Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Since 43cc71ee, the platform
modalias is prefixed with "platform:". Add MODULE_ALIAS() to the
hotpluggable I2C platform drivers, to allow module auto loading.

[ db: add some more drivers ]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This is required to let hwmon drivers attach to the adapter.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

It turns out that platform_device.id is a "u32" so testing it for being
nonnegative is useless when setting up an i2c bitbang device.  Instead,
do what the platform_bus code does and test it against the value "-1". 
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

i2c_gpio_getsda() and i2c_gpio_getscl() are only used in this file.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Use i2c_bit_add_numbered_bus() so that the i2c-gpio adapter works well
with new-style pre-declared devices.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
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>