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w1-gpio: handle of_get_gpio() returning -EPROBE_DEFER better

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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>
This commit is contained in:
Uwe Kleine-König 2014-02-13 23:05:28 +01:00 committed by Greg Kroah-Hartman
parent c9afbb05a9
commit 0b336cea56
1 changed files with 14 additions and 5 deletions
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19
drivers/w1/masters/w1-gpio.c
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@ -89,11 +89,22 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
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 @@ static int w1_gpio_probe(struct platform_device *pdev)
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);