[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[Pramod Gurav]

This patch adds a remove function to platform_driver to unload
the driver in a cleaner way. This also releases gpiochip related
resources by calling gpiochip_remove when gpiochip_irqchip_add fails.

CC: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
CC: Srinivas Kandagatla <srinivas.kandagatla@linaro.com>
CC: Maxime Coquelin <maxime.coquelin@st.com>
CC: Patrice Chotard <patrice.chotard@st.com>
CC: Linus Walleij <linus.walleij@linaro.org>
CC: Bjorn Andersson <bjorn.andersson@sonymobile.com>

Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
---
 drivers/pinctrl/pinctrl-st.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 5475374..9296845 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1517,6 +1517,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
 					   0, handle_simple_irq,
 					   IRQ_TYPE_LEVEL_LOW);
 		if (err) {
+			gpiochip_remove(&bank->gpio_chip);
 			dev_info(dev, "could not add irqchip\n");
 			return err;
 		}
@@ -1685,6 +1686,29 @@ static int st_pctl_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int st_pctl_remove(struct platform_device *pdev)
+{
+	struct st_pinctrl *info = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *child;
+	struct gpio_chip gpio_chip;
+	int bank = 0;
+
+	if (info->nbanks) {
+		for_each_child_of_node(np, child) {
+			if (of_property_read_bool(child, "gpio-controller")) {
+				gpio_chip = info->banks[bank].gpio_chip;
+				gpiochip_remove(&gpio_chip);
+				bank++;
+			}
+		}
+	}
+
+	pinctrl_unregister(info->pctl);
+
+	return 0;
+}
+
 static struct platform_driver st_pctl_driver = {
 	.driver = {
 		.name = "st-pinctrl",
@@ -1692,6 +1716,7 @@ static struct platform_driver st_pctl_driver = {
 		.of_match_table = st_pctl_of_match,
 	},
 	.probe = st_pctl_probe,
+	.remove = st_pctl_remove,
 };
 
 static int __init st_pctl_init(void)
-- 
1.7.0.4

[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[Linus Walleij]

On Sat, Aug 30, 2014 at 4:45 PM, Pramod Gurav
<pramod.gurav@smartplayin.com> wrote:

> This patch adds a remove function to platform_driver to unload
> the driver in a cleaner way. This also releases gpiochip related
> resources by calling gpiochip_remove when gpiochip_irqchip_add fails.
>
> CC: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
> CC: Srinivas Kandagatla <srinivas.kandagatla@linaro.com>
> CC: Maxime Coquelin <maxime.coquelin@st.com>
> CC: Patrice Chotard <patrice.chotard@st.com>
> CC: Linus Walleij <linus.walleij@linaro.org>
> CC: Bjorn Andersson <bjorn.andersson@sonymobile.com>
>
> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>

Srinivas/Patrice: can you have a look at this?

Yours,
Linus Walleij

[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[Srinivas Kandagatla]

Pramod,
sorry for delay in reply as I was travelling, still in Jet lag.
> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
> ---
>   drivers/pinctrl/pinctrl-st.c |   25 +++++++++++++++++++++++++
>   1 files changed, 25 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 5475374..9296845 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1517,6 +1517,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
>   					   0, handle_simple_irq,
>   					   IRQ_TYPE_LEVEL_LOW);
>   		if (err) {
> +			gpiochip_remove(&bank->gpio_chip);
This change-set looks good.
IMO, you can send a patch for this change set.

>   			dev_info(dev, "could not add irqchip\n");
>   			return err;
>   		}
> @@ -1685,6 +1686,29 @@ static int st_pctl_probe(struct platform_device *pdev)
>   	return 0;
>   }
>

> +static int st_pctl_remove(struct platform_device *pdev)
> +{
Ideally this driver will not be removed, as other drivers depend on 
this, even the serial.

so I see no big achievement in adding the remove functionality, as this 
is going to be a dead code and would never be tested.

> +	struct st_pinctrl *info = platform_get_drvdata(pdev);
> +	struct device_node *np = pdev->dev.of_node;
> +	struct device_node *child;
> +	struct gpio_chip gpio_chip;
> +	int bank = 0;
> +

> +	if (info->nbanks) {
> +		for_each_child_of_node(np, child) {
> +			if (of_property_read_bool(child, "gpio-controller")) {
We should not re-parse the DT nodes once we are done with it in the probe.

> +				gpio_chip = info->banks[bank].gpio_chip;
> +				gpiochip_remove(&gpio_chip);
> +				bank++;
> +			}
> +		}
> +	}
> +

I think the logic is very simple:

	while (nbanks--)
		gpiochip_remove(&info->banks[bank++].gpio_chip))


thanks,
srini
> +	pinctrl_unregister(info->pctl);
> +
> +	return 0;
> +}
> +
>   static struct platform_driver st_pctl_driver = {
>   	.driver = {
>   		.name = "st-pinctrl",
> @@ -1692,6 +1716,7 @@ static struct platform_driver st_pctl_driver = {
>   		.of_match_table = st_pctl_of_match,
>   	},
>   	.probe = st_pctl_probe,
> +	.remove = st_pctl_remove,
>   };
>
>   static int __init st_pctl_init(void)
>

[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[Pramod Gurav]

Hi Srini,

Thanks for review.

On 04-09-2014 11:38 PM, Srinivas Kandagatla wrote:
> Pramod,
> sorry for delay in reply as I was travelling, still in Jet lag.
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---
>>   drivers/pinctrl/pinctrl-st.c |   25 +++++++++++++++++++++++++
>>   1 files changed, 25 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> index 5475374..9296845 100644
>> --- a/drivers/pinctrl/pinctrl-st.c
>> +++ b/drivers/pinctrl/pinctrl-st.c
>> @@ -1517,6 +1517,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
>>   					   0, handle_simple_irq,
>>   					   IRQ_TYPE_LEVEL_LOW);
>>   		if (err) {
>> +			gpiochip_remove(&bank->gpio_chip);
> This change-set looks good.
> IMO, you can send a patch for this change set.
Will resend just this.

> 
>>   			dev_info(dev, "could not add irqchip\n");
>>   			return err;
>>   		}
>> @@ -1685,6 +1686,29 @@ static int st_pctl_probe(struct platform_device *pdev)
>>   	return 0;
>>   }
>>
> 
>> +static int st_pctl_remove(struct platform_device *pdev)
>> +{
> Ideally this driver will not be removed, as other drivers depend on 
> this, even the serial.
> 
> so I see no big achievement in adding the remove functionality, as this 
> is going to be a dead code and would never be tested.
> 
>> +	struct st_pinctrl *info = platform_get_drvdata(pdev);
>> +	struct device_node *np = pdev->dev.of_node;
>> +	struct device_node *child;
>> +	struct gpio_chip gpio_chip;
>> +	int bank = 0;
>> +
> 
>> +	if (info->nbanks) {
>> +		for_each_child_of_node(np, child) {
>> +			if (of_property_read_bool(child, "gpio-controller")) {
> We should not re-parse the DT nodes once we are done with it in the probe.
Thanks. :)
> 
>> +				gpio_chip = info->banks[bank].gpio_chip;
>> +				gpiochip_remove(&gpio_chip);
>> +				bank++;
>> +			}
>> +		}
>> +	}
>> +
> 
> I think the logic is very simple:
> 
> 	while (nbanks--)
> 		gpiochip_remove(&info->banks[bank++].gpio_chip))
Thanks again. Remove is not needed hence will not do this. But good know.
> 
> 
> thanks,
> srini
>> +	pinctrl_unregister(info->pctl);
>> +
>> +	return 0;
>> +}
>> +
>>   static struct platform_driver st_pctl_driver = {
>>   	.driver = {
>>   		.name = "st-pinctrl",
>> @@ -1692,6 +1716,7 @@ static struct platform_driver st_pctl_driver = {
>>   		.of_match_table = st_pctl_of_match,
>>   	},
>>   	.probe = st_pctl_probe,
>> +	.remove = st_pctl_remove,
>>   };
>>
>>   static int __init st_pctl_init(void)
>>
> --
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> 

[PATCH] pinctrl: st: Add remove function and remove gpio_chip on failure

[Maxime Coquelin]

Hi Pramod, Srini

On 09/04/2014 08:08 PM, Srinivas Kandagatla wrote:
> Pramod,
> sorry for delay in reply as I was travelling, still in Jet lag.
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---
>>   drivers/pinctrl/pinctrl-st.c |   25 +++++++++++++++++++++++++
>>   1 files changed, 25 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> index 5475374..9296845 100644
>> --- a/drivers/pinctrl/pinctrl-st.c
>> +++ b/drivers/pinctrl/pinctrl-st.c
>> @@ -1517,6 +1517,7 @@ static int st_gpiolib_register_bank(struct
>> st_pinctrl *info,
>>                          0, handle_simple_irq,
>>                          IRQ_TYPE_LEVEL_LOW);
>>           if (err) {
>> +            gpiochip_remove(&bank->gpio_chip);
> This change-set looks good.
> IMO, you can send a patch for this change set.

Removing the gpiochip here looks good to me too.

>
>>               dev_info(dev, "could not add irqchip\n");
>>               return err;
>>           }
>> @@ -1685,6 +1686,29 @@ static int st_pctl_probe(struct platform_device
>> *pdev)
>>       return 0;
>>   }
>>
>
>> +static int st_pctl_remove(struct platform_device *pdev)
>> +{
> Ideally this driver will not be removed, as other drivers depend on
> this, even the serial.
>
> so I see no big achievement in adding the remove functionality, as this
> is going to be a dead code and would never be tested.

Agree too.

Thanks,
Maxime