[i2c] [PATCH] gpio: max732x: add support for MAX7319, MAX7320-7327 I2C Port Expanders

[David Brownell]

On Saturday 12 July 2008, Jean Delvare wrote:
> > > +#include <linux/i2c.h>
> > > +#include <linux/i2c/max732x.h>
> > > +
> > > +#include <asm/gpio.h>
> > 
> > For consistency, make that <linux/gpio.h> and put it up above.
> > I like to see blank lines delineating groups, like <linux/*>
> > and <linux/i2c/*>, too.
> 
> You probably want to fix all gpio drivers to do the same then,
> otherwise contributors will keep copying the wrong practice.

When I get time.  ;)


> > > +	chip->client[0] = client;
> > > +
> > > +	switch (client->addr & 0x70) {
> > > +	case 0x60:
> > > +		chip->client[1] = i2c_new_dummy(client->adapter,
> > > +					(client->addr & 0x0f) | 0x50);
> > > +		chip->client_group_a = chip->client[0];
> > > +		chip->client_group_b = chip->client[1];
> > > +		break;
> > > +	case 0x50:
> > > +		chip->client[1] = i2c_new_dummy(client->adapter,
> > > +					(client->addr & 0x0f) | 0x60);
> > > +		chip->client_group_a = chip->client[1];
> > > +		chip->client_group_b = chip->client[0];
> > > +		break;
> > 
> > Why not just insist the 0x5x address be registered/probed?  This
> > extra stuff is needless and confusing.
> 
> Because some of the chips supported by this driver (max7319, max7321,
> max7322 and max7323) only use address 0x6x.

That's not the behavior implemented here though ... it's always
creating a dummy, even when it's not needed.


> I agree that the way the two clients are handled seems to be more
> complex than it needs to be, but the diversity of supported chips is
> such that even simplifying it as much as possible will still result in
> non-trivial code.

For what it *does* it **IS** more complex than it needs to be.
There's no "seems" about it.

For what was *intended*, it's evidently not yet complex enough.  :(

- Dave