diff options
| author |   Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-08-22 15:43:55 +0200 |
|---|---|---|
| committer |   Samuel Ortiz <sameo@linux.intel.com> | 2011-10-24 14:09:10 +0200 |
| commit | 881de67046f424fc3a6e05b1c681c12afd94e802 (patch) | |
| tree | 3f83b7d051532c785a598d442daa64267c2be210 /drivers/mfd/wm8994-core.c | |
| parent | mfd: Make sure to request twl6030 IRQ before using the irq_num (diff) | |
| download | linux-dev-881de67046f424fc3a6e05b1c681c12afd94e802.tar.xz linux-dev-881de67046f424fc3a6e05b1c681c12afd94e802.zip | |
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.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c index 96479c9b1728..1f15743460a0 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 |