The current driver uses input clock source frequency to calculate
values for [SS|FS]_[HC|LC] registers. However, when booting ACPI, we do not
currently have a good way to provide the frequency information.
Instead, we can leverage the SSCN and FFCN ACPI methods, which can be used
to directly provide these values. So, the clock information should
no longer be required during probing.

However, since clk can be invalid, additional checks must be done where
we are making use of it.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: NLoc Ho <lho@apm.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

RuntimePM of the adapter device is now taken care of by the core. So, we
can remove these calls.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The adapter device is a logical device. Because of that, it already uses
pm_runtime_no_callbacks() in the core. To ensure proper propagation from
the children (i2c devices) to the parent of the adapter (the HW device),
make sure RuntimePM is enabled in any case.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Set the i2c_adapter retries field to a sensible value. This allows the i2c core
to retry master_xfer() when it returns -EAGAIN. Currently the i2c-designware
driver returns -EAGAIN only on Tx arbitration failure (DW_IC_TX_ARB_LOST).
Reported-by: Rolland Chau <zourongrong@gmail.com>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Fixes: e1dba01c ("i2c: add generic routine to parse DT for timing information")
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add device HID AMDI0510 to match the I2C controlers on AMD Seattle platform
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: NWolfram 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: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use to_platform_device() instead of open-coding it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use to_pci_dev() instead of open-coding it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Broadcoms DSL, CM (cable modem)and STB I2C core implementation have
8 data in/out registers that can transfer 8 bytes or 32 bytes max.
Cable and DSL "Peripheral" i2c cores use single byte per data
register and the STB can use 4 byte per data register transfer.
Adding support to take care of this difference. Accordingly added
the compatible string for SoCs using the "Peripheral" I2C block.
Signed-off-by: NKamal Dasu <kdasu.kdev@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

For mt8173 platform with auto restart support, when doing i2c multi
transfer in high speed, we should ignore the first restart irq after
the master code, otherwise the first transfer will be discarded.
Signed-off-by: NLiguo Zhang <liguo.zhang@mediatek.com>
Reviewed-by: NEddie Huang <eddie.huang@mediatek.com>
Signed-off-by: NWolfram 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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NGao Pan <b54642@freescale.com>
Signed-off-by: NWolfram 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: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NWolfram 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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NGao Pan <b54642@freescale.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
[wsa: sorted includes]
Signed-off-by: NWolfram 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: NGao Pan <b54642@freescale.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

In multi master mode, the IP core needs to be always active for
arbitration reasons. Get the config from DT and set up PM depending on
the config.
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

These macros don't really hide complexity, but C idioms. Removing them
makes the code easier to read IMO and make a planned extension easier.
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In version 3.3 of the IP when transaction halt is set, an interrupt
will be generated after each byte of a transfer instead of after
every transfer but before the stop bit.
Due to this behaviour we have to be careful that every time we
release the transaction halt we have to re-enable it straight away
so that we only process a single byte, not doing so will result in
all remaining bytes been processed and a stop bit being issued,
which will prevent us having a repeated start.

This change will have no effect on earlier versions of the IP.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Master halt is issued after each byte of a transaction is processed in
IP version 3.3.
Master halt will stall the bus by holding the SCK line low until the
halt bit in the scb_general_control is cleared.

After the last byte of a transfer is processed we can use the Master
Halt interrupt to facilitate a repeated start transfer without
issuing a stop bit.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Stop Detected interrupt is triggered when a Stop bit is detected on
the bus, which indicates the end of the current transfer.

When the end of a transfer is indicated by the Stop Detected interrupt,
drain the FIFO and signal completion for the transaction.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Now that we are using the transaction halt interrupt to safely control
repeated start transfers, we no longer need to handle the fifo
emptying interrupts.

Handling this interrupt along with Transaction Halt interrupt can
cause erratic behaviour.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This commit adds support for the I2C_M_IGNORE_NAK protocol
modification.

Such behaviour can only be implemented in atomic mode. So, if a
transaction contains a message with such flag the drivers
switches to atomic mode. The implementation consists simply in
treating NAKs as ACKs.
Signed-off-by: NSifan Naeem <sifan.naeem@imgtec.com>
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This function used to be DT only, so it lived inside a CONFIG_OF block.
Now it uses device attributes and must be moved outside of it. No
further code changes, only one whitespace improvement.
Reported-by: NJim Davis <jim.epost@gmail.com>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Until we have proper support to make I2C slave support fully optional,
select it to prevent build errors on randconfigs.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The Sigma Designs variant of this controller has the ability to generate
interrupts.  This is controlled using two additional registers, oddly
enough overlapping with the defined but unused HDSTATIM.

This patch adds support for using this feature instead of busy-looping
if an IRQ is specified.
Signed-off-by: NMans Rullgard <mans@mansr.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The BYTECNT register holds the transfer size minus one.  Setting it to
the correct value removes the need for a dummy read/write at the end of
each transfer.  As zero-length transfers are not supported, do not
advertise I2C_FUNC_SMBUS_QUICK.

In other words, this patch makes the driver transfer the number of bytes
requested unless this is zero, which is not supported by the hardware
and is thus refused.
Signed-off-by: NMans Rullgard <mans@mansr.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Sigma Designs chips use a variant of this controller with the following
differences:

- The BUSY bit in the STATUS register is inverted
- Bit 8 of the CONFIG register must be set
- The controller can generate interrupts

This patch adds support for the first two of these.  It also calculates
and sets the correct clock divisor if a clk is provided.  The bus
frequency is optionally speficied in the device tree node.
Signed-off-by: NMans Rullgard <mans@mansr.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is code to divide by "bus_speed" some lines below.
To eliminate the possibility of division by zero, bail out if
"clock-frequency" is specified as zero.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This input clock is used to generate the sampling clock for I2C bus.
If the clock rate is zero, there is something wrong with the clock
driver.  Bail out with the appropriate error message in such a case.
It would make it easier to find the root cause of failure.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is code to divide by "bus_speed" some lines below.
To eliminate the possibility of division by zero, bail out if
"clock-frequency" is specified as zero.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This input clock is used to generate the sampling clock for I2C bus.
If the clock rate is zero, there is something wrong with the clock
driver.  Bail out with the appropriate error message in such a case.
It would make it easier to find the root cause of failure.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Switch to the new generic functions. Plain convert, no functionality
added yet.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The probe function is a little bit messy, something here, something
there. Rework it so that there is some order: first init the private
structure, then the adapter, then do HW init. This also allows us to
remove the device argument of the clock calculation function, because it
now can be deduced from the private structure. Also, shorten some lines
where possible. This is a preparation for further refactoring.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Inspired from the i2c-rk3x driver (thanks guys!) but refactored and
extended. See built-in docs for further information.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add I2C slave provider using the generic slave interface.
Signed-off-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Allow the eg20t I2C driver to be built for MIPS platforms, in
preparation for use on the MIPS Boston board.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Set the I2C adapter devices of_node to that of the PCI device, such that
I2C clients may be instantiated via device tree.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The hold field allows to configure the data hold time which can be set
with the help of the generic binding 'i2c-sda-hold-time-ns'. This
feature has been introduced with SAMA5D4 SoC family.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

smatch rightfully says:
drivers/i2c/busses/i2c-piix4.c:504 piix4_access warn: unused return: i = inb_p()
drivers/i2c/busses/i2c-piix4.c:537 piix4_access warn: unused return: i = inb_p()
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NChristian Fetzer <fetzer.ch@gmail.com>