This driver creates a number of const structures that it stores in
the data field of an of_device_id array.
The data field of an of_device_id structure has type const void *, so
there is no need for a const-discarding cast when putting const values
into such a structure.
Furthermore, adding const to the declaration of the location that
receives a const value from such a field ensures that the compiler
will continue to check that the value is not modified. The
const-discarding cast on the extraction from the data field is thus
no longer needed.
Done using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
As of v4.15, Kbuild warns about missing MODULE_LICENSE tags:
WARNING: modpost: missing MODULE_LICENSE() in drivers/i2c/busses/i2c-acorn.o
This adds a license, author and description tag, matching the
comment at the start of the acorn i2c driver.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We can force levels of SCL and SDA, so we can use that for bus recovery.
Note that we cannot read SDA back, because we will only get the internal
state of the bus free detection.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Exynos-I2C uses default timeout of 1 second for the whole transaction,
including re-transmissions due to arbitration lost errors (-EAGAIN).
To allow re-transmissions driver's internal timeout should be significantly
lower, 100ms seems to be good candidate.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use only a portion of the data buffer for DMA transfers, which is always
16-byte aligned. This makes the DMA buffer address 16-byte aligned and
compensates for spurious hardware parity errors that may appear when the
DMA buffer address is not 16-byte aligned.
The data buffer is enlarged in order to accommodate any possible 16-byte
alignment offset and changes the DMA code to only use a portion of the
data buffer, which is 16-byte aligned.
The symptom of the hardware issue is the same as the one addressed in
v3.12-rc2-5-gbf41691 and manifests by transfers failing with EIO, with
bit 9 being set in the ERRSTS register.
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove the facility for setting the prescaler value at compile time
entirely. It was only used for two SoCs, duplicating the actual value
for one of them and setting sometimes bogus value for another. Make all
MPC8xxx SoCs obtain their actual I2C clock prescaler from a single place
in the code.
Changes from v2:
- left Device Tree compatibles in place
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
According to the reference manuals for the corresponding SoCs, SEC
frequency ratio configuration is indicated by bit 26 of the POR Device
Status Register 2. Consequently, SEC_CFG bit should be tested by mask 0x20,
not 0x80. Testing the wrong bit leads to selection of wrong I2C clock
prescaler on those SoCs.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Commit 8ce795cb0c ("i2c: mpc: assign the correct prescaler from SVR")
introduced the common helper function for obtaining the actual clock
prescaler value for MPC85xx. However, getting the prescaler for MPC8544
which depends on the SEC frequency ratio on this platform, has been always
performed separately based on the corresponding Device Tree configuration.
Move special handling of MPC8544 into that common helper. Make it dependent
on the SoC version and not on Device Tree compatible node, as is the case
with all other SoCs. Handle MPC8533 the same way which is similar
to MPC8544 in this regard, according to AN2919 "Determining the I2C
Frequency Divider Ratio for SCL".
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Obtaining the actual I2C clock prescaler value in mpc_i2c_setup_8xxx() only
happens when the clock parameter is set to something other than
MPC_I2C_CLOCK_LEGACY. When the clock parameter is exactly
MPC_I2C_CLOCK_LEGACY, the prescaler parameter is used in arithmetic
division as provided by the caller, resulting in a division by zero
for the majority of processors supported by the module.
Avoid division by zero by obtaining the actual I2C clock prescaler
in mpc_i2c_setup_8xxx() unconditionally regardless of the passed clock
value.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch dumps general and master registers at the end of transactions
when debugging is enabled. Previously, registers were only dumped before
submitting new descriptors (at the beginning of transactions).
This helps debugging if some registers change as result of a failed
transaction (e.g. bits are set in the ERRSTS general register).
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Make use of the new formula for more precise bus frequencies.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The formula to generate the desired bus speeds has changed a little over
time. Implement the new formula and allow drivers to opt-in by changing
to this new config set. Ensure in probe that we don't divide by zero.
The returned values on a R-Car H2 (r8a7790/Lager board) match the
suggested values in the datasheet.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Because we will add a second formula soon, put the sanity checks for the
computed results into a separate function.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Start RuntimePM a bit earlier, so we can use it to enable the clock
during probe for frequency calculations. Make sure it is enabled before
calling setup().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Require the setup callback and move the frequency calculation into it.
This is in preparation for supporting multiple formulas.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The setup callback will be more generic and, thus, need to be able to
return error codes. Change the return type to 'int' for that.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For refactoring reasons, we will need this information before the setup
callback. Also, simplify the comment to a oneliner.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
"Slow" GPIOs (usually those connected over an SPI or an I2C bus) are,
well, slow in their operation. It is generally a good idea to avoid
using them for time-critical operation, but sometimes the hardware just
sucks, and the software has to cope. In addition to that, the I2C bus
itself does not actually define any strict timing limits; the bus is
free to go all the way down to DC. The timeouts (and therefore the
slowest acceptable frequency) are present only in SMBus.
The `can_sleep` is IMHO a wrong concept to use here. My SPI-to-quad-UART
chip (MAX14830) is connected via a 26MHz SPI bus, and it happily drives
SCL at 200kHz (5µs pulses) during my benchmarks. That's faster than the
maximal allowed speed of the traditional I2C.
The previous version of this code did not really block operation over
slow GPIO pins, anyway. Instead, it just resorted to printing a warning
with a backtrace each time a GPIO pin was accessed, thereby slowing
things down even more.
Finally, it's not just me. A similar patch was originally submitted in
2015 [1].
[1] https://patchwork.ozlabs.org/patch/450956/
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Make sure i2c module clock has been enabled before i2c registers
access.
Signed-off-by: Jun Gao <jun.gao@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add i2c compatible for MT2712. Compare to MT8173 i2c controller,
internal divider of i2c source clock need to be configured for
MT2712 i2c speed calculation.
Signed-off-by: Jun Gao <jun.gao@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Merge tag 'at24-4.16-updates-for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-4.16
"AT24 updates for 4.16 merge window
The driver has been converted to using regmap instead of raw i2c and
smbus calls which shrank the code significantly.
Device tree binding document has been cleaned up. Device tree support in
the driver has been improved and we now support all at24 models as well
as two new DT properties (no-read-rollover and wp-gpios).
We no longer user unreadable magic values for driver data as the way it
was implemented caused problems for some EEPROM models - we switched to
regular structs.
Aside from that, there's a bunch of coding style fixes and minor
improvements all over the place."
...which takes care of proper format and size of the value.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Alter the DaVinci GPIO recovery fetch to use descriptors
all the way down into the board files.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
<linux/of_gpio.h> is not used in this file, by
<linux/gpio/consumer.h> is.
Someone is just lucky with their implicit includes.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The port number shift is still hard-coded to 1 while it now depends
on the hardware.
Thankfully 0 is always 0 no matter how you shift it, so this was a
bug without consequences.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 0fe16195f8 ("i2c: piix4: Fix SMBus port selection for AMD Family 17h chips")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When converting to GPIOD, the GPIO directions of SCL/SDA have been
swapped. Fix it!
Fixes: ad36a27959 ("i2c: imx: switch to using gpiod for bus recovery gpios")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
platform_device_id are not supposed to change at runtime. All functions
working with platform_device_id provided by <linux/platform_device.h>
work with const platform_device_id. So mark the non-const structs as
const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This HW is prone to races, so it needs to setup new messages in irq
context. That means we can't alloc bounce buffers if a message buffer is
not DMA safe. So, in that case, simply fall back to PIO.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This ensures that we fall back to PIO if the message length is too small
for DMA being useful. Otherwise, we use DMA. A bounce buffer might be
applied by the helper if the original message buffer is not DMA safe.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add fault injection capabilities to the i2c-gpio driver. When connected
to another I2C bus, it can create unusual states which the other I2C bus
master driver needs to handle. Only for debugging!
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The designware core and platform are built as separate modules.
Export i2c_dw_prepare_clk() so it can be used by the platform
driver.
Fixes: a34a0b6da2 ("i2c: designware: move i2c_dw_plat_prepare_clk to common")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
On Apollo Lake devices the BIOS does not set up IRQ routing for the i801
SMBUS controller IRQ, so we end up with dev->irq set to IRQ_NOTCONNECTED.
Detect this and do not try to use the irq in this case silencing:
i801_smbus 0000:00:1f.1: Failed to allocate irq -2147483648: -107
Cc: stable@vger.kernel.org
BugLink: https://communities.intel.com/thread/114759
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The datasheet was a bit vague, but after consultation with HW designers,
we came to the conclusion that we should set the SCP bit always when
dealing only with the ICE bit. A set SCP bit is ignored, and thus fine,
a cleared one may trigger STOP on the bus.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We initiate STOP (or REP_START) on the second last WAIT interrupt
currently. This works fine but is not according to the datasheet which
says to do it on the last WAIT interrupt. This also simplifies the code
quite a lot, so let's do it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is no data when the first WAIT interrupt arrives. No need to read
something then.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No need to do it manually.
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We can use the ternary operator for easier reading.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
ICE bit is for resetting the module. Other bits don't matter then, so we
don't need to use the iic_set_clr() function but can use iic_wr().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Those two functions are very short and only called once. The code
becomes easier to understand if the code is directly put into the main
xfer function.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No need to clear the interrupt registers because right after that we
disable the IP core which will reload registers with their initial
values anyhow.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Following the documentation, we initialize the HW before each START in
start_ch(). No need to do the same in activate_ch().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Change the driver to use the gpio descriptors for the bus recovery
information instead of the deprecated integer interface.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Change the driver to use the gpio descriptors for the bus recovery
information instead of the deprecated integer interface.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch contains much input from Phil Reid and has been tested
on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
SCL and SDA GPIO's.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For consistency with the rest of the file rename function and parameter to
be consistent with the reset of the common file.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move the i2c_dw_plat_prepare_clk funciton to common file in preparation
for its use also by the master driver.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
According to data sheet SCL timing parameters and DW_IC_CON SPEED mode
bits are not used when operating in slave mode.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
