I did not receive a single bug report after interrupt support was
added for a limited number of chips. So I'd say the code is good and
should be enabled for all supported chips, that is: ICH5 and later.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Reviewed-by: NDaniel Kurtz <djkurtz@chromium.org>

Add support for probing slave devices parsed from the device tree.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Signed-off-by: NJean Delvare <khali@linux-fr.org>

Arbitrarily selecting GPIOLIB causes trouble on some architectures,
so don't do that. Instead, just make the optional multiplexing code
depend on CONFIG_I2C_MUX_GPIO instead of CONFIG_I2C_MUX for now. We
can revisit if the i2c-i801 driver ever supports other multiplexing
flavors.

Also make that optional code depend on DMI, as it won't do anything
without that.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>

Now that i2c-mux-gpio is able to find the GPIO chip by itself, we can
delegate this task. The great thing here is that i2c-mux-gpio can
defer device probing until the gpio chip is available, so we no longer
depend on the module loading order.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add support for SMBus multiplexing on Asus Z8 motherboard series. On
these boards, the memory slots are behind a GPIO-controlled I2C
multiplexer. Models with 6 or 12 memory slots have 2 segments behind
the multiplexer, while models with 18 memory slots have 3 such
segments.

On these boards, only the memory slots are behind the multiplexer,
so it is possible to keep the autodetection mechanism.

The code is generic enough so it could work on other boards as long as
the multiplexer is controlled by GPIO pins. For other forms of
multiplexing (for example using an I2C device) additional code will be
needed.

Thanks to Asus for providing a board to develop and test this feature,
as well as all the technical information required.

At the moment, the GPIO driver must be loaded before the i2c-i801
driver, but I hope to solve this soon, using deferred probing on
the i2c-mux-gpio side.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add the SMBus Device IDs for the Intel Lynx Point-LP PCH.
Signed-off-by: NJames Ralston <james.d.ralston@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Byte-by-byte transactions are used primarily for accessing I2C devices
with an SMBus controller.  For these transactions, for each byte that is
read or written, the SMBus controller generates a BYTE_DONE IRQ.  The isr
reads/writes the next byte, and clears the IRQ flag to start the next byte.
On the penultimate IRQ, the isr also sets the LAST_BYTE flag.

There is no locking around the cmd/len/count/data variables, since the
I2C adapter lock ensures there is never multiple simultaneous transactions
for the same device, and the driver thread never accesses these variables
while interrupts might be occurring.

The end result is faster I2C block read and write transactions.

Note: This patch has only been tested and verified by doing I2C read and
write block transfers on Cougar Point 6 Series PCH, as well as I2C read
block transfers on ICH5.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Enable interrupts on more devices. ICH5, ICH7(-M) and ICH10 have been
tested to work OK. ICH8 and ICH9 are expected to work just fine as
they are very close to ICH7 and ICH10.

Ultimately we want to enable this feature on at least every device
since the ICH5, but for now we limit the exposure. We'll enable it for
other devices if we don't get negative feedback.

As a bonus, let the user know when interrupts are used.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Daniel Kurtz <djkurtz@chromium.org>

Add a new 'feature' to i2c-i801 to enable using PCI interrupts.
When the feature is enabled, then an isr is installed for the device's
PCI IRQ.

An I2C/SMBus transaction is always terminated by one of the following
interrupt sources: FAILED, BUS_ERR, DEV_ERR, or on success: INTR.

When the isr fires for one of these cases, it sets the ->status variable
and wakes up the waitq.  The waitq then saves off the status code, and
clears ->status (in preparation for some future transaction).
The SMBus controller generates an INTR irq at the end of each
transaction where INTREN was set in the HST_CNT register.

No locking is needed around accesses to priv->status since all writes to
it are serialized: it is only ever set once in the isr at the end of a
transaction, and cleared while no interrupts can occur.  In addition, the
I2C adapter lock guarantees that entire I2C transactions for a single
adapter are always serialized.

For this patch, the INTREN bit is set only for SMBus block, byte and word
transactions, but not for I2C reads or writes.  The use of the DS
(BYTE_DONE) interrupt with byte-by-byte I2C transactions is implemented in
a subsequent patch.

The interrupt feature has only been enabled for COUGARPOINT hardware.
In addition, it is disabled if SMBus is using the SMI# interrupt.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

(Based on earlier work by Daniel Kurtz.)

Come up with a consistent, driver-wide strategy for event polling. For
intermediate steps of byte-by-byte block transactions, check for
BYTE_DONE or any error flag being set. At the end of every transaction
(regardless of PEC being used), check for both BUSY being cleared and
INTR or any error flag being set. This ensures proper action for all
transaction types.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Daniel Kurtz <djkurtz@chromium.org>

Later patches enable interrupts.  This preliminary patch removes the older
unsupported ENABLE_INT9 flag.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Rename the SMBHSTCNT register bit access constants to match the style of
other register bits.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

If an error is detected in the polling loop, abort the transaction and
return an error code.

 * DEV_ERR is set if the device does not respond with an acknowledge, and
the SMBus controller times out (minimum 25ms).
 * BUS_ERR is set if a bus arbitration collision is detected.  In other
words, when the SMBus controller tries to generate a START condition, but
detects that the SMBDATA is being held low, usually by another SMBus/I2C
master.
 * FAILED is only set if a transaction is stopped by software (using
the SMBHSTCNT KILL bit).
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Writing back the whole status register could clear unwanted bits.
In particular, it could clear the "INUSE_STS" bit, which is a
'hardware semaphore', that might be useful to use some day.
To prepare for this, let's ban writing back the whole status to register
HST_STS, of which this is the only instance.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

As a slight optimization, pull some logic out of the polling loop during
byte-by-byte transactions by just setting the I801_LAST_BYTE bit, as
defined in the i801 (PCH) datasheet, when reading the last byte of a
byte-by-byte I2C_SMBUS_READ.
Signed-off-by: NDaniel Kurtz <djkurtz@chromium.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Use usleep_range instead of msleep when waiting for command
completion. Most SMBus commands complete in less than 2 jiffies so
this brings a pleasant performance boost.

Strongly inspired from a similar change by Olivier Sobrie to the
i2c-isch driver.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Olivier Sobrie <olivier@sobrie.be>

Add the SMBus controller device IDs for the Intel Lynx Point PCH.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Convert static struct pci_device_id *[] to static DEFINE_PCI_DEVICE_TABLE
tables.

Use DEFINE_PCI_DEVICE_TABLE ensures we make the pci_device_id table const
and marked as __devinitconst.

This also fixes some warnings from checkpatch:
e.g.
WARNING: Use DEFINE_PCI_DEVICE_TABLE for struct pci_device_id
#1096: FILE: i2c/busses/i2c-intel-mid.c:1096:
+static struct pci_device_id intel_mid_i2c_ids[] = {
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Acked-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Cc: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Don't let other driver config options influence us, as it makes the
code more complex and fragile for a small benefit. There's nothing
wrong with instantiating I2C devices even if they don't have a driver.
And we're talking about 835 extra bytes in the binary on x86-64,
that's hardly worth arguing about.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: David Woodhouse <david.woodhouse@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>

Scanning the BIOS memory for the apanel information is costly, so
avoid doing it on non-Fujitsu machines.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

I don't know if Fujitsu is ever going to produce Patsburg-based
machines, but if they do, I'd rather not probe the secondary (IDF)
SMBus channels. At least not until we have a good reason for doing so.

On a side note, I'm not even sure if it is right to enable detection
of HWMON and DDC devices on the IDF channels. Time will tell...
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds the SMBus controller DeviceID for the Intel Panther Point PCH.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Move the SMBus device ID definitions of recent devices from pci_ids.h
to the i2c-i801.c driver file. They don't have to be shared, as they
are clearly identified and only used in this driver. In the future,
such IDs will go to i2c-i801 directly. This will make adding support
for new devices much faster and easier, as it will avoid cross-
subsystem patch sets and merge conflicts.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Seth Heasley <seth.heasley@intel.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Add the SMBus Controller DeviceIDs for the Intel DH89xxCC PCH.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Commit 5a0e3ad6 added direct inclusion
of <linux/slab.h> to those source files that appeared to need it, but
somehow missed this.  On most architectures <linux/slab.h> is still
indirectly included, but there are exceptions such as alpha.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

These are the extra 'Integrated Device Function' SMBus controllers found
on the Patsburg chipset. Mention the absence of slave mode support.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

It's poor form to keep driver state in global variables rather than
per-instance. It never really mattered in practice when there was only
one controller on the chipset, but the latest chipsets do have more
than one controller, so now we care.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add support for the Intel Patsburg PCH SMBus Controller.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This patch updates the defines for Intel devices in
include/linux/pci_ids.h, referenced in arch/x86/pci/irq.c and
drivers/i2c/busses/i2c-i801.c, reflecting approved legal branding, and
using fuller code-names for products under development.
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fujitsu slightly changed the DMI strings in their recent machines,
(for example the D2778) and this breaks the automatic loading of the
needed fschmd driver. Being more tolerant on string comparison fixes
the issue.

This closes bug #15634:
https://bugzilla.kernel.org/show_bug.cgi?id=15634Signed-off-by: NJean Delvare <khali@linux-fr.org>
Tested-by: NSergey Spiridonov <sena@hurd.homeunix.org>
Cc: Hans de Goede <hdegoede@redhat.com>

Fix all checkpatch warnings. No functional changes are made.
Signed-off-by: NIvo Manca <pinkel@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Only the oldest devices lack some of the features supported by this
driver. List them explicitly, and default to all features enabled for
all other chips, including the ones added through sysfs. This will
make future driver maintenance easier.

In the unlikely event of a not yet supported device not implementing
all the features, one can always use the disable_features module
parameter to prevent the driver from attempting to use them.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NSeth Heasley <seth.heasley@intel.com>

Let the user disable selected features normally supported by the
device. This makes it possible to work around possible driver or
hardware bugs if the feature in question doesn't work as intended
for whatever reason.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Felix Rubinstein <felixru@gmail.com>

Experience has shown that the block buffer can only be used for SMBus
(not I2C) block transactions, even though the datasheet doesn't
mention this limitation.
Reported-by: NFelix Rubinstein <felixru@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Oleg Ryjkov <oryjkov@gmail.com>
Cc: stable@kernel.org

Add the Intel Cougar Point (PCH) SMBus controller device IDs.
Signed-off-by: NSeth Heasley <seth.heasley@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The id_table field of the struct pci_driver is constant in <linux/pci.h>
so it is worth to make initialization data also constant.

The semantic match that finds this kind of pattern is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
disable decl_init,const_decl_init;
identifier I1, I2, x;
@@
	struct I1 {
	  ...
	  const struct I2 *x;
	  ...
	};
@s@
identifier r.I1, y;
identifier r.x, E;
@@
	struct I1 y = {
	  .x = E,
	};
@c@
identifier r.I2;
identifier s.E;
@@
	const struct I2 E[] = ... ;
@depends on !c@
identifier r.I2;
identifier s.E;
@@
+	const
	struct I2 E[] = ...;
// </smpl>
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The Intel 82801 is sometimes used on systems with a BMC connected. The
BMC can access the SMBus, resulting in lost arbitration for the 82801.
We should let i2c-core retry transactions for us in this case.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

When an ACPI resource conflict is detected, error messages are already
printed by ACPI. There's no point in causing the driver core to print
more error messages, so return one of the error codes for which no
message is printed.

This fixes bug #14293:
http://bugzilla.kernel.org/show_bug.cgi?id=14293Signed-off-by: NJean Delvare <khali@linux-fr.org>