Make the documentation on how to write and port i2c drivers more in
line with the current state of things:
* i2c-isa is deprecated and soon gone, so stop advertising it.
* Drop many sensors-specific references. Most of them were outdated
  anyway.
* Update the example code to reflect the recent and not-so-recent
  API and coding style preference changes.
* Simplify the example init and cleanup functions.

This should make things less complex to understand for newcomers.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

SPIN_LOCK_UNLOCKED cleanup, use __SPIN_LOCK_UNLOCKED instead.
Signed-off-by: NMilind Arun Choudhary <milindchoudhary@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The new generic i2c-gpio driver should be used instead.
The obsolete drivers will be removed in September 2007.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Deepak Saxena <dsaxena@plexity.net>
Cc: Jordan Crouse <jordan.crouse@amd.com>

Platform driver for the Simtec CPLD based simple I2C logic.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This is a very simple bitbanging I2C bus driver utilizing the new
arch-neutral GPIO API. Useful for chips that don't have a built-in
I2C controller, additional I2C busses, or testing purposes.

To use, include something similar to the following in the
board-specific setup code:

  #include <linux/i2c-gpio.h>

  static struct i2c_gpio_platform_data i2c_gpio_data = {
	.sda_pin	= GPIO_PIN_FOO,
	.scl_pin	= GPIO_PIN_BAR,
  };
  static struct platform_device i2c_gpio_device = {
	.name		= "i2c-gpio",
	.id		= 0,
	.dev		= {
		.platform_data	= &i2c_gpio_data,
	},
  };

Register this platform_device, set up the I2C pins as GPIO if
required and you're ready to go. This will use default values for
udelay and timeout, and will work with GPIO hardware that does not
support open drain mode, but allows sensing of the SDA and SCL lines
even when they are being driven.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Allow the whole I2C menu to be disabled at once without diving into
the submenus for deselecting all options (should the user desire so).
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add back the i2c_smbus_read_block_data helper function, it is needed
by the upcoming lm93 hardware monitoring driver and possibly others.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

It was reported to me that the i2c-pxa driver was not able to process
more that 50 transactions per second. Investigation revealed that the
I2C unit was busy for 20 ms after every transaction. The reason seems
to be that we forget to clear the STOP and ACKNACK bits at the end of
the transaction. According to the PXA27x developer's manual, we shall
do so.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Nicolas Pitre <nico@cam.org>

Improve the debugging features of the i2c-algo-bit driver:
* Make it possible to compile the driver without debugging support
  at all, making it much smaller.
* Use dev_dbg() for debugging messages where possible, and dev_err()
  for error messages.
* Remove redundant debugging messages.

These changes allowed for minor code cleanups, which are included
as well.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The original i2c-algo-bit implementation uses a 33/66 SCL duty cycle
when bits are being written on the bus. While the I2C specification
doesn't forbid it, this prevents us from driving the I2C bus to its
max speed, limiting us to 66 kbps max on standard I2C busses.

Implementing a 50/50 duty cycle instead lets us max out the bandwidth
up to the theoretical max of 100 kbps on standard I2C busses. This is
particularly important when large amounts of data need to be transfered
over the bus, as is the case with some TV adapters when the firmware is
being uploaded.

In fact this change even allows, at least in theory, fast-mode I2C
support at 125, 166 and 250 kbps. There's no way to reach the
theoretical max of 400 kbps with this implementation. But I don't
think we want to put efforts in that direction anyway: software-driven
I2C is very CPU-intensive and bad for latency.

Other timing changes:
* Don't set SDA high explicitly on error, we're going to issue a stop
  condition before we leave anyway.
* If an error occurs when sending the slave address, yield the CPU
  before retrying, and remove the additional delay after the new start
  condition.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Update the OMAP I2C driver to use i2c_add_numbered_adapter(), so that
later patches can convert boards to using new-style drivers.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The i2c linux driver for blackfin architecture which supports blackfin
on-chip TWI controller i2c operation.
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Reviewed-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Make i2c_del_driver a void function, like all other driver removal
functions. It always returned 0 even when errors occured, and nobody
ever actually checked the return value anyway. And we cannot fail
a module removal anyway.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Move the declaration of i2c-isa-only exported symbols to i2c-isa
itself, that's the best way to ensure nobody will attempt to use them.
Hopefully we'll get rid of the exports themselves soon anyway.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Document the new i2c_new_device(), i2c_new_probed_device() and
i2c_unregister_device() functions.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add a new helper function to instantiate an i2c device. It is meant as a
replacement for i2c_new_device() when you don't know for sure at which
address your I2C/SMBus device lives. This happens frequently on TV
adapters for example, you know there is a tuner chip on the bus, but
depending on the exact board model and revision, it can live at different
addresses. So, the new i2c_new_probed_device() function will probe the bus
according to a list of addresses, and as soon as one of these addresses
responds, it will call i2c_new_device() on that one address.

This function will make it possible to port the old i2c drivers to the
new model quickly.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add i2c_bit_add_numbered_bus(), which is equivalent to i2c_bit_add_bus
except that it calls i2c_add_numbered_adapter() at the end instead of
i2c_add_adapter().
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Make i2c-core.c obey Documentation/CodingStyle better by snugging
the EXPORT_SYMBOL declarations next to the relevant definitions.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This adds a call, i2c_add_numbered_adapter(), registering an I2C adapter
with a specific bus number and then creating I2C device nodes for any
pre-declared devices on that bus.  It builds on previous patches adding
I2C probe() and remove() support, and that pre-declaration of devices.

This completes the core support for "new style" I2C device drivers.
Those follow the standard driver model for binding devices to drivers
(using probe and remove methods) rather than a legacy model (where the
driver tries to autoconfigure each bus, and registers devices itself).
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This provides partial support for new-style I2C driver binding.  It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board.  This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.

There are two models for declaring such devices:

 * LATE -- using a public function i2c_new_device().  This lets modules
   declare I2C devices found *AFTER* a given I2C adapter becomes available.
   
   For example, a PCI card could create adapters giving access to utility
   chips on that card, and this would be used to associate those chips with
   those adapters.

 * EARLY -- from arch_initcall() level code, using a non-exported function
   i2c_register_board_info().  This copies the declarations *BEFORE* such
   an i2c_adapter becomes available, arranging that i2c_new_device() will
   be called later when i2c-core registers the relevant i2c_adapter.

   For example, arch/.../.../board-*.c files would declare the I2C devices
   along with their platform data, and I2C devices would behave much like
   PNPACPI devices.  (That is, both enumerate from board-specific tables.)

To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.

Pending later patches using these new APIs, this is effectively a NOP.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Update Documentation/i2c to match previous patches updating probe()
and remove() logic.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

More update for new style driver support:  add a remove() method, and
use it in the relevant code paths.

Again, nothing will use this yet since there's nothing to create devices
feeding this infrastructure.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

One of a series of I2C infrastructure updates to support enumeration using
the standard Linux driver model.

This patch updates probe() and associated hotplug/coldplug support, but
not remove().  Nothing yet _uses_ it to create I2C devices, so those
hotplug/coldplug mechanisms will be the only externally visible change.
This patch will be an overall NOP since the I2C stack doesn't yet create
clients/devices except as part of binding them to legacy drivers.

Some code is moved earlier in the source code, helping group more of the
per-device infrastructure in one place and simplifying handling per-device
attributes.

Terminology being adopted:  "legacy drivers" create devices (i2c_client)
themselves, while "new style" ones follow the driver model (the i2c_client
is handed to the probe routine).  It's an either/or thing; the two models
don't mix, and drivers that try mixing them won't even be registered.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Port the i2c-pca-isa driver to the new device driver model. I'm
using Rene Herman's new isa bus type, as it fits the needs nicely. One
benefit is that we can now give a proper parent to our i2c adapter.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Port the i2c-elektor driver to the new device driver model. I'm
using Rene Herman's new isa bus type, as it fits the needs nicely. One
benefit is that we can now give a proper parent to our i2c adapter.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Also fix a small race on driver unload: we need to unregister the
i2c adapter before we power it off.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

When unloading the driver, we really want to unregister the i2c adapter
before we power it off, rather than the other way around.

Also speed up the bus a bit when we can sense SCL. The slaves will
stretch the line as needed.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The scx200_acb driver supports two kind of devices, PCI ones and ISA
ones. Even ISA ones are detected using the presence of a given PCI
device, and we get a reference to it, but never put it back, so we
have a leak. Fix it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Clean up the includes of <linux/i2c.h>. Only include this header file
when we actually need it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Hans-Frieder Vogt <hfvogt@gmx.net>

Initialize the fields of the i2c_adapter structure individually,
rather than copying a whole static template structure. This shaves
off 474 bytes or 14% (on i386) from the binary size.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Now that i2c-core lets the i2c bus drivers emulate the SMBus block read
and SMBus block process call transaction types, let's implement that in
the popular i2c bit-banging driver. This will also act as a reference
implementation for other bus drivers which want to do the same.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Let the I2C bus drivers emulate the SMBus Block Read and Block Process
Call transactions if they wish. This requires to define a new message
flag, which i2c-core will use to let the underlying I2C bus driver
know that the first received byte will specify the length of the read
message.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The i2c-algo-bit driver doesn't behave well on read errors: it'll
bail out without even sending a stop condition on the bus, so the bus
will be stuck. So make sure that we always send a stop condition on
the bus before we leave. The best way to make sure is to always send
it at the end of function bit_xfer.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Rename dev_to_i2c_adapter() as to_i2c_adapter(), since the previous
syntax was a surprising and needless difference from normal naming
conventions in Linux.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This patch is a minor cleanup/code shrink, using class infrastructure
in i2c-core to manage the i2c_adapter attribute.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This shrinks the size of "struct i2c_client" by 40 bytes:

 - Substantially shrinks the string used to identify the chip type
 - The "flags" don't need to be so big
 - Removes some internal padding

It also adds kerneldoc for that struct, explaining how "name" is really a
chip type identifier; it's otherwise potentially confusing.

Because the I2C_NAME_SIZE symbol was abused for both i2c_client.name
and for i2c_adapter.name, this needed to affect i2c_adapter too.  The
adapters which used that symbol now use the more-obviously-correct
idiom of taking the size of that field.

JD: Shorten i2c_adapter.name from 50 to 48 bytes while we're here, to
avoid wasting space in padding.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Minor cleanup in i2c_register_driver():  use list_for_each_entry().
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Kill i2c_adapter_driver as it doesn't make sense and it prevents
further i2c-core cleanups. i2c_adapter devices are virtual devices
(ex-class devices) and as such they don't need a driver.
Signed-off-by: NJean Delvare <khali@linux-fr.org>