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authorVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>2015-10-12 15:29:03 +0300
committerLee Jones <lee.jones@linaro.org>2015-10-15 14:06:28 +0300
commitdc881123aa1aeff02ce2dc94c2b810d37173aa90 (patch)
treee89785cb92f8cb8eb05b40f8d9ba977fa354e212 /drivers/video/backlight
parentf85de2d9e24ee0b286ae54434f405d4a22f565f0 (diff)
downloadlinux-dc881123aa1aeff02ce2dc94c2b810d37173aa90.tar.xz
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/backlight')
-rw-r--r--drivers/video/backlight/pwm_bl.c19
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");