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authorMark Brown <broonie@opensource.wolfsonmicro.com>2011-08-22 15:43:55 +0200
committerSamuel Ortiz <sameo@linux.intel.com>2011-10-24 14:09:10 +0200
commit881de67046f424fc3a6e05b1c681c12afd94e802 (patch)
tree3f83b7d051532c785a598d442daa64267c2be210 /drivers/mfd/wm8994-core.c
parent862de70c12bb6227943e155251c75e7fa4558068 (diff)
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>
Diffstat (limited to 'drivers/mfd/wm8994-core.c')
-rw-r--r--drivers/mfd/wm8994-core.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 96479c9b172..1f15743460a 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -281,6 +281,13 @@ static int wm8994_suspend(struct device *dev)
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 @@ static int wm8994_resume(struct device *dev)
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 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
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