
Signed-off-by: Joel Stanley <joel@jms.id.au>
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commit 7dd91d52a813f99a95d20f539b777e9e6198b931 upstream.
There is the only failure path in efm32_i2c_probe(),
where clk_disable_unprepare() is missed.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b5b23718b84 ("i2c: efm32: new bus driver")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Added slave mode irq handler as well as reg_slave and unreg_slave
functions to the i2c-aspeed's i2c_algorithm.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
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Supports the fourteen bus masters present in the ast2400 and ast2500 BMC
SoCs by Aspeed.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Milton Miller <miltonm@us.ibm.com>
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of_address_to_resource return 0 on successful call but
devm_ioremap_resource is called only if it returns non-zero value
Signed-off-by: Lukasz Gemborowski <lukasz.gemborowski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
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Commit 497fbe24987b ("i2c: tegra: enable multi master mode for tegra210")
enables the Tegra I2C 'div_clk' for adapters using the multi-master mode
during the device probe. Although the probe error path was updated to
disable the clock on probe failure, there is one place after calling
tegra_i2c_init() where the clock will not be disabled on failure. Correct
the error path so that the 'div_clk' is disabled if calling
tegra_i2c_init() fails.
Fixes: 497fbe24987b ("i2c: tegra: enable multi master mode for tegra210")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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As of next-20160607 with allyesconfig we get this linker failure:
MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from
the function intel_scu_devices_create() to the function
.init.text:i2c_register_board_info()
This is caused by the fact that intel_scu_devices_create() calls
i2c_register_board_info() and intel_scu_devices_create() is not
annotated with __init. This typically involves manual code
inspection and if one is certain this is correct we would
just peg intel_scu_devices_create() with a __ref annotation.
In this case this would be wrong though as the
intel_scu_devices_create() call is exported, and used in
the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c.
The issue is that even though builtin_pci_driver(ipc_driver)
is used this just exposes the probe routine, which can occur
at any point in time if this bus supports hotplug. A race
can happen between kernel_init_freeable() that calls the init
calls (in this case registeres the intel_scu_ipc.c driver, and
later free_initmem(), which would free the i2c_register_board_info().
If a probe happens later in boot i2c_register_board_info() would
not be present and we should get a page fault.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
[wsa: made function declaration a one-liner]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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index gets incremented during check to determine if the
messages can be transferred with dma. But not reset after
that, resulting in wrong start value in subsequent loop,
causing failure. Fix it.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
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of_match_table was not filled which prevents device to be
instantiated from device tree node.
Signed-off-by: Lukasz Gemborowski <lukasz.gemborowski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Remove the warning about a too long SMBUS message because
the ipmi_ssif driver triggers this warning too frequently so it
spams the message log.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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During receive the controller requires the AAK flag for all
bytes but the final one. This was wrong in case of I2C_M_RECV_LEN,
where the decision if the final byte is to be transmitted
happened before adding the additional received length byte.
Set the AAK flag if additional bytes are to be received.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Many Intel systems the BIOS declares a SystemIO OpRegion below the SMBus
PCI device as can be seen in ACPI DSDT table from Lenovo Yoga 900:
Device (SBUS)
{
OperationRegion (SMBI, SystemIO, (SBAR << 0x05), 0x10)
Field (SMBI, ByteAcc, NoLock, Preserve)
{
HSTS, 8,
Offset (0x02),
HCON, 8,
HCOM, 8,
TXSA, 8,
DAT0, 8,
DAT1, 8,
HBDR, 8,
PECR, 8,
RXSA, 8,
SDAT, 16
}
There are also bunch of AML methods that that the BIOS can use to access
these fields. Most of the systems in question AML methods accessing the
SMBI OpRegion are never used.
Now, because of this SMBI OpRegion many systems fail to load the SMBus
driver with an error looking like one below:
ACPI Warning: SystemIO range 0x0000000000003040-0x000000000000305F
conflicts with OpRegion 0x0000000000003040-0x000000000000304F
(\_SB.PCI0.SBUS.SMBI) (20160108/utaddress-255)
ACPI: If an ACPI driver is available for this device, you should use
it instead of the native driver
The reason is that this SMBI OpRegion conflicts with the PCI BAR used by
the SMBus driver.
It turns out that we can install a custom SystemIO address space handler
for the SMBus device to intercept all accesses through that OpRegion. This
allows us to share the PCI BAR with the AML code if it for some reason is
using it. We do not expect that this OpRegion handler will ever be called
but if it is we print a warning and prevent all access from the SMBus
driver itself.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=110041
Reported-by: Andy Lutomirski <luto@kernel.org>
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
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The call to put_i2c_dev() frees "i2c_dev" so there is a use after
free when we call cdev_del(&i2c_dev->cdev).
Fixes: d6760b14d4a1 ('i2c: dev: switch from register_chrdev to cdev API')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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I stumbled multiple times over 'return_i2c_dev', especially before the
actual 'return res'. It makes the code hard to read, so reanme the
function to 'put_i2c_dev' which also better matches 'get_free_i2c_dev'.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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i2c-dev had never moved away from the older register_chrdev interface to
implement its char device registration. The register_chrdev API has the
limitation of enabling only up to 256 i2c-dev busses to exist.
Large platforms with lots of i2c devices (i.e. pluggable transceivers)
with dedicated busses may have to exceed that limit.
In particular, there are also platforms making use of the i2c bus
multiplexing API, which instantiates a virtual bus for each possible
multiplexed selection.
This patch removes the register_chrdev usage and replaces it with the
less old cdev API, which takes away the 256 i2c-dev bus limitation.
It should not have any other impact for i2c bus drivers or user space.
This patch has been tested on qemu x86 and qemu powerpc platforms with
the aid of a module which adds and removes 5000 virtual i2c busses, as
well as validated on an existing powerpc hardware platform which makes
use of the i2c bus multiplexing API.
i2c-dev busses with device minor numbers larger than 256 have also been
validated to work with the existing i2c-tools.
Signed-off-by: Erico Nunes <erico.nunes@datacom.ind.br>
[wsa: kept includes sorted]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The ARCH name was changed during the review process of the mach, and
this driver was forgotten to be converted. Fix it now.
http://article.gmane.org/gmane.linux.ports.arm.kernel/456331
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
[wsa: updated commit message slightly]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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When the DMA configuration fails, there is a log reporting that we can't
use DMA and indicating the error number. When booting the kernel, it is
annoying to see this error number. Moreover, people can think something
is going wrong. It is not the case, it means that DMA can't be used but
it doesn't prevent to use i2c.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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If NO_DMA=y:
drivers/built-in.o: In function `rcar_i2c_dma_unmap':
i2c-rcar.c:(.text+0x6f06c6): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `rcar_i2c_dma':
i2c-rcar.c:(.text+0x6f07e2): undefined reference to `bad_dma_ops'
i2c-rcar.c:(.text+0x6f0838): undefined reference to `bad_dma_ops'
Add a dependency on HAS_DMA to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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New drivers should not use dma_request_slave_channel_reason() but
dma_request_chan(). The former is a macro to the later so this change do
not effect the driver in any way.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
- Peter Rosin did some major rework on the locking of i2c muxes by
seperating parent-locked muxes and mux-locked muxes.
This avoids deadlocks/workarounds when the mux itself needs i2c
commands for muxing. And as a side-effect, other workarounds in the
media layer could be eliminated. Also, Peter stepped up as the i2c
mux maintainer and will keep an eye on these changes.
- major updates to the octeon driver
- add a helper to the core to generate the address+rw_bit octal and
make drivers use it
- quite a bunch of driver updates
* 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (84 commits)
i2c: rcar: add DMA support
i2c: st: Implement bus clear
i2c: only check scl functions when using generic recovery
i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static
i2c: tegra: disable clock before returning error
[media] rtl2832: regmap is aware of lockdep, drop local locking hack
[media] rtl2832_sdr: get rid of empty regmap wrappers
[media] rtl2832: change the i2c gate to be mux-locked
[media] si2168: change the i2c gate to be mux-locked
iio: imu: inv_mpu6050: change the i2c gate to be mux-locked
i2c: mux: document i2c muxes and elaborate on parent-/mux-locked muxes
i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
i2c: muxes always lock the parent adapter
i2c: allow adapter drivers to override the adapter locking
i2c: uniphier: add "\n" at the end of error log
i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionals
i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}
i2c: mv64xxx: handle probe deferral for the clock
i2c: mv64xxx: enable the driver on ARCH_MVEBU
i2c: octeon: Add workaround for broken irqs on CN3860
...
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Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address and some data is still handled using
the old state machine, it is sending the bulk of the data that is done
via DMA.
The first byte of a transmission and the last two bytes of reception are
sent/received using PIO. This is needed for the HW to have access to the
first byte before DMA transmit and to be able to set the STOP condition
for DMA reception.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: fixed a checkpatch warning]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>From I2C specifications:
http://www.nxp.com/documents/user_manual/UM10204.pdf
Chapter 3.1.16, when the i2c device held the SDA line low, the master
should send 9 clocks pulses to try to recover.
Signed-off-by: Frederic Pillon <frederic.pillon@st.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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A custom recovery function doesn't need these pointers to be populated
because it may work differently internally.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
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i2c_bit_quirk_no_clk_stretch is used in i2c-algo-bit.c only, so
declare it as static.
Signed-off-by: Michele Curti <michele.curti@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Disable clock before returning error in tegra_i2c_init() as its leaves
i2c clock ON in case of error and never turns off again as it will have
unbalanced clock enable/disable
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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With a i2c topology like the following
GPIO ---| ------ BAT1
| v /
I2C -----+----------+---- MUX
| \
EEPROM ------ BAT2
there is a locking problem with the GPIO controller since it is a client
on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1)
will lock the whole i2c bus prior to attempting to switch the mux to the
correct i2c segment. In the above case, the GPIO device is an I/O expander
with an i2c interface, and since the GPIO subsystem knows nothing (and
rightfully so) about the lockless needs of the i2c mux code, this results
in a deadlock when the GPIO driver issues i2c transfers to modify the
mux.
So, observing that while it is needed to have the i2c bus locked during the
actual MUX update in order to avoid random garbage on the slave side, it
is not strictly a must to have it locked over the whole sequence of a full
select-transfer-deselect mux client operation. The mux itself needs to be
locked, so transfers to clients behind the mux are serialized, and the mux
needs to be stable during all i2c traffic (otherwise individual mux slave
segments might see garbage, or worse).
Introduce this new locking concept as "mux-locked" muxes, and call the
pre-existing mux locking scheme "parent-locked".
Modify the i2c mux locking so that muxes that are "mux-locked" locks only
the muxes on the parent adapter instead of the whole i2c bus when there is
a transfer to the slave side of the mux. This lock serializes transfers to
the slave side of the muxes on the parent adapter.
Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved
gpio/pinctrl devices have a parent that is an i2c adapter in the same
adapter tree that is muxed, and request a "mux-locked mux" if that is the
case.
Modify the select-transfer-deselect code for "mux-locked" muxes so
that each of the select-transfer-deselect ops locks the mux parent
adapter individually.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Instead of checking for i2c parent adapters for every lock/unlock, simply
override the locking for muxes to always lock/unlock the parent adapter
directly.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and
unlock_bus ops in the adapter. These funcs/ops take an additional flags
argument that indicates for what purpose the adapter is locked.
There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they
are both implemented the same. For now. Locking the root adapter means
that the whole bus is locked, locking the segment means that only the
current bus segment is locked (i.e. i2c traffic on the parent side of
a mux is still allowed even if the child side of the mux is locked).
Also support a trylock_bus op (but no function to call it, as it is not
expected to be needed outside of the i2c core).
Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking
scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag).
Locking the root adapter and locking the segment is the same thing for
all root adapters (e.g. in the normal case of a simple topology with no
i2c muxes). The two locking variants are also the same for traditional
muxes (aka parent-locked muxes). These muxes traverse the tree, locking
each level as they go until they reach the root. This patch is preparatory
for a later patch in the series introducing mux-locked muxes, which behave
differently depending on the requested locking. Since all current users
are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER,
we only need to annotate the calls that will not need to lock the root
adapter for mux-locked muxes. I.e. the instances that needs to use
I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those
instances are in the i2c_transfer and i2c_smbus_xfer functions, so that
mux-locked muxes can single out normal i2c accesses to its slave side
and adjust the locking for those accesses.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Just in case.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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When clock support was added to the i2c-mv64xxx, not all clk functions
had stubs when for !CONFIG_HAVE_CLK configurations. However, nowadays,
both "struct clk" and all the clock framework functions have stubs
when CONFIG_HAVE_CLK is not enabled, so it no longer makes sense to
carry such compile-time conditionals in the driver.
This commit was compile tested on both ARM64 (which has both
CONFIG_OF=y and CONFIG_HAVE_CLK=y) and PowerPC c2k_defconfig (which
has CONFIG_OF=y, CONFIG_HAVE_CLK disabled, and the i2c-mv64xxx driver
enabled).
The only non-trivial change is in the mv64xxx_of_config() function,
which was returning -ENODEV unconditionally if CONFIG_HAVE_CLK was
disabled. Simply removing this condition works fine because the first
test done by the function is to verify if drv_data->clk points to a
valid clock, and if it doesn't, we return -ENODEV. When
CONFIG_HAVE_CLK is disabled, devm_clk_get() unconditionally returns
NULL, so mv64xxx_of_config() will return -ENODEV when no clock is
provided, which is the intended behavior.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Instead of separately calling clk_prepare()/clk_enable(), use
clk_prepare_enable(), and instead of calling
clk_disable()/clk_unprepare(), use clk_disable_unprepare(). Those
handy shortcuts have been introduced specifically to simplify the
numerous call sites were both functions were called in sequence.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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If a clock is registered by a platform driver and not by the
OF_CLK_DECLARE() mechanism, it might show up after the first attempt
to probe i2c-mv64xxx. In order to solve this, we need to handle
-EPROBE_PREFER as a special return value of devm_clk_get(), and return
the same error code from probe().
This gives us three situations:
- There is no reference to a clock in the DT. In this case,
devm_clk_get() returns an error that is not -EPROBE_DEFER
(something like -ENODEV), and we continue the probing without
enabling the clock.
- There is a reference to the clock in the DT, and the clock is
ready. devm_clk_get() returns a valid reference to the clock, and
we prepare/enable it.
- There is a reference to the clock in the DT, but the clock is not
ready. devm_clk_get() returns -EPROBE_DEFER, and we exit from
probe() with the same error code so that probe() is tried again
later.
This is needed for Marvell Armada 7K/8K, where the clock driver is a
platform driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The new ARM64 Marvell Armada 7K/8K SoC family is using the same I2C
controller as the 32-bits Marvell EBU SoCs, so this commit allows
mv64xxx to be enabled when ARCH_MVEBU=y.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Documentation/timers/timers-howto.txt recommends to use
usleep_range on delays > 10usec. According to my test results
with Neonode zForce touchscreen driver, usleep_range indeed
reduces CPU load.
Stats collected with "./perf record -a -g -F 1000 sleep 10"
i2c-imx with udelay(50):
34.19% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread
---irq_thread
|--33.75%--irq_thread_fn
| |--19.27%--0x7f08a878
| | i2c_master_recv
| | i2c_transfer
| | __i2c_transfer
| | i2c_imx_xfer
| | |--11.71%--i2c_imx_trx_complete
| | |--5.70%--i2c_imx_start <<<<----------------
| | | |--5.38%--__timer_const_udelay
| | | | __timer_delay
| | | | --5.07%--read_current_timer
i2c-imx with usleep_range(50,100)
29.08% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread
---irq_thread
|--28.89%--irq_thread_fn
| |--17.21%--0x7f08a878
| | i2c_master_recv
| | |--17.14%--i2c_transfer
| | | __i2c_transfer
| | | i2c_imx_xfer
| | | |--14.29%--i2c_imx_trx_complete
| | | |--1.42%--i2c_imx_start <<<<----------
| | | | |--0.71%--usleep_range
| | | | |--0.53%--i2c_imx_bus_busy
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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There is a race between the TWSI interrupt and the condition
that is required before proceeding:
Low-level: interrupt flag bit must be set
High-level controller: valid bit must be clear
If the interrupt comes too early and the condition is not met
the wait will time out, and the transfer is aborted leading
to very poor performance.
To avoid this race retry for the condition ~80 µs later.
The retry is avoided on the very first invocation of
wait_event_timeout() (which tests the condition before entering
the wait and is therefore always wrong in this case).
EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's
achievable, and much better than the worst-case 100 bytes/sec before.
While at it remove the debug print from the low-level wait function.
Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Zero-length message support (SMBUS QUICK or i2c) never worked with
the Octeon hardware. Disable SMBUS QUICK support and bail out in
case of a zero-length i2c request.
After this change 'i2c-detect -q' will return an error on Octeon but
the previously reported results were wrong anyway.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The clk_prepare_enable() function can fail so check the return
value and propagate the error in case of a failure.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The driver not always prints the error code in case of a failure but this
information can be very useful for debugging. So let's print if available.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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