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authorChris Rattray <crattray@opensource.wolfsonmicro.com>2012-06-12 00:43:35 +0800
committerSamuel Ortiz <sameo@linux.intel.com>2012-07-09 00:16:11 +0200
commit78a27cd3e891e8da343942aec10c926eaffabd63 (patch)
tree0d366f5c203a3ec151520dcc518a64658615876e
parenta834e81051fd51890bd9a64e109b587f8e12199a (diff)
mfd: Restore wm8994 pin configuration after reset during suspend
Ensure that we leave the device with the pins in the expected configuration if we leave it in reset over suspend, avoiding any interoperation problems with other devices in the system. Signed-off-by: Chris Rattray <crattray@opensource.wolfsonmicro.com> 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.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 1e321d349777..f75cdccd1043 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -196,6 +196,7 @@ static int wm8994_suspend(struct device *dev)
{
struct wm8994 *wm8994 = dev_get_drvdata(dev);
int ret;
+ int gpio_regs[WM8994_NUM_GPIO_REGS];
/* Don't actually go through with the suspend if the CODEC is
* still active (eg, for audio passthrough from CP. */
@@ -277,12 +278,24 @@ static int wm8994_suspend(struct device *dev)
WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);
+ /* Save GPIO registers before reset */
+ regmap_bulk_read(wm8994->regmap, WM8994_GPIO_1, gpio_regs,
+ WM8994_NUM_GPIO_REGS);
+
/* Explicitly put the device into reset in case regulators
* don't get disabled in order to ensure consistent restart.
*/
wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
+ /* Restore GPIO registers to prevent problems with mismatched
+ * pin configurations.
+ */
+ ret = regmap_bulk_write(wm8994->regmap, WM8994_GPIO_1, gpio_regs,
+ WM8994_NUM_GPIO_REGS);
+ if (ret != 0)
+ dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);
+
regcache_cache_only(wm8994->regmap, true);
regcache_mark_dirty(wm8994->regmap);