R-Car I2C is similar with SH7760 I2C.
But the SH7760 I2C driver had many workaround operations, since H/W had bugs.
Thus, it was pointless to keep compatible between SH7760 and R-Car I2C drivers.
This patch creates new Renesas R-Car I2C driver.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat
API to the new PM QoS API.
Since the constraint is on the MPU subsystem, use the PM_QOS_CPU_DMA_LATENCY
class of PM QoS. The resulting MPU constraints are used by cpuidle to
decide the next power state of the MPU subsystem.

The I2C device latency timing is derived from the FIFO size and the
clock speed and so is applicable to all OMAP SoCs.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Here we apply the bindings required for successful Device Tree
probing of the i2c-nomadik driver.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

The parameter passed to pca9665_reset is adap->data (which is bus driver
specific), not i2c_algp_pca_data *adap. pca9665_reset expects it to be
i2c_algp_pca_data *adap. All other wrappers from the algo call back to
the bus driver, which knows to handle its custom data. Only pca9665_reset
resides inside the algorithm code and does not know how to handle a custom
data structure. This can result in a kernel crash.

Fix by re-factoring pca_reset() from a macro to a function handling chip
specific code, and only call adap->reset_chip() if the chip is not PCA9665.
Signed-off-by: Thomas Kavanagh <tkavanagh@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

mpc_i2c_stop() only initiates STOP but does not wait for it to
hit the I2C bus. This is a problem when using I2C devices which
uses fairly long clock stretching just before STOP if you also
have an i2c-mux which may switch to another bus before STOP has
been processed.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

As a first step towards migrating davinci platforms to use common clock
framework, replace all instances of clk_enable() with clk_prepare_enable()
and clk_disable() with clk_disable_unprepare(). Until the platform is
switched to use the CONFIG_HAVE_CLK_PREPARE Kconfig variable, this just
adds a might_sleep() call and would work without any issues.

This will make it easy later to switch to common clk based implementation
of clk driver from DaVinci specific driver.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

When booting using a device tree, the adapter number is dynamically
assigned after the log message is sent.
This patch modifies the log message to get a correct adapter id.
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Tested-by: Benoit Cousson <b-cousson@ti.com>
Acked-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

move the goto out label one line down, so that
it can be used when stat is read as zero. All
other exits, can be done with a break statement.

While at that, also break out as soon as we
complete draining IRQ, since at that time
we know we transferred everything there was
to be transferred.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

this helps us reduce unnecessary pm transitions
in case we have another i2c message starting soon.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

before starting any messages we call pm_runtime_get_sync()
which will make sure that by the time we program a transfer
and our IRQ handler gets called, we're not suspended
anymore.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

for OMAP2, we can easily switch over to threaded
IRQs on the I2C driver. This will allow us to
spend less time in hardirq context.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[Trivial formating changes]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Currently omap_i2c_ack_stat doesn't use the stat variable.
After the read of the I2C_STAT_REG it is not used.
Remove the redundant read of the status register.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

we can ack stat and complete the command from
the errata handling itself.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

This patch will try to avoid the usage of
draining feature by reconfiguring the FIFO
the start condition of each message based
on the message's size.

By doing that, we will be better utilizing
the FIFO when doing big transfers.

While at that also drop the now unneeded
check for dev->buf_len as we always know
the amount of data to be transmitted.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

instead of having multiple return points, use
a goto statement to make that clearer.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Always return IRQ_HANDLED otherwise we could get our IRQ line disabled due
to many spurious IRQs.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[Trivial changes to commitlogs]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

omap_i2c_dev is allocated with kzalloc(),
so we need not initialize b_hw to zero.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

that way we can ignore TX IRQs while in receiver
mode and ignore RX IRQs while in transmitter mode.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[Remove unnecessary braces]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

that's a nice helper from drivers core which
will give us the exact IRQ number, instead
of a pointer to an IRQ resource.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

According to flow diagrams on OMAP TRMs,
we should ACK the IRQ as they happen.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[Ack the stat OMAP_I2C_STAT_AL in case of arbitration lost]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

this will make sure that we execute at least once.
No functional changes otherwise.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

re-factor the common parts to a separate function,
so that code is easier to read and understand.

No functional changes.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Make it not depend on ISR's local variables
in order to make it easier to re-factor the
transmit data loop.
Also since we are waiting for XUDF(Transmitter underflow) just before
writing data lets not flag the underflow.
This is anyways going to go once we write
the data.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

While they do pretty much the same thing, there
are a few peculiarities. Specially WRT erratas,
it's best to split those out and re-factor the
read/write loop to another function which both
cases call.

This last part will be done on another patch.

While at that, also avoid an unncessary register
read since dev->fifo_len will always contain the
correct amount of data to be transferred.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

stat & BIT(1) is the same as BIT(1), so let's
simplify things a bit by removing "stat &" from
all omap_i2c_ack_stat() calls.

Code snippet (extremely simplified):

if (stat & NACK) {
        ...
        omap_i2c_ack_stat(dev, stat & NACK);
}

if (stat & RDR) {
        ...
        omap_i2c_ack_stat(dev, stat & RDR);
}

and so on. The tricky place is only WRT errata handling, for example:

if (*stat & (NACK | AL)) {
        omap_i2c_ack_stat(dev, *stat & (XRDY | XDR));
        ...
}

but in this case, the errata says we must clear XRDY and XDR if that
errata triggers, so if they just got enabled or not, it doesn't matter.

Another tricky place is RDR | RRDY (likewise for XDR | XRDY):

if (stat & (RDR | RRDY)) {
        ...
        omap_i2c_ack_stat(dev, stat & (RDR | RRDY));
}

again here there will be no issues because those IRQs never fire
simultaneously and one will only after after we have handled the
previous, that's because the same FIFO is used anyway and we won't shift
data into FIFO until we tell the IP "hey, I'm done with the FIFO, you
can shift more data"
Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
[Added the explaination from the discurssion to the commit logs]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

trivial patch to aid readability. No functional
changes.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

The patch intends to decrease the indentation level on the
data handling
by using the fact that else of if (dev->buf_len) is same as
if (!dev->buf_len)

if (dev->buf_len) {
	aaa;
} else {
	bbb;
	break;
}

to

if (!dev->buf_len) {
        bbb;
        break;
}
aaa;

Hence no functional changes.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

trivial patch, no functional changes

If the fifo is disabled or fifo_size is 0 the num_bytes
is set to 1. Else it is set to fifo_size or in case of a
draining interrupt the remaining bytes in the buff stat.
So the zero check is redundant and can be safely optimised.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

that helps deleting some boiler plate code
and lets driver-core manage our resources
for us.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Still use i2c-gpio on boards which have a SoC with a TWI IP which
doesn't have clock stretching in transmission mode.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Add TWI nodes for atmel SoCs but keep i2c-gpio ones in order to let the
choice to the user in dts files.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

As indicated in the datasheet, TWD and TWCK must not be programmed as
open-drain.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

The G45 datasheets explicitly states that setting the open drain property
on peripheral function gpios is not allowed. (How about other A91 chips?)
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

This driver has the following properties compared to the old driver:
1. Support for multiple interfaces.
2. Interrupt driven I/O as opposed to polling/busy waiting.
3. Support for _one_ repeated start (Sr) condition, which is enough
   for most real-world applications including all SMBus transfer types.
   (The hardware does not support issuing arbitrary Sr conditions on the
    bus.)

testing: SoC: at91sam9g45
	 - BQ20Z80 battery SMBus client.
	 - on a 2.6.38 kernel with several i2c clients (temp-sensor,
	   audio-codec, touchscreen-controller, w1-bridge, io-expanders)
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Tested-by: Hubert Feurstein <h.feurstein@gmail.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>

[wsa: squashed with the following patches from Ludovic to have some flaws
fixed:
        i2c: at91: use managed resources
        i2c: at91: add warning about transmission issues for some devices
        i2c: at91: use an id table for SoC dependent parameters
]
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

It will get replaced by a superior one. Safe to remove since this one
depends on BROKEN anyhow.
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>

[wsa: added commit message]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

The old driver used con_id clock entries. Convert to use dev_id
for clock lookup via standard method.
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

The regulator fetched by the Nomadik I2C driver is actually a
voltage domain regulator. Stop doing this in the driver and
let the power domain code handle any regulators, as discussed
on the list.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>