[PATCH 4.6 69/81] gpio: zynq: initialize clock even without CONFIG_PM

Greg Kroah-Hartman
2016-06-22T22:51:01Z

From: Helmut Grohne <h.grohne@intenta.de>

commit 0f84f29ff30bdb1bca23017b118b4ea3999cac32 upstream.

When the PM initialization was moved in the commit referenced below, the
code enabling the clock was removed from the probe function. On
CONFIG_PM=y kernels, this is not a problem as the pm resume hook enables
the clock, but when power management is disabled, all those pm_*
functions are noops and the clock is never enabled resulting in a
dysfunctional gpio controller.

Put the clock initialization back to support CONFIG_PM=n.

Signed-off-by: Helmut Grohne <h.grohne@intenta.de>
Fixes: 3773c195d387 ("gpio: zynq: Do PM initialization earlier to support gpio hogs")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpio/gpio-zynq.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -709,7 +709,13 @@ static int zynq_gpio_probe(struct platfo
dev_err(&pdev->dev, "input clock not found.\n");
return PTR_ERR(gpio->clk);
}
+ ret = clk_prepare_enable(gpio->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable clock.\n");
+ return ret;
+ }

+ pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0)
@@ -747,6 +753,7 @@ err_pm_put:
pm_runtime_put(&pdev->dev);
err_pm_dis:
pm_runtime_disable(&pdev->dev);
+ clk_disable_unprepare(gpio->clk);

return ret;
}