From 881de67046f424fc3a6e05b1c681c12afd94e802 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 22 Aug 2011 15:43:55 +0200 Subject: 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 Signed-off-by: Samuel Ortiz --- drivers/mfd/wm8994-core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/mfd/wm8994-core.c') 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 -- cgit v1.2.3