Improve the error handling in i2c_imx_dma_request() and let it return an error
indication that the caller then can handle accordingly.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

At least on i.MX5x, the DMA events for I2C and SDHC use the same channel
and there can only be a single user. So in this case there should be no
message emitted that looks like an error if the I2C device doesn't have
an assigned DMA channel. In contrast real problems that were only
emitted at debug level before should be described at a higher level
to be better visible and so understandable.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Probe deferral is a normal operating condition in the probe function,
so don't spam the log with an error in this case.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Always update the stopped state when busy status have been checked.
This is identical to what was done before, with the exception of error
handling.
Without this change, some errors cause the stopped state to be left in
incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and
i2c_imx_xfer().

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This fixes a race condition, where the DMAEN bit ends up being set after
I2C slave has transmitted a byte following the dummy read.  When that
happens, an interrupt is generated instead, and no DMA request is generated
to kickstart the DMA read, and a timeout happens after DMA_TIMEOUT (1 sec).

Fixed by setting the DMAEN bit before the dummy read.

Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

I2C is open drain, so request the GPIO accordingly, even if pinmux did
set it up correctly for in-kernel users in this case.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make sure to call reinit_completion() before dma is started to avoid race
condition where reinit_completion() is called after complete() and before
wait_for_completion_timeout().

Signed-off-by: Esben Haabendal <eha@deif.com>
Fixes: ce1a7884 ("i2c: imx: add DMA support for freescale i2c driver")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

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>

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This is unsafe, as the runtime PM callbacks are called from the PM
workqueue, so this may deadlock when handling an i2c attached clock,
which may already hold the clk_prepare mutex from another context.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Instead of repeatedly calling clk_get_rate for each transfer, register
a clock notifier to update the cached divider value each time the clock
rate actually changes.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.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>

When converting to GPIOD, the GPIO directions of SCL/SDA have been
swapped. Fix it!

Fixes: ad36a279 ("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>

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>

The arguments for SDA and SCL were swapped. Fix it.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Some SoC share one irq number between I2C controllers.
For example, on the LS2088 board, I2C 1 and I2C 2 share
one irq number. In this case, only one I2C controller
can register successfully, and others will fail.

Signed-off-by: Wei Jinhua <wei.jinhua1@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The i2c-imx driver incorrectly uses readb()/writeb() to read and
write to the appropriate registers when performing a repeated start.
The appropriate imx_i2c_read_reg()/imx_i2c_write_reg() functions
should be used instead. Performing a repeated start results in
a kernel panic. The platform is imx.

Signed-off-by: Michail G Etairidis <m.etairidis@beck-ipc.com>
Fixes: ce1a7884 ("i2c: imx: add DMA support for freescale i2c driver")
Fixes: 054b62d9 ("i2c: imx: fix the i2c bus hang issue when do repeat restart")
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Declare i2c_algorithm structures as const as they are only stored in the
algo field of an i2c_adapter structure. This field is of type const, so
i2c_algorithm structures having this property can be made const too.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> for
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Some SoC might load the GPIO driver after the I2C driver and
using the I2C bus recovery mechanism via GPIOs. In this case
it is crucial to defer probing if the GPIO request functions
do so, otherwise the I2C driver gets loaded without recovery
mechanisms enabled.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Since commit 1c4b6c3b ("i2c: imx: implement bus recovery") the
driver starts to use gpio/pinctrl to support optional bus recovery
feature.  But pinctrl is not always usable.  There are platforms such
as ls1021a and ls1043a that don't support pinctrl, and it could just
be broken due to old/broken device tree.  The patch makes it really
optional that the probe function won't bailout on pinctrl problems
instead it just disables bus recovery and prints out notification when
there is problem with pinctrl.  Since pinctrl is only used by bus
recovery in this driver, move pinctrl initialization into bus recovery
init function to prevent confusion.

Signed-off-by: Li Yang <leoyang.li@nxp.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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>

Documentation/timers/timers-howto.txt recommends to use
usleep_range on delays > 10usec. According to my test results
with Neonode zForce touchscreen driver, usleep_range indeed
reduces CPU load.

Stats collected with "./perf record -a -g -F 1000 sleep 10"

i2c-imx with udelay(50):
34.19% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread
    ---irq_thread
       |--33.75%--irq_thread_fn
       |    |--19.27%--0x7f08a878
       |    |     i2c_master_recv
       |    |     i2c_transfer
       |    |     __i2c_transfer
       |    |     i2c_imx_xfer
       |    |     |--11.71%--i2c_imx_trx_complete
       |    |     |--5.70%--i2c_imx_start <<<<----------------
       |    |     |     |--5.38%--__timer_const_udelay
       |    |     |     |      __timer_delay
       |    |     |     |      --5.07%--read_current_timer

i2c-imx with usleep_range(50,100)
29.08% 0.00% irq/220-Neonode  [kernel.kallsyms] [k] irq_thread
    ---irq_thread
       |--28.89%--irq_thread_fn
       |    |--17.21%--0x7f08a878
       |    |     i2c_master_recv
       |    |     |--17.14%--i2c_transfer
       |    |     |     __i2c_transfer
       |    |     |     i2c_imx_xfer
       |    |     |     |--14.29%--i2c_imx_trx_complete
       |    |     |     |--1.42%--i2c_imx_start <<<<----------
       |    |     |     |      |--0.71%--usleep_range
       |    |     |     |      |--0.53%--i2c_imx_bus_busy

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Dmitriy Baranov <dbaranov@dev.rtsoft.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

In i2c_imx_dma_xfer(), when dmaengine_submit() returns error,
the context goto label err_submit and then return. However, the
memory allocated for txdesc has not been freed yet, which
leads to resource leak.

Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

These multi-lines comments do not follow the standard kernel coding
style. In fact, they are not useful comments, so get rid of them.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Replace of_get_named_gpio_flags with of_get_named_gpio because
the latter has less parameters, which improves code readability.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

When DMA cannot be used, it is better to state that the I2C controller
will operate in PIO mode.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

In our former i2c driver, i2c clk is enabled and disabled in
xfer function, which contributes to power saving. However,
the clk enable process brings a busy wait delay until the core
is stable. As a result, the performance is sacrificed.

To weigh the power consumption and i2c bus performance, runtime
pm is the good solution for it. The clk is enabled when a i2c
transfer starts, and disabled after a specifically defined delay.

If CONFIG_PM is disabled the net result of this patch is that the
clock is never disabled.

Without the patch the test case (many eeprom reads) executes with approx:
real 1m7.735s
user 0m0.488s
sys 0m20.040s

With the patch the same test case (many eeprom reads) executes with approx:
real 0m54.241s
user 0m0.440s
sys 0m5.920s

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Gao Pan <b54642@freescale.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[wsa: sorted includes]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

During driver probe, i2c_imx_init_recovery_info() must come before
i2c_add_numbered_adapter(), because the get/set_scl() functions
are assigned in i2c_register_adapter() under the conditon that bus
recover_info are initialized. Otherwise, get/set_scl() function
pointers never get assigned.

In such case, when i2c_generic_gpio_recovery() is used for bus recovery,
there will be kernel crash because bri->set_scl is NULL.

The solution to this bug is moving i2c_imx_init_recovery_info() before
i2c_register_adapter().

Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

During driver probe, i2c_imx_init_recovery_info() must come before
i2c_add_numbered_adapter(), because the get/set_scl() functions
are assigned in i2c_register_adapter() under the conditon that bus
recover_info are initialized. Otherwise, get/set_scl() function
pointers never get assigned.

In such case, when i2c_generic_gpio_recovery() is used for bus recovery,
there will be kernel crash because bri->set_scl is NULL.

The solution to this bug is moving i2c_imx_init_recovery_info() before
i2c_register_adapter().

Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

drivers/i2c/busses/i2c-imx.c:978:2: error: implicit declaration of
function ‘pinctrl_select_state’ [-Werror=implicit-function-declaration]
  pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
  ^

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

According to Documentation/i2c/fault-codes the response to a bus NACK
should be -ENXIO, so fix the error code.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Implement bus recovery methods for i2c-imx so we can recover from
situations where SCL/SDA are stuck low.

Once i2c bus SCL/SDA are stuck low during transfer, config the i2c
pinctrl to gpio mode by calling pinctrl sleep set function, and then
use GPIO to emulate the i2c protocol to send nine dummy clock to recover
i2c device. After recovery, set i2c pinctrl to default group setting.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The platform_device_id is not modified by these drivers and core uses it
as const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int.
An appropriate variable of type unsigned long is introduced and the
assignments fixed up.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch fixes up some whitespace issues and addresses a few
checkpatch warnings.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The ret variable is set and never used in the error path of i2c_imx_dma_request.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

wait_for_completion_timeout does not return negative values so
"result" handling here should be simplified to cover the actually
possible cases only.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Yao Yuan <yao.yuan@freescale.com>

Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
DMA is optional, even DMA request unsuccessfully, i2c can also work well.

Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>