diff options
| author |   Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> | 2015-10-12 15:29:03 +0300 |
|---|---|---|
| committer |   Lee Jones <lee.jones@linaro.org> | 2015-10-15 12:06:28 +0100 |
| commit | dc881123aa1aeff02ce2dc94c2b810d37173aa90 (patch) | |
| tree | e89785cb92f8cb8eb05b40f8d9ba977fa354e212 /drivers/video | |
| parent | backlight: 88pm860x_bl: Add missing of_node_put (diff) | |
| download | linux-dev-dc881123aa1aeff02ce2dc94c2b810d37173aa90.tar.xz linux-dev-dc881123aa1aeff02ce2dc94c2b810d37173aa90.zip | |
backlight: pwm: Reject legacy PWM request for device defined in DT
Platform PWM backlight data provided by board's device tree should be
complete enough to successfully request a pwm device using pwm_get()
API. This change fixes a bug, when an arbitrary (first found) PWM is
connected to a "pwm-backlight" compatible device, when explicit PWM
device reference is not given.
Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
already describes "pwms" as a required property, instead of blind
selection of a potentially wrong PWM reject legacy PWM device
registration request, leave legacy API only for non-dt cases.
Based on initial implementation done by Dmitry Eremin-Solenikov.
Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/backlight/pwm_bl.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index eff379b234cc..ae3c6b6fd5db 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -271,19 +271,18 @@ static int pwm_backlight_probe(struct platform_device *pdev) } pb->pwm = devm_pwm_get(&pdev->dev, NULL); - if (IS_ERR(pb->pwm)) { - ret = PTR_ERR(pb->pwm); - if (ret == -EPROBE_DEFER) - goto err_alloc; - + if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER + && !pdev->dev.of_node) { dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); pb->legacy = true; pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); - if (IS_ERR(pb->pwm)) { - dev_err(&pdev->dev, "unable to request legacy PWM\n"); - ret = PTR_ERR(pb->pwm); - goto err_alloc; - } + } + + if (IS_ERR(pb->pwm)) { + ret = PTR_ERR(pb->pwm); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "unable to request PWM\n"); + goto err_alloc; } dev_dbg(&pdev->dev, "got pwm for backlight\n"); |