This patch adds a algorithm to calculate some ac-timing parameters
which can fully meet I2C Spec.
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Allow slave mode for PCI enumerated devices by calling a common i2c_dw_probe()
instead of i2c_dw_probe_master().

While dropping dependency to platform driver in slave module, move its
configuration section above, closer to core.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

As a preparatory patch to support slave mode for PCI enumerated devices rename
i2c_dw_probe() to i2c_dw_probe_master() and split common i2c_dw_probe() as
inline helper.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Since we have available helper to configure master mode, let's use it
in the PCI driver instead of spread open-coded variant.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Move configuration routines to respective modules, i.e. master and slave.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Use devm_platform_ioremap_resource() instead of
platform_get_resource() + devm_ioremap_resource().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Use master-abort to send the stop condition after an address cycle
rather than resetting the controller.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

If we timeout during a message transfer, the control register may
contain bits that cause an action to be set. Read-modify-writing the
register leaving these bits set may trigger the hardware to attempt
one of these actions unintentionally.

Always clear these bits when cleaning up after a message or after
a timeout.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Remove unnecessary show_state() in the loop inside
i2c_pxa_pio_set_master(), which can be unnecessarily verbose.

Remove the i2c_pxa_scream_blue_murder() in i2c_pxa_pio_xfer(), which
will trigger if we are probing the I2C bus and a slave does not
respond; this is a normal event, and not something to report.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Ensure that the various timeout messages can identify where in the code
they were produced from to aid debugging.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Running i2cdetect on a PXA I2C adapter is very noisy; it complains
whenever a slave fails to respond to the address cycle.  Since it is
normal to probe for slaves in this way, we should not fill the kernel
log.  This is especially true with SFP modules that take a while to
respond on the I2C bus, and probing via the I2C bus is the only way to
detect that they are ready.

Fix this by changing the internal transfer return code from I2C_RETRY
to a new NO_SLAVE code (mapped to -ENXIO, as per the I2C documentation
for this condition, but we still return -EREMOTEIO to the I2C stack to
maintain long established driver behaviour.)
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Most of i2c_pxa_pio_xfer() and i2c_pxa_xfer() are identical; the only
differences are that i2c_pxa_pio_xfer() may reset the bus, and they
use different underlying transfer functions. The retry loop is the
same. Consolidate these two functions.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Use a shorter SPDX identifier instead of pasting the whole license.

While here, replace duplicating PCA954x with PCA984x.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

device_create_file() is called the last in ->probe() but pca954x_cleanup(),
which is called earlier in error path, tries to remove never created file.
Move device_remove_file() call outside of pca954x_cleanup() to make it
slightly closer to what pca954x_init() is doing.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Device property API allows to gather device resources from different sources,
such as ACPI. Convert the drivers to unleash the power of device property API.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Refactor pca954x_irq_handler() to:
  - use for_each_set_bit() macro
  - use IRQ_RETVAL() macro

Above change makes code easy to read and understand.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

After a transfer timeout, some faulty I2C slave devices might hold down
the SDA pin. We can generate a bus clear command, hoping that the slave
might release the pins.
If the CLEAR command is not supported, we will use gpio recovery, if
available, to reset the bus.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Fix i2c_pxa_wait_bus_not_busy()'s boundary conditions, so that a
coincidental success and timeout results in the function returning
success.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Clean up decode_bits() to use pr_cont(), and move the newline into the
function rather than at its two callsites. Avoid printing an
unnecessary space before the newline.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The IRQ log output is supposed to appear on a single line.  However,
commit 3a2dc167 ("i2c: pxa: Update debug function to dump more info
on error") resulted in it being printed one-entry-per-line, which is
excessively long.

Fixing this is not a trivial matter; using pr_cont() doesn't work as
the previous dev_dbg() may not have been compiled in, or may be
dynamic.

Since the rest of this function output is at error level, and is also
debug output, promote this to error level as well to avoid this
problem.

Reduce the number of always zero prefix digits to save screen real-
estate.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Move the ID tables into one place, near the device dependent data.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Move driver-private definitions out of the i2c-pxa.h platform data
header file into the driver itself. Nothing outside of the driver
makes use of these constants.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Always set the fm and hs members of struct pxa_reg_layout. These
members are already taking space, we don't need code as well.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add definitions for the bits in the IBMR register, and use them in the
code. This improves readability.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Arrange the register field definitions to be grouped together, rather
than the Armada-3700 definitions being separated from the rest of the
definitions.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Re-arrange the PXA I2C code to avoid forward declarations, and keep
similar functionality (e.g. the non-IRQ mode support) together. This
improves code readability.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Arrange the includes to be in alphabetical order to help avoid
duplicated includes.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c-pxa does not need linux/sched.h nor linux/time.h includes, so
remove these.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c-pxa was created before i2c_8bit_addr_from_msg() was implemented,
and used its own i2c_pxa_addr_byte() which is functionally the same.
Sadly, it was never updated to use this new helper. Switch it over.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

In i2c_powermac_register_devices(), variable 'found_onyx' is bool and
assigned '0' and 'true' in different places. Use 'false' instead of '0'.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We want to break with "i" set to zero whether we find the rate we want
or not.  In the current code, if we don't find the rate we want then it
exits the loop with "i" set to -1 and results in an array underflow.

Fixes: 09cc9a3b ("i2c: stm32f7: allows for any bus frequency")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Move away from the deprecated API and return the shiny new ERRPTR where
useful.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add support for SMBUS quick command.

SMBUS quick command passes single bit of information to the
slave (target) device. Can be used to turn slave device on or off.

By default i2c_detect tool uses the smbus quick cmd to try and
detect devices. Without this support it will not detect some slaves.
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use of_property_read_u32 to read the "reg" and "i2c-address" property
instead of using of_get_property to check the return values.
Signed-off-by: Aishwarya R <aishwaryarj100@gmail.com>
Tested-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The '>' expression itself is bool, no need to convert it to bool again.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

If there is no interrupt defined then an error is logged due
to the use of platform_get_irq. The driver handles not having
the interrupt by falling back to polling, therefore make
the appropriate call when claiming it.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Some bindings are for the bus master, some are for the slaves.
Regroup them and give them separate headings to make it clear.
Also, remove references to "generic names" which is for nodes and not
for compatibles.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Do not limitate to the 3 (100KHz, 400KHz, 1MHz) bus frequency but
instead allows any frequency (if it matches timing requirements).
Depending on the requested frequency, use the spec data from either
Standard, Fast or Fast Plus mode.

Hardcoding of min/max bus frequencies is removed and is instead computed.

The driver do not use anymore speed identifier but instead handle
directly the frequency and figure out the spec data (necessary
for the computation of the timing register) based on the frequency.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For STM32F7, STM32H7 and STM32MP1 SoCs, if timing parameters
match, the bus clock frequency can be from 1Hz to 1MHz.
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Do not print an error trace when deferring probe for some resource.
Fix as well the error message in case of tx dma_request_chan failure.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>