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 <[email protected]> Signed-off-by: Vladimir Zapolskiy <[email protected]> Acked-by: Thierry Reding <[email protected]> Acked-by: Lee Jones <[email protected]> --- The change is based on lee-backlight/for-backlight-next Changes from v1 to v2: * rebased on top of Nicolas' commit 68feaca0b13 ("backlight: pwm: Handle EPROBE_DEFER while requesting the PWM") Links to previous discussions of the change: * https://patchwork.ozlabs.org/patch/483993/ * https://patchwork.ozlabs.org/patch/398849/ drivers/video/backlight/pwm_bl.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index eff379b..ae3c6b6 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"); -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
