Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-ocores.c:253: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:267: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:299: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:347: warning: expecting prototype for It handles an IRQ(). Prototype was for ocores_process_polling() instead
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Since commit 7723f4c5

 ("driver core: platform: Add an error message to
platform_get_irq*()"), platform_get_irq() will call dev_err() on an error.
In case of i2c ocores this leads to a false-positive error being logged:

[ 4.173989] 007: ocores-i2c ocores-i2c: IRQ index 0 not found

i2c ocores already handles the case when the IRQ cannot be found and
therefore there is no benefit in having this error message being logged.

This commit switches to platform_get_irq_optional(), which does not log
in case the IRQ cannot be found.
Signed-off-by: Stefan Lässer <stefan.laesser@omicronenergy.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The FU540-C000 has a broken IRQ and support was added earlier
so that it will operate in polling mode, but seems to work only
in case interrupts property is missing from the i2c0 dt-node.
This should not be the case and the driver should handle polling
mode with the interrupt property present in i2c0 node of the
device tree.
So check if it's the FU540-C000 soc and enable polling mode master
xfers, as the IRQ for this chip is broken.

Fixes commit c45d4ba8

 ("i2c: ocores: add polling mode workaround
for Sifive FU540-C000 SoC")
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Move away from the deprecated API and return the shiny new ERRPTR where
useful.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c-ocores device is an HDL component that get instantiated in FPGA.
The software stack used to drive an FPGA can be very different, and the
i2c-ocore ip-core must work in different context. With respect to this
patch the IRQ controller behind this device, and its driver, can have
different implementations (nested threads). For this reason, it is safer
to use `request_any_context_irq()` to avoid errors at probe time.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c-ocore driver already has a polling mode interface.But it needs
a workaround for FU540 Chipset on HiFive unleashed board (RevA00).
There is an erratum in FU540 chip that prevents interrupt driven i2c
transfers from working, and also the I2C controller's interrupt bit
cannot be cleared if set, due to this the existing i2c polling mode
interface added in mainline earlier doesn't work, and CPU stall's
infinitely, when-ever i2c transfer is initiated.

Ref:
	commit dd7dbf0e

 ("i2c: ocores: refactor setup for polling")

The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for
FU540-COOO SoC.

The polling function identifies a SiFive device based on the device node
and enables the workaround.
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Update device id table for Opencore's I2C master based re-implementation
used in FU540-c000 chipset on HiFive Unleashed platform.

Device ID's include Sifive, soc-specific device for chip specific tweaks
and sifive IP block specific device for generic programming model.
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The driver already has the routine in place, tie it to the new callback.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

By properly setting up the algorithm at probe time, we can skip the
check at every transfer. This allows us to get rid of the flags
completely.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

gcc complains, rightfully so, I think:

drivers/i2c/busses/i2c-ocores.c:32: warning: Cannot understand  * @process_lock: protect I2C transfer process.
 on line 32 - I thought it was a doc line

Make it a simple comment.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add the I2C bus clock speed to the platform data structure.
If not set, default to 100KHz as before.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Some implementations of the OCORES i2c bus master use IO mapped
registers. Add support for getting the IO registers from the platform
data, and register accessor functions.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Miscellaneous style fixes from checkpatch
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

It adds the SPDX tag and it removes the old text about the GPLv2.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This driver assumes that an interrupt line is always available for
the I2C master. This is not always the case and this patch adds support
for a polling version.

Report from Andrew Lunn:

  I did some timing tests for this. On my box, we request a udelay of
  80uS. The kernel actually delays for about 79uS. We then spin in
  ocores_wait() for an additional 10-11uS, which is 3 to 4 iterations.

  There are actually 9 bits on the wire, not 8, since there is an
  ACK/NACK bit after the actual data transfer. So i changed the delay to
  (9 * 1000) / i2c->bus_clock_khz. That resulted in ocores_wait() mostly
  not looping at all. But for reading an 4K AT24 EEPROM, it increased
  the read time by 10ms, from 424ms to 434ms. So we should probably keep
  with 8.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

If the Interrupt Flag (IF) is not set, we should not handle the IRQ:
- the line can be shared with other devices
- it can be a spurious interrupt

To avoid reading twice the status register, the ocores_process() function
expects it to be read by the caller.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Detecting a timeout is ok, but we also need to assert a STOP command on
the bus in order to prevent it from generating interrupts when there are
no on going transfers.

Example: very long transmission.

1. ocores_xfer: START a transfer
2. ocores_isr : handle byte by byte the transfer
3. ocores_xfer: goes in timeout [[bugfix here]]
4. ocores_xfer: return to I2C subsystem and to the I2C driver
5. I2C driver : it may clean up the i2c_msg memory
6. ocores_isr : receives another interrupt (pending bytes to be
                transferred) but the i2c_msg memory is invalid now

So, since the transfer was too long, we have to detect the timeout and
STOP the transfer.

Another point is that we have a critical region here. When handling the
timeout condition we may have a running IRQ handler. For this reason I
introduce a spinlock.

In order to make easier to understan locking I have:
- added a new function to handle timeout
- modified the current ocores_process() function in order to be protected
  by the new spinlock
Like this it is obvious at first sight that this locking serializes
the execution of ocores_process() and ocores_process_timeout()
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The old @sunsite.dk address is no longer active, so update the references.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Because it looks neater.

For diolan, this allows factoring out some code that is now common
between if and else.

For eg20t, pch_i2c_writebytes is always called with a write in
msgs->flags, and pch_i2c_readbytes with a read.

For imx, i2c_imx_dma_write and i2c_imx_write are always called with a
write in msgs->flags, and i2c_imx_read with a read.

For qup, qup_i2c_write_tx_fifo_v1 is always called with a write in
qup->msg->flags.

For stu300, also restructure debug output for resends, since that
code as a result is only handling debug output.

Reviewed-by: Guenter Roeck <linux@roeck-us.net> [diolan]
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [efm32 and imx]
Acked-by: Linus Walleij <linus.walleij@linaro.org> [stu300]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The URL is broken. This patch fixes it.
Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
[wsa: shortened the URL a bit]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This header only contains platform_data. Move it to the proper directory.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Lee Jones <lee.jones@linaro.org>

Make these const as they are only used in a copy operation.
Done using Coccinelle.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The core will do this for us now.
Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

clk_disable_unprepare() is missed on failure paths in ocores_i2c_probe().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This allows using OpenCores I2C controller attached to its host in
native-endian mode with bi-endian CPUs. Example of such system is Xtensa
XTFPGA platform.
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For, !HAVE_CLK the clk API returns a NULL cookie. Rework the
initialization code to handle that. If clk_get_rate() delivers 0, we use
the fallback mechanisms. The patch is pretty easy when ignoring white
space issues (git diff -b).
Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>

Allow bus clock specification as a common clock handle. This makes this
controller easier to use in a setup based on common clock framework.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

clock-frequency property is meant to control the bus frequency for i2c bus
drivers, but it was incorrectly used to specify i2c controller input clock
frequency.
Introduce new attribute, opencores,ip-clock-frequency, that specifies i2c
controller clock frequency and make clock-frequency attribute compatible
with other i2c drivers. Maintain backwards compatibility in case
opencores,ip-clock-frequency attribute is missing.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
While we are here, remove the indentation for the array setup because
such things always break after some time.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Peter Korsgaard <peter@korsgaard.com>

Make of_device_id array const, because all OF functions
handle it as const.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove unneeded error handling on the result of a call to
platform_get_resource when the value is passed to devm_ioremap_resource.

Move the call to platform_get_resource adjacent to the call to
devm_ioremap_resource to make the connection between them more clear.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@@
expression pdev,res,n,e,e1;
expression ret != 0;
identifier l;
@@

- res = platform_get_resource(pdev, IORESOURCE_MEM, n);
  ... when != res
- if (res == NULL) { ... \(goto l;\|return ret;\) }
  ... when != res
+ res = platform_get_resource(pdev, IORESOURCE_MEM, n);
  e = devm_ioremap_resource(e1, res);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SIMPLE_DEV_PM_OPS are only used when
the CONFIG_PM_SLEEP is enabled.

drivers/i2c/busses/i2c-ocores.c:460:12: warning: 'ocores_i2c_suspend' defined but not used [-Wunused-function]
drivers/i2c/busses/i2c-ocores.c:471:12: warning: 'ocores_i2c_resume' defined but not used [-Wunused-function]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: Wolfram Sang <wsa@the-dreams.de>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>

After commit a000b8c1

 [i2c: ocores: Add support for the GRLIB port of the
controller and use function pointers for getreg and setreg function],
compiling i2c-ocores.c for 64-bit gives the following warning:

  drivers/i2c/busses/i2c-ocores.c: In function 'ocores_i2c_of_probe':
  drivers/i2c/busses/i2c-ocores.c:334:15: warning: cast from pointer to integer of different size

Fix it by casting the pointer to long.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>