2012-11-07 11:43:10

by Peter Ujfalusi

[permalink] [raw]
Subject: [PATCH] leds: leds-pwm: Convert to use devm_get_pwm

Update the driver to use the new API for requesting pwm so we can take
advantage of the pwm_lookup table to find the correct pwm to be used for the
LED functionality.
If the devm_get_pwm fails we fall back to legacy mode to try to get the pwm.

Signed-off-by: Peter Ujfalusi <[email protected]>
---
drivers/leds/leds-pwm.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index f2e44c7..6bf9445 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -47,6 +47,19 @@ static void led_pwm_set(struct led_classdev *led_cdev,
}
}

+static struct pwm_device *led_pwm_request_pwm(struct platform_device *pdev,
+ struct led_pwm *cur_led)
+{
+ struct pwm_device *pwm;
+
+ pwm = devm_pwm_get(&pdev->dev, cur_led->name);
+ if (IS_ERR(pwm)) {
+ dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
+ pwm = pwm_request(cur_led->pwm_id, cur_led->name);
+ }
+ return pwm;
+}
+
static int led_pwm_probe(struct platform_device *pdev)
{
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
@@ -67,8 +80,7 @@ static int led_pwm_probe(struct platform_device *pdev)
cur_led = &pdata->leds[i];
led_dat = &leds_data[i];

- led_dat->pwm = pwm_request(cur_led->pwm_id,
- cur_led->name);
+ led_dat->pwm = led_pwm_request_pwm(pdev, cur_led);
if (IS_ERR(led_dat->pwm)) {
ret = PTR_ERR(led_dat->pwm);
dev_err(&pdev->dev, "unable to request PWM %d\n",
--
1.8.0


2012-11-10 01:48:59

by Bryan Wu

[permalink] [raw]
Subject: Re: [PATCH] leds: leds-pwm: Convert to use devm_get_pwm

On Wed, Nov 7, 2012 at 3:42 AM, Peter Ujfalusi <[email protected]> wrote:
> Update the driver to use the new API for requesting pwm so we can take
> advantage of the pwm_lookup table to find the correct pwm to be used for the
> LED functionality.
> If the devm_get_pwm fails we fall back to legacy mode to try to get the pwm.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> drivers/leds/leds-pwm.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> index f2e44c7..6bf9445 100644
> --- a/drivers/leds/leds-pwm.c
> +++ b/drivers/leds/leds-pwm.c
> @@ -47,6 +47,19 @@ static void led_pwm_set(struct led_classdev *led_cdev,
> }
> }
>
> +static struct pwm_device *led_pwm_request_pwm(struct platform_device *pdev,
> + struct led_pwm *cur_led)
> +{
> + struct pwm_device *pwm;
> +
> + pwm = devm_pwm_get(&pdev->dev, cur_led->name);
> + if (IS_ERR(pwm)) {
> + dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
> + pwm = pwm_request(cur_led->pwm_id, cur_led->name);

Looks good, but why we still need to keep the old API pwm_request(),
if devm_pwm_get() is the right replacement. AFAIK, devm_***() API will
help to clean up if device probing fails.

So if it is good enough, we can just replace pwm_request() to the devm_pwm_get()

Thanks,
-Bryan

> + }
> + return pwm;
> +}
> +
> static int led_pwm_probe(struct platform_device *pdev)
> {
> struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
> @@ -67,8 +80,7 @@ static int led_pwm_probe(struct platform_device *pdev)
> cur_led = &pdata->leds[i];
> led_dat = &leds_data[i];
>
> - led_dat->pwm = pwm_request(cur_led->pwm_id,
> - cur_led->name);
> + led_dat->pwm = led_pwm_request_pwm(pdev, cur_led);
> if (IS_ERR(led_dat->pwm)) {
> ret = PTR_ERR(led_dat->pwm);
> dev_err(&pdev->dev, "unable to request PWM %d\n",
> --
> 1.8.0
>

2012-11-12 08:41:17

by Peter Ujfalusi

[permalink] [raw]
Subject: Re: [PATCH] leds: leds-pwm: Convert to use devm_get_pwm

On 11/10/2012 02:48 AM, Bryan Wu wrote:
> On Wed, Nov 7, 2012 at 3:42 AM, Peter Ujfalusi <[email protected]> wrote:
>> Update the driver to use the new API for requesting pwm so we can take
>> advantage of the pwm_lookup table to find the correct pwm to be used for the
>> LED functionality.
>> If the devm_get_pwm fails we fall back to legacy mode to try to get the pwm.
>>
>> Signed-off-by: Peter Ujfalusi <[email protected]>
>> ---
>> drivers/leds/leds-pwm.c | 16 ++++++++++++++--
>> 1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
>> index f2e44c7..6bf9445 100644
>> --- a/drivers/leds/leds-pwm.c
>> +++ b/drivers/leds/leds-pwm.c
>> @@ -47,6 +47,19 @@ static void led_pwm_set(struct led_classdev *led_cdev,
>> }
>> }
>>
>> +static struct pwm_device *led_pwm_request_pwm(struct platform_device *pdev,
>> + struct led_pwm *cur_led)
>> +{
>> + struct pwm_device *pwm;
>> +
>> + pwm = devm_pwm_get(&pdev->dev, cur_led->name);
>> + if (IS_ERR(pwm)) {
>> + dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
>> + pwm = pwm_request(cur_led->pwm_id, cur_led->name);
>
> Looks good, but why we still need to keep the old API pwm_request(),
> if devm_pwm_get() is the right replacement. AFAIK, devm_***() API will
> help to clean up if device probing fails.
>
> So if it is good enough, we can just replace pwm_request() to the devm_pwm_get()

I have greped for "leds_pwm" in arch/ and the only place it is used is the
arch/arm/mach-omap2/board-sdp4430sdp.c and that is not working at all (using
wrong ID for the PWM).
I think I can remove the legacy way of requesting the pwm from the driver
safely (I can also mark the pwm_id in struct led_pwm as deprecated at the same
time).
Will send the v2 soon.

Thank you,
P?ter

>
> Thanks,
> -Bryan
>
>> + }
>> + return pwm;
>> +}
>> +
>> static int led_pwm_probe(struct platform_device *pdev)
>> {
>> struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
>> @@ -67,8 +80,7 @@ static int led_pwm_probe(struct platform_device *pdev)
>> cur_led = &pdata->leds[i];
>> led_dat = &leds_data[i];
>>
>> - led_dat->pwm = pwm_request(cur_led->pwm_id,
>> - cur_led->name);
>> + led_dat->pwm = led_pwm_request_pwm(pdev, cur_led);
>> if (IS_ERR(led_dat->pwm)) {
>> ret = PTR_ERR(led_dat->pwm);
>> dev_err(&pdev->dev, "unable to request PWM %d\n",
>> --
>> 1.8.0
>>