[U-Boot] [PATCH 13/17] post/i2c: Add ability to ignore I2C devices
Heiko Schocher
hs at denx.de
Thu Sep 30 08:10:48 CEST 2010
Hello Peter,
Peter Tyser wrote:
> Add the ability to not report an I2C POST error for a set of given I2C
> addresses on bootup. This is useful for the following cases:
>
> - Some form factors such as XMC and Compact PCI Express have an I2C
> EEPROM whose address changes based on geographical address. Eg
> installed in one slot its EEPROM address is, 0x50, in another its
> 0x51, etc. This allows multiple devices to have their EEPROMs present
> on the same I2C bus. Thus the I2C devices present for an XMC or
> CPCIe card depend on if and where other cards are installed in the
> same system.
>
> - Some cards have optional I2C devices. Eg one hardware build
> configuration has different I2C devices than another.
>
> - Some cards have optional daughtercards with I2C devices on them.
>
> - I2C EEPROMs address range depends on their size. Its possible to
> support differently size EEPROMs by only probing the EEPROM's base
> address and ignoring the other addresses that are impacted by its
> size.
>
> A new I2C_ADDR_IGNORE_LIST define has been added which specifies a list
> of I2C addresses for the I2C POST to ignore.
>
> Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
> CC: hs at denx.de
> ---
> post/drivers/i2c.c | 16 ++++++++++++++++
> 1 files changed, 16 insertions(+), 0 deletions(-)
Maybe you can add a little info in the README?
> diff --git a/post/drivers/i2c.c b/post/drivers/i2c.c
> index 2dd128e..9e1fd50 100644
> --- a/post/drivers/i2c.c
> +++ b/post/drivers/i2c.c
> @@ -40,6 +40,20 @@
>
> #if CONFIG_POST & CONFIG_SYS_POST_I2C
>
> +static int i2c_ignore_device(unsigned int chip)
> +{
> +#ifdef I2C_ADDR_IGNORE_LIST
Hmm.. as this is only used in post code, this should be visible
in the defines name, what with:
I2C_POST_ADDR_IGNORE_LIST
?
bye,
Heiko
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