diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-08-22 13:43:55 (GMT) |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2011-10-24 12:09:10 (GMT) |
| commit | 881de67046f424fc3a6e05b1c681c12afd94e802 (patch) | |
| tree | 3f83b7d051532c785a598d442daa64267c2be210 | |
| parent | 862de70c12bb6227943e155251c75e7fa4558068 (diff) | |
| download | linux-881de67046f424fc3a6e05b1c681c12afd94e802.tar.xz | |
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>
| -rw-r--r-- | drivers/mfd/wm8994-core.c | 19 | ||||
| -rw-r--r-- | include/linux/mfd/wm8994/core.h | 2 | ||||
| -rw-r--r-- | include/linux/mfd/wm8994/pdata.h | 7 |
3 files changed, 28 insertions, 0 deletions
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 @@ 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 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 @@ struct wm8994 { 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 @@ struct wm8994_pdata { /* 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 |