drm/tilcdc: panel: make better use of gpiod API

Since 39b2bbe3d715 (gpio: add flags argument to gpiod_get*() functions)
which appeared in v3.17-rc1, the gpiod_get* functions take an additional
parameter that allows to specify direction and initial value for output.

Furthermore there is devm_gpiod_get_optional which is designed to get
optional gpios.

Simplify driver accordingly.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

1 files changed, 7 insertions, 15 deletions

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.c b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
index 7a0315855e90..0af8bed7ce1e 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_panel.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@@ -375,25 +375,17 @@ static int panel_probe(struct platform_device *pdev)
                 dev_info(&pdev->dev, "found backlight\n");
         }
 
-        panel_mod->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
+        panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+                                                         GPIOD_OUT_LOW);
         if (IS_ERR(panel_mod->enable_gpio)) {
                 ret = PTR_ERR(panel_mod->enable_gpio);
-                if (ret != -ENOENT) {
-                        dev_err(&pdev->dev, "failed to request enable GPIO\n");
-                        goto fail_backlight;
-                }
-
-                /* Optional GPIO is not here, continue silently. */
-                panel_mod->enable_gpio = NULL;
-        } else {
-                ret = gpiod_direction_output(panel_mod->enable_gpio, 0);
-                if (ret < 0) {
-                        dev_err(&pdev->dev, "failed to setup GPIO\n");
-                        goto fail_backlight;
-                }
-                dev_info(&pdev->dev, "found enable GPIO\n");
+                dev_err(&pdev->dev, "failed to request enable GPIO\n");
+                goto fail_backlight;
         }
 
+        if (panel_mod->enable_gpio)
+                dev_info(&pdev->dev, "found enable GPIO\n");
+
         mod = &panel_mod->base;
         pdev->dev.platform_data = mod;