w1-gpio: handle of_get_gpio() returning -EPROBE_DEFER better
of_get_gpio() might return -EPROBE_DEFER meaning that the driver
providing the gpio isn't ready yet. If that happens for the first gpio
the resulting kernel output without this patch is:
w1-gpio somename: Failed to parse DT
platform somename: Driver w1-gpio requests probe deferral
The first message is misleading and so is suppressed with this patch.
Further if determining the gpio to switch the external pullup yields
-EPROBE_DEFER this error should be passed back to the caller instead of
just continuing without pullup.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index 9709b8b..1d111e5 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -89,11 +89,22 @@
pdata->is_open_drain = 1;
gpio = of_get_gpio(np, 0);
- if (gpio < 0)
+ if (gpio < 0) {
+ if (gpio != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Failed to parse gpio property for data pin (%d)\n",
+ gpio);
+
return gpio;
+ }
pdata->pin = gpio;
- pdata->ext_pullup_enable_pin = of_get_gpio(np, 1);
+ gpio = of_get_gpio(np, 1);
+ if (gpio == -EPROBE_DEFER)
+ return gpio;
+ /* ignore other errors as the pullup gpio is optional */
+ pdata->ext_pullup_enable_pin = gpio;
+
pdev->dev.platform_data = pdata;
return 0;
@@ -107,10 +118,8 @@
if (of_have_populated_dt()) {
err = w1_gpio_probe_dt(pdev);
- if (err < 0) {
- dev_err(&pdev->dev, "Failed to parse DT\n");
+ if (err < 0)
return err;
- }
}
pdata = dev_get_platdata(&pdev->dev);