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Merely enabling compile-testing should not enable additional
functionality.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/36b2923241f285595f43bb9565da352fd366c63e.1733242595.git.geert+renesas@glider.be
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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The AMBA bus header files do not generate compilation errors even
when the AMBA bus is not enabled in Kconfig via ARM_AMBA.
This allows the Nomadik driver to be compiled for testing
purposes with the COMPILE_TEST option enabled.
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241210221641.2661577-1-andi.shyti@kernel.org
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Return -EPROBE_DEFER when dma_request_slave_channel() because DMA driver
have not ready yet.
Move i2c_imx_dma_request() before registering I2C adapter to avoid
infinite loop of .probe() calls to the same driver, see "e8c220fac415
Revert "i2c: imx: improve the error handling in i2c_imx_dma_request()""
and "Documentation/driver-api/driver-model/driver.rst".
Use CPU mode to avoid stuck registering i2c adapter when DMA resources
are unavailable.
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20241226062521.1004809-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Nuvoton slave enable was in user space API call master_xfer, so it is
subject to delays from the OS scheduler. If the BMC is not enabled for
slave mode in time for master to send response, then it will NAK the
address match. Then the PLDM request timeout occurs.
If the slave enable is moved to the EOB interrupt service routine, then
the BMC can be ready in slave mode by the time it needs to receive a
response.
Signed-off-by: Charles Boyer <Charles.Boyer@fii-usa.com>
Signed-off-by: Vivekanand Veeracholan <vveerach@google.com>
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
Link: https://lore.kernel.org/r/20241219090859.18722-5-kfting@nuvoton.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Modify i2c frequency from table parameters for NPCM i2c modules.
Supported frequencies are:
1. 100KHz
2. 400KHz
3. 1MHz
The original equations were tested on a variety of chips and base clocks.
Since we added devices that use higher frequencies of the module we
saw that there is a mismatch between the equation and the actual
results on the bus itself, measured on scope.
Meanwhile, the equations were not accurate to begin with.
They are an approximation of the ideal value. The ideal value is
calculated per frequency of the core module.
So instead of using the equations we did an optimization per module
frequency, verified on a device.
Most of the work was focused on the rise time of the SCL and SDA,
which depends on external load of the bus and PU.
Different PCB designs, or specifically to this case: the number
and type of targets on the bus, impact the required values for
the timing registers.
Users can recalculate the numbers for each bus and get an even better
optimization, but our users chose not to.
We manually picked values per frequency that match the entire valid
range of targets (from 1 to max number). Then we check against the
AMR described in SMB spec and make sure that none of the values
is exceeding.
This process was led by the chip architect and included a lot of testing.
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
Link: https://lore.kernel.org/r/20241219090859.18722-4-kfting@nuvoton.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Store the client address earlier since it might get called in
the i2c_recover_bus() logic flow at the early stage of
npcm_i2c_master_xfer().
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
Link: https://lore.kernel.org/r/20241219090859.18722-3-kfting@nuvoton.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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The users want to connect a lot of masters on the same bus.
This timeout is used to determine the time it takes to take bus ownership.
The transactions are very long, so waiting 35ms is not enough.
Increase the timeout and treat it as the total timeout, including retries.
The total timeout is 2 seconds now.
The i2c core layer will have chances to retry to call the i2c driver
transfer function if the i2c driver reports that the bus is busy and
returns -EAGAIN.
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Tali Perry <tali.perry1@gmail.com>
Link: https://lore.kernel.org/r/20241219090859.18722-2-kfting@nuvoton.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Switch different pinctrl state in different system power status.
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20241223034343.544002-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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resume_noirq()
Put runtime PM to resume state between suspend() and suspend_noirq(),
resume_noirq() and resume(), because some I2C devices need the controller
on to perform communication during this period.
The controller can't be woken up once runtime pm is disabled and in
runtime autosuspended state.
The problem can be easily reproduced on the I.MX8MQ platform:
the PMIC needs to be used to enable regulator when the system resumes.
When the PMIC uses the I2C controller, I2C runtime pm has not been enabled,
so in i2c xfer(), pm_runtime_resume_and_get() will return an error,
which causes data transfer to fail. Therefore, regulators cannot
be enabled and system resume hangs.
Here is resume error log:
[ 53.888902] galcore 38000000.gpu3d: PM: calling genpd_resume_noirq @ 529, parent: platform
[ 53.897203] i2c_imx_xfer, pm_runtime_resume_and_get is -13
[ 53.902713] imx-pgc imx-pgc-domain.5: failed to enable regulator: -EACCES
[ 53.909518] galcore 38000000.gpu3d: PM: genpd_resume_noirq returned 0 after 12331 usecs
[ 53.917545] mxc_hantro 38300000.vpu: PM: calling genpd_resume_noirq @ 529, parent: soc@0
[ 53.925659] i2c_imx_xfer, pm_runtime_resume_and_get is -13
[ 53.931157] imx-pgc imx-pgc-domain.6: failed to enable regulator: -EACCES
I.MX8MQ system resume normally after applying the fix. Here is resume log:
[ 71.068807] galcore 38000000.gpu3d: PM: calling genpd_resume_noirq @ 530, parent: platform
[ 71.077103] i2c_imx_xfer, pm_runtime_resume_and_get is 0
[ 71.083578] galcore 38000000.gpu3d: PM: genpd_resume_noirq returned 0 after 6490 usecs
[ 71.091526] mxc_hantro 38300000.vpu: PM: calling genpd_resume_noirq @ 530, parent: soc@0
[ 71.099638] i2c_imx_xfer, pm_runtime_resume_and_get is 0
[ 71.106091] mxc_hantro 38300000.vpu: PM: genpd_resume_noirq returned 0 after 6458 usecs
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241125142108.1613016-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Add "i2c_clk_rate / 2" check to avoid "divide by zero warning".
i2c_clk_rate may be zero if i2c clock is disabled.
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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No need to check the argument of i2c_unregister_device() because the
function itself does it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Similar to the list of auto-detected clients, we can also replace the
list of userspace-created clients with flagging such client devices.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: fixed description of the new flag; reordered new code in
'device_store' to have single exit point; fixed whitespace errors;
folded cleanup patch into this one]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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So far a list is used to track auto-detected clients per driver.
The same functionality can be achieved much simpler by flagging
auto-detected clients.
Two notes regarding the usage of driver_for_each_device:
In our case it can't fail, however the function is annotated __must_check.
So a little workaround is needed to avoid a compiler warning.
Then we may remove nodes from the list over which we iterate.
This is safe, see the explanation at the beginning of lib/klist.c.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: fixed description of the new flag]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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Running i2c-detect currently produces an output akin to:
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 08 -- 0a -- 0c -- 0e --
10: 10 -- 12 -- 14 -- 16 -- UU 19 -- 1b -- 1d -- 1f
20: -- 21 -- 23 -- 25 -- 27 -- 29 -- 2b -- 2d -- 2f
30: -- -- -- -- -- -- -- -- 38 -- 3a -- 3c -- 3e --
40: 40 -- 42 -- 44 -- 46 -- 48 -- 4a -- 4c -- 4e --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: 60 -- 62 -- 64 -- 66 -- 68 -- 6a -- 6c -- 6e --
70: 70 -- 72 -- 74 -- 76 --
This happens because for an i2c_msg with a len of 0 the driver will
mark the transmission of the message as a success once the START has
been sent, without waiting for the devices on the bus to respond with an
ACK/NAK. Since i2cdetect seems to run in a tight loop over all addresses
the NAK is treated as part of the next test for the next address.
Delete the fast path that marks a message as complete when idev->msg_len
is zero after sending a START/RESTART since this isn't a valid scenario.
CC: stable@vger.kernel.org
Fixes: 64a6f1c4987e ("i2c: add support for microchip fpga i2c controllers")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20241218-outbid-encounter-b2e78b1cc707@spud
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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At present, where repeated sends are intended to be used, the
i2c-microchip-core driver sends a stop followed by a start. Lots of i2c
devices must not malfunction in the face of this behaviour, because the
driver has operated like this for years! Try to keep track of whether or
not a repeated send is required, and suppress sending a stop in these
cases.
CC: stable@vger.kernel.org
Fixes: 64a6f1c4987e ("i2c: add support for microchip fpga i2c controllers")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20241218-football-composure-e56df2461461@spud
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Compatible string "fsl,imx7d-i2c" is not exited at i2c-imx driver
compatible string table, at the result, "fsl,imx21-i2c" will be
matched, but it will cause erratum ERR007805 not be applied in fact.
So Add "fsl,imx7d-i2c" compatible string in i2c-imx driver to apply
the erratum ERR007805(https://www.nxp.com/docs/en/errata/IMX7DS_3N09P.pdf).
"
ERR007805 I2C: When the I2C clock speed is configured for 400 kHz,
the SCL low period violates the I2C spec of 1.3 uS min
Description: When the I2C module is programmed to operate at the
maximum clock speed of 400 kHz (as defined by the I2C spec), the SCL
clock low period violates the I2C spec of 1.3 uS min. The user must
reduce the clock speed to obtain the SCL low time to meet the 1.3us
I2C minimum required. This behavior means the SoC is not compliant
to the I2C spec at 400kHz.
Workaround: To meet the clock low period requirement in fast speed
mode, SCL must be configured to 384KHz or less.
"
"fsl,imx7d-i2c" already is documented in binding doc. This erratum
fix has been included in imx6_i2c_hwdata and it is the same in all
I.MX6/7/8, so just reuse it.
Fixes: 39c025721d70 ("i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit")
Cc: stable@vger.kernel.org # v5.18+
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Fixes: 39c025721d70 ("i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit")
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20241218044238.143414-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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A regression was introduced with the implementation of single-master
mode, preventing proper stop conditions from being generated. Devices
that require a valid stop condition, such as EEPROMs, fail to function
correctly as a result.
The issue only affects devices with the single-master property enabled.
This commit resolves the issue by re-enabling I2C bus busy bit (IBB)
polling for single-master mode when generating a stop condition. The fix
further ensures that the i2c_imx->stopped flag is cleared at the start
of each transfer, allowing the stop condition to be correctly generated
in i2c_imx_stop().
According to the reference manual (IMX8MMRM, Rev. 2, 09/2019, page
5270), polling the IBB bit to determine if the bus is free is only
necessary in multi-master mode. Consequently, the IBB bit is not polled
for the start condition in single-master mode.
Fixes: 6692694aca86 ("i2c: imx: do not poll for bus busy in single master mode")
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20241216151829.74056-1-eichest@gmail.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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i2c-i801 to dell-lis3lv02d
Various Dell laptops have an lis3lv02d freefall/accelerometer sensor.
The lis3lv02d chip has an interrupt line as well as an I2C connection to
the system's main SMBus.
The lis3lv02d is described in the ACPI tables by an SMO88xx ACPI device,
but the SMO88xx ACPI fwnodes are incomplete and only list an IRQ resource.
So far this has been worked around with some SMO88xx specific quirk code
in the generic i2c-i801 driver, but it is not necessary to handle the Dell
specific instantiation of i2c_client-s for SMO88xx ACPI devices there.
The kernel already instantiates platform_device-s for these with an
acpi:SMO88xx modalias. The drivers/platform/x86/dell/dell-smo8800.c
driver binds to this platform device but this only deals with
the interrupt resource. Add a drivers/platform/x86/dell/dell-lis3lv02d.c
which will matches on the same acpi:SMO88xx modaliases and move
the i2c_client instantiation from the generic i2c-i801 driver there.
Moving the i2c_client instantiation has the following advantages:
1. This moves the SMO88xx ACPI device quirk handling away from the generic
i2c-i801 module which is loaded on all Intel x86 machines to a module
which will only be loaded when there is an ACPI SMO88xx device.
2. This removes the duplication of the SMO88xx ACPI Hardware ID (HID) table
between the i2c-i801 and dell-smo8800 drivers.
3. This allows extending the quirk handling by adding new code and related
module parameters to the dell-lis3lv02d driver, without needing to modify
the i2c-i801 code.
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20241209183557.7560-3-hdegoede@redhat.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Currently, the RIIC driver may run the I2C bus faster than requested,
which may cause subtle failures. E.g. Biju reported a measured bus
speed of 450 kHz instead of the expected maximum of 400 kHz on RZ/G2L.
The initial calculation of the bus period uses DIV_ROUND_UP(), to make
sure the actual bus speed never becomes faster than the requested bus
speed. However, the subsequent division-by-two steps do not use
round-up, which may lead to a too-small period, hence a too-fast and
possible out-of-spec bus speed. E.g. on RZ/Five, requesting a bus speed
of 100 resp. 400 kHz will yield too-fast target bus speeds of 100806
resp. 403226 Hz instead of 97656 resp. 390625 Hz.
Fix this by using DIV_ROUND_UP() in the subsequent divisions, too.
Tested on RZ/A1H, RZ/A2M, and RZ/Five.
Fixes: d982d66514192cdb ("i2c: riic: remove clock and frequency restrictions")
Reported-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: <stable@vger.kernel.org> # v4.15+
Link: https://lore.kernel.org/r/c59aea77998dfea1b4456c4b33b55ab216fcbf5e.1732284746.git.geert+renesas@glider.be
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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The OF match table is not NULL-terminated.
Fix this by adding a sentinel to nmk_i2c_eyeq_match_table[].
Fixes: a0d15cc47f29be6d ("i2c: nomadik: switch from of_device_is_compatible() to of_match_device()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Since commit f63b94be6942 ("i2c: pnx: Fix potential deadlock warning
from del_timer_sync() call in isr") jiffies are stored in
i2c_pnx_algo_data.timeout, but wait_timeout and wait_reset are still
using it as milliseconds. Convert jiffies back to milliseconds to wait
for the expected amount of time.
Fixes: f63b94be6942 ("i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr")
Signed-off-by: Vladimir Riabchun <ferr.lambarginio@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Commit cdd30ebb1b9f ("module: Convert symbol namespace to string
literal") only converted MODULE_IMPORT_NS() and EXPORT_SYMBOL_NS(),
leaving DEFAULT_SYMBOL_NAMESPACE as a macro expansion.
This commit converts DEFAULT_SYMBOL_NAMESPACE in the same way to avoid
annoyance for the default namespace as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.
Scripted using
git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
do
awk -i inplace '
/^#define EXPORT_SYMBOL_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/^#define MODULE_IMPORT_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/MODULE_IMPORT_NS/ {
$0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
}
/EXPORT_SYMBOL_NS/ {
if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
$0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
$0 !~ /^my/) {
getline line;
gsub(/[[:space:]]*\\$/, "");
gsub(/[[:space:]]/, "", line);
$0 = $0 " " line;
}
$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
"\\1(\\2, \"\\3\")", "g");
}
}
{ print }' $file;
done
Requested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The continual trickle of small conversion patches is grating on me, and
is really not helping. Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:
/*
* .remove_new() is a relic from a prototype conversion of .remove().
* New drivers are supposed to implement .remove(). Once all drivers are
* converted to not use .remove_new any more, it will be dropped.
*/
This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.
I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.
Then I just removed the old (sic) .remove_new member function, and this
is the end result. No more unnecessary conversion noise.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch fixes a coding style issue in the alignment of parameters
in the function i2c_smbus_write_bytes(). It replaces spaces with tabs for
alignment, as per the coding style guidelines.
Signed-off-by: Liam Zuiderhoek <zuiderhoekl@gmail.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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Add GPIO support to the simple helpers for the I2C OF component prober.
Components that the prober intends to probe likely require their
regulator supplies be enabled, and GPIOs be toggled to enable them or
bring them out of reset before they will respond to probe attempts.
Regulator supplies were handled in the previous patch.
The assumption is that the same class of components to be probed are
always connected in the same fashion with the same regulator supply
and GPIO. The names may vary due to binding differences, but the
physical layout does not change.
This supports at most one GPIO pin. The user must specify the GPIO name,
the polarity, and the amount of time to wait after the GPIO is toggled.
Devices with more than one GPIO pin likely require specific power
sequencing beyond what generic code can easily support.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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Add helpers to do regulator management for the I2C OF component prober.
Components that the prober intends to probe likely require their
regulator supplies be enabled, and GPIOs be toggled to enable them or
bring them out of reset before they will respond to probe attempts.
GPIOs will be handled in the next patch.
The assumption is that the same class of components to be probed are
always connected in the same fashion with the same regulator supply
and GPIO. The names may vary due to binding differences, but the
physical layout does not change.
This set of helpers supports at most one regulator supply. The user
must specify the node from which the supply is retrieved. The supply
name and the amount of time to wait after the supply is enabled are
also given by the user.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
|
Some devices are designed and manufactured with some components having
multiple drop-in replacement options. These components are often
connected to the mainboard via ribbon cables, having the same signals
and pin assignments across all options. These may include the display
panel and touchscreen on laptops and tablets, and the trackpad on
laptops. Sometimes which component option is used in a particular device
can be detected by some firmware provided identifier, other times that
information is not available, and the kernel has to try to probe each
device.
This change attempts to make the "probe each device" case cleaner. The
current approach is to have all options added and enabled in the device
tree. The kernel would then bind each device and run each driver's probe
function. This works, but has been broken before due to the introduction
of asynchronous probing, causing multiple instances requesting "shared"
resources, such as pinmuxes, GPIO pins, interrupt lines, at the same
time, with only one instance succeeding. Work arounds for these include
moving the pinmux to the parent I2C controller, using GPIO hogs or
pinmux settings to keep the GPIO pins in some fixed configuration, and
requesting the interrupt line very late. Such configurations can be seen
on the MT8183 Krane Chromebook tablets, and the Qualcomm sc8280xp-based
Lenovo Thinkpad 13S.
Instead of this delicate dance between drivers and device tree quirks,
this change introduces a simple I2C component probe function. For a
given class of devices on the same I2C bus, it will go through all of
them, doing a simple I2C read transfer and see which one of them responds.
It will then enable the device that responds.
This requires some minor modifications in the existing device tree. The
status for all the device nodes for the component options must be set
to "fail-needs-probe". This makes it clear that some mechanism is
needed to enable one of them, and also prevents the prober and device
drivers running at the same time.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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In commit 35eba185fd1a ("i2c: designware: Calculate SCL timing parameter
for High Speed Mode") the SCL high period count and low period count for
high speed mode are calculated based on fixed tHIGH = 160 and tLOW = 120.
However, the set of two fixed values is only applicable to the combination
of hardware parameters IC_CAP_LOADING is 400 and IC_CLK_FREQ_OPTIMIZATION
is true. Outside of this combination, the SCL frequency may not reach
3.4 MHz because the fixed tHIGH and tLOW are not small enough.
If IC_CAP_LOADING is 400, it means the bus capacitance is 400pF;
Otherwise, 100 pF. If IC_CLK_FREQ_OPTIMIZATION is true, it means that the
hardware reduces its internal clock frequency by reducing the internal
latency required to generate the high period and low period of the SCL line.
Section 3.15.4.5 in DesignWare DW_apb_i2b Databook v2.03 says that when
IC_CLK_FREQ_OPTIMIZATION = 0,
MIN_SCL_HIGHtime = 60 ns for 3.4 Mbps, bus loading = 100pF
= 120 ns for 3.4 Mbps, bus loading = 400pF
MIN_SCL_LOWtime = 160 ns for 3.4 Mbps, bus loading = 100pF
= 320 ns for 3.4 Mbps, bus loading = 400pF
and section 3.15.4.6 says that when IC_CLK_FREQ_OPTIMIZATION = 1,
MIN_SCL_HIGHtime = 60 ns for 3.4 Mbps, bus loading = 100pF
= 160 ns for 3.4 Mbps, bus loading = 400pF
MIN_SCL_LOWtime = 120 ns for 3.4 Mbps, bus loading = 100pF
= 320 ns for 3.4 Mbps, bus loading = 400pF
In order to calculate more accurate SCL high period count and low period
count for high speed mode, two hardware parameters IC_CAP_LOADING and
IC_CLK_FREQ_OPTIMIZATION must be considered together. Since there're no
registers controlliing these these two hardware parameters, users can
declare them in the device tree so that the driver can obtain them.
Signed-off-by: Michael Wu <michael.wu@kneron.us>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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- BRCR value must go into the BRCR1 field when in high-speed mode.
It goes into BRCR2 otherwise.
- Remove fallback to standard mode if priv->sm > I2C_FREQ_MODE_FAST.
- Set SM properly in probe; previously it only checked STANDARD versus
FAST. Now we set STANDARD, FAST, FAST_PLUS or HIGH_SPEED.
- Remove all comment sections saying we only support low-speeds.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
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Current BRCR computation is:
brcr = floor(i2cclk / (clkfreq * div))
With brcr: "baud rate counter", an internal clock divider,
and i2cclk: input clock rate (24MHz, 38.4MHz or 48MHz),
and clkfreq: desired bus rate,
and div: speed-mode dependent divider (2 for standard, 3 otherwise).
Assume i2cclk=48MHz, clkfreq=3.4MHz, div=3,
then brcr = floor(48MHz / (3.4MHz * 3)) = 4
and resulting bus rate = 48MHz / (4 * 3) = 4MHz
Assume i2cclk=38.4MHz, clkfreq=1.0MHz, div=3,
then brcr = floor(38.4MHz / (1.0MHz * 3)) = 12
and resulting bus rate = 38.4MHz / (12 * 3) = 1066kHz
The current computation means we always pick the smallest divider that
gives a bus rate above target. We should instead pick the largest
divider that gives a bus rate below target, using:
brcr = floor(i2cclk / (clkfreq * div)) + 1
If we redo the above examples:
Assume i2cclk=48MHz, clkfreq=3.4MHz, div=3,
then brcr = floor(48MHz / (3.4MHz * 3)) + 1 = 5
and resulting bus rate = 48MHz / (5 * 3) = 3.2MHz
Assume i2cclk=38.4MHz, clkfreq=1.0MHz, div=3,
then brcr = floor(38.4MHz / (1.0MHz * 3)) + 1 = 13
and resulting bus rate = 38.4MHz / (13 * 3) = 985kHz
In kernel C code, floor(x) is DIV_ROUND_DOWN() and,
floor(x)+1 is DIV_ROUND_UP().
This is much less of an issue with slower bus rates (ie those currently
supported), because the gap from one divider to the next is much
smaller. It however keeps us from always using bus rates superior to
the target.
This fix is required for later on supporting faster bus rates:
I2C_FREQ_MODE_FAST_PLUS (1MHz) and I2C_FREQ_MODE_HIGH_SPEED (3.4MHz).
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
|
Add EyeQ6H support to the nmk-i2c AMBA driver. It shares the same quirk
as EyeQ5: the memory bus only supports 32-bit accesses. Avoid writeb()
and readb() by reusing the same `priv->has_32b_bus` flag.
It does NOT need to write speed-mode specific value into a register;
therefore it does not depend on the mobileye,olb DT property.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
|
Compatible-specific behavior is implemented using a if-condition on the
return value from of_device_is_compatible(), from probe. It does not
scale well when compatible number increases. Switch to using a match
table and a call to of_match_device().
We DO NOT attach a .of_match_table field to our amba driver, as we do
not use the table to match our driver to devices.
Sort probe variable declarations in reverse christmas tree to try and
introduce some logic into the ordering.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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Enable DWAPB I2C controller support on FUJITSU-MONAKA.
This will be used in the FUJITSU-MONAKA server scheduled
for shipment in 2027.
The DSDT information obtained when verified using an
in-house simulator is presented below.
Device (SMB0)
{
Name (_HID, "FUJI200B") // _HID: Hardware ID
Name (_UID, Zero) // _UID: Unique ID
...
Name (_CRS, ResourceTemplate ()
{
Memory32Fixed (ReadWrite,
0x2A4B0000, // Address Base
0x00010000, // Address Length
)
Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive, ,, )
{
0x00000159,
}
})
...
}
The expression SMB0 is used to indicate SMBus HC#0,
a string of up to four characters.
Created the SMB0 object according to the following
specifications:
ACPI Specification
13.2. Accessing the SMBus from ASL Code
https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/13_ACPI_System_Mgmt_Bus_Interface_Spec/accessing-the-smbus-from-asl-code.html
IPMI Specification
Example 4: SSIF Interface(P574)
https://www.intel.co.jp/content/www/jp/ja/products/docs/servers/ipmi/ipmi-second-gen-interface-spec-v2-rev1-1.html
Signed-off-by: Yoshihiro Furudera <fj5100bi@fujitsu.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
|
There's no reason for this driver to use OF-specific property helpers.
Drop the last one in favor of the generic variant and no longer include
of.h.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Core:
- drivers can now use a GPIO as a side channel for SMBus Alerts using
a generic binding
- regular stuff like mem leak fix, Makefile maintenance...
Host improvements and refactoring:
- All controllers using the 'remove_new' callback have been reverted
to use the 'remove' callback
- Intel SCH controller underwent significant refactoring, this brings
love and a modern look to the driver
- PIIX4 driver refactored to enable usage by other drivers (e.g., AMD
ASF)
- iMX/MXC improved message handling to reduce protocol overhead:
Refactored DMA/non-DMA read/write and bus polling mechanisms to
achieve this.
- ACPI documentation for PIIX4
New host features:
- i2c-cadence support for atomic transfers
- Qualcomm CII support for a 32MHz serial engine clock
Deprecated features:
- Dropped outdated support for AMD756 S4882 and NFORCE2 S4985. If
somebody misses this, Jean will rewrite support using the proper
i2c mux framework.
New hardware IDs for existing drivers:
- Intel Panther Lake
- S32G2/S32G3 SoCs
- HJMC01 DesignWare ACPI HID
- PIC64GX to Microchip Core
- Qualcomm SDM670 to Qualcomm CCI
New drivers:
- AMD ASF
- Realtek RTL I2C Controller
at24 updates:
- add support for the lockable page on ST M24256E"
* tag 'i2c-for-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (59 commits)
docs: i2c: piix4: Add ACPI section
i2c: Add driver for the RTL9300 I2C controller
i2c: qcom-cci: Remove unused struct member cci_clk_rate
dt-bindings: i2c: Add Realtek RTL I2C Controller
i2c: busses: Use *-y instead of *-objs in Makefile
i2c: imx: add support for S32G2/S32G3 SoCs
dt-bindings: i2c: imx: add SoC specific compatible strings for S32G
i2c: qcom-cci: Remove the unused variable cci_clk_rate
i2c: Drop legacy muxing pseudo-drivers
i2c: imx: prevent rescheduling in non dma mode
i2c: imx: separate atomic, dma and non-dma use case
i2c: imx: do not poll for bus busy in single master mode
i2c: designware: Add a new ACPI HID for HJMC01 I2C controller
i2c: qcom-geni: Keep comment why interrupts start disabled
dt-bindings: i2c: microchip: corei2c: Add PIC64GX as compatible with driver
i2c: designware: constify abort_sources
i2c: Switch back to struct platform_driver::remove()
i2c: qcom-geni: Support systems with 32MHz serial engine clock
i2c: qcom-cci: Stop complaining about DT set clock rate
dt-bindings: i2c: qcom-cci: Document SDM670 compatible
...
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git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"Three new drivers, support for some new models in existing ones and
lots of various tweaks and improvements across the board (switching to
using recommended APIs, code shrink and simplification, etc.).
Also a new feature in the character device uAPI where we now notify
the user-space about changes triggered by in-kernel users as well, not
only when they were done by other user-space agents.
Summary:
GPIOLIB core:
- use the new mem_is_zero() instead of memchr_inv(s, 0, n)
- don't store debounce period twice needlessly
- clean-up debugfs handling
- remove leftover comments referring to no longer used spinlocks
- unduplicate some operations like SRCU locks and initializing GPIO
descriptors
- constify the sysfs class struct
- use lock guards in GPIO sysfs code
- update GPIO uAPI internal flags all at once atomically for
consistency with other places
- modify the behavior of the sysfs interface by no longer exporting
lines that are named inside the driver code or board files with the
sysfs links bearing the line names as this has for many years been
largely unused due to the prevalence of DT, ACPI and firmware nodes
over board files and made the API inconsistent
- for GPIO interrupt providers: free irqs that are still requested by
users when removing the chip
GPIO uAPI:
- notify user-space about changes to GPIO lines' state (requested,
released, reconfigured) triggered from the kernel as well (until
now we'd only do this for changes triggered from user-space)
- to that end: modify the internal workings of the notification
mechanism by switching to an atomic notifier which allows us to
send events from atomic context
- also to that end store the debounce period in the GPIO descriptor
struct and not in the character device context struct
- while at it, also cover the corner-case of users introducing
changes over sysfs while others watch them via the character device
- don't report GPIO lines requested as interrupts as "used" to
user-space as it can still request them as GPIOs
New drivers:
- GPIO part of the MFD Congatec Board Controller
- PolarFire GPIO controller
- GPIOs on FTDI FT2232H
Driver improvements:
- use generic device property accessors instead of OF-specific ones
across many GPIO drivers (mpc8xxx, vf610, eic-sprd, davinci,
ts4900, xilinx, mvebu)
- use devres helpers to simplify error paths and either shrink or
entirely remove the driver's remove() callback (grgpio, amdpt,
menz127, max730x, ftgpio010, 74x164, ljca)
- use helper variables to store the address of pdev->dev and avoid
some line-breaks
- use device_for_each_child_node_scoped() to avoid having to put the
fwnode on breaks or errors (gpio-sim, gpio-dwapb, gpiolib-acpi)
- use a scoped bitmap to simplify the code and drop goto labels in
gpio-aggregator
- drop unneeded Kconfig dependencies on OF_GPIO (grgpio, mveby,
xilinx)
- add support for new models to gpio-aspeed, gpio-rockchip and
gpio-dwapb
- clean-up ACPI handling and some other bits in gpio-xgene-sb
- replace deprecated PCI functions in pcie-idio-24 and pci-idio-16
- allow to build davinci and mvebu drivers with COMPILE_TEST=y
- remove dead code in gpio-mb86s7x
- switch back to using platform_driver::remove() (after the
conversion to remove_new()) across the GPIO drivers
- remove remaining uses of GPIOF_ACTIVE_LOW across the tree and drop
this deprecated symbol
- convert the gpio-altera driver to no longer pull in the deprecated
legacy-of-mm-gpiochip.h header
- use of_property_present() instead of of_property_read_bool() in
gpiolib-of and gpio-rockchip
- allow to build the tegra186 driver on Tegra234 platforms in Kconfig
Late fixes:
- add a missing return value check after devm_kasprintf() to
gpio-grgpio
DT bindings:
- document the ngpios property of gpio-mmio
- add support for a new aspeed model
- fix the example for st,nomadik-gpio
Other:
- kernel doc and comments tweaks
- fix typos in TODO
- reorder headers alphabetically in some drivers
- fix incorrect format specifiers in gpio tools"
* tag 'gpio-updates-for-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (98 commits)
gpio: tegra186: Allow to enable driver on Tegra234
gpio: grgpio: Add NULL check in grgpio_probe
tools: gpio: Fix several incorrect format specifiers
gpio: mpfs: add CoreGPIO support
gpio: rockchip: support new version GPIO
gpio: rockchip: change the GPIO version judgment logic
gpio: rockchip: explan the format of the GPIO version ID
gpiolib: cdev: use !mem_is_zero() instead of memchr_inv(s, 0, n)
MAINTAINERS: add gpio driver to PolarFire entry
gpio: Get rid of GPIOF_ACTIVE_LOW
USB: gadget: pxa27x_udc: Avoid using GPIOF_ACTIVE_LOW
pcmcia: soc_common: Avoid using GPIOF_ACTIVE_LOW
leds: gpio: Avoid using GPIOF_ACTIVE_LOW
Input: gpio_keys_polled - avoid using GPIOF_ACTIVE_LOW
Input: gpio_keys - avoid using GPIOF_ACTIVE_LOW
gpio: Use of_property_present() for non-boolean properties
gpio: mpfs: add polarfire soc gpio support
gpio: altera: Drop legacy-of-mm-gpiochip.h header
gpio: pcie-idio-24: Replace deprecated PCI functions
gpio: pci-idio-16: Replace deprecated PCI functions
...
|
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git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-mergewindow
i2c-host updates for v6.13, part 1
Major Improvements and Refactoring:
- All controllers using the 'remove_new' callback have been
reverted to use the 'remove' callback.
- Intel SCH controller underwent significant refactoring,
this brings love and a modern look to the driver.
- PIIX4 driver refactored to enable usage by other drivers
(e.g., AMD ASF).
- iMX/MXC improved message handling to reduce protocol overhead:
Refactored DMA/non-DMA read/write and bus polling mechanisms
to achieve this.
- ACPI documentation for PIIX4.
New Features:
- i2c-cadence added support for atomic transfers.
- Qualcomm CII added support for a 32MHz serial engine clock.
Deprecated Features:
- Dropped outdated support for AMD756 S4882 and NFORCE2 S4985. If
somebody misses this, Jean will rewrite support using the proper
i2c mux framework.
New Hardware Support:
- Added support for:
- Intel Panther Lake (new ID)
- AMD ASF (new driver)
- S32G2/S32G3 SoCs (new ID)
- Realtek RTL I2C Controller (new driver)
- HJMC01 DesignWare ACPI HID (new ID)
- PIC64GX to Microchip Core (new ID)
- Qualcomm SDM670 to Qualcomm CCI (new ID)
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Add support for the I2C controller on the RTL9300 SoC. There are two I2C
controllers in the RTL9300 that are part of the Ethernet switch register
block. Each of these controllers owns a SCL pin (GPIO8 for the fiorst
I2C controller, GPIO17 for the second). There are 8 possible SDA pins
(GPIO9-16) that can be assigned to either I2C controller. This
relationship is represented in the device tree with a child node for
each SDA line in use.
This is based on the openwrt implementation[1] but has been
significantly modified
[1] - https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/realtek/files-5.15/drivers/i2c/busses/i2c-rtl9300.c
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
The removal of the supply clock rate check implies a need to remove
some unnecessary left-over data from the driver as well.
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
*-objs suffix is reserved rather for (user-space) host programs while
usually *-y suffix is used for kernel drivers (although *-objs works
for that purpose for now).
Let's correct the old usages of *-objs in Makefiles.
While at it, fix an obvious typo in help section of the Kconfig.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
Some S32G2/S32G3 SoC I2C particularities exist
such as different <clock divider, register value> pairs.
Those are addressed by adding specific S32G2 and S32G3
compatible strings.
Co-developed-by: Ionut Vicovan <Ionut.Vicovan@nxp.com>
Signed-off-by: Ionut Vicovan <Ionut.Vicovan@nxp.com>
Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
Variable cci_clk_rate is not effectively used, so delete it.
drivers/i2c/busses/i2c-qcom-cci.c:526:16: warning: variable ‘cci_clk_rate’ set but not used.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=11532
Fixes: 8284750a1829 ("i2c: qcom-cci: Stop complaining about DT set clock rate")
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
The i2c-amd756-s4882 and i2c-nforce2-s4985 muxing pseudo-drivers were
written at a time when the i2c core did not support muxing. They are
essentially board-specific hacks. If we had to add support for these
boards today, we would implement it in a completely different way.
These Tyan server boards are 19 years old by now, so I very much doubt
any of these is still running today. So let's just drop this clumsy
code. If anyone really still needs this support and complains, I'll
rewrite it in a proper way on top of i2c-mux.
This also fixes the following warnings:
drivers/i2c/busses/i2c-amd756.c:286:20: warning: symbol 'amd756_smbus' was not declared. Should it be static?
drivers/i2c/busses/i2c-nforce2.c:123:20: warning: symbol 'nforce2_smbus' was not declared. Should it be static?
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Andi Shyti <andi.shyti@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
|
|
We are experiencing a problem with the i.MX I2C controller when
communicating with SMBus devices. We are seeing devices time-out because
the time between sending/receiving two bytes is too long, and the SMBus
device returns to the idle state. This happens because the i.MX I2C
controller sends and receives byte by byte. When a byte is sent or
received, we get an interrupt and can send or receive the next byte.
The current implementation sends a byte and then waits for an event
generated by the interrupt subroutine. After the event is received, the
next byte is sent and we wait again. This waiting allows the scheduler
to reschedule other tasks, with the disadvantage that we may not send
the next byte for a long time because the send task is not immediately
scheduled. For example, if the rescheduling takes more than 25ms, this
can cause SMBus devices to timeout and communication to fail.
This patch changes the behavior so that we do not reschedule the
send/receive task, but instead send or receive the next byte in the
interrupt subroutine. This prevents rescheduling and drastically reduces
the time between sending/receiving bytes. The cost in the interrupt
subroutine is relatively small, we check what state we are in and then
send/receive the next byte. Before we had to call wake_up, which is even
less expensive. However, we also had to do some scheduling, which
increased the overall cost compared to the new solution. The wake_up
function to wake up the send/receive task is now only called when an
error occurs or when the transfer is complete.
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Separate the atomic, dma and non-dma use case as a preparation step for
moving the non-dma use case to the isr to avoid rescheduling while a
transfer is in progress.
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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According to the i.MX8M Mini reference manual chapter "16.1.4.2
Generation of Start" it is only necessary to poll for bus busy and
arbitration lost in multi master mode. This helps to avoid rescheduling
while the i2c bus is busy and avoids SMBus devices to timeout. For
backward compatibility, the single-master property needs to be
explicitly set to disable the bus busy polling.
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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Define a new ACPI HID for HJMC01
Signed-off-by: Hunter Yu <hunter.yu@hj-micro.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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The to-be-fixed commit rightfully reduced a race window, but also
removed a comment which is still helpful after the fix. Bring the
comment back.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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We never modify abort_sources, mark it as const.
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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