[U-Boot] [PATCH] i2c:gpio:s5p: I2C GPIO Software implementation

Lukasz Majewski l.majewski at samsung.com
Wed Jul 6 11:36:45 CEST 2011


On Wed, 06 Jul 2011 07:56:20 +0200
Heiko Schocher <hs at denx.de> wrote:

> Hello Mike,
> 
> Mike Frysinger wrote:
> > On Tuesday, July 05, 2011 08:23:41 Lukasz Majewski wrote:
> >> This commit adds I2C software support for Samsung's S5PC110
> >> family of processors.
> >> The generic drivers/i2c/soft_i2c framework is used, with
> >> routines provided by this commit.
> > 
> > if you simply implemented the generic gpio layer (asm/gpio.h), the
> > soft_i2c.c code already handles gluing to GPIO pins.  then you
> > wouldnt need a sep driver at all.  you can see the bf561-ezkit
> > already using this code. -mike
> 
> Yes, that was my thought too. No seperate i2c driver should be needed
> here.
> 
> bye,
> Heiko

Thanks Mike and Heiko for reply.

However I've got some extra question.

In the bf651-ezkit.h file I can see the I2C definition:

#define CONFIG_SOFT_I2C
#define CONFIG_SOFT_I2C_GPIO_SCL GPIO_PF0
#define CONFIG_SOFT_I2C_GPIO_SDA GPIO_PF1

My concern is about the situation when SoC needs more than one Software
I2C run via GPIO?

Please consider following scenario: 
One sensor is connected to pins 1(SCL) and 3(SDA) and another to 4(SCL)
and 5(SDA) in a GPIO port.

As fair as I've understood the software_i2c framework, it is supposed to
run only one instance of GPIO I2C.

Is there any way to "instantiate" more than one I2C GPIO interface via
software_i2c?

-- 
Best regards,

Lukasz Majewski

Samsung Poland R&D Center
Platform Group


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