[PATCH 1/2] mfd: wm8994: Fix driver operation if loaded as modules

[PATCH 1/2] mfd: wm8994: Fix driver operation if loaded as modules

[Marek Szyprowski]

WM8994 chip has built-in regulators, which might be used for chip
operation. They are controlled by a separate wm8994-regulator driver,
which should be loaded before this driver calls regulator_get(), because
that driver also provides consumer-supply mapping for the them. If that
driver is not yet loaded, regulator core substitute them with dummy
regulator, what breaks chip operation, because the built-in regulators are
never enabled. Fix this by adding a comment and a call to module_request()
helper.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/mfd/wm8994-core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 1e9fe7d92597..f15f12d8bccc 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -321,6 +321,13 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 	int ret, i, patch_regs = 0;
 	int pulls = 0;
 
+	/*
+	 * Request a driver for built-in regulators first, because they are
+	 * default supplies for "AVDD1" and "DCVDD". Otherwise, getting them
+	 * fails due to lack of consumer mapping defined by that driver.
+	 */
+	request_module("wm8994_regulator");
+
 	if (dev_get_platdata(wm8994->dev)) {
 		pdata = dev_get_platdata(wm8994->dev);
 		wm8994->pdata = *pdata;
-- 
2.17.1

[PATCH 2/2] mfd: wm8994: Fix unbalanced calls to regulator_bulk_disable()

[Marek Szyprowski]

When runtime PM is enabled, regulators are being controlled by the
driver's suspend and resume callbacks. They are also unconditionally
enabled at driver's probe(), and disabled in remove() functions. Add
more calls to runtime PM framework to ensure that the device's runtime
PM state matches the regulators state:
1. at the end of probe() function: set runtime PM state to active, so
there will be no spurious call to resume();
2. in remove(), ensure that resume() is called before disabling runtime PM
management and unconditionally disabling the regulators.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/mfd/wm8994-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index f15f12d8bccc..f2668f52a6bd 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -591,6 +591,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 		goto err_irq;
 	}
 
+	pm_runtime_set_active(wm8994->dev);
 	pm_runtime_enable(wm8994->dev);
 	pm_runtime_idle(wm8994->dev);
 
@@ -610,7 +611,9 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 
 static void wm8994_device_exit(struct wm8994 *wm8994)
 {
+	pm_runtime_get_sync(wm8994->dev);
 	pm_runtime_disable(wm8994->dev);
+	pm_runtime_put_noidle(wm8994->dev);
 	wm8994_irq_exit(wm8994);
 	regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies);
 	regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
-- 
2.17.1