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.

Also there is a variant to find optional gpios that returns NULL if there is no gpio instead of -ENOENT.

Make use of both features to simplify the driver.

This makes error checking more strict because errors like -ENOSYS ("no gpio support compiled in") or -EPROBE_DEFER ("gpio not ready yet") are handled correctly now.

Furthermore this is one caller less that stops us making the flags argument to gpiod_get*() mandatory.

Reviewed-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de ---

Notes: Changes since (implicit) v1 sent with Message-Id: 1432021249-24183-1-git-send-email-u.kleine-koenig@pengutronix.de:

- remove now unused variable ret (thanks to the kbuild test robot) - add Reviewed-by for Linus W. (I hope that's ok in spite of the above change) - drop Fixes: line

drivers/gpu/drm/msm/dsi/dsi_host.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 956b22492c9a..bf0d1727ab77 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1351,36 +1351,19 @@ static irqreturn_t dsi_host_irq(int irq, void *ptr) static int dsi_host_init_panel_gpios(struct msm_dsi_host *msm_host, struct device *panel_device) { - int ret; - - msm_host->disp_en_gpio = devm_gpiod_get(panel_device, - "disp-enable"); + msm_host->disp_en_gpio = devm_gpiod_get_optional(panel_device, + "disp-enable", + GPIOD_OUT_LOW); if (IS_ERR(msm_host->disp_en_gpio)) { DBG("cannot get disp-enable-gpios %ld", PTR_ERR(msm_host->disp_en_gpio)); - msm_host->disp_en_gpio = NULL; - } - if (msm_host->disp_en_gpio) { - ret = gpiod_direction_output(msm_host->disp_en_gpio, 0); - if (ret) { - pr_err("cannot set dir to disp-en-gpios %d\n", ret); - return ret; - } + return PTR_ERR(msm_host->disp_en_gpio); }

- msm_host->te_gpio = devm_gpiod_get(panel_device, "disp-te"); + msm_host->te_gpio = devm_gpiod_get(panel_device, "disp-te", GPIOD_IN); if (IS_ERR(msm_host->te_gpio)) { DBG("cannot get disp-te-gpios %ld", PTR_ERR(msm_host->te_gpio)); - msm_host->te_gpio = NULL; - } - - if (msm_host->te_gpio) { - ret = gpiod_direction_input(msm_host->te_gpio); - if (ret) { - pr_err("%s: cannot set dir to disp-te-gpios, %d\n", - __func__, ret); - return ret; - } + return PTR_ERR(msm_host->te_gpio); }

return 0;