[PATCH] max730x: Added setup/teardown hooks

[PATCH] max730x: Added setup/teardown hooks

[stigge]

max730x: Added setup/teardown hooks

This patch adds setup and teardown hooks for configuration of GPIO lines via
platform_data, similar to the pca953x driver.

Signed-off-by: Roland Stigge <stigge@antcom.de>

diff --git a/drivers/gpio/max730x.c b/drivers/gpio/max730x.c
index 94ce773..ccd624d 100644
--- a/drivers/gpio/max730x.c
+++ b/drivers/gpio/max730x.c
@@ -219,6 +219,12 @@ int __devinit __max730x_probe(struct max7301 *ts)
 	if (ret)
 		goto exit_destroy;
 
+	if (pdata->setup) {
+		ret = pdata->setup(ts->chip.base,
+				ts->chip.ngpio, pdata->context);
+		if (ret < 0)
+			dev_warn(dev, "setup failed, %d\n", ret);
+	}
 	return ret;
 
 exit_destroy:
@@ -230,12 +236,24 @@ EXPORT_SYMBOL_GPL(__max730x_probe);
 
 int __devexit __max730x_remove(struct device *dev)
 {
+	struct max7301_platform_data *pdata;
 	struct max7301 *ts = dev_get_drvdata(dev);
 	int ret;
 
 	if (ts == NULL)
 		return -ENODEV;
 
+	pdata = dev->platform_data;
+
+	if (pdata && pdata->teardown) {
+		ret = pdata->teardown(ts->chip.base,
+				ts->chip.ngpio, pdata->context);
+		if (ret < 0) {
+			dev_err(dev, "teardown failed, %d\n", ret);
+			return ret;
+		}
+	}
+
 	dev_set_drvdata(dev, NULL);
 
 	/* Power down the chip and disable IRQ output */
diff --git a/include/linux/spi/max7301.h b/include/linux/spi/max7301.h
index bcaa2f7..02d685a 100644
--- a/include/linux/spi/max7301.h
+++ b/include/linux/spi/max7301.h
@@ -28,6 +28,13 @@ struct max7301_platform_data {
 	 * ports of the controller are not used, too.
 	 */
 	u32		input_pullup_active;
+
+	void		*context;	/* param to setup/teardown */
+
+	int		(*setup)(unsigned gpio, unsigned ngpio,
+				void *context);
+	int		(*teardown)(unsigned gpio, unsigned ngpio,
+				void *context);
 };
 
 extern int __max730x_remove(struct device *dev);

Re: [PATCH] max730x: Added setup/teardown hooks

[Grant Likely]

On Fri, Feb 11, 2011 at 5:00 AM,  <stigge@antcom.de> wrote:
> max730x: Added setup/teardown hooks
>
> This patch adds setup and teardown hooks for configuration of GPIO lines via
> platform_data, similar to the pca953x driver.

Why?  What actions are these hooks going to perform?

g.

Re: [PATCH] max730x: Added setup/teardown hooks

[Roland Stigge]

On 03/03/2011 07:59 PM, Grant Likely wrote:
> On Fri, Feb 11, 2011 at 5:00 AM,  <stigge@antcom.de> wrote:
>> max730x: Added setup/teardown hooks
>>
>> This patch adds setup and teardown hooks for configuration of GPIO lines via
>> platform_data, similar to the pca953x driver.
> 
> Why?  What actions are these hooks going to perform?

In board configurations, ARM systems are set up with GPIO lines
configured as Input or Output etc. See also arch/arm/*/*. See usage of
pca953x - how it is already done there.

Thanks,

Roland

Re: [PATCH] max730x: Added setup/teardown hooks

[Grant Likely]

On Thu, Mar 03, 2011 at 08:26:44PM +0100, Roland Stigge wrote:
> On 03/03/2011 07:59 PM, Grant Likely wrote:
> > On Fri, Feb 11, 2011 at 5:00 AM,  <stigge@antcom.de> wrote:
> >> max730x: Added setup/teardown hooks
> >>
> >> This patch adds setup and teardown hooks for configuration of GPIO lines via
> >> platform_data, similar to the pca953x driver.
> > 
> > Why?  What actions are these hooks going to perform?
> 
> In board configurations, ARM systems are set up with GPIO lines
> configured as Input or Output etc. See also arch/arm/*/*. See usage of
> pca953x - how it is already done there.

It appears to simply be notifying the platform code that the gpio chip
has been registered.  My point is that it doesn't seem to make any
sense whatsoever to have driver specific hooks to inform platform code
that a gpio controller has shown up.  It is something that should be
part of the infrastructure.  I would much rather see this get
implemented with a notifier or something similar in gpiochip_add().

Other drivers may currently be doing driver-specific callbacks, but it
is a bad pattern and I don't want any more drivers to do so.

g.