Re: [PATCH 2/5 v2] Input: bu21013_ts - Move GPIO init and exitfunctions into the driver

From: Lee Jones
Date: Tue Nov 27 2012 - 04:07:32 EST


On Mon, 26 Nov 2012, Dmitry Torokhov wrote:

> Hi Lee,
>
> On Mon, Nov 26, 2012 at 12:01:43PM +0000, Lee Jones wrote:
> > /**
> > + * bu21013_gpio_board_init() - configures the touch panel
> > + * @reset_pin: reset pin number
> > + *
> > + * This function is used to configure the voltage and
> > + * reset the touch panel controller.
> > + */
> > +static int bu21013_gpio_board_init(int reset_pin)
> > +{
> > + int retval = 0;
> > +
> > + retval = gpio_request_one(reset_pin, GPIOF_INIT_HIGH, "touchp_reset");
>
> Also need to specify dircetion (even though it defaults to output).

You do? Okay, I'll do that.

> > + if (retval) {
> > + printk(KERN_ERR "Unable to request gpio reset_pin");
> > + return retval;
> > + }
> > +
> > + return retval;
> > +}
> > +
> > +/**
> > + * bu21013_gpio_board_exit() - deconfigures the touch panel controller
> > + * @reset_pin: reset pin number
> > + *
> > + * This function is used to deconfigure the chip selection
> > + * for touch panel controller.
> > + */
> > +static int bu21013_gpio_board_exit(int reset_pin)
> > +{
> > + int retval = 0;
> > +
> > + retval = gpio_direction_output(reset_pin, 0);
> > + if (retval < 0) {
> > + printk(KERN_ERR "%s: gpio direction failed\n",
> > + __func__);
> > + return retval;
>
> You should not return here, as gpio has to be freed even if you unable
> to toggle it.

You're right.

> > + }
> > + gpio_set_value(reset_pin, 0);
> > + gpio_free(reset_pin);
> > +
> > + return retval;
> > +}
> > +
> > +/**
> > * bu21013_init_chip() - power on sequence for the bu21013 controller
> > * @data: device structure pointer
> > *
> > @@ -449,6 +493,8 @@ static int __devinit bu21013_probe(struct i2c_client *client,
> > return -EINVAL;
> > }
> >
> > + pdata->irq = gpio_to_irq(pdata->touch_pin);
> > +
>
> No, you still can not do it since pdata is a const pointer. Does not
> your compiler throw a warning here?
>
> I already sent you a version of the patch that does not have these
> issues, is there a particular reason why you needed to roll your own
> instead of simply trying out the one I sent?

I didn't see the other patch, sorry.

I'll check my mail and apply it.

--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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