mfd: Allow WM8994 LDO enable pulls to be disabled
In systems where the LDO enables are always driven (for example, being
connected to an always on supply rail or a GPIO which is driven by the
CPU even in suspend) then we can disable the pull downs on the LDO for
a small power savings.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 96479c9..1f15743 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -281,6 +281,13 @@
return 0;
}
+ /* Disable LDO pulldowns while the device is suspended if we
+ * don't know that something will be driving them. */
+ if (!wm8994->ldo_ena_always_driven)
+ wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
+ WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
+ WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);
+
/* GPIO configuration state is saved here since we may be configuring
* the GPIO alternate functions even if we're not using the gpiolib
* driver for them.
@@ -350,6 +357,11 @@
if (ret < 0)
dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);
+ /* Disable LDO pulldowns while the device is active */
+ wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
+ WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
+ 0);
+
wm8994->suspended = false;
return 0;
@@ -513,8 +525,15 @@
pdata->gpio_defaults[i]);
}
}
+
+ wm8994->ldo_ena_always_driven = pdata->ldo_ena_always_driven;
}
+ /* Disable LDO pulldowns while the device is active */
+ wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
+ WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
+ 0);
+
/* In some system designs where the regulators are not in use,
* we can achieve a small reduction in leakage currents by
* floating LDO outputs. This bit makes no difference if the
diff --git a/include/linux/mfd/wm8994/core.h b/include/linux/mfd/wm8994/core.h
index f0b69cd..5ab71bd 100644
--- a/include/linux/mfd/wm8994/core.h
+++ b/include/linux/mfd/wm8994/core.h
@@ -63,6 +63,8 @@
void *control_data;
+ bool ldo_ena_always_driven;
+
int gpio_base;
int irq_base;
diff --git a/include/linux/mfd/wm8994/pdata.h b/include/linux/mfd/wm8994/pdata.h
index 97cf4f2..ea32f30 100644
--- a/include/linux/mfd/wm8994/pdata.h
+++ b/include/linux/mfd/wm8994/pdata.h
@@ -167,6 +167,13 @@
/* WM8958 microphone bias configuration */
int micbias[2];
+
+ /* Disable the internal pull downs on the LDOs if they are
+ * always driven (eg, connected to an always on supply or
+ * GPIO that always drives an output. If they float power
+ * consumption will rise.
+ */
+ bool ldo_ena_always_driven;
};
#endif