> From the datasheet:
[...]
> So, you should provide both a direction_input and direction_output.
He did in V2 of this patch (what made me also download the datasheet ;)).
Regards,
Wolfram
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
On Tuesday, February 01, 2011 1:02 AM, Wolfram Sang wrote:
>> From the datasheet:
>>[...]
>> So, you should provide both a direction_input and direction_output.
>
> He did in V2 of this patch (what made me also download the datasheet ;)).
Ok. Just looked at the v2 patch.
> +static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
> +{
> + struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
> + struct pca9532_led *led = &data->leds[offset];
> +
> + /* To use as input ensure pin is not driven */
> + led->state = PCA9532_OFF;
> + pca9532_setled(led);
> +
> + return 0;
> +}
> +
This looks good. When configured as an input the pin needs to be set high-impedance,
00 which is PCA9532_OFF).
> +static int pca9532_gpio_direction_output(struct gpio_chip *gc,
> unsigned offset, int val)
> +{
> + return 0;
> +}
> +
Not good. When the pin is configured as an output, the direction_output method also
requests that the pin be set to a desired level. For this driver that means that the
pca9532_gpio_direction_output function just needs to call pca9532_gpio_set_value.
Regards,
Hartley
On 2/1/11, H Hartley Sweeten <[email protected]> wrote:
> On Tuesday, February 01, 2011 1:02 AM, Wolfram Sang wrote:
>>> From the datasheet:
>>>[...]
>>> So, you should provide both a direction_input and direction_output.
>>
>> He did in V2 of this patch (what made me also download the datasheet ;)).
>
> Ok. Just looked at the v2 patch.
>
>> +static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned
>> offset)
>> +{
>> + struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
>> + struct pca9532_led *led = &data->leds[offset];
>> +
>> + /* To use as input ensure pin is not driven */
>> + led->state = PCA9532_OFF;
>> + pca9532_setled(led);
>> +
>> + return 0;
>> +}
>> +
>
> This looks good. When configured as an input the pin needs to be set
> high-impedance,
> 00 which is PCA9532_OFF).
>
>> +static int pca9532_gpio_direction_output(struct gpio_chip *gc,
>> unsigned offset, int val)
>> +{
>> + return 0;
>> +}
>> +
>
> Not good. When the pin is configured as an output, the direction_output
> method also
> requests that the pin be set to a desired level. For this driver that means
> that the
> pca9532_gpio_direction_output function just needs to call
> pca9532_gpio_set_value.
ops, I overlooked the 'val' parameter in the direction_output
function. I will create a v3.
Seems like I have been a bit careless with the direction setting... I
didn't really think through it since PCA9532 has no explicit direction
register.
Thanks for looking!
regards
Joachim Eastwood
> Regards,
> Hartley
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>
> > +static int pca9532_gpio_direction_output(struct gpio_chip *gc,
> > unsigned offset, int val)
> > +{
> > + return 0;
> > +}
> > +
>
> Not good. When the pin is configured as an output, the direction_output method also
> requests that the pin be set to a desired level. For this driver that means that the
> pca9532_gpio_direction_output function just needs to call pca9532_gpio_set_value.
Ack, missed that. Thanks a lot!
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |